I. The effect of Aureomycin in pelleted or whole grain creep rations fed to suckling lambs II. The effect
of Thyroprotein, Thiouracil, and Stilbestrol on gains of fattening lambs
by Charles A Daley
A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree
of Master of Science in Animal Industry
Montana State University
© Copyright by Charles A Daley (1956)
Abstract:
I. The first portion of the thesis presents the results of a study to determine the effect of Aureomycin in
pelleted and whole grain creep rations fed to suckling lambs. ' Thirty-two ewes of three breeds, all with
twin lambs, were randomly divided by breed into four equal groups. Variables consisted of four creep
feeds which were offered free choice to the month-old lambs in a fifty-day feeding trial. Rate of gain,
feed efficiency, and general health of the lambs were observed to determine (l) the effect of pelleting a
simple oat-beet pulp ration, (2) the effect of adding Aureomycin at 20 mg. per pound of a simple
oat-beet pulp pellet, and (3) the effect of using a commercial type creep pellet containing Aureo-mycin
at 20 mg. per pound of ration. Addition of Aureomycin apparently increased rate of gain during the
first two weeks of the trial. Lambs on a whole grain ration (without Aureomycin) had the lowest rate of
gain and feed consumption per lamb during this period. At the end of the fifty-day trial, feed cost and
feed cost per hundredweight of gain were lowest for the whole grain group (without Aureomycin), and
highest for the group on the commercial type pellet (with Aureomycin. The lambs on the whole grain
ration appeared "pot-bellied" which would have adversely affected carcass grades, had the lambs been
marketed then. The cost of including Aureomycin at 20 mg. per pound in an oat-beet pulp pellet was
more than repaid through increased feed efficiency. Rate of gain was not affected. Incidence of scours
was approximately equal among the four groups. Because of the low occurrence of scours, the value of
Aureomycin in controlling scours could not be determined.
II. In the second trial, eleven lots of three wether lambs each were hand-fed a grain and alfalfa hay
ration; weight gains were observed. Variables included combinations of thyroprotein, thiouracil, or
stilbestrol in a soybean meal carrier, and stilbestrol pellets implanted subcutaneously. Lambs showed a
marked dislike for thiouracil when it was included in the ration. There was a highly significant
difference ((P<0.01) in gains per lamb among lots. A 12 mg. stilbestrol implant gave the highest rate of
gain (0.60 pounds per day), while 0.5 gm. thiouracil orally per head daily gave the lowest (0.23 pounds
per day). Addition of 0.3 gm. thiouracil orally per head daily to the ration of lambs already implanted
with a 12 mg. stilbestrol pellet lowered daily gains by 0.07 pounds per day. Levels of 0.5, 1.0, and 2.0
mg, stilbestrol orally per head daily resulted in rate of gain increases of 0.14, 0.08, and 0.13 pounds per
day respectively over the controls. Feed requirement per hundred pounds of gain was improved by 99,
101, and 68 pounds, respectively. Oral intake of stilbestrol with either thyroprotein or thiouracil
increased feed efficiency over that of the controls but did not affect rate of gain. Carcass grades of one
animal from each lot showed the lambs were not fat. The control animal graded average choice, the
highest of all the eleven lots. The pituitary, adrenal, and thyroid glands were removed and weighed,
after which the glands were preserved for future histological study* I.
II.
THE EFFECT OF AUEEOMYGIN IN PELLETED OR MOLE GRAIN CREEP RATIONS
FED TO SUCKLING LAMBS
THE EFFECT OF THYROPROTEIN, THTOURACIL, AND STILBESTROL ON GAINS
OF FATTENING LAMBS
by
CHARLES A. DALEY
A THESIS
S u bm itted to th e G raduate F a c u lty
'
-
■'
""
■ p a r t i a l f u l f i l l m e n t o f th e re q u ire m e n ts
f o r th e d e g re e o f
M aster o f S cien ce i n Animal In d u s tr y
at
Montana S ta te C o lleg e
A pproved:
Head, M ajor D epartm ent
Chai'rm;
lin in g Committee
Bean,' G raduated/D ivision
Bozeman, Montana ■
Ju n e, 1956
'■ % (
hj
H37y
- 2 -
T) /ff e
ACKNOWLEDGEMENT
The a u th o r w ishes to e x p re ss h is s in c e r e a p p r e c ia tio n to th e
fo llo w in g s t a f f members o f Montana S ta te C o lle g e ; Bozeman, Montana:
D r, 0 , 0 . Thomas and P r o f e s s o r J , L, Van Horn o f th e Animal In d u s try
and Range Management D epartm ent f o r t h e i r in v a lu a b le a s s is ta n c e in
o rg a n iz in g th e t r i a l s and f o r t h e i r guidance i n t h e p r e p a r a tio n o f
th e m a n u sc rip t; D r. E. B. H arvey o f th e Zoology and Entomology D ep art­
ment f o r h is c o o p e ra tio n i n th e c o l l e c t i o n o f th e e n d o crin e g lands
and h is s u g g e s tio n s i n th e rev iew o f th e m a n u sc rip t.
G r a te f u l acknowledgement i s made t o s tu d e n ts S. H. Smyrl and
Vernon R o b ertso n who a s s i s t e d i n th e fe e d in g and w eig h in g , r e s p e c tiv e ly ,
o f th e an im als i n th e second t r i a l .
A p p re c ia tio n i s extended to Dr. R. F . E l l i o t t o f The American
Cyanamid Company f o r su p p ly in g th e A urofac 2A and t h i o u r a c i l , to D r.
Wm. S . D avidson o f Wick and F ry , I n c . f o r f u r n is h in g th e s t i l b e s t r o l
im p la n ts , to D r. C. F. Chappel o f E li L i l l y and Company f o r th e S t i l b o so l p rem ix, to D r. G. 0 . K ohler o f th e C erophyl L a b o ra to rie s , I n c .
f o r th e c o n tr ib u tio n o f th e Protam one, and to W. A. H a rris o f th e H olly
Sugar Co. f o r t h e Sugapulp u sed .
118856
- 3 A b s t r a c t ............................................ ■ *
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JJxperiment X •
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In trod u ction
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Review o f L i t e r a t u r e .
A n tib io tic s .
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A ureom ycin.i n Chick R a tio n s .
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Aureomycin i n Swine R a tio n s .
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Aureomycin i n Young C a lf R a tio n s
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Aufeomycin i n S te e r Rumen S tu d ie s
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Aureomycin i n Sheep F a tte n in g R a tio n s
Ili
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Aureomycin i n S u ck lin g Lamb R a tio n s ................................................... 25
Summary:
O b je c tiv e s • .
P ro c e d u re
Aureomycin i n R a tio n s o f Farm A nim als.
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R e s u lts and D is c u s sio n .. .............................................................................................31;
Summary
lj.3
L i t e r a t u r e C ite d .
E xperim ent I I .
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I n tr o d u c ti o n ................................................................................................................ 50
Review o f L i t e r a t u r e ................................................................................................52
E f fe c t o f F eeding S t i l b e s t r o l
to Farm Animals
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E f f e c t o f F eed in g T h io u ra c il and T h y ro p ro tein . to Farm Animals
O b j e c t i v e s ..................................................... ........
P ro ced u re
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R e s u lts and D i s c u s s i o n ...........................................
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L i t e r a t u r e C ite d .
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ABSTRACT
I . The f i r s t p o r t i o n o f t h e t h e s i s p r e s e n ts th e r e s u l t s o f a s tu d y to
d eterm in e th e e f f e c t o f Aureomycin i n p e l l e t e d an d w hole g r a in c re ep
r a t i o n s f e d to s u c k lin g lam bs. ' T h irty -tw o ewes o f th r e e b re e d s , a l l w ith
tw in"lam bs," w ere random ly d iv id e d b y b re e d i n t o fo u r e q u al g ro u p s. V ari­
a b le s c o n s is te d o f fo u r c re ep fe e d s which w ere o f f e r e d f r e e c h o ice to th e
m o n th-old lambs i n a f i f t y - d a y fe e d in g t r i a l . R ate o f g a in , fe e d e f f i ­
c ie n c y , and g e n e ra l h e a lt h o f th e lambs were o b serv ed to d eterm in e ( l ) th e
e f f e c t o f p e l l e t i n g a sim ple o a t- b e e t p u lp r a t i o n , ( 2 ) th e e f f e c t o f add­
in g Aureomycin a t 20 mg. p e r pound o f a sim p le o a t- b e e t p u lp p e l l e t , and
(3) th e e f f e c t o f u s in g a com m ercial ty p e c re ep p e l l e t c o n ta in in g A ureomycin a t 20 mg. p e r pound o f r a t i o n . A d d itio n o f Aureomycin a p p a re n tly
in c r e a s e d r a t e o f g a in d u rin g th e f i r s t two weeks o f th e t r i a l . Lamhsl' on
a whole g r a in r a t i o n (w ith o u t Aureomycin) had th e lo w e st r a t e of. g a in an d :
fe e d consum ption p e r lamb d u rin g t h i s p e r i o d . . At th e end o f t h e . f i f t y - d a y
t r i a l , fe e d c o s t and fe e d c o s t p e r hundredw eight o f g a in were lo w e st f o r
th e whole g r a in group (w ith o u t A ureom ycin), and h ig h e s t f o r th e group on
th e com m ercial ty p e p e l l e t (w ith A ureom ycin).. The lambs on th e-w h o le
g r a in r a t i o n appeared " p o t- b e llie d " w hich would have a d v e rs e ly a f f e c te d
c a r c a s s g ra d e s , had th e lambs been m arketed th e n . The c o s t o f in c lu d in g
Aureomycin a t 20 mg. p e r pound i n an o a t- b e e t p u lp p e l l e t was more th a n
r e p a id th ro u g h in c r e a s e d fe e d e f f i c i e n c y . R ate o f g a in was n o t a f f e c t e d .
In c id e n c e o f sc o u rs was a p p ro x im a te ly e q u a l among th e f o u r g ro u p s. Be­
cause o f th e low o c c u rre n c e o f s c o u rs , th e v a lu e of Aureomycin i n c o n tr o l­
l i n g sc o u rs co u ld n o t be d e te rm in e d .
I I . I n th e second t r i a l , e le v e n l o t s o f t h r e e w eth er lambs each were
h a n d -fe d a g r a in and a l f a l f a h ay r a t i o n ; w eig h t g a in s w ere o b serv ed .
V a ria b le s in c lu d e d co m binations o f th y r o p r o te in , t h i o u r a c i l , o r s t i l b e s t r o l
i n a soybean m eal c a r r i e r , and s t i l b e s t r o l p e l l e t s im p la n te d su b cu tan ­
e o u s ly . Lambs showed a marked d i s l i k e f o r t h i o u r a c i l when i t was in c lu d e d
i n t h e r a t i o n . There was a h ig h ly s i g n i f i c a n t d if f e r e n c e (P O .O l) i n
g a in s p e r lamb among l o t s . A 12 mg. s t i l b e s t r o l im p la n t gave th e .h ig h ­
e s t r a t e o f g a in ( 0 .6 0 pounds p e r d a y ), w h ile 0 .3 gm. t h i o u r a c i l o r a l l y ’
p e r head d a i l y gave th e lo w e st (0 ,2 3 pounds p e r day). A d d itio n o f 0 .3
gm. t h i o u r a c i l o r a l l y p e r head d a ily to th e r a t i o n o f lam bs a lre a d y im­
p la n te d w ith a 12 mg. s t i l b e s t r o l p e l l e t lo w ered d a ily g a in s by 0 . 0?
pounds p e r d a y . L ev els o f 0 ,3 , 1 . 0, and 2 . 0 . mg. s t i l b e s t r o l o r a l l y p e r
head d a ily r e s u l t e d i n r a t e o f g a in in c r e a s e s o f O .lL , 0 , 08, and 0.1 3
pounds p e r day r e s p e c t i v e l y ov er th e c o n t r o l s . Feed re q u ire m e n t p e r
hundred pounds o f g a in was im proved by 99, 101, and 68 p o u n d s, r e s p e c tiv e ­
l y . O ral in ta k e o f s t i l b e s t r o l w ith e i t h e r th y r o p r o te in o r t h i o u r a c i l
in c re a s e d fe e d e f f i c i e n c y o v e r t h a t o f th e c o n tr o ls b u t d id n o t a f f e c t
r a t e o f g a in . C arcass grades o f one an im al from each l o t showed th e lambs
w ere n o t f a t . The c o n tr o l anim al graded av erag e c h o ic e , th e h ig h e s t o f
a l l th e e le v e n l o t s . The p i t u i t a r y , a d re n a l, and th y r o id g la n d s were
removed and w eighed, a f t e r w hich t h e g la n d s w ere p re s e rv e d f o r f u tu r e
h i s t o l o g i c a l study*
- 6 INTRODUCTION
The m ost im p o rta n t fe e d f o r th e new -born lamb i s m ilk .
A fte r two
Treeks o f age th e rumen becomes in c r e a s in g ly f u n c tio n a l, and th e lamb can
th e n consume in c r e a s in g amounts o f o th e r feeds, such as g r a in s - and h a y s.
P a s tu re p lu s a few pounds o f m ilk d a i l y p ro v id e an a d e q u a te so u rce o f
n u t r i e n t s f o r p ro d u c tio n o f h e a lth y , norm al-grow ing lam bs.
Lambs b o rn e a r l y i n t h e y e a r , b e fo re g reen g ra s s i s a v a ila b le , b e n e f it
by h a v in g a c c e ss t o c re ep f e e d .
T h is fe e d i s p la c e d i n an e x c lo s u re t h a t
p e rm its sm all, lambs to e n t e r , b u t e x c lu d e s th e ewes.
I n g r e d ie n ts used i n a lamb creep fe e d can v a ry w id e ly , b u t th e end
r e s u l t sh o u ld be a r a t i o n t h a t i s p a l a t a b l e t o th e lam bs.
A lthough good
r e s u l t s have been o b ta in e d on o n ly o a ts o r c o rn , a m ix tu re o f s e v e ra l
'
(
feed p i s u s u a ll y recommended. The young lambs sh o u ld be o f f e r e d 'a ro u g h •
,
'
age such as good a l f a l f a hay as w ell- a s a c o n c e n tra te m ix tu re .-
Choice
a l f a l f a hay can be chopped, m ixed w ith th e c o n c e n tra te , and o ff e re d f r e e
c h o ic e .
A nother way i s to l i m i t th e c o n c e n tra te and fe e d th e hay. f r e e
c h o ic e i n ra c k s w hich th e ewes can n o t r e a c h .
alw ays be c le a n and f r e s h .
Feed o f f e r e d lambs should
Lambs' w i l l r e f u s e to e a t much fe e d t h a t i s •
o ld , s p o ile d , o r c o n ta m in a te d .
There i s a tr e n d i n Montana to w ard more fa rm f lo c k s o f sh eep .
Home-
grown g r a in s and o th e r fe e d s are a v a il a b le and cheap on fa rm s $ th e r e f o r e
lambs a re som etim es c re e p -f e d and s o ld on th e e a r ly m a rk e t.
I n th e p a s t s e v e r a l y e a r s , r e s e a r c h w o rk ers and com m ercial fe e d e rs
have o b ta in e d d e s ir a b le e f f e c t s on n o n -ru m in a n ts, and to a l e s s e r e x te n t
on ru m in a n ts , by in c lu d in g a n t i b i o t i c s i n t h e r a t i o n .
These e f f e c t s have
7 - .
in c lu d e d more r a p id grow th, b e t t e r fe e d u t i l i z a t i o n , and h e a l t h i e r a n im a ls »
The Montana A g r ic u ltu r a l Experim ent S ta tio n conducted a fe e d in g t r i a l V
d u rin g th e S p rin g o f 1 9 # i n re sp o n se t o many re q u e s ts r e c e iv e d f o r
s p e c i f i c in fo rm a tio n on th e v a lu e of a n t i b i o t i c s i n lamb c re e p r a t i o n s »
Only tw in lam bs w ere s e le c te d f o r t h i s e x p erim en t, as any p o t e n t i a l bene­
f i t from t h e a n t i b i o t i c would b e e x p re ss e d more r e a d i l y th a n w ith .s in g le
lam bs.
— 8 *"»
REVIEW OF LITERATURE
A n tib io tic s
A n tib io tic s a re growth i n h i b i t o r s o r b a c t e r i c i d a l agerjts which are
form ed by l i v i n g o rg an ism s, and which a r e a c ti v e i n v e ry low c o n cen tra­
tio n s
e
D r. Flem ing d is c o v e re d th e f i r s t r e a l l y e f f e c t i v e a n t i b i o t i c i n 1928,
when he s tu d ie d a v a r i a t i o n o f S ta p h y lo c o c cu s, a id found t h a t around a
la r g e c o lo n y o f a c o n ta m in a tin g organism th e S tap h y lo co ccu s c o lo n ie s b e ­
came tr a n s p a r e n t and underw ent l y s i s .
This work was ig n o re d u n t i l 19^1.
Then th e demands o f World W a r 'll s tim u la te d an i n t e r n a t i o n a l p r o je c t to
i s o l a t e and p u r i f y th e a c ti v e m a te r ia l p ro d u ced by F le m in g 's co n tam in atin g
o rg an ism .
Today t h i s m a te r ia l i s known th e w orld o v er as. P e n i c i l l i n ,
■' S tu d ie s i n th e a n t i b i o t i c s f i e l d expanded g r e a t l y fo llo w in g s u c c e ss ­
f u l work .w ith P e n i c i l l i n .
Duggar (191:8) and a s s o c ia te s o f th e L e d e rle
L a b o ra to rie s announced th e d is c o v e ry o f c h l o r t e t r a c y c l i n e a t a c o n feren ce
h e ld by th e New York Academy' o f S c ie n ce s i n J u ly , 19I4.8 ,
T his a n t i b i o t i c
i s produced by an A ctinom ycetes, S trep to m y ces a u re o fa c ie n s , w hich was
f i r s t i s o l a t e d from a sample o f s o i l c o l l e c t e d from a tim o th y f i e l d i n ■
M is s o u ri,
D uring c e r t a i n s ta g e s .o f grow th t h i s s p e c ie s i s c h a r a c te r iz e d
by a golden y e llo w c o lo r , and th e i s o l a t e d a n t i b i o t i c i s s i m i l a r l y c o lo re d .
The m an u fa ctu rin g p ro c e s s f o r c h lo r te tr a c y c lin e i s p a te n te d by
L e d e rle L a b o r a to r ie s , and th e p ro d u c t i s s o ld under th e tr a d e name o f
Aureomyein, o r A urofac in " th e case o f liv e s to c k su p p lem en ts.
been r e p o r te d on t h e e x a c t m a n u fa ctu rin g p ro c e d u re u s e d .
L i t t l e has
R aper (1952),
i n d i c a t e s a fe rm e n ta tio n medium u sed i s composed as f o llo w s :
Corn s te e p
- 9 li q u o r , I p e r c e n t; s u c ro s e , I p e r c e n t; (NH^)2HPOii , 0 .2 p e r c e n t; KH2POj4,
0 .2 p e r c e n t; MgSO^.THgO, 0 .0 2 5 p e r c e n t; OaCO^, 0 .1 p e r c e n t; p lu s s e v e r a l
o th e r c a t i o n s .
F e rm e n ta tio n i s conducted in la r g e (10,000 g a llo n ) a e r a te d ta n k s
•which a re a g ita te d as i n t h e m an u factu re o f o th e r a n t i b i o t i c d ru g s.
The
p u r i f i e d c r y s t a l l i n e form i s o b ta in e d by p r e c i p i t a t i n g th e c h lo r te tr a c y c lin e w ith calcium io n s , and th e n in tr o d u c in g HCl to form th e s a l t known
as Aureomycin HCl.
Stephens e t a l .
(1 9 5 2 ), g iv e s th e s t r u c t u r e o f c h lo r te tr a c y c lin e a s
shown i n F ig u re I .
F ig u re I .
S tr u c tu r e o f c h l o r t e t r a c y c l i n e .
Aureomycin i s h ig h ly a c ti v e a g a in s t g ram -n eg ativ e ro d s and d is p la y s
v e ry low t o x i c i t y to h ig h e r a n im a ls .
and e x c r e te d .
I t i s r a p id ly a b so rb e d , c i r c u l a t e d ,
Because o f th e s e f a c t o r s i t can cause a lm o st com plete
s t e r i l i z a t i o n o f th e i n t e s t i n e , a c c o rd in g to Thimann, (1955)•
b a c t e r i a som etim es alm ost d is a p p e a r from t h e f e c e s .
In man,
O c c a s io n a lly the
s t e r i l i z e d fe c e s becomes in f e c te d w ith a p a th o g an ic y e a s t s p e c ie s which
c a u se s s e r io u s seco n d ary i n f e c t i o n s .
I h i l e th e t r i a l r e p o rte d i n t h i s t h e s i s used Aureomycin as th e a n t i ­
b i o t i c , o th e r a n t i b i o t i c s a re a v a ila b le w hich a re r e l a t e d c h e m ic a lly , and
which g iv e somewhat s im ila r r e s u l t s i n t h e i r e f f e c t on t h e p h y sio lo g y o f
-IG farm anim als*
T erram ycin i s th e tr a d e name f o r o x y te tr a c y c lin e , which i s
s im ila r to c h l o r t e t r a c y c l i n e , and i s w id e ly u se d .
Many o th e r a n t i b i o t i c s
have been d is c o v e re d , b u t o n ly th e most p ro m isin g ones a re employed in
e x te n s iv e t r i a l s w ith l i v e s t o c k .
B esid es th e two a lr e a d y m entioned,
B a c itr a c in , S trep to m y cin , P ro c a in e p e n i c i l l i n , and a r e c e n t one, t e t r a ­
c y c lin e , a re th e more im p o rta n t ones u sed i n su p p lem en ta tio n o f commer­
c i a l feed s*
Aureongrcin i n Ghiok R atio n s
Aureomycin was u sed e x c lu s iv e ly a s human m e d ic a tio n u n t i l i t was i n ­
d i r e c t l y found b e n e f i c i a l t o farm an im als a s w e l l .
Animal n u t r i t i o n i s t s
b y 19U8 had found a d e f i n i t e growth re sp o n se i n a n im a ls, p a r t i c u l a r l y
c h ic k s , from fe e d in g l i v e r e x t r a c t s , f i s h m eal, o r cow m anure*■ A lso some
su b sta n c e i n th e s e m a te r ia ls was found e s s e n t i a l f o r h a t c h i b i l i t y o f hen
e g g s.
T his unknown su b sta n c e was te rm e d "Animal P r o te in F a c to r ."
C ry s ta l'
l i n e V itam in B^g was found to b e th e crude Animal P r o te in F a c to r su b sta n c e
t h a t gave such b e n e f i c i a l re sp o n se i n c h ic k s .
R ick s e t a l . (Ipl)B) th e n d is c o v e re d V itam in B^g a c t i v i t y in c u ltu r e
b ro th s o f v a rio u s s m a ll b a c t e r i a and A ctin o m y eetes, in c lu d in g th e s t r e p ­
to m y cin -p ro d u cin g o rg an ism .
I t was shown also, t h a t V itam in B^g was p ro ­
duced i n o th e r m ic r o b ia l f e r m e n ta tio n s .
Aureomycin and o th e r c u ltu r e f i l ­
t r a t e s fo rm e rly d is p o s e d o f a s w a ste s w ere now c o n c e n tra te d , and became
a c h ie f so u rce o f V itam in B^g f o r c l i n i c a l u s e , and i n th e form o f A .P .F .
supplem ents w ere u sed t o s a t i s f y th e sk y ro c k e tin g demands o f fe e d manufac­
tu re rs .
E f f o r t s w ere s u c c e s s f u lly made to f i n d s t r a i n s of m icro -o rg an ism s
cap ab le of g iv in g h ig h y ie ld s o f V itam in B]_g.
- 11
S to k s ta d e t al« (l9ij.9), a t th e L e d e rle L a b o ra to rie s , f e d Aureomycin
fe rm e n ta tio n A .P .F . supplem ents and o b ta in e d a grow th re sp o n se w ith c h ick s
t h a t was more th a n c o u ld be e x p e c te d from V itam in
by i t s e l f e
The .
supplem ents were known to c o n ta in Aureomycin r e s id u e j th e in v e s t i g a t o r s
t h e r e f o r e th e o riz e d - t h a t th e e x t r a grow th.w as due to Aureomyoim*
S to k s ta d and Jukes (1950) f e d c h ic k s a d i e t w ith ad eq u ate le v e l s o f
Vi t a mi n .
a nd when sm all amounts o f Aureomycin w ere added to th e r a t i o n ,
a s i g n i f i c a n t e x tr a grow th re sp o n se was o b ta in e d .
T his p ro v ed co n clu ­
s i v e l y t h a t th e a n t i b i o t i c i t s e l f h ad a b e n e f i c i a l e f f e c t on c h ick grow th.
W ith th e a n t i b i o t i c , th e amount o f V itam in B^g needed was o f te n found to
be re d u c e d .
T h e . a d d itio n of V itam in B^g and a n t i b i o t i c s to a r a t i o n does
not a l t e r t h e need f o r o th e r B-complex v ita m in s .
C oats e t a l . (193>l), L i l l i e e t . a l . (1953) and H i l l e t a l . (1953),
in d i c a t e c h ic k s r e a r e d i n new or c lea n q u a r te r showed no grow th re sp o n se s
when f e d a n t i b i o t i c s .
H i l l and L arson (1955) s t a t e t h a t w orkers a t th e
Lobund I n s t i t u t e o f N otre Dame f i r s t re p o rte d g erm -free c h ic k s and p o u lts
f a i l t o show grow th re s p o n s e s when f e d a n t i b i o t i c s , b u t . l a t e r work showed
sp o rad ic, g ro w th -in c re a s e s f o r b o th g e rm -free c h ic k s and p o u lts f e d a n t i ­
b io tic s .
Aureomycin i n Sw ine■R a tio n s
L a sle y e t aL. (195U), summarized w ork of s e v e r a l y e a r s from v a rio u s
s t a t i o n s on th e re sp o n se o f swine to d i f f e r e n t a n t i b i o t i c s when b a sa l
r a t i o n s c o n ta in e d p r o te in frcm p l a n t o r p l a n t and an im al s o u r c e s .
The d a ta f o r norm al, h e a lth y p ig $ from w eanling to m arket w eights
showed c l e a r l y t h a t a n t i b i o t i c s w ere e f f e c t i v e i n most t r i a l s w ith an
— 12 —
av erag e in c r e a s e (ij.8 t r i a l s ) o f a b o u t 17 p e rc e n t i n d a i l y g a in s , 1 1 .£
p e r c e n t i n d a i l y fe e d consum ption, and a sav in g o f 3 .9 p e r c e n t in amount
o f fe e d r e q u ir e d p e r u n it o f g a in , compared t o p ig s on t h e b a s a l r a t i o n s .
There was l i t t l e d if f e r e n c e among Aureomycin, T erram ycin, P ro c a in e p e n i c i l ­
l i n , and S trep to m y cin i n a b i l i t y t o in c r e a s e av erag e d a i l y g a in s and fe e d
consum ption.
There was no c l e a r - c u t ev id en ce t h a t any one a n t i b i o t i c
t e s t e d was s u p e r io r t o any o th e r one i n in c r e a s in g e f f i c i e n c y o f fe e d
u tiliz a tio n .
,
A n tib io tic s seemed t o be s l i g h t l y more e f f e c t i v e when added to an
a l l - p l a n t p r o t e i n r a t i o n th a n when added t o one c o n ta in in g p r o te in s from
b o th p l a n t and anim al s o u rc e s .
A l e v e l o f ab o u t 5 m illig ra m s a n t i b i o t i c
p e r pound o f t o t a l r a t i o n , o r 20 to 25 m illig ra m s p e r pound o f p r o te in
supplem ent seemed t o g iv e optimum re s p o n s e from .normal, h e a lth y p ig s .
It
was su g g e ste d t h a t h ig h e r l e v e l s would be b e n e f i c i a l when p ig s a re in f e c te d
w ith c e r t a i n ty p e s o f p a th o g e n ic o rg a n ism s.
A n tib io tic s i n p ig r a t i o n s seem to b e e f f e c t i v e i n c o n tr o llin g c e r t a i n
k in d s o f b a c t e r i a lo c a te d i n th e d ig e s tiv e t r a c t which cau se s c o u rs .
Many ■
r e p o r ts in d i c a t e t h a t a n t i b i o t i c s a re e f f e c t i v e in. c o n t r o l l i n g c e r t a i n
ty p e s o f s c o u r s .
D ata a re p re s e n te d co n ce rn in g u n t h r i f t y p ig s , showing an
a v erag e o f 9 6 .2 p e r c e n t in c r e a s e o v er c o n tr o ls in r a t e o f g a in when a n t i ­
b i o t i c s w ere f e d , and an av erag e in c r e a s e o f 2 2 .9 p e rc e n t i n e f f ic ie n c y
i n g a in s .
The perform ance o f th e c o n tr o l groups o f th e s e u n t h r i f t y p ig s
w as, how ever, f a r below n orm al.
One ex p erim en t was rev iew ed i n w hich a creep r a t i o n c o n ta in in g one
p e r c e n t Aureomycin was o f f e r e d s u c k lin g p ig s , and 0*5 p e r c e n t Aureomycin
— 13
s u p p lie d i n th e sow r a t i o n .
was in c r e a s e d 1 1 .pounds.
The ' av erag e £6-d a y weaning w e ig h t o f th e p ig s
The o p in io n was t h a t th e a n t i b i o t i c was n o t
t r a n s f e r r e d th ro u g h th e sow s’ m ilk , b u t was ta k e n i n a d eq u a te amounts v ia th e c re e p feed*
L a s le y review ed a n o th e r t r i a l i n w hich k3 l i t t e r s o f p ig s were u sed
to t e s t P ro c a in e p e n i c i l l i n a t l e v e l s o f ^ mg. and 20 mg. p e r pound o f
p ig s t a r t e r .
Feed consumption, and r a t e o f g a in o f th e p ig s .b o th in c r e a s e d .
S cours w ere n o t e lim in a te d , b u t w ere m arkedly re d u c e d .
A l e v e l o f 2 .5 mg.
p e r pound o f r a t i o n showed no s i g n i f i c a n t e f f e c t on fe e d consum ption o r
r a t e o f g a in .
Aureomycin was r e p o r te d to have a s p a rin g a c tio n on p r o t e i n r e q u i r e ­
m ents o f g ro w in g -fa tte n in g p ig s when r a t i o n s c o n ta in in g I h t o 20 p e r c e n t
crude p r o t e i n w ere compared.
In a n o th e r t r i a l u sin g T erram ycin fe d w ith
d i f f e r e n t l e v e l s o f p r o t e i n , p ig s r e c e iv in g a 1$ p e rc e n t p r o t e i n r a t i o n
(red u ced to 12 p e r c e n t a t 100 pounds) d id j u s t a s w e ll a s p ig s re c e iv in g
an 18 p e r c e n t p r o t e i n r a t i o n (red u ced to 1$ p e r c e n t a t 100 p o u n d s).
It
. was su g g e s te d t h a t th e p r e s e n t s ta n d a rd s f o r p r o te in f o r p ig s m a y b e
,h ig h e r th a n n e c e s s a ry when r a t i o n s in c lu d e ad eq u ate amount o f B v ita m in s .
High l e v e l s o f B v ita m in s i n a p r o t e i n supplem ent seem to in c re a s e th e ■
e ffic ie n c y of p ro te in u t i l i z a t i o n .
Summarizing s e v e r a l r e p o r t s , L a sle y s t a t e d t h a t th e r e seemed to be
l i t t l e o r no advantage from fe e d in g a n t i b i o t i c s to bro o d sows d u rin g
g e s t a t i o n , as m easured by l i t t e r s i z e , and s iz e and l i v e a b i l i t y o f new­
b o rn p i g s .
.
Anreomycin i n Young; C a lf R a tio n s
From abundant r e s e a r c h ev id en ce t h a t h as accum ulated d u rin g th e p a s t
s e v e r a l y e a r s , i t i s e v id e n t t h a t swine and p o u ltr y re sp o n d fa v o ra b ly Wien
a n t i b i o t i c s a r e in c lu d e d . i n t h e i r r a t i o n s .
The n u t r i t i o n o f th e v e ry
young ru m in an t can be e x p ec te d to b e 's i m i l a r to t h a t o f m o n o -g a stric
anim als becau se o f s im ila r p h y s io lo g ic a l f u n c tio n s .
T h e re fo re i t would
be re a s o n a b le to e x p e c t a fa v o ra b le r e a c t i o n o f th e v e ry young ru m in an t '
to a n tib io tic s .
T h is h a s been b ro u g h t o u t re g a rd in g th e work done w ith
young c a lv e s , m ost o f w hich were o f d a ir y b re e d in g .
S tu d ie s by B a r tle y e t a l . (1950) (195k)» R u so ff e t a l . (1951), Jacob­
son a t a l . (1 9 5 1 ), Knodt and Ross (1 9 5 2 ), EacKay e t a l . (1 9 5 2 ), Bloom and
Khodt (1953) and o t h e r s , u s in g Aureomycin on young d a ir y c a lv e s have shown
b e n e f i t s th ro u g h in c r e a s in g growth r a t e s and d e c re a sin g o ccu rren c e o f
sco u rs.
Some W o rk e rs--B e ll et_ a l . ( I 9 5 l ) , H u rley e t a l . (1 9 5 2 ), R u soff
e t a l . (1 9 5 3 )—have found t h a t u se of a n t i b i o t i c s r e s u l t s i n improved fe e d
e ffic ie n c y .
However, B a r tle y e t a l . (1 9 5 0 ), B e ll e t a l . (1 9 5 1 ), Jacobson
e t a l . (1 9 5 1 ), L o o s li e t a l . (1 9 5 1 ), H u rle y e t a l . (1 9 5 2 ), and o th e rs found
no d if f e r e n c e i n th e amount, o f ■fe e d needed to produce a u n i t o f g a in i n
body w e ig h t.
H u rley e t a l . (1 9 5 2 ), s ta t e d Aureomycin fe d to c a lv e s r e s u l t e d i n no
e f f e c t on u t i l i z a t i o n o f d ry m a tte r , c a rb o h y d ra te s , n itr o g e n , or a sh .
These c a lv e s r e c e iv e d a r e s t r i c t e d d i e t o f n o n - f a t d ry m ilk s o l i d s .
o f g a in was n o t a f f e c t e d .
R ate
K e sle r and Knodt (1 9 5 2 ), r e p o r te d m icro -o rg an ­
ism s from T e rram y c in -fed c a lv e s d ig e s te d 2 2 .R p e rc e n t l e s s c e ll u lo s e th a n
th e c o n tr o ls , a s d e term in e d by th e a r t i f i c i a l rumen m e th o d .. R addison e t
a l . (1953)j u s in g th e a r t i f i c i a l rumen a ls o , found Aureomycin added to
rum en-sam ples from young c a lv e s d e c re a se d d ig e s tio n o f f i l t e r p a p er c e ll u ­
lo s e b u t had no e f f e c t on a l f a l f a hay d i g e s t io n .
L a s s i t e r e t a l . (l9 $ 3 ) found Aureomycin d id n o t a f f e c t d ry m a tte r
d i g e s t i b i l i t y i n d a iry s t e e r s , b u t d id s i g n i f i c a n t l y d e p re ss d i g e s t i b i l i t y
o f th e crude f i b e r .
L a s s i t e r e t a l . (1 9 3 3 ), u sin g new -born d a ir y c a lv e s ,
r e p o r te d a b o o s t i n g a in , improvement i n fe e d e f f i c i e n c y , and low ered
in c id e n c e o f sc o u rs w ith Aureomycin.
There was no e f f e c t on d i g e s t i b i l i t y
o f fe e d n u t r i e n t s , d ig e s tio n o f cru d e f i b e r , and u re a n itr o g e n blo o d
le v e ls .
Aureomycin d id a p p ea r to low er n o n -p r o te in n itr o g e n b lo o d .le v e ls
f o r th e f i r s t seven w e e k s ;,th is d e p re s s io n c o rre sp o n d e d c lo s e ly w ith
s tim u la tio n of grow th t h a t o c c u rre d i n t h i s p e r io d .
P r i t c h a r d , e t a l . (1 9 3 3 ), u sin g Aureomycin on young id e n tic a l- tw in
m ale c a lv e s , r e p o r ts in c re a s e d grow th r a t e and im proved fe e d e f f ic ie n c y
f o r th e f i r s t e ig h t weeks of a g e .
A sev en -d ay c o l l e c t i o n p e r io d a t th e
end o f th e e ig h th week showed p r a c t i c a l l y no d if f e r e n c e s i n d i g e s t i b i l i t y
o f d ry m a tte r , a sh , p r o t e i n , curd e f i b e r , n itr o g e n - f r e e e x t r a c t , o r f a t ,
Mann e t a l . (1 9 3 3 ), s tu d ie d th e changes i n c o n c e n tra tio n o f Aureom ycin i n th e d ig e s t iv e t r a c t s o f c alv e s o f in c r e a s in g ag e, and a ls o com­
p a re d th e r e s p e c tiv e m ic r o f lo r a and m ic ro fa u n a o f s e v e r a l s e ts o f A ureom y c in -fed and c o n tr o l c a lv e s .
Anim als w ere a l l o f s im ila r - a g e and b re e d in g
and w ere h a n d led to s im u la te American p r a c t i c e s .
Aureomycin HCl a t ij.0-60
mg, was fe d d a i l y i n a g ru e l from about th e t w e l f t h day o f age to a b o u t
th e 3 th , 8t h , and 1 2 th week of a g e .
1
to g e th e r w ith a c o n tr o l a n im a l.
At th e s e tim es an im als were k i l l e d .
'
The t r e a t e d anim als had l a r g e r and l e s s
- 16 a c id rumen c o n te n ts which re a ch e d a rumen pH o f more th a n 6 .0 ( s u ita b le
f o r in te n s iv e rumen b a c t e r i a l a c tio n ) a t a much e a r l i e r age th a n c o n tr o ls .
Aureomycin was n e v e r d e te c te d i n th e rumen o r th e caecum, o n ly tr a c e s
w ere found i n th e omasum, and i t was d e f i n i t e l y found i n th e abomasum,
u s u a ll y a t 2-j? mg. p e r gram o f c o n te n ts .
There was l i t t l e d if f e r e n c e i n
f i n a l developm ent o f a t y p i c a l ru m e n -v ia b le s tr e p to c o c c a l p o p u la tio n .
These w orkers concluded th a t Aureomycin ta k en by mouth does n o t a c t d i r ­
e c t l y on rumen m ic ro -o rg an ism s, b u t p ro b a b ly does a f f e c t them by making
th e anim al a b e t t e r h o s t,
Aureomycin was alw ays found in th e abomasum
w here b a c t e r i a l a c tio n i s n i l , and. where t h e a c id pH c o rre sp o n d s to th e
c o n d itio n a t w hich Aureomycin p o s s e s s e s a maximum o f s t a b i l i t y .
The s t a t e s
ment was made t h a t a com plete c i l i a t e m icro fau n a was e s ta b lis h e d a t e ig h t '
weeks of ag e.
I f t h i s i s alw ays t r u e , th e b e n e f ic ia l e f f e c t s of a n t i ­
b i o t i c s sh o u ld become e v id e n t a t an e a r l y a g e .
H e ste r e t a l . (l95>lt) s tu d ie d a b s o r p tio n , d i s t r i b u t i o n , arid e x c r e tio n
o f Aureomycin i n th e body o f c a lv e s w hich re c e iv e d doses o f £0-90 mg,
d a i l y o r a l l y , o r I4.OO mg. w eekly by i n j e c t i o r i .
Compared t o t h e c o n tr o ls ,
grow th was in c r e a s e d 19 p e rc e n t i n 16 w eeks.
A n tib io tic was found p r e s e n t
i n b lo o d p lasm a, b i l e , and u r i n e . . The h ig h e s t c o n c e n tra tio n was found i n
u r in e o f i n j e c t e d c a lv e s , and th e lo w e st l e v e l s i n b lo o d p lasm a.
L iv e rs
and k id n ey s o f i n j e c t e d an im als c o n ta in m easu rab le amounts o f Aureomycin,
w h ile a tr a c e was found i n th e l i v e r and k id n e y o f one c a l f o r a l l y - f e d .
The s p le e n , thymus-, p i t u i t a r y , and m uscle showed no a n t i b i o t i c i n any c a l f .
No- Aureomycin was found i n th e rumen o f th e i n je c te d c a lv e s .
p a t t e r n -of d i s t r i b u t i o n was e s ta b lis h e d i n th e i n t e s t i n e s .
A d e fin ite
A n tib io tic i n -
- 17 - •
c re a s e d i n c o n c e n tr a tio n from th e u p p er end to th e lo w er p o r tio n o f th e
sm all i n t e s t i n e , and d e c re a se d i n c o n c e n tra tio n betw een th e low er sm all
i n t e s t i n e and th e a n a l end o f th e la r g e i n t e s t i n e .
Aureomycin i n S te e r Rumen S tu d ie s
Work has a lso been perform ed on o ld e r c a t t l e .
B e ll e t a l . (19^1),
fe d Aureomycin to s t e e r s and found a d e f i n i t e d e c re a se i n d i g e s t i b i l i t y
of a ll n u trie n ts .
Chance e t a l . (1953) s tu d ie d th e in flu e n c e o f A ureo-
mycin on rumen d ig e s tio n and r a t e ,of p a ssa g e o f n u t r i e n t s from th e rumen.
Two r u m e n - f is tu la te d s t e e r s w ere u s e d .
Aureomycin was f e d a t 0*5 gm. p e r
day f o r 15 d ay s, and th e n 1 .0 gm. p e r day f o r th e n e x t 15 d a y s.
The p e r ­
io d when no a n t i b i o t i c was g iv en was th e c o n tr o l p e rio d * • R um en.contents
were c o m p le te ly e v acu ated , w eig h ed , sam pled, and r e p la c e d i n th e rumen b e ­
f o r e fe e d in g (z e ro h o u r), and a g a in a t s i x and tw elv e h o u rs a f t e r feed in g *
R ate o f rem oval o f d ry m a t t e r , crude f i b e r , crude p r o t e i n and n itro g e n ^
f r e e e x t r a c t was h ig h e s t when 0*5 gm. l e v e l was fe d ..
A ccum ulation o f d ry
m a tte r , crude p r o t e i n , and n i tr o g e n - f r e e e x tr a c t i n th e rumen o c c u rre d a t
th e zero h o u r when 1 .0 gm. l e v e l was f e d , s u g g e s tin g a s l i g h t d e p re ss io n '
i n d i g e s t i b i l i t y o f th e c o n s ti tu e n ts may have ta k e n p la c e .
There w as-a
d e f i n i t e accu m u latio n o f e th e r e x tr a c t i n th e rumen a t th e zero hour when
e i t h e r l e v e l o f Aureomycin was fe d .Hungate e t a l . (1955) m easured t o t a l .fe rm e n ta tio n p ro d u c tio n of rumen
c o n te n ts o f Aureomyci n - f e d and c o n tro l s t e e r s , b o th i n th e p re se n c e and
absence o f a d d itio n a l Aureomycin.
I n h i b i t i o n by added a n t i b i o t i c was
g r e a t e r i n th e c o n tr o l a n im a ls, i n d ic a tin g t h a t th e Aureomycin fe d f i r s t
a l t e r e d th e co m p o sitio n o f t h e m ic ro b ia l p o p u la tio n .
Methane p ro d u c tio n
- 18 was re d u c e d by th e added Aureomyci n , b u t t h i s whs th o u g h t to be a seco n d ary
r e s u l t from i n h i b i t i o n o f p ro d u c tio n of th e in te rm e d ia te s hydrogen and f o r ­
m a te .
The m icro -o rg an ism s seemed to be more s e n s i t i v e t o Aureomyciri th a n
to S tre p to m y c in .
Aureomycin and P e n i c i l l i n a t d i f f e r e n t l e v e l s o f in ta k e were s tu d ie d
(Horn e t a l . 1 9 # ) i n d ig e s tio n and n itr o g e n b a la n c e t r i a l s w ith s t e e r s .
He found Aureomycin had a g r e a t e r d e p re s s in g e f f e c t th a n P e n i c i l l i n on th e
d i g e s t i b i l i t y o f p r o t e i n and cru d e f i b e r .
The tiro a n t i b i o t i c s had an
e q u a l e f f e c t i n d e c re a s in g n itr o g e n r e t e n t i o n . . At th e l e v e l o f 100 mg.
■
p e r day, Aureomycin r e s u l t e d in a l e s s d e s ir a b le rumen f l o r a l co m p o sitio n
f o r roughage d ig e s t io n , a s eviden ced b y .a d e c re a se d a b i l i t y t o d ig e s t f i b e r
in an a r t i f i c i a l rumen.
Aureomycin i n Sheep F a tte n in g R atio n s
y
.
Colby e t a l . (1950) f e d Aureomycin a t IQO mg, d a ily ,, o r a l l y by cap­
s u le , to f a t t e n i n g lam bs, and a lso th e same l e v e l p lu s a l l known B v i t a ­
m in s.
The t r e a t e d g ro u p s w ent alm ost e r i t i r e l y o f f f e e d .
P e n ic illir p ja o d .
S trep to m y cin w ere g iv en a t t h e same l e v e l s and by t h e same methods... Those,
two compounds w ere l e s s s e v e re i n t h e i r e f f e c t s compared t o Aureomycin,
W eight g ain s o f a l l tre a tm e n ts were l e s s , th a n t h a t o f th e controls,* some
anim als (Aureomycin tre a tm e n t) l o s t w e ig h t.
At South D akota, Jo rd an (1952) f e d n a tiv e and w e s te rn f a t t e n i n g lambs
a r a t i o n o f s h e ll e d y e llo w c o rn , a l f a l f a hay and soybean m e al.
Aureomycin
was added to th e soybean m eal and was f e d a t le v e ls o f 7 .2 m g,, 1 0 ,0 m g.,
and I Lu It mg. p e r lamb d a i l y .
R e s u lts o f fo u r s e p a ra te t r i a l s showed t h a t
lambs d id n o t go o f f fe e d or sco u r e x c e s s iv e ly .
Feed consum ption was n o t
-19
-
s tim u la te d , b u t i n two t r i a l s th e lambs w ere more e a s i l y p u t on f u l l feed *
The lU«k mg. l e v e l re d u c e d r a t e o f g a in and fe e d e f f i c i e n c y i n b o th t r i a l s
where i t was em ployed.
Aureomycin d id n o t give com plete p r o te c tio n from
e n te r o toxem ia, b u t d id reduce i t m a te r ia lly i n th e l a s t t r i a l .
Gains were
im proved i n one t r i a l w here u n t h r i f t y lambs were. u se d .
Jo rd a n and B e ll (l9E>l) conducted two t r i a l s u sin g 21 and 16 lambs r e ­
s p e c tiv e ly i n w hich th e y f u l l - f e d a s ta n d a rd c o r n - a l f a l f a hay r a t i o n p lu s ,
a n tib io tic s .
A c o n tr o l group was in c lu d e d .
I n th e f i r s t t r i a l , th e lam bs
w ere supplem ented w ith 6 .0 mg. Aureomyein p e r lamb d a i l y and had an a v e r­
age g a in o f 0 . 14.9 pounds p e r lamb d a i l y , compared w ith 0 .3 9 pounds p e r
lamb d a i l y f o r th e c o n t r o l s .
Also 22 p e rc e n t l e s s c o n c e n tra te s p e r 100
pounds o f g a in was r e q u ir e d .
I n t h e second t r i a l , 1 0 .8 mg. Aureomycin p e r
lamb d a i l y was s u p p lie d , and th e a n im a ls g a in ed O4I4O pounds p e r lamb d a i l y ,
compared to O.36 pounds p e r lamb d a i l y f o r .th e c o n tr o ls .
The t r e a t e d
lambs i n t h i s case r e q u ir e d 20 p e r c e n t l e s s fe e d .
T u rn er and H odgetts (19£2), i n A u s t r a lia , fe d s in g le 750 mg. doses
o f Aureomycin HCl o r a l l y to a d u l t Merino sh e e p .
t o 2 3 .6 -2 7 mg. p e r k g. o f body w e ig h t.
w ith in two h o u r s .
T h is dosage was e q u iv a le n t
Rumen f l o r a was re d u c e d 75 p e r c e n t
T his re d u c e d l e v e l p e r s i s t e d f o r two. d ay s, and th e s u r­
v iv in g b a c t e r i a w ere p re d o m in a n tly G pam -positive ro d s and c o c c i.
O th er
e f f e c t s in c lu d e d marked d e p re s s io n i n rumen fe rm e n ta tio n , re d u c tio n o f
o rg a n ic a c id p ro d u c tio n , d e p re ss e d a p p e t i t e , and w eight l o s s .
The anim als
resp o n d ed f a v o r a b ly to a d m in is tr a tio n o f rumen f l u i d and y e a s t e x t r a c t .
E l l i o t and E llsw o rth (1953) fe d f a t t e n i n g lambs Aureomycin a t 10 mg.
and 20 mg. p e r pound o f f e e d , and had th r e e ro u g h a g e -g ra in r a t i o s — 80-20,
- 20 -
60-b0, and ij0-60»
The 20 mg. l e v e l o f Aureomycin showed, a s i g n i f i c a n t i n ­
c re a s e i n g a in w ith th e h ig h e r le v e l s o f roughage, b u t showed a l o s s a t
th e h ig h g r a in l e v e l . 'B rid g e s e t a l . (1953) a t Texas f e d f a t t e n i n g lambs
Aureomycin a t 1 .1 mg. p e r pound of fe e d , 2 .2 m g., 3 .2 m g., U.3 m g., 5 .0
m g., and 15 mg.
The b a s a l r a t i o n was m ilo and a l f a l f a hay o r m ilo , c o tto n ­
se e d m eal, and a l f a l f a h a y .
The Aureomycin r e s u l t e d i n r e l a t i v e l y sm all
in c r e a s e s i n r a t e o f g a in , w hich were n o t s t a t i s t i c a l l y s i g n i f i c a n t s . Feed
e f f i c i e n c y was a p p a r e n tly im proved a t th e 2 .2 and 5*0 mg. l e v e l s .
B otkin (1953) a t Wyoming fe d 30 mg. Aureomycin p e r lamb d a ily and
s tim u la te d g a in s to 28 days b u t produced no ad v an tag e o v e r a c o n tr o l group
when th e 117-day fe e d in g p e rio d en d ed .
i n c a r c a s s g ra d e s .
There was no a p p a re n t d if f e r e n c e
D re ssin g p e rc e n ta g e s were s l i g h t l y h ig h e r fo r the
supplem ented lam bs.
K e ith and L e h e re r (195U) fe d lambs in d iv id u a lly , tw ic e a day, a con­
c e n tr a te o f e q u al p a r t s b a r le y and o a ts w ith -tw o p e rc e n t s a l t , p lu s p u re
c r y s t a l l i n e Aureomycin HGl a t 10 mg. p e r pound o f t o t a l f e e d .
Compared
to a c o n tr o l g ro u p , th e lambs consumed from 12 to 30 p e r c e n t l e s s t o t a l
f e e d , made 36 to 53 p e r c e n t l e s s av erag e g a in (0*17 to O.32 pounds p e r
d a y ), and r e q u ir e d 20 to 3)4 p e rc e n t more fe e d p e r u n i t p f g a in .
Thompson and G rain g er (195W o f th e U n iv e rs ity of K entucky conducted
a s e r i e s o f th r e e m etabolism t r i a l s c o n s is tin g o f th r e e groups o f two
w e th e rs each ( I — C o n tro l; I I —b a s a l p lu s 10 mg. p u re c r y s t a l l i n e A ureom ycin HCl p e r pound o f r a t i o n ; I I I - ^ b a s a l p lu s A urofac t o f u r n is h 10 mg.
Aureomycin HCl p e r pound of r a t i o n ) .
The r a t i o n was composed o f 61t0 gm.
ground c o rn cobs; 116.88 gm. soybean m eal; 16 gm. a l f a l f a m eal; 16 gm.
-
21
-
m o lassesj' p lu s m in e ra ls (Ca, P , . Na, C l, and Co) and cod l i v e r o i l ,
A
10-d a y p r e lim in a r y p e r io d was fo llo w e d b y a 10-d a y c o l l e c t i o n p e rio d .
W ethers in Groups I I and I I I showed a n o re x ia w ith in lj:8 to 72 h o u rs a f t e r
a n t i b i o t i c s were supplem ented.
th r e e d a y s .
A p p e tite r e tu r n e d to norm al a f t e r two o r
Average a p p a re n t d ig e s tio n c o e f f i c i e n t s f o r crude f ib e r were
71oIi.j 60,1]., and 5 9 ,7 f o r Groups I , I I , a n d , I I I r e s p e c t i v e l y .
These d i f ­
fe re n c e s were s t a t i s t i c a l l y s i g n i f i c a n t * ■ There was no d if f e r e n c e in
n itr o g e n r e t e n t i o n among g ro u p s.'
A pparent d i g e s t i b i l i t y o f d ry m a tte r,
n itr o g e n - f r e e e x t r a c t , and energy was low ered f o r th e t r e a t e d anim als,
b u t d if f e r e n c e s w ere n o t s i g n i f i c a n t ,
T illm an and MacVicar (X9$k) s tu d ie d th e e f f e c t o f 10 mg. c r y s t a l l i n e
Aureomycin d a i l y on d i g e s t i b i l i t y o f r a t i o n components f e d w e th er lam bs.
They found no s i g n i f i c a n t e f f e c t on th e amount p f n itr o g e n r e ta in e d o r on
d i g e s t i b i l i t y o f th e r a t i o n .
•
H a tf ie ld e t a l . (1951].), a t I l l i n o i s , ra n th r e e t r i a l s u s in g w e ste rn
b la c k fa c e d w e th e r lambs f e d ground c o rn , soybean m eal, and a l f a l f a , p lu s
Aureomycin as A urofac o r Aureomycin HCl.
7 .2 mg. p e r pound o f fe e d .a n d 7 .6 mg.
L e v e ls o f th e a n t i b i o t i c were
Combining r e s u l t s o f th e th r e e
t r i a l s , , av erag e d a i l y g a in s' a r e 'h i g h e r by 0 .0 5 5 - O.Oli] pounds, a v erag e
fe e d e f f i c i e n c i e s w ere h ig h e r , and av erag e c a rc a s s g ra d e s.w e re h ig h e r fo r
th e Aureomycin supplem ented g ro u p s .
A urofa c - f e d lambs n e a r ly p a r a l l e l l e d
av erag e perform ance o f th e lambs r e c e iv in g Aureomycin HCle • The a u th o rs
th o u g h t a n t i b i o t i c s have a p r a c t i c a l u se i n g ro w in g -fa tte n in g r a tio n s f o r
lambs by im proving r a t e and e f f i c i e n c y o f g a in s , and by re d u c in g th e num­
b e r o f u n t h r i f t y lam bs.
- 22 K ercher and Sm ith (1 9 5 5 )j . a t C o rn e ll, worked w ith lambs on c o b a lt d e fic ie n t d ie ts .
Aureomycin fe d a t 10. mg. per. day seemed t o r e t a r d body
w e ig h t lo s s e s and in c r e a s e d hay consum ption s l i g h t l y .
The Aureomycin
■
d e f i n i t e l y c o u ld n o t s u b s t i t u t e f o r th e c o b a lt t h a t was a b se n t i n th e
d i e t , how ever.
'
Jo rd a n (1954) u sed fo u r lots", o f 12 lambs each end f e d f o u r d i f f e r e n t
r a t i o n s —L o t I —lo n g a l f a l f a h a y and c o rn i n e q u al p r o p o r tio n s j l o t I I —
ground a l f a l f a hay and c o rn i n e q u a l p r o p o r tio n s mixed and p e l l e t e d , p lu s
0 .3 pounds lo n g a l f a l f a p e r lamb d a i l y ; L ot I I I — same a s L o t I I p lu s 10
mg. Aureomycin p e r pound o f p e l l e t e d r a t i o n s ; Lot IV-—t h r e e pounds ground,
a l f a l f a h ay and one pound ground c o rn , p lu s 10 mg. Aureomycin p e r pound
o f m ix.
T his l a s t m ix tu re was p e l l e t e d and f e d 'along w ith lo n g a l f a l f a '
a t 0 .3 pounds p e r lamb d a i l y .
Average d a i l y g a in s w ere— 0 .5 1 , 0 .5 4 , 0 .6 0 ,
and 0 .5 7 pounds p e r lamb f o r L ots I , I I , I I I , and IV r e s p e c t i v e l y .
P e l l e t i n g o r Aureomycin d id n o t in c r e a s e fe e d consum ption.
T o ta l fe e d
consum ption p e r lamb was h ig h e s t i n Lot IV, b u t co m consum ption was
lo w e st h e r e .
P e l l e t i n g d id n o t in c r e a s e fe e d e f f i c i e n c y , b u t d id in c r e a s e
fe e d c o s ts m a t e r i a l l y .
Lot I I I lambs (Aureomycin supplem ented) re q u ire d
10 p e r c e n t l e s s f e e d p e r pound o f g a in th a n d id lambs i n L ot I I .
B o tk in and P a u le s (1954) a t Wyoming fe d r a t i o s o f ro u g h a g e -to c o n c e n tra te o f 1 : 1 , '1 . 5 : 1 , and 2 :1 .
The c o n c e n tra te c o n s is te d o f b a r le y ,
d r ie d b e e t p u l p , ■and ground a l f a l f a h a y .
a f f e c t e d b y th e d i f f e r e n t r a t i o n s .
Response to Aureomycin was n o t
The c o n tr o l group (l5 3 lam bs) av erag ed
0 . 28? pounds g a in p e r lamb d a i l y , and r e q u ir e d 7 .5 0 pounds t o t a l d ig e s t­
i b l e n u t r i e n t s p e r pound o f g a in .
Those lambs g e ttin g 10 mg. Aureomycin
- 23 p e r pound o f r a t i o n g a in ed O .3OJ4 pounds p e r day, and consumed 7 $2ij. pounds
t o t a l d i g e s t i b l e n u t r i e n t s p e r pound o f g a in .
At Texas, Kunkel (195>1|.), h a n d -fe d lambs a . com plete r a t i o n o f hay,
c o tto n s e e d -m e a l, m ilo and m in e ra ls f o r $6 days-. - Xhe c o n tr o l g ro ip had an
av erag e d a i l y g a in o f 0 „lj5 pounds p e r day a rid -re q u ire d 7 .it? pounds fe e d
-
p e r pound o f g a in ; a group supplem ented m t h 5. m g.' Aureomycin- p e r poundo f fe e d g a in e d O0IUt pounds' p e r lamb d a i l y and .consumed 7 .17 pounds fe e d
p e r pound o f g a in , w h ile a l o t r e c e iv in g 10 mg. Aureomycin p e r pound o f
r a t i o n g a in ed an a v erag e o f 0 og 2 pounds d a i l y and took 7 . 2 6 .p o u n d s'o f '
fe e d p e r pound o f g a in .
C a rc a s s-g ra d e s w ere ab o u t e q u a l among th e th r e e
g ro u p s.
I n ..another S6-d a y t r i a l , K inkel .s e l f - f e d a .complete r a t i o n o f
•
p e r c e n t c o tto n s e e d h u l l s , 37.-3 p e rc e n t m ilo , 7 .5 p e rc e n t c o tto n s e e d m qal,
and 10 p e r c e n t m o la s se s.
Again th r e e l o t s were employed3 L ot I was th e
C o n tro lj L o t I I r e c e iv e d th e b a s a l r a t i o n p lu s 7 .5 mg. Aureomycin p e r
pound o f fe e d ; L ot I I I g o t th e .b a sa l r a tio n , p lu s 1 5 .0 mg. .Aureomydn- p e r
.
pound o f fe e d . Average d a i l y g a in s were 0 .3 0 , 0 ,3 2 , and 0*36-pounds, and
fe e d r e q u ir e d p e r pound o f g a in was 1 3 .1 , 1 1 .2 , and 1 2 .0 pounds f o r L ots
I , I I , and I I I , r e s p e c t i v e l y .
The m ost r e c e n t work from Texas ( Kunlcel and P a c k e tt, 1955) was w ith
20 lam bs f e d 15 mg. Aureomycin p e r pound of. r a t i o n a n d a c o n tr o l group o f
20 lambs fe d th e same r a t i o n w ith o u t a n t i b i o t i c s .
The supplem ented
group g ain ed 0 .U6 pounds p e r head d aily .-o n 6 , 7b pounds' fe e d p e r pound -o f
g a in ; t h e c o n tr o ls g a in ed O.I4.3 pounds d a i l y on 7.03 pounds fe e d p e r pound
o f g a in .
The Aureomycin. group d re s s e d o u t a b o u t one p e rc e n ta g e p o in t
— 2k "•
h ig h e rj th e r e was no d if f e r e n c e i n c a rc a s s g ra d e s .
P 'a c k e tt e t a l . (i9 $ 5 ) summarized d e a th lo s s e s i n fo u r y e a rs o f th e
Texas w ork.
Aureomycin a t v a ry in g l e v e l s g e n e r a lly showed a d ecrease i n
e n te ro to x e m ia .
Of 230 lambs i n c o n tr o l g ro u p s, 10 an im als d ie d o f e n te r o -
toxem ia (k»3 p e r c e n t) , and 12 d ie d from a l l c au ses (5*2 p e r c e n t) .
D uring
t h i s game p e rio d 353 lambs w ere fe d r a t i o n s in c lu d in g Aureomycin a t v a rio u s
le v e ls .
Here th e r e w ere no d e a th s from e n te ro to x e m ia , and o n ly s ix d e a th s
(1 .7 p e r c e n t) from a l l c a u s e s .
Lambs fg d th e a n t i b i o t i c o f te n s t a r t e d o f f
e a tin g l e s s , apd sc o u rin g was le ss , in te n s e and. of- a s h o r t e r d u ra tio n th a n
w ith th e c o n t r o l s .
I t was .su g g e ste d t h a t th e g r e a te s t v alu e o f a n t i b i o t i c s
i n fe e d e r lamb r a t i o n s was a c o n d itio n e r allo w in g g r e a te r e a se of
g e t t i n g lambs on f u l l f e e d .
Three t r i a l s were r e p o r te d b y Bohiqan e t a l . (1955) in which lambs
w ere f e d 0 .0 , 5*0, 1 0 .0 , and 2 0 .0 mg. l e v e l s o f Aureomycin p e r p o u n d ,o f
g r a in mix, w ith and w ith o u t B-V itam in su p p le m e n ta tio n .
The h ig h e r a n t i ­
b i o t i c l e v e l s to g e th e r w ith p re se n c e o f B -V itam ins were, s l i g h t l y more
fa v o ra b le th a n th e c o n tr o ls i n r a te o f gain and fe e d e f f ic ie n c y , b u t
d if f e r e n c e s w ere n o t s t a t i s t i c a l l y s i g n i f i c a n t .
n o tic e d among th e t r e a t e d g ro u p s.
No a d v erse e f f e c t s -were
The a u th o rs su g g e ste d t h a t e i t h e r a n t i ­
b i o t i c s do n o t i n h i b i t a c ti o n o f rumen p iioro-organism s t h a t n o rm ally
s y n th e s iz e B -V itam ins, o r t h a t th e fe e d s u sed i n t h i s s tu d y meet th e
B -V itam in re q u ire m e n ts o f th e f a t t e n i n g lam b s, B-V itam in c o n te n t o f th e
r a t i o n s was n o t d e te rm in e d .
A nglem ier and O ld f ie ld (1955) a t Oregon found t h a t h e a lth y ,lambs on
a s ta n d a rd g r a in and legume hay r a t i o n a p p a re n tly d id n o t b e n e f i t from t h e
- 25
a d d itio n i n th e d i e t o f 10 mg.- A nrofac p e r pound o f t o t a l f e e d .
I n an o th er
tiri& l} ..'u n th rifty lam bs..on a n o b v io u s ly u n s a t i s f a c t o r y d i e t .of g r a s s ,.s ila g e
p lu s e i t h e r g r a in o r ammoniated m o la s s e s .d id h o t resp o n d to a n t i b i o t i c s
a t th e same r a t e .
Ih e n g ra s s hay was s u b s t i t u t e d f o r th e g r a s s . s i l a g e to
th e p o in t where th e lambs' g a in ed i n w e ig h t, a s i g n i f i c a n t improvement in
r a t e o f g a in o v er th e c o n tro ls .w a s e v id e n t in a l l groups, fe d Aureomyci n .
I t was th e o r iz e d t h a t th e a n t i b i o t i c a id e d in ,.some way i n t h e r e e s t a b l i s h ­
ment o f a d e s ir a b le rumen f l o r a a f t e r ad v erse fe e d in g c o n d itio n s have b e en
im proved.
-
'
B otkin and P a u le s (1955) fe d e ig h t l o t s o f 50 lambs each In a s tu d y
o f p e l l e t i n g and a n t i b i o t i c s .
-Feeding p e l l e t s gave c o n s id e ra b ly f a s t e r
and.m ore e f f i c i e n t g a in s , b u t fe e d c o s ts p e r pound o f gain, w ere h ig h e s t
f o r th e p e l l e t e d r a t i o n s .
Less la b o r was needed when p e l l e t s were u sed ,
and th e lambs re a c h e d m arket w eig h t 30 days e a r l i e r th an lambs on a
s im ila r r a t i o n n o t . p e l l e t e d .
A n tib io tic s (Aureomycin' a t 19 mg. p e r day,
o r T erram ycin a t 18 m g ."p er day) r e s u l t e d i n s l i g h t l y f a s t e r and more
e f f i c i e n t g a in s , b u t th e f e e d p o s t p e r pound o f gain-w as s l i g h t l y h ig h e r
f o r lambs r e c e iv in g a n t i b i o t i c s .
Lamb fe d r a t i o n s c o n ta in in g b a r le y ,
e i t h e r p e l l e t e d o r u n p e lle te d , made f a s t e r and more e f f i c i e n t -gains th a n
lam bs fe d r a t i o n s c o n ta in in g c o m .
The b a r le y r a t i o n was a ls o c h ea p e r.
Aureomycin i n S u c k lin g Lamb ■R a tio n s’
Colby e t a l . (1950) r e p o r te d no b e n e f ic ia l, r e s u l t s when 0 . 5- 1 .0
p e r c e n t A .P .F ., supplem ent c o n ta in in g 0 .6 mg. V itam in
and h.O mg.
Aureomycin p e r gm. was added to a r a t i o n f o r s u c k lin g lam b s.
Kinsman and R id d e ll (1 9 5 3 ), d iv id e d k9 s u c k lin g lambs i n t o f iv e
- 26 groups and f e d each group th e same b a s a l r a t i o n o f c o rn , o a ts , b ra n , and
li n s e e d m eal f o r e ig h t w eeks.
F iv e .a n t i b i o t i c s were f e d a t . I ^ mg. p e r
pound o f C o n c e n tra te -G ro u p I —Aureomycin^ I I —T erram ycinj I I I —P e n ic illin ,*
IV— C o n tro l; and V— Terram y cin and V itam in
There was no a p p aren t
d if f e r e n c e i n r a t e s o f d a i l y g a in , th e extrem es b ein g 0®j?ll pounds f o r
Group I , and O.^li.6 pounds f o r Group V.
pound Of g a in was as f o llo w s :
3 .1 2 ; and V— 3 .1 7 .
Feed, consum ption i n pounds p e r
Group I — 2 .8 3 ; I I — 2 .8 8 ; I I I — 3 . 48; IV—
G e n e ra lly s p e a k in g , a l l groups were on a p a r i n t h r i f t ­
in e s s and c o n d itio n .
Luce et_ a l , (1953) c re e p -f e d Hampshire lambs u s in g 10 mg. Aureomycin.
T reatm en ts w ere as fo llo w s :
L ot I —C o n tro l; I I —10 mg. Aureomycin p e r lamb
d a i l y i n th e c re e p fe e d f o r 14 days; I I I — same a s I I b u t f o r 21 days; IV—
10 mg. from seven days o f age to w eaning; V—LO mg. from th re e - w eeks' of
age to w eaning.
and V.
Lots. I , I I , and I I I made h ig h e r t o t a l g ain s th a n L o ts IV
There was no d if f e r e n c e i n s u r v iv a l r a t e o r h e a lth o f lambs betw een
g ro u p s.
H a tf ie ld e t al_. (1954) ra n two t r i a l s on c r e e p -f e e d in g su c k lin g lambs*
The b a s a l r a t i o n ( f i r s t t r i a l ) was 30 p e r c e n t c o m , 30 p e r c e n t o a t s , 30
p e r c e n t w heat b ra n , and 10 p e r c e n t soybean mealy
p e r pound o f r a t i o n was added.
Aureomycin a t 7.2 mg,
A lf a lf a was f e d f r e e c h o ic e .
I n th e seco n d
t r i a l th e r a t i o n was composed o f 88*5 p e r c e n t co rn -an d -co b m eal; 10 p e rc e n t
soybean m eal; and 1 .5 p e r c e n t m in e ra l m ix tu re (bonem eal and tr a c e - m in e r a l­
iz e d s a l t ) .
Aureomycin was s u p p lie d a t a b o u t 7*5 mg. p e r pound o f r a t i o n ,
and a l f a l f a hay was a g a in o f f e r e d f r e e c h o ic e .
The a n tib io tic -s u p p le m e n te d
r a t i o n s gave s m a ll ( n o n s ig n if ic a n t) b u t c o n s i s t e n t l y h ig h e r average d a i l y
- 27 r a t e s o f g a in and fe e d e f f i c i e n c i e s .
th e c o n t r o l s .
Also c a r c a s s g ra d e s w ere h ig h e r th a n
The a u th o rs th o u g h t t h a t a n t i b i o t i c s may h e lp re d u c e th e
number o f u n t h r i f t y an d ■p o o r-d o in g la m b s .■
A nother t r i a l , G a ith e r e t a l . (1 9 5 ^ ), c o n s is te d o f s e lf - f e e d i n g 2Q
lam bs from two weeks o f age to m arket a g e .
The r a t i o n was made up o f 60
p e rc e n t c o rn , 20 p e r c e n t f i n e l y ground cob, 10 p e r c e n t a l f a l f a m eal, 10
p e r c e n t soybean m eal, and m in e r a ls .
pound o f r a t i o n was supplem ented .
Anreomycin a t th e r a te o f 7 .0 mg. p e r
S i g n i f i c a n t l y h ig h e r a v erag e d a ily
g a in s were re c o rd e d ; however, fe e d e f f i c i e n c y was re d u c e d s l i g h t l y .
Jo rd an and BeI l (195>U)> r a n two ex p erim en ts w ith s u c k lin g lam b s. . The.
f i r s t experim ent c o n s is te d o f fo u r s e p a ra te p a r t s i n w hich Aureomycin was
f e d a t l e v e l s o f 5 .0 mg. p e r lamb d a i l y , U..3 m g., U.S'mgo,,- a n d .1 0.8 mg. f o r 33 to 5>0 d a y s.
I n th r e e o u t o f th e fo u r t r i a l s , , r a t e o f g ain was in ­
c re a s e d (a v . o f 0 .6 5 pounds p e r lamb d a i l y a s compared to 0 .5 9 pounds f o r
th e c o n t r o l s ) , and fe e d e f f i c i e n c y was a ls o s l i g h t l y in c r e a s e d .
d ig e s t iv e d is tu rb a n c e s w ere r e p o r te d .
No
I n t h e i r second e x p e rim e n t, th e s e
w orkers i n j e c t e d 80 mg. Aureomycin HCl stib c u tan e o u sly n e a r t h e f o r e - r i b o f
h a l f th e lam bs.
The f i r s t two t r i a l s of t h i s experim ent had s i x to n in e -
day o ld G o rrie d a le lam bs, and th e t h i r d t r i a l h ad o n e -d a y .o ld lam bs.
c re e p fe e d was u se d .
No
The d if f e r e n c e s i n av erag e d a ily g a in are s l i g h t ,
b u t f a v o r th e c o n tr o l groups i n two o u t o f th e t h r e e tr i a l s * .
Bohman et_ a l . (1955) fe d 20 orphan lambs from tw o to f o u r weeks o f
age to m arket w e ig h t.
t r a t e was s u p p lie d .
A urofac a t th e r a t e o f 10 mg. p e r pound o f concen­
Some o f th e s e lambs re c e iv e d Aureomycin i n th e m ilk
i n a d d itio n , a t th e r a t e o f 10 mg. d a i l y .
Each lamb was h a n d -fe d 0 .6
-2 8 pounds o f m ilk tw ic e d a ily f o r th,e f i r s t $0 d a y s .
f r e e c h o ice along w ith th e .c o n c e n tra te .
A lf a lf a h ay was o ff e re d
The tr e a tm e n ts d id n o t s i g n i f i ­
c a n tl y im prove r a t e o f g a in , d re s s in g p e rq e n ta g e , o r c a rc a s s g ra d e .
No
a d v erse e f f e c t s w ere n o tic e d t h a t c o u ld be a s s o c ia te d Tifith t h e tr e a tm e n ts .
Beeson e t a l . (195k) im p la n te d tw o-day o ld su c k lin g lam bs su b cu tan ­
e o u s ly w ith th e fo llo w in g a n t i b i o t i c s :
Wi mg. B a c itr a c in ; 88 mg. B a c it­
r a c i n ; 22 mg. B a c itr a c in and 9*k mg. P e n i c i l l i n ; IiU mg. B a c itr a c in and 18 .8
mg. P e n i c i l l i n ; lUO mg. Aureomycin HCl; 132 mg. B a c itr a c in ..
None o f th e se
tr e a tm e n ts had a s i g n i f i c a n t e f f e c t on grow th r a t e ,
Madsen e t a l . (1955) ra n a one-week t r i a l in v o lv in g 63 s u c k lin g lambs
I
from UO R a m b o u ille t, Columbia, and Hampshire ewes. : A c re e p r a t i o n o f r o l l ­
ed b a r le y , £0 p e r c e n t; r o l l e d o a ts , 30 p e r c e n t; d r ie d m o lasses b e e t p u lp ,
10 p e r c e n t; and c o tto n s e e d m eal, 10 p e r c e n t was o f f e r e d f r e e c h o ic e .
A l f a l f a hay was o f f e r e d s e p a r a te ly .
head d a i l y , p lu s a l f a l f a h a y .
The ewes' re c e iv e d one pound b a r le y p e r
A urofac was s u p p lie d a t th e r a t e o f 10 mg.
Aureomycin p e r pound o f c re e p m ix tu re to a p o r ti o n o f th e lam b s.
No
s i g n i f i c a n t e f f e c t was r e p o r te d on grow th r a t e o r fe e d consum ption.
Summary:
Aureomycin i n R a tio n s o f Farm Animals
The v a lu e o f a n t i b i o t i c s to farm a n im a ls can be summarized i n g e n e r a l.
A d e f i n i t e im provem ent i s o bserv ed i n r a t e o f g a in , fe e d e f f ic ie n c y , and
g e n e r a l h e a lt h when a n t i b i o t i c s a re a p p lie d to p o u ltr y and swine r a t i o n s . •
The l e s s fa v o ra b le th e environm ent i s from a h e a lt h s ta n d p o in t, th e more
re sp o n se can be e x p e c te d from a n t i b i o t i c s .
D a iry c a lv e s sco u r l e s s , w hich r e s u l t s i n a low er m o r t a l i t y r a t e .
W hile r a t e o f g a in m a y b e in c re a s e d i n e a r ly l i f e , t h i s e f f e c t i s u s u a lly
— 29 —
l o s t a s th e an im al approaches m a tu rity *
E a r ly work w ith sheep and s t e e r s r e s u l t e d i n u n d e s ir a b le r e s u l t s .
T his was due a t l e a s t i n p a r t to th e h ig h l e v e l s o f a n t i b i o t i c s u s e d .
Some b e n e f i t s a re r e a liz e d - from use o f low (10 mg, p e r pound o f r a t i o n )
l e v e l s o f a n t i b i o t i c s i n sheep f a t t e n i n g r a t i o n s , b u t. th e e f f e c t s a re
d e f i n i t e l y l e s s s p e c ta c u la r th a n w ith sw ine and p o u ltr y .
W hile u s u a lly
n o t s t a t i s t i c a l l y s i g n i f i c a n t , r e s u l t s show a s l i g h t tr e n d to w ard more
fa v o ra b le r a t e o f g a in , and b e t t e r f e e d e f f ic ie n c y .
P erhaps th e b ig g e s t
a d v an ta g e s a re t h a t sheep go on f e e d w ith l e s s t r o u b l e , e x p e rie n c e l e s s
e n te ro to x e m ia , and e x p e rie n c e l e s s s c o u rin g , e s p e c ia ll y under commercial
f e e d - l o t c o n d itio n s where d is e a s e may be an im p o rta n t fa c to r*
— 30 — .
OBJECTIVES
T h is ex p erim en t was designed, to s tu d y th e e f f e c t s o f fo u r d i f f e r e n t
c re e p r a t i o n s on r a t e o f g a in , fe e d e f f i c i e n c y , and g e n e ra l h e a lt h o f suck
l i n g tw in la m b s.
The o b je c tiv e 's o f th e t r i a l were ( l ) t o determ ine, th e
e f f e c t o f p e l l e t i n g a sim ple o a t- b e e t p u lp r a t i o n , (2 ) t o d e te rm in e th e
e f f e c t o f adding Aureomycin a t 20 mg. p e r pound o f r a t i o n to a sim ple o a t b e e t p u lp c re ep p e l l e t , a n d '( 3 ) to d e te rm in e th e e f f e c t o f u s in g a commer­
c i a l ty p e c re e p p e l l e t c o n ta in in g Aureomycin h t 20 m g ..p e r pound o f r a t i o n
- 31 ■ PROCEDURE
T h irty -tw o ewes o f S u f fo lk , H am pshire, a n d w h ite fa c e b re e d in g were
random ly d iv id e d by b re e d in to , f o u r groups .o f e ig h t ewes p e r group*
Each
ewe s e le c te d f o r th e t r i a l had two h e a lth y lam bs, v a c c in a te d f o r e n te r o to x em ia, a t h e r s id e .
D uring th e e x p e rim e n ta l p e r io d , a l l f o u r groups p h ared a d jo in in g
s e c tio n s o f a m e ta l-c o v e re d frame shed t h a t w as.open to th e s o u th .
Each
group was c o n fin e d i n a pen tw elve f e e t w ide and. f i f t y - e i g h t f e e t lo n g ,
t h i r t y - f i v e f e e t o f w hich was under th e s h e d .
ends o f e ac h pen under th e s h e d .
Creeps, w ere b u i l t a t th e
I n each creep was p la c e d a fe e d tro u g h
m easu rin g tw e lv e in c h e s w ide, n in e ty inph'es lo n g , and th r e e in c h e s deep.-.
To keep lambs from sta n d in g i n t h e tro u g h and c o n tam in atin g th e creep
fe e d , a o n e -b y -s ix in c h board was c e n te re d and s u p p o rte d ab o u t e lev e n
in c h e s above th e tro u g h f l o o r , ru n n in g th e le n g th o f t h e tro u g h .
The c re ep f e e d form ulae and t h e d e s ig n .o f th e ex p erim en ts a re g iv en
i n T ab le I .
R a tio n s I and 2 c o n ta in e d eq u al.am o u n ts p f th e same in g r e d i­
e n t s , th e o n ly v a r i a b l e b e in g t h a t R a tio n I was i n b u lk form and R a tio n 2
i n p e l l e t form .
Sugapulp was in c lu d e d in -R a tio n I so th e r a t i o n would
c o n ta in th e e q u iv a le n t o f 10 p e r c e n t' m o la sse s.
R a tio n 3 d i f f e r e d from
R a tio n 2 o n ly by c o n ta in in g A urofac 2A At a l e v e l o f 20 mg. Aureomycin
p e r pound o f fe e d . . R a tio n It c o n ta in e d t h e same c o n c e n tra tio n o f Aureomycin as d id R a tio n 3* b u t th e co m p o sitio n was p a tte r n e d a f t e r a commer­
c i a l fe e d p e l l e t , and was composed o f a l a r g e r v a r i e t y o f in g r e d ie n ts .
S u f f i c i e n t c re ep f e e d was w eighed and d i s t r i b u t e d each m orning to
have fe e d a v a ila b le t o t h e lambs a t a l l tim es,.
Feed n o t e a te n a f t e r
32
Table !«■ Experiqiental Design and R ation Composition.
R a tio n No*
I .
2
3
Number o f Ewes:
Hampshire
S u ffo lk
W hite fa c e ■
■ T o ta l Ewes
h
'3
I .
F
5
2
I
F
5
2
I
F
Number o f Lambs
16
16
16
"■
' h
.
5
2
I
F ■
16
Feed T reatm ent ( l b s , p e r day p e r Ewe)
A lf a lf a , F i r s t C u ttin g
ad l i b . ad l i b . ad l i b . ad l i b .
O ats, Whole I /
' 1 .5
1 .5 . 1 .5
1 .5
Feed T reatm ent (Lambs)
R a tio n No *
Whole G rain
I
I n g r e d ie n ts (p e rc e n t)
O a ts, w h o le .
O a fs, p u lv e riz e d .
B a rle y , p u lv e riz e d
Wheat mixed fe e d . ( m illru n )
Soybean O il Meal
L in seed O il Meal
A lf a lf a Meal
Y e a s t, a c ti v e d r ie d
Y e a st, i r r a d i a t e d
A urofac 2A
T race M in erals
D icalcium p h o sp h ate
S a lt
B eet p u lp , d r ie d m o lasses
M olasses, b e e t
Sugapulp, (80$ M olasses)
P e l l e t e d R a tio n s
2
3
4
8 7.50
———
—————
■•wwi-ee—
8 7.50
—————
—————
—————
——
———
—
—————
—————
—
'-T——
•
— ——
— ——
—————
2.5 0
■1P..00
■— —
—————
—————
—————
we*-,™.
1 2 .5 0
100*00
— —
100.00
8 6 .9 2
-W-W7I
——W
W
—
—————
—————
— ——
3040P
25.00
15.79
5 .0 0
5.00
5 ,oo
2.00
0 .0 1
.0 .5 5
0*15
0 .5 0
1.0 0
W
ewwwweei7
o ,5 5
.......
——
—— —
2 .5 0
1.0,00
10,00
————— •wen—
10 0 ,0 0 100,00
l / O ats .were fe d a t 1 ,0 lb s * p e r ewe d a i l y f o r th e f i r s t two w eeks.
- 33 two days was w eighed back and n o t o f f e r e d a g a in ,
Weighbacks o f u n e a te n
fe e d d u rin g th e f i r s t p a r t of th e t r i a l c o n s is te d c h i e f l y o f f in e m a te r ia l
from p e l l e t s ,
Ag th e lambs in c re a s e d i n s iz e and a p p e ti te , t h i s f in e
m a te r ia l was e a te n more r e a d i l y .
The ewes w ere fe d o a ts a t th e r a te , o f one pound p e r head p e r day f o r
th e f i r s t two w eeks, a t which tim e th e l e v e l .was r a i s e d to .one. and a h a l f
pounds p e r head d a i l y .
F i r s t c u ttin g b a le d a l f a l f a hay was s u p p lie d ad
lib id u m tw ic e d a i l y i n .s e l f - f e e d e r bunks*.
U neaten fe e d was co m p le tely
removed and w eighed each m orning.
W ater from a w e ll was p ro v id e d i n wash tu b s and made a v a il a b le to th e
lambs and ew es.
G ra n u la te d (n o n -io d iz e d ) s a l t was a v a ila b le i n each pen
t o b o th ewes and lam b s.
S a l t consum ption f o r th e t h ir ty - tw o ewes and
s i x ty - f o u r ' lambs was a p p ro x im a te ly one hundred pounds d u rin g th e f i f t y day
fe e d in g t r i a l .
The sheep w ere fe d i n d ry l o t f o r f i f t y days (A p ril 11 to May.31,
1935) a t th e F o rt E l l i s farm o f th e Montana A g r ic u ltu r a l E x p erim en tal
S ta tio n n e a r Bozeman, M ontana.
week f o r b o th ewes and lam bs.
D uring t h i s tim e , w e ig h ts w ere ta k en each
F o llo w in g th e d r y l o t p e r io d , th e y were
k e p t on p a s tu r e w ith o u t su p p lem en tal f e e d .
1955j a t w hich tim e w e ig h ts w ere o b ta in e d .
Lambs were weaned J u ly 29,
- 3h -
RESULTS MD DISCUSSION
The w e ig h t g a in s and fe e d c o s ts o f tw in lambs f o r t h e f i f t y - d a y fe e d ­
in g p e r io d a re summarized i n T able 1 1 .
The lambs i n th e d i f f e r e n t groups
w ere o f a p p ro x im a te ly th e same ag e, av erag in g s l i g h t l y o v e r one month.
Each group contained s ix te e n lambs o f th ree, d if fe r e n t b r e ed s.
Average
i n i t i a l w eight o f th e lambs .was approxim ately tw enty-nine pounds.
A lf a lf a hay was a v a il a b le t o th e ewes and lambs a t a l l tim e s .
Hay
consum ption averaged lj.8,3 pounds p e r day f o r each pen o f e ig h t ewes and
s ix te e n lam b s.
Weighback was ab o u t 17 p e r c e n t o f t h e t o t a l hay o f f e r e d .
D uring th e f i r s t p a r t o f th e t r i a l , a l l lambs e x h ib ite d a p re fe re n c e f o r
a l f a l f a le a v e s t h a t c o lle c te d i n th e bpttom s of. th e hay b u n k s, in s te a d
o f th e c re e p fe e d o f f e r e d them .
Hoirever, d u rin g th e l a s t t e n days o f
th e t r i a l , lambs i n Croup I a te th e c re ep fe e d i n p re fe re n c e to th e a l ­
f a l f a le a v e s .
■The o a t r a t i o n f e d th e ewes was in c r e a s e d from one pound p e r head
p e r day, to one and a h a l f pounds, b ecau se t h e ewes began lo s in g w e ig h t.
W eight l o s s was much l e s s ra p id when ewes w ere, f e d a t th e h ig h e r g ra in
le v e l.
A f te r f i v e weeks on th e h ig h e r c o n c e n tra te l e v e l , ewe w eig h ts i n
Group k le v e le d o f f , w h ile t h e ewes i n thp o th e r groups c o n tin u e d to lo s e
from o n e - h a lf to one and a h a l f pounds p e r week.
The lambs e a g e r ly consumed a maximum o f th e o a t r a tio n o ffe r e d the
ewes.
As th e lambs became la r g e r and str o n g e r , th e g ra in consumed by
them in c r ea se d in to a con sid era b le amount.
The strong a ttr a c tio n the
lambs d isp la y ed fo r th e grain i s in t e r e s t in g , in view o f th e fa c t th a t
creep fe e d was always a v a ila b le to them.
I t was noted th a t lambs in
- 32 Table I I . .Weight Gains and Costs o f Suckling Twin Lambs Fed Fopr
Creep R ations
R a tio n No.
Feed T reatm ent
Aureomycin
I
2
3
it
Whole G rain . - P e l l e t e d R atio n s
O
. 0
X
X
Average I n i t i a l Age o f Lambs (Days). .
3k
31
No. o f Lambs on E xperim ent
16
16
F i r s t Two Weeks o f T r i a l :
Average W eights ( l b s . )
In itia l
F in a l
D a ily Gain
Feed Consumption p e r Laiqb ( l b s , )
Feed Consumption p e r Cwt. Gain
Feed C ost p e r Cwt♦
Feed C ost p e r Cwt* Gain
F i r s t ■T h i r ty - f i v e ' Days o f T r i a l :
Average W eights ( l b s . )
■I n i t i a l
F in d l
D a ily Gain
Feed Consumption p e r Lamb ( l b s . )
Feed Consumption p e r Cwt, Gain .
. Feed C ost p e r Cwt.
Feed Cost p e r Cwt. Gain
'
3 0 .L
3 5 .2
0.3L
Feed C ost p e r Cwt,
Feed C ost p e r Cwt, Gain
Feed C ost p e r Lamb
35
■16
16
i
28.9
35.8
29.3
. 3 6 .it
0 .1 9 • 0 .7 1
29.3
. 36.3
0 ,7.1 ■
6 .1
5.9
. 85.9 8it,3
$3.12
I2.LU
#3.33 #3.47
#2.69 #2.76 #2.86 $2,93
■„ 6 .1
5 .3
1 1 0 .5 ' 8
8.it
: 30.L
lt9 .9
0 ,5 6
28.9
Lt9.1
0.58
.
29.3
it8.9
0 .5 6
29,3
"
0.63
51 .1
35.8
29.8 3it.lt
32 .it
1
6
0
,i
t
,
,1
5
2 .0 . .15 7 .8
132.3 ; .
.# 3 .1 2
#3.33 #3.47
#3.22 $5.oo #5.05 #5.48
■$ 2 . LtLt
R e s u lts o f Complete T r i a l :
Average W eights ( l b s . )
In itia l'
30.lt
F in a l
6 0 ,6
D a ily Gain
0 .6 0
D a ily Feed Consumption ( l b s , ) I 0.96
Feed Consumption p e r Lamb ( l b s . )
Feed Consumption p e r Cwt. Gain
'
31
'
Lt8,l
1 5 9 .2
28.9 29,3 29.3
64.2
59.3 6 0 .5
0.61 0.62 0.70 ■
1 .0 8
1.36
1 .2 1
60.it
■198.7
5U.2
.1 7 3 .7
68.0
194*6
# 2 . Ltlt •#3.12 #3.33 #3.47'
#3.88 ■#6.20' #5.78 #6.75
$1.88
$ 1 .8 0
#2.36
#1.17
36 —
Group I on a c re ep fe e d o f s e v e n -e ig h th s whole o a ts e x h ib ite d l e s s d e s ir e
to consume t h e i r dams' g r a in r a t i o n th a n .d id - lambs h aving c re e p fe e d
a v a ila b le i n p e l l e t form ..
Lambs on th e o a t-S u g a p u lp r a t i o n (Group l ) te n d ed a t f i r s t to e a t
a l l th e Sugapulp and le a v e s m a ll amounts, o f o a ts from day to day.
e v e r, th e o a t r e s id u e d id n o t accum ulate e x c e s s iv e ly .
How­
Toward th e l a t t e r -
p a r t o f th e t r i a l , b o th Sugapulp and o a ts were e v en ly consumed each day.
Comparison o f P e l l e t e d and Whole Gyain R a tio n s
P e l l e t i n g th e fe e d , r a t h e r th a n fe e d in g a whole g r a in r a t i o n , i n ­
c re a s e d fe e d consum ption d u rin g th e f i r s t two--week p e rio d , a s w e ll 'a s ■
d u rin g th e e n t i r e t r i a l .
The in c r e a s e d fe e d consum ption was r e f l e c t e d
by a d if f e r e n c e i n g a in o f O.lj? pounds p e r day f o r th e f i r s t two w eeks,
i n fa v o r o f th e group g e ttin g p e l l e t s .
Lambs o f Group I , on whole g r a in ,
av erag ed as heavy a t th e end o f f i f t y d ay s a s d id th e -p e lle t- f e d lambs
o f Group 2, and consumed 1 2 .3 pounds l e s s fe e d p e r lam b, o r 3 9 .5 pounds
l e s s fe e d p e r hundredw eight o f g a in , ' C ost o f fe e d p e r hundredw eight'
fa v o re d Group I,. w hich to g e th e r w ith t h e g r e a te r f e e d e f f i c i e n c y r e s u l t e d
i n a d if f e r e n c e o f $2.32 i n fe e d c o st p e r hundredw eight o f g a in i n fa v o r
o f Group I .
F in a l l y , th e r e was a d if f e r e n c e i n fe e d c o s t p e r .lamb o f
$ 0.71 i n fa v o r o f Group I .
D uring th e l a s t p a r t o f t h e - t r i a l , Jambs i n Group I had a " p o t- b e llie d "
a p p e a ra n c e .
I t was th o u g h t t h a t c a rc a s s s c o re s o f t h i s group would be
low ered somewhat becau se o f t h i s c o n d itio n .
Comparison o f P e l l e t e d R a tio n s W ith and W ithout Aureomycin S u p p lem en tatio n
Lambs i n Groups 2 and 3 b o th r e c e iv e d a r a t i o n s i m i l a r i n co m position
■
37 -
to lambs o f Group I , but in p e lle t e d form.
R ations 2 and. 3 d iffe r e d o n ly
in th a t R ation 3 contain ed Aureomycin at th e r a te o f 20 mg, per pound o f
fe e d , w h ile R ation 2 contained no Aureomyci n .
I t i s q u ite apparent th a t
Aureomycin had an e f f e c t on r a te o f g a in duping th e f i r s t two weeks o f the
t r i a l , as th ere was a d iffe r e n c e in d a ily g a in o f 0,22 pounds in fa v o r o f •
th e Aureomycin group.
Feed consumption probably had no e f f e c t on the
d iffe r e n c e s in r a te o f g a in , as lambs o f Gpoups 2 ' and 3 both consumed an
average o f 6 .1 pounds o f fe e d . . . Although Aureomycin in crea sed the ra te o f
gain co n sid era b ly during th e f i r s t two-week p erio d , th e in crea sed feed
c o s t , due to in c lu s io n o f Aureomycin, more th an o f f s e t t h is advantage.
The end r e s u lt fo r the f i r s t two-week p erio d was a d iffe r e n c e o f $0.10 in
fe e d c o s t per'hundredw eight o f gain fa v o r in g lambs o f Group 2 .
At the end o f th e f i r s t t h i r t y - f i v e days, the d a ily r a te s o f gain were
alm ost eq u a l.
The d iffe r e n c e in fe e d c o s t p er hundredweight o f gain be­
tween the two groups had been reduced by h a l f ,
.
At the end o f f i f t y days, th e d a il y r a te s o f gain were v ir t u a lly
th e same fo r th e two groups o f lambs.
Feed consumption per lamb and fe e d
consumption per hundredweight o f gain were somewhat lower, fo r the Aureo­
mycin supplemented anim als.
This advantage more than o f f s e t th e higher
r a tio n c o s t , r e s u lt in g in a f i n a l d iffe r e n c e o f $0.08 in t o t a l feed c o st
per lamb, fa v o r in g th e Aureomycin group.
Comparison o f Simple and Complex P e lle te d R ations Both C ontaining
Aureomycin
lambs in Groups 3 and
k
both r e c e iv e d p e lle t e d creep ra tio n s co n ta in ­
in g 20 mg. Aureomycin per pound o f fe e d .
The r a tio n s d iffe r e d o n ly in
- 38 th a t R ation 3 was composed o f o a ts , b e e t p u lp ,. and beet m o la sses, whilp
R ation
k
contain ed a la r g e r v a r ie ty o f in g r e d ie n ts .
Table I in d ic a te s .
th e com position o f each r a tio n .
During, th e f i r s t two-week p e r io d , d a i l y r a t e s o f g a in were i d e n t i c a l
f o r lambs i n Groups 3 and Iw
There was s l i g h t l y l e s s fe e d consum ption i n
Group U, b u t t h i s advantage was o f f s e t b y th e h ig h e r fe e d c o s t p e r hundred­
w e ig h t.
The d if f e r e n c e i n feed . Cbpt p e r hundredw eight o f g a in was $D.07
i n fa v o r o f Group 3»
By th e end o f th e f i r s t t h i r t y - f i v e days, d a ily r a te s o f gain favored
.lambs fe d th e complex r a tio n .
This in c r ea se d gain i s a t l e a s t p a r t ia lly
ex p la in a b le by the in crea sed fe e d consumption o f lambs in Group Iw
How­
ev er, i t s t i l l took l e s s .f e e d per hundredweight o f gain for.lam b s in Group
3, and t h is f a c t , p lu s th e lower feed p r ic e , made a d iffe r e n c e o f $0.1j3 in '
fe e d c o st per hundredweight o f g a in in favor o f Group 3«
R e s u lts f o r th e w hole f i f t y - d a y t r i a l show lambs i n Group h c o n tin u e d
t o g a in a t a f a s t e r r a t e th a n th o s e i n Group 3«
t o fa v o r Group 3 lam b s.
Feed e f f i c i e n c y c o n tin u e d
There was a f i n a l d if f e r e n c e o f $0.97 i n fe e d
c o s t p e r hundredw eight o f g a in , in d ic a tin g R a tio n 3 d e f i n i t e l y made ch eap er
g a in s th a n R a tio n If.
F in a l fe e d c o s t p e r lamb was $ 2 .3 6 f o r R a tio n 1|,
compared to $ 1 ,8 0 f o r R a tio n 3»
I t sh o u ld be n o te d , how ever, t h a t lambs
o f Group h w ere a p p ro x im a te ly fo u r pounds h e a v ie r th a n th o s e o f Group 3»
O y e r-a ll Comparison o f th e Four R atio n s a t th e End o f th e F eeding T r i al.
D uring th e f i r s t two weeks Aureomycin a p p a re n tly in c r e a s e d r a t e o f
g a in i n lam bs o f Groups 3 and U, compared t o th o s e i n Groups I and 2.
Feed consum ption d u rin g t h i s p e r io d was a p p ro x im a te ly e q u al f o r a l l groups
- 39 g e ttin g p e l l e t s .
Lambs on th e w hole g r a in r a t i o n (Group l ) had th e lo w e st
r a t e o f g a in and fe e d consum ption o f th e fo u r groups s u g g e s tin g r a t e o f
g a in was in flu e n c e d by fe e d consum ption, and i n d i r e c t l y by fe e d p a l a t a b ility .
Feed c o s t p e r hundredw eight o f g a in was lo w e st f o r Group I .
By th e end o f f i v e weeks th e r e was a d e f i n i t e d if f e r e n c e between
groups i n b o th fe e d consum ption and r a t e o f g a in .
Lambs' i n Group I had th e
lo w e st consum ption and th o s e i n Group It th e h ig h e s t .
R ate o f g a in was ■
n e a r ly th e same f o r lambs i n Groups I , 2 , and 3, b u t d e f i n i t e l y h ig h e r f o r
lambs o f Group I4.
Feed c o s t p e r hundredw eight o f g a in c o n tin u e d to b e
•
lo w e st f o r Group I and h ig h e s t fo r.G ro u p I*.
The f i n a l v a lu e s f o r d a i l y g ain s show Qroups I , 2 , and 3 were v i r ­
t u a l l y th e same,- w h ile th e v a lu e f o r Group L was d e f i n i t e l y h ig h e r .
Feed
consum ption p e r lamb was lo w e st f o r Group I , and h ig h e s t f o r Group U,
w h ile Groups 2 and 3' were in te r m e d ia te .
Lambs from Group I gave t h e .b e s t ,
fe e d e f f i c i e n c y , w h ile th o s e from Group 2 gave th e p o o r e s t.
Feed c o s t was lo w e st f o r Group I b ecau se no p e l l e t i n g ch arg e was i n ­
v o lv e d .
The p e l l e t f e d lambs- o f Group 3 was s l i g h t l y more ex p en siv e th an
th e p e l l e t f o r lambs i n Group 2 because o f th e added Aureom ycin.
The Group
h p e l l e t was th e m ost c o s t l y , due to p e l l e t i n g c h a rg e , added Aureomycin,
and more e x p e n siv e i n g r e d ie n ts .
Group I lambs made th e c h e a p e st g a in s , due to th e low fe e d c o st and
m ost fa v o ra b le fe e d e f f i c i e n c y .
However, th e l e s s fa v o ra b le con fo rm atio n
o f th e la m b s -d e tra c te d from t h i s o th e rw is e d e s ir a b le r a t i o n .
Feed c o s t p e r lamb was lo w e st f o r Group I , and h ig h e s t f o r Group I+.
A d d itio n o f Aureomycin to a p e l l e t re d u c e d fe e d c o s ts $0.08 p e r lamb i n
th is t r i a l
The h e a lt h o f th e anim als u sed i n t h i s t r i a l was good.
One lamb i n
Group I (no Aureomycin) had sc o u rs duping th e second and t h i r d w eeks, and
a n o th e r lamb had a c a se d u ring th e t h i r d week o n ly .
Group 2 (no Aureo­
m ycin) had one case o f sc o u rs d u rin g th e second, t h i r d , and f o u r th w eeks.
There was one d e f i n i t e case and. one b o r d e r lin e case i n Group 3 (A u re o -.
m ycin su p p lem en ted )j b o th c a se s occu fp ed d u rin g th e f o u r th week,
■The in c id e n c e o f sc o u rs fo llo w e d no d e f in ite , p a t t e r n betw een g ro u p s .
The e f f e c t o f Aureomycin on sc o u rs wag n o t e s ta b lis h e d due to th e low
in c id e n c e o f sc o u rs i n t h i s t r i a l .
E a rly i n t h e t r i a l th r e e S u ffo lk ewes-became lam e, each i n a r e a r ’ '
fo o t.
S u lfa p i l l s g iv en o r a l l y had l i t t l e e f f e c t ; how ever, l i b e r a l a p p li­
c a tio n o f s u l f a powder on th e open wound and bandaging gave good r e s u l t s
i n two o u t o f th e th r e e c a s e s .
P a s tu re P e rio d F ollow ing th e F eed in g T r i a l
F ollow ing th e c o n c lu s io n o f th e c re ep fe e d in g p e r io d , a l l groups were
combined and ru n f i f t y - e i g h t days on p a s tu r e w ith no a d d itio n a l fe e d .
T able I I I g iv e s r a t e o f g a in and w eaning w eig h t d a ta f o r th e lam bs.
I
Lambs' from a l l fo u r groups g a in ed a t a p p ro x im a te ly th e same r a t e when
on p a s t u r e .
Lambs i n Group I g ain ed th e slo w e s t (0 .3 1 pounds p e r d a y ),
lam bs i n Groups 3 and I4. were in te rm e d ia te (O .3I4 pounds p e r d a y ), and Group
2 lambs g a in ed th e f a s t e s t (O.36 pounds p e r d a y ).
The lambs t h a t re c e iv e d
th e whole g ra in r a t i o n gained th e slo w e st on p a s tu r e , s u g g e s tin g th e y w e re ■
a t a s l i g h t d is a d v a n ta g e compared to lambs t h a t g o t fe e d i n p e l l e t form .
Creep fe e d consum ption was h ig h e r f o r a l l lambs on p e l l e t s th a n on whole
- Ill -
T able I I I . .
R e s u lts o f 58-d a y P a s tu re P e rio d Follow ing Creep Feeding
R a tio n N o ..
Feed. T reatm ent
Aureomycin
■
I
• Whole G rain
Q
2
3 ■
U
P e lle te d R atio n s
0
X . ' X
F i f t y - e i g h t Days on P a s tu r e :
'
Average W eights ( l b s . )
S t a r t o f P a s tu re P e rio d
End o f P a s tu re P e rio d
D a ily Gain on P asture..
D a ily Gain S ince B eginh in g o f Experim ent
(109 d ay s)
• 6 0 .6
78.£
' 0 .3 1 .
#.3
80.0
O.36
Ochh
O.U7
6U.2
6 0 .3 '
8 0 .0 . 8U.0
0.3U . 0.3U
.
0.U6
0.3 0
'
g r a in , and t h i s p o s s ib ly had some e f f e c t .
The Group I). lambs continued to hold t h e ir w eight advantage, as th ey
weighed o f f p astu re sev e r a l pounds h ea v ier than did lambs o f the other
groups,.
F ig u r e s ' f o r o v e r - a l l r a t e o f g a in p e r lamb a re g iv e n , which in c lu d e
b o th th e £0-day fe e d in g p e rio d and th e 58-d a y i n t e r v a l on p a s t u r e .
on t h e w hole. g ra in r a t i o n (Group l ) g a ip ed th e slo w est
Lambs
pounds p e r
d a y ), and Group It'lam bs .gained th e f a s t e s t (0 ,5 0 pounds p e r d a y ).
T his
d if f e r e n c e p ro b a b ly r e f l e c t s th e e f f e c t o f t o t a l poynds o f fe e d consumed
w h ile th e lam bs.w ere on creep f e e d , , a s Group I. lambs .consumed th e l e a s t
( lt8 ,l pounds p e r lamb) and Group it lambs consumed th e m ost (6 8 .0 pounds
p e r la m b ).
The f i n a l r a t e o f g a in v a lu e s f o r lambs' o f Groups 2 and 3 were
a lm o st i d e n t i c a l , in d ic a tin g Aureomycin i n t h i s t r i a l had l i t t l e , o v e r - a ll
e f f e c t on g a in in g r a t e .
*- b-3 —
SUMMARY
T h irty -tw o S u ffo lk , H am pshire-and w h ite fa c e ewes, a l l w ith tw in ■
lam bs, were random ly d iv id e d by b re e d i n t o f o u r e q u al g ro u p s, and fe d 1 .5 pounds whole o a ts d a i l y p lu s a l f a l f a h ay f r e e c h o ic e .
c re e p fe e d s w ere s u p p lie d th e m onth-old lambs f r e e c h o ic e .
Four d i f f e r e n t
R a tio n I con­
ta in e d seven p a r t s whole o a ts t o one p a r t ' "Sugapulp. V .R atio n 2 c o n ta in e d
th e same in g r e d ie n ts a s R a tio n I , b u t i n p e l l e t , form .
R a tio n 3 was a
p e l l e t s im ila r to R a tio n 2 , b u t supplem ented w ith 20 mg, Aureomycin p e r
pound.
R a tio n I; was d e sig n e d t o s im u la te a co m m ercial-type c re ep p e l l e t ,
supplem ented w ith 20 mg. Aureomycin p e r pound.
Rate o f g a in , feed e f f ic ie n c y , and g en era l h e a lth o f th e lambs were
compared.
During the f i r s t two weeks o f th e seven-week t r i a l , Aureomycin
app arently in c r ea se d r a te o f g a in .
Group I lambs fe d the whole grain r a ­
t io n (no Aureomycin) had the lo w e st r a te o f g a in and fe e d consumption per
lamb fo r t h i s p e r io d .
At th e end o f f i v e weeks, lambs' op th e whole grain r a tio n were con­
suming th e l e a s t feed per lamb, and lambs on th e commercial type p e l l e t
w ith Aureomycin (Group U were consuming th e most fe e d per lamb.
Rate o f
g ain was h ig h e s t fo r lambs fe d th e commercial p e l l e t and were equal fo r
th e oth er th re e groups.
This same fe e d consumption and r a te o f gain r e ­
la tio n s h ip between groups e x is t e d a t th e end o f the t r i a l .
Feed c o s t and fe e d c o s t per hundredweight o f g a in were lo w est fo r
Group I on whole g ra in .
These lambs appeared " p o t-b e llie d " which was
thought would be r e f le c t e d in a sm aller d ressin g percentage and lower
r
'
- li.ii. -
c a r c a s s g rad e compared w ith lam bs from th e o th e r th r e e groups®
Feed c o s t and f e e d .c o s t p e r h undredw eight o f g a in was h ig h e s t f o r '
Group U on th e com m ercial ty p e p e l l e t p l u s ' Aureomyci n .
The c o s t o f in c lu d in g Aureomycin a t 20 mg. p e r pound i n an o a t- b e e t
p u lp p e l l e t was more th a n r e p a id th ro u g h in c re a s e d fe e d e f f i c i e n c y .
G eneral h e a lt h o f th e ewe's and lam bs was good.
In c id e n c e o f sco u rs
among th e lambs was d iv id e d alm ost e q u a lly among th e fo u r g ro u p s.
Because
o f th e low in c id e n c e o f sc o u rs i n t h i s t r i a l , th e v a lu e o f Aureomycin i n
c o n tr o llin g sc o u rs was n o t d e te rm in e d .
At th e end o f a f i f t y - e i g h t d a y p a s tu r e p e rio d fo llo w in g th e fe e d in g
t r i a l , o v e r - a l l d a i l y g a in s w ere s m a lle s t (O9Iii* pounds p e r d ay ) f o r th e
w hole g r a in group, and h ig h e s t ( 0 .5 0 pounds p e r day) f o r th e com m ercial
p e l l e t g ro u p .
P e l l e t i n g th e c re ep r a t i o n te n d e d to in c r e a s e g a in s s l i g h t ­
l y , b u t a d d itio n o f Aureomycin to th e o a t- b e e t pulp p e l l e t had no e f f e c t
on su b seq u en t r a t e o f g a in o f lam bs on p a s t u r e .
A nglem ierj ■A» F . and J . E. O ld fie ld * 1955® R esponses to Aureomyein
S u p p lem en tatio n b y Lambs Under D if f e r e n t F eeding C o n d itio n s . Amer.
Soc. Anim*. P ro d . 6 :1 8 ? .
B a r tle y j -E. E ., F . C. F o u n ta in e j and F . W. A tkeso n . 1950. The E f fe c t of
an A .P .F . C o n ce n tra te C o n ta in in g -Aureomycin on th e Growth and W ell­
b e in g o f Young C alves. J o u r. Anim. S c i . 9 :6 ^ 6 .
B a r tle y j E . Eej F . W. A tkesonj H. C. F ra y e rj and F . C. F o u n ta in s . 195L*
A n tib io tic s i n D airy C a ttle N u tr it io n , I I I . E f f e c ts o f D if f e r e n t
L e v e ls o f Aureomycin In ta k e Upon t h e Growth and W ell-b ein g , o f D airy
C alv es, and t h e A s s o c ia tio n o f D iffe re n c e s W ith Changes in ' E nviron­
m ent. J o u r . Anim. S c i. 37:259..
B eeson, W. M., T. W.- P e r r y , W., A. S t i t t , and J . B. O uthouse. 195^. A n ti­
b i o t i c P e l l e t Im p la n ts f o r S u c k lin g Lambs. J o u r. Anim. S c i. l3 :2 U 2 . .
B e ll, M. C ., C. K. W h ite h a ir and W. D. G a llu p . 1951» The E f f e c t o f A ureomycin on D ig e s tio n i n S te e r s . J o u r. Anim. S c i. 1 0:1039.
Bloom, S . and C. B. Knodt.. 1953« Aureomycin S u p p lem en tatio n o f R atio n s
f o r D a iry C a lv e s. J o u r . D a iry S c i . 36:633»
BohmaPf V. R ., J . E. Hunter, and LeGyand Walker. 1955»
B-Vitamins fo r Lambs. Jour. Anim. S c i . 1^:111.
A n tib io tic s and
B otkin, M. P . and Leon P a u les. Control o f Death Loss and D ig e stiv e D istu r ­
bances in Feeder Lambs. Univ. o f Wyo. A gric« Exp. S t a . Mimeo. C ir.
No. 33.
B o tk in , M. P . and Leon P a u le s . 195U» E f f e c t o f Aureomycin i n V arious
R a tio s o f Roughage to C o n ce n tra te f o r F eed er Lambs. U niv. o f Wyo.
•A g ric. Exp. S ta . Mimeo. C ir . No. Wi.
B o tk in , M. P , and Leon P a u le s . 1955» The E f f e c ts o f P e l l e t i n g and o f
A n tib io tic s i n Lamb F a tte n in g R a tio n s . Amer. Soc. Anim. P ro d . 6 :1 6 3 .
B rid g e s, J , H ., J . C . M ille r , W. G. Kammlade, J r . , and H, 0 . K in k e l.
1953» E f f e c ts o f V ario u s LeVels o f Aureomycin i n F a tte n in g Lambs.
J o u r. Anim. S c i . 12:660*
Chance, C. M ., C. F . Huffman, and C. W. Duncan. 1953» A n tib io tic s i n
Rumen D ig e s tio n and S y n th e s is . I . The E f fe c t o f Aureomycin on Rumen
D ig e s tio n and th e P assag e o f N u tr ie n ts from th e Rumen D uring S p e c ific
I n t e r v a l s A fte r F e e d in g ., J o u r. D a iry S c i. 3 6 :253.
C o a ts, M. E ., C. D* D ic k in so n , G. F . H a rris o n , S. K. Kon, S. H., Cummins,
and W. F . J . C u th b e rtso n . 1951» Mode o f A ctio n o f A n tib io tic s i n
S tim u la tin g Growth o f C hicks, N atu re 168:332.
C olby, R. W., F. A. Rau, and F. A.' Couch, 1950» E f f e c t o f Feeding an
"Animal P r o te in F a c to r" C o n c e n tra te ■to- Young Lambs. J o u r , P h y s io l.
163: ltl6 .
C olby,' R. W., F* A. Rau, and J . C. M i l l e r . 1950«
mycin and Type o f R a tio n on F a tte n in g Lambs.
9 :6 5 2 .
The E f f e c t o f Aureo-r
J o u r. Anim. S c i.
D ugger, B. M. 19US. Aureomycin—A P ro d u ct o f th e C o n tin u in g Search f o r
New A n t i b i o t i c s . A nnals o f - th e New York Acadamey o f S c ie n c e s .
51:177»
'
E l l i o t , R. F . and S. A. E lls w o rth , .1953« The E f f e c t o f Aureomycin and
Type o f R a tio n on F a tte p in g Lambs. J o u r. Anim. S c i. 12 :9 !U .
G a ith e r, W. E ., E. H a tf ie ld , and U. S . G a rrig u s . 195b. H hat About High
O il Corn f o r Lamb F eeding? U niv. 111. A g ric . Exp. S t a . Mimeo.
. ASb02a.
H a tf ie ld , E. E ., U. S. G a rrig u s , and H. W. •N orton. 195b. A n tib io tic
• Supplem ents i n R a tio n s f o r Growing and F a tte n in g Lambs. . J o u r. Anim.
S c i . 1 3 :7 1 5 .
H e s te r, H. H ., F . T. L andagora, and L , L, R u s o ff, 195b. The D is tr ib u ­
t i o n o f Aureomycin i n th e Body o f D a iry C alves Showing a Growth
Response When th e A n tib io tic i s A d m in istered O ra lly o r In tram u scu ­
l a r l y . J o u r . Anim. S c i , 1 3 :9 8 8 .
H i l l , D. C ., H. D. Bra n io n , S. J f S lin g e P j and G. W. A nderson. 1953«
In f lu e n c e o f Environm ent on th e Growth Response o f C hicks to P e n i­
c i l l i n , P o u ltr y S c i. 3 2 :b62 .
H i l l , Eldon G ., and Nora L. L a rso n . 1955. E f f e c t o f C h lo r te tr a c y c lin e
S u p p lem en tatio n on Growth and Feed U t i l i z a t i o n o f U nsuckled Baby
P ig s O b tained by H ysterectom y. J o u r. Anim, S c i. I b : l l l 6 .
Horn, L. H. J r . , R. R. Snapp, and L. 5 . G a ll. 1955« The E f f e c t o f A n ti­
b i o t i c s Upon.th e D ig e s tio n o f Feed N u trie n ts by Y e a rlin g S te e r s ,' With
B a c te r io lo g ic a l D a ta . J o u r. Anim. S c i . Ib:2b3«
H ungate, R. E ., D. W. F le tc h e r , and I . A. D yer. 1955» E f f e c ts o f C h lo rt e t r a c y c l i n e F eeding on Bovine Rumen M icro -o rg an ism s. J o u r, Anim.
S c i . lb :9 9 7 «
Jaco b so n , N. L ,, L. G. K a ffe n tz a k is and W,,R. H u rley , 1951* Response o f
R um inating D a iry C alves to Aureomycin F e e d in g . (A b s tra c t) J o u r. Anim
S c i . 10:1050.
- It7 -
Jo rd a n , R. M. 1952. Aurecmycin Supplem ents i n Lamb F a tte n in g R a tio n s .
J o u r. Anim. S c i . 1 1 :5 6 6 .
Jo rd a n , R. M. 1951t. Lamb R esponses to A n tib io tic s and P e l l e t e d R a tio n s .
(A b s tra c t) J o u r. Anim. S c i. 1 3:1009.
Jo rd a n , R.. M, and D. T, B e ll. 1951. E f f e c t o f Aureomycin on Growing- a n d '
F a tte n in g Lambs. (A b s tra c t) J o u r. Anim. S c i. 1 0 :1 0 5 1 .
J o rd a n , R* M, and D, T-. B e l l. 195b. E f f e c t o f Aureomypin Supplem ents bn
S u c k lin g Lambs. J o u r. Anim, S c i. 1 3 :lt5 0 , '
Kammlade, W. G.
53b p p .-
19b7.
Sheep S cien ce..
J . B .. L ip p in c o tt C o., KT. Y ., N. Y .,
K e ith , T. B. and W. P . L e h re r, J r . 195b. Growth Response o f Lambs Fed
Three L ev els o f Roughage and Pure C r y s ta l lin e Aurebmycin HCl. P ro c .
Amer. Soc. Anim. P ro d . ( ¥ .3 . ) 5:117*
K eroher, C. J . and S. E. S m ith. 1955« The Response o f C o b a lt- d e f ic ie n t
lambs to -L evovorin and C h lo r te tr a c y c lin e ,. J o u r, Anim. S c i. lb:878»
K e s le r, E. M, and C, B. K nodt. 1952. E f f e c t of Terram ycin on Growth and
and Rumen F u n c tio n i n H o ls te in C a lv e s. J o u r. Apim. S c i. 1 1 :7 6 8 . ■
Kinsman, D. M, and W. H. R i d d e l l . 1953• A n tib io tic i n Creep R a tio n s o f
S u c k lin g Lambs. J o u r. Anim.. S c i. 1 1 :7 6 9 .
Knodt, C. B. and E. B. R o ss. 1952. The Value o f V arious L ev els o f A ureomycin i n H l k R eplacem ents f o r D a iry C alv es. J o u r. D a iry S c i.
35?b93.
:
K unkel, H. 0 . 195b. Taken from a Pam phlet b y E l l i o t t , R. F, and H. M.
Haddock. 1955. The C ontinuous Feeding o f Aureomycin to Lambs.
American Cyanamid C o., 30 R o c k e fe lle r P la z a , N. Y. 20, N. Y. .
KunkeI , H. 0 . and L. 0 . P a c k e tt, J r . 1955. Taken from a Pam phlet by
E l l i o t t ,• R. F . and H. M, Haddock. 1955» The C ontinuous Feeding o f '
Aureomycin to Lambs. American Cyanamid C o ,, 30 R o c k e fe lle r P la z a ,
N. Y. 20, N. Y.
'
■
L a s le y , J . F . , L. F . T r ib b le , and A. G. Hogan. 195b. V alue o f A n tib io tic s
i n Swine R a tio n s . M isso u ri A gr. Exp. S ta . R es. B u i. 5b3.
L a s s i t e r , C. A ., T. W. Dpnto n , and G. I . B a s tin . 1953« The Value of
C e r ta in S u r f a c ta n ts as Growth S tim u la n ts When Fed t o C a v le s . J o u r .
D a iry S c i. 3 6 :5 9 2 .
L a s s i t e r , C, A ., T. W. D e n to n ,' and J . W. R u s t. 1955- The E f f e c t o f C h lo rt e t r a c y c l i n e and Ethomid C /l£ on Growfch, A pparent D i g e s t i b i l i t y , and
Blood L ev els o f Urea and T o ta l N o n -p ro tein n itr p g e n i n Young D airy
C a lv e s. J o u r. Anim. S c i . ll|.:7 6 0 e
L i l l i e , R. J . , J . R. Sizem ore, and H, R. B ind. 195>3* Environm ent and
S tim u la tio n o f Growth o f Chicks by A n t ib io t ic s . P o u ltr y S c i, 3 2 :^ 6 6 . •
L o o s li, J , K ., R. H. Wasserman, and L. S. G a ll. 19!?1»
W ith D a iry C a lv e s. . J o u r. D airy S c i, 31;:£00»
A n tib io tic S tu d ie s
Luce, L. C . , B . H . S c h n id e r, E. D. Tayson, and E. E. Goodwin,
A n tib io tic s f o r Lambs. N a tio n a l Wool Grower. 143:17.
1933.
' MacEay, A. M., W. H. R id d e ll, and R. F itzsim m o n s. 1932. Feed Supplement
C o n tain in g Aureomycin and V itam in Bip f o r D airy C alv es. J o u r. Anini.
S c i, l l : 3 l a .
Madsen, M. A ., D. J . Matthews, and R. E. T aylor. 1933* . The E ffe c t o f ■
Aureomycin in th e Creep R ation o f Suckling. Lambs. Amer. Soc. Anim.
Prod. 6 :1 3 9 .
Mann, S. O ., F ran ces M» Masson, and A. E. O xford. 193U* E f f e c t o f Feeding
Aureomycin to I C alves upon th e E s ta b lis h m e n t o f T h e ir Normal Rumpn
M ic ro flo ra and M icrofauna.' " B r i t , . J o u r. N u tr it io n . 8 :2 ^ 6 .
M urley, W. R ., N. L. Jaco b so n , and R. S . A lle n . 1932. E ffe q t o f A ureomycin S u p p lem en tatio n on Growth and Feed U t i l i z a t i o n o f Young D airy
C a l v e s J o u r . D a iry S c i. 3 3 :8 ^ 6 .
P a c k e tt, L. V. J r . , J . H. B rid g e s, Marcus H o elch er, and H. 0 . E ih k e l.
1933* The Use o f A n tib io tic s i n S e lf - f e e d in g Lambs, (A b s tra c t) ■
J o u r. Anim. S c i. 114:1219.
P ritch a rd , G. 1«, J . A. Newlander and W. H. R id d e ll. 1933* Aureomycin
E f f e c ts : Growth and D i g e s t i b i l i t y S tu d ie s W ith I d e n t i c a l Twin C alv es.
J o u r. Anim. S c i. 1^:336*
R ahdison, J . J . , E. E, B a r tle y , F . C. F o u n ta in s , and F., W. A tk eso n . 1933.
E f fe c t o f Aureomycin a n d /o r G rass J u ic e C o n ce n tra te on C e llu lo se
D ig e s tio n i n an A r t i f i c i a l Rumen as In flu e n c e d by D if f e r e n t Sources
o f N u tr ie n ts . J o u r. Anim. S c i. 1 2 :9 2 9 .
R aper, K. B. 1932.
U lt( I ) :! .
A Decade o f A n tib io tic s i n A m erica.
M ycologia.
R ick s, E. Lf , N. G* Brink, F. R. Koniuszy, T. R. Wood, and K. F o lk ers.
19U8. Comparative Data on Vitamin B^g from L iver and a New Source,
Streptom yces G riseu s. S c ie n c e. 1Q8:63U*'
-
1*9
-
Ru1SSGff, L. L .,' J . ' A. A lfo rd , .and C. E. Hyde. 19^3. E f f e c t o f Type o f
P r o te in on th e Response o f Young D a iry C alves to Aureomycin With Data
on th e I n t e s t i n a l M ic r o flo ra . J o u r. D a iry S c i. 36;IjJ?.
R u s s o ffji L. L . , A. V. D av is, and J . A. A lf o r d . 19^1. Growth Prom oting
E f f e c t o f Auredmycin oh Young C alves Weaned from M ilk .a t an E a rly Age.
J o u r. N u t r i t i o n . 1*5j 289.
S te p h e n s, C. R ., L . H. Conover, F-. A. H o c h ste in , P . P . Regna, F . J . .
P ilg r im , K. j . B runings, and R. B. Woodward. 1952. J o u r. Amer. Chem.
Soc. 75:1*976..
S to c k s ta d , E. L. R ,, and T. H. J u k e s . 1950. F u tu re O b se rv a tio n s on th e
Animal P r o te i n F a c to r . P ro c . Soc. E x p er. B io l, and Med.- 73:523.
S to c k s ta d , E, L. R ., T. H. Ju k e s, J . V. P ie r c e , A. C. Page, J r . , and A. L,. '
F h a n k lin . 191*9. The M u ltip le N atu re o f th e Animal P r o te i n F a c to r.
J o u r, B io l. Chem. 180:61*7.
Thimann, K, V. ■1955.
773 Pi?.
The Life- o f B a c te r ia .
Thompson, C. M., and R. B. G ra in g e r♦ 1951*.
t i o n o f Low Q u a lity Roughage b y Sheep.
13: 1002.
Turner, A. W., and V. E. H odgetts.
■ in Adult. Sheep by -Aureomycin.
.
.
The M acm illian C o., N. Y. ■
E ffe c t o f Aureomyein on D iges­
(A b s tra c t) J o u r. Anim, S c i.
.
1952. D epression o f Ruminal D ig estio n
Jour. Dairy S c i. 3 6 (3 ):A 3 9 .
INTRODUGTXON
The endocrine glands, are im portant in r e g u la tin g p h y s io lo g ic a l fun­
c tio n s o f th e body*
Of th e s e endocripe g la n d s, thp sex glands are.
c lo s e ly a s so c ia te d -with animal growth and f i n a l a d u lt s i z e , as w e ll as
l i b i d o , rep rod u ction , and secondary sex c h a r a c t e r is t ic s .
Recent work
has shown th a t some chemical substan ces p o s s e s s sex hormone a c t i v i t y
which a lt e r th e growing and f a t t e n in g •c h a r a c t e r is tic s o f farm animals
and are th ereby b e n e f ic ia l fo r animal p rod u ction .
The s y n th e tic compound d ie th y ls t i l b e s t r o l , commonly r e fe r r e d t o in
animal produ ction jo u rn a ls a s s t i l b e s t r o l , p o s s e s se s a c t i v i t y sim ila r
to th e fem ale sex hormones and i s se v e r a l tim es as p o te n t a s e str o n e ,
S t ilb e s t r o l i s cheaper to manufacture than th e n a tu ra l fem ale sex hormones
and i s e f f e c t i v e when given o r a lly ,
"Whether the s t i l b e s t r o l m olecule
i s changed in to th e s tr u c tu r e o f one o f th e fem ale sex hormones or
whether th e compound i s effectiv e" i n i t s o r ig in a l form i s unknown.
S t i l b e s t r o l has been in v e s tig a te d and a ccep ted a s having a favor­
ab le in flu e n c e on ra te and e f f ic ie n c y o f production o f c e r ta in c la s s e s o f anim als.
More inform ation i s needed on how s t i l b e s t r o l in te r a c ts
w ith c l a s s , breed, age, and sex o f farm an im als.
The in t e r e s t in g e f f e c t
o f s t i l b e s t r o l and oth er drugs on animal production a lso warrants
in v e s t ig a t io n .
That th e th y ro id gland i s in v o lv ed in th e r e g u la tio n o f general
body metabolism* as w e ll as growth and development, i s now w e ll esta b ­
l is h e d .
U n til r ec e n t years, study o f th e fu n c tio n s o f t h is gland was
lim ite d t o the use o f expensive gland ular e x tr a c ts or s u r g ic a l a lte r a tio n
o f th e gland*
The thyroid' i s th e o n ly gland in which in te r n a l se c r e tio n s
can now be e n t ir e ly c o n tr o lle d by use o f chem ical compounds which are
in ex p en siv e and r e a d ily a v a ila b le to th e r e se a r c h e r .
Varying degrees o f
hyperthyroidism can be prod u ced .in anim als by fe e d in g io d in a te d c a se in ,
or thyroprotein*
The hypothyroid c o n d itio n can be induced by feed in g
s y n th e tic g o itro g en s such a s th io u r a c il, th io u r e a , and th io b a r b ita l.
S t i l b e s t r o l , t h io u r a c il, and th y ro p ro tein a s.th e p a ten ted product
VProtamone" were, used in v a r io u s com binations in t h is experim ent to stu d y
t h e ir e f f e c t s o n .r a te o f g a in , feed e f f ic ie n c y , and c a r c a ss q u a lity o f
whether lambs
— 52 —
E E V im OF LITERAT UEE
E f f e c t o f F eed in g S t l l b e s t r o l t6 Farm Animals
A d m in is tra tio n o f s t l l b e s t r o l to b r o i l e r s r e s u l t s i n in c re a s e d
gro-mth r a t e , im proved c a r c a s s q u a l i t y , and more f a t d e p o s itio n (L orenz,
19b$S T hayer, Ja a p , and P e n q u ite , 19h5s and Andrews and Bohren, 19U7)..
D inusson e t a l . (1 9 5 0 ), i n two d i f f e r e n t e x p e rim e n ts, im p lan ted
i;2 mg. o f s t l l b e s t r o l su b cu ta n e o u sly i n th e sh o u ld e r re g io n o f b e e f
h e ife rs .
I n th e f i r s t ex p erim en t, c o n tr o ls g a in e d 2 .07 pounds p e r head
d a i l y , compared to 2*32 pounds f o r th e t r e a t e d group.
■■
I n th e second e x -
■
■
p e rim e n t, c o n tr o ls g ain ed 1 .7 2 pounds p e r head d a ily , w h ile th e s t i I b e s t r o l - t r e a t e d group g a in e d 2 .0 0 pounds d a ily *
The t r e a t e d h e i f e r s a te
more and had g r e a t e r fe e d e f f i c i e n c y th a n th e c o n t r o l s . ' T re a te d anim als
had. a more p ro m in en t mammary developm entj how ever, th is , mammary d ev elo p ­
ment d id n o t make a s i g n i f i c a n t d if f e r e n c e i n c a r c a s s g ra d e s o r d re s s in g
p e rc e n ta g e .
S t l l b e s t r o l te n d e d to lo w e r th e e ry th ro c y te c o u n t, b u t had
n o 'e f f e c t on blood l i p i d , c h o l e s t e r o l , o r calcium c o n te n t.
Andrews e t a l . (l9j?0) gave y e a r lin g s t e e r s 60 mg. and 120 mg*
im p la n ts o f s t l l b e s t r o l .
head d a i l y .
The c o n tr o l groups g a in ed 2 ,2 ^ ,pounds p e r
Animals t r e a t e d w ith tb e 60 mg. dose g a in ed 2.1+7 pounds,
and th o s e g iv e n 120 mg. dose g a in e d 2.6 8 pounds p e r h ead d a i l y .
The
t r e a t e d an im als a te more and u t i l i z e d t h e i r f e e d more e f f i c i e n t l y th a n
th e c o n tr o l g ro u p s.
Some mammary developm ent was n o tic e d .
D ressin g
p e rc e n ta g e and c a r c a s s g rad es w ere s im ila r f o r th e c o n tr o l and t r e a t e d
g ro u p s, a lth o u g h some o f th e c a r c a s s e s o f th e t r e a t e d group were d e s c rib e d
as "hooky".
“ 53 “*
I n g e n e r a l, c a t t l e t r e a t e d w ith s t i l b e s t r o l im p la n ts show c e r ta in
u n d e s ir a b le c h a r a c t e r i s t i c s , in c lu d in g r a i s e d t a i l heads and mammary
developm ent„
D r. Wise Burroughs o f Iowa S ta te C o lleg e was in s tru m e n ta l
i n d e v e lo p in g th e te c h n iq u e o f g iv in g s t i l b e s t r o l a t low l e v e l s i n th e
d a ily r a tio n .
The Iowa S ta te C o lleg e R ese arch F o u n d atio n , I n c . has now ■
lic e n s e d The E l i L i l l y Co. to m an u factu re a. prem ix p r e p a r a tio n c o n ta in in g
s tilb e s tro l.
Soybean meal i s u sed as a c a r r i e r . f o r t h e d ru g .
The
p ro d u c t i s s o ld under th e tr a d e name lrS t i l b o s o l l' and i s a v a ila b le o n ly
to fe e d m a n u fa ctu rers' f o r in c o r p o r a tio n i n fe e d su p p lem en ts.
The a p p lic a tio n o f s t i l b e s t r o l as a minute percentage o f th e r a tio n
r e s u lt s in a minimum o f un d esirab le sid e e f f e c t s .
D ressin g .p ercen ta g es
and fe d e r a l c a r c a ss grades o f c a t t le fe d th e drug o r a lly are very sim ila r
to th a t o f c o n tr o l groups.
There i s no d if f e r e n c e .in amounts o f f a t ,
le a n , bone, or m oisture in r ib -e y e s e c tio n s in co n tro l and supplemented b e e f anim als.
The E li L i l l y Co* (1955) h a s summarized r e s u l t s o f fe e d in g s t i l b e s ­
t r o l to c a t t l e a t a g r i c u l t u r a l e x p erim en t s t a t i o n s , i n C o lo rad o , Iowa,
M ichigan, N ebraska, O hio, In d ia n a , T ennessee, G eorgia, T exas, C olorado,
and K ansas.
T h e ir summary in d i c a t e s t h a t s t i l b e s t r o l f e d to c a t t l e r e ­
s u l t s i n in c r e a s e d d a ily g a in s and re d u c e d fe e d c o s ts .
l e v e l of s t i l b e s t r o l , fe d o r a l l y , i s 10 mg. d a i l y .
T h e ir recommended
D ata from tw e n ty -s ix
s e p a r a te e x p erim en ts u s in g s t i l b e s t r o l a t t h i s l e v e l i n c a t t l e and c a l f
r a t i o n s show in c r e a s e d a v erag e d a i l y g a in s i n tw e n ty -fiv e o f t h e e x p e ri­
m e n ts.
Animals w eighing o v e r s i x hundred pounds g ain ed on th e average '
16 p e r c e n t f a s t e r th a n c o n tr o ls on h ig h -e n e rg y o r h ig h -ro u g h ag e r a t i o n s .
C alves (u n d er s i x hundred pounds) g a in ed an av erag e o f 12 p e rc e n t f a s t e r
on h ig h -e n e rg y r a t i o n s th a n d id c o n t r o l s .
e v id e n t i n a l l tw e n ty -s ix e x p e rim e n ts.
In c re a s e d fe e d e f f ic ie n c y was
M ature c a t t l e on h ig h -e n e rg y
r a t i o n s r e q u ir e an a v erag e o f 13 p e rc e n t Ie s p fe e d p e r pound o f g a in .
When on h ig h -ro u g h ag e r a t i o n s , an av erag e o f 17 p e rc e n t l e s s fe e d p e r
pound o f g a in was n eeded.
C alves on h ig h -e n e rg y r a tio n s showed 10 p e r ­
c e n t in c r e a s e i n fe e d e f f i c i e n c y , w h ile c a lv e s on h ig h -ro u g h ag e r a tio n s
showed a sa v in g o f 3 p e r q e n t.
D ata f o r s t i l b e s t r o l - t r e a t e d an im als on p a s tu r e a re more lim ite d
th a n f o r c a t t l e ,te s te d i n d ry l o t .
Clegg and Cole (195k) r e p o r t th a t
s t e e r s su b c u ta n e o u sly im p la n te d w ith 120 mg. o f s t i l b e s t r o l and ru n on
p a s tu r e where su p p lem en ta l fe e d was a v a ila b le made g r e a t e r g a in s th a n
s t i l b e s t r o l - i m p l a n t e d s t e e r s on p a s tu r e a lo n e .
T re a te d h e i f e r s on
p a s tu r e showed no in c r e a s e i n g a in o v e r th e c o n tr o l g ro u p s.
Feed con­
sum ption was in c r e a s e d s l i g h t l y and economy o f fe e d u t i l i z a t i o n was
in c r e a s e d m arkedly f o r a l l t r e a t e d a n im a ls.
A g r e a te r p e rc e n ta g e o f th e
h ig h e r c a r c a s s g rad es was c o n s is te n tly found i n th e u n tr e a te d an im als i n
b o th s t e e r and h e i f e r g ro u p s.
The a u th o rs gave s e v e r a l re a s o n s f o r th e
f a i l u r e o f t r e a t e d c a r c a s s e s t o re a ch th e sqme g rad e a s th e c o n t r o l s .
The m uscle f i b e r s w ere l a r g e r , had a more c o a rs e a p p ea ra n ce , and were
d a rk e r re d i n c o lo r th a n th e m eat o f th e c o n t r o l s .
was d i s t i n c t l y lo w e r.
E x te n t o f m arb lin g
The amount o f b o th i n t e r n a l and e x t e r n a l f a t
d e p o s itio n among t r e a t e d anim als was c o n s id e ra b ly lo w e r.
S h o u ld ers and
rounds w ere h e a v ie r , b u t th e l o in s were l i g h t e r th a n t h a t o f th e con­
tro ls .
C onform ation was a t y p i c a l .
C a rc a sse s appeared s im ila r to th o se
-
o f s ta g s .
55 --
There was no d if f e r e n c e i n d r e s s in g p e rc e n ta g e s o r i n th e p e r ­
c e n ta g e o f s h rin k betw een h o t and c o ld c a r c a s s w e ig h ts o f t r e a t e d o r con­
t r o l a n im a ls.
0 1H ary and C u llis o n (1 956), a t G eorgia, re p o rte d on two ex p erim en ts
in v o lv in g a t o t a l o f t h i r t y - s i x head o f y e a r lin g and tw o -y e a r-o ld s t e e r s
ru n on m ixed g r a s s and legume p a s t u r e s .
P a s tu re was ad eq u ate a l l d u rin g
th e e x p e rim e n ts, and no su p p lem en tal fe e d was g iv e n .
T reatm ent o f h a l f
th e an im als w ith 2k mg. o f s t i l b e s t r o l r e s u l t e d i n a d a i l y g a in o f 0.6 9
pounds p e r s t e e r o v er c o n tr o l groups i n Experim ent I .
I n Experim ent I I ,
th e same tre a tm e n t showed a h ig h ly s i g n i f i c a n t d a ily in c r e a s e i n g ain o f
0 .5 8 pounds.
D inusson e t a l . (1951) in v e s t ig a te d th e e f f e c t o f s t i l b e s t r o l im­
p l a n t s on g ro w in g -fa tte n in g sw in e.
g a in was a p p a r e n t.
No c o n s i s t e n t s tim u lu s to r a t e o f
Response was somewhat h ig h e r a t w e ig h ts o f n in e ty to
one hundred pounds th a n a t lig h t e r .w e i g h t s , b u t th e d if f e r e n c e s were n o t
g re a t.
g a in .
C o n tro ls r e q u ir e d 5 .2 to 1 3 .7 p e r c e n t more fe e d p e r pound o f
G ilts responded m ore th a n b a rro w s .
I n two t r i a l s , 12 mg. p e l l e t s
were im p la n te d s u b c u ta n e o u sly i n th e e a r j t h i s lo c a tio n r e s u l t e d in
c y s ti c e n c a p s u lin g d f th e p e l l e t .
I n th e t h i r d t r i a l , 2k mg. o f p e l l e t s
w ere p la c e d i n th e s c r o t a l sac o f th e b arrow s and i n th e d o r s a l re g io n
o f th e necks i n g i l t s .
P r a c t i c a l swine r a t i o n s were f e d .
Out o f e lev e n
g i l t s t r e a t e d w ith s t i l b e s t r o l , fo u r s u f f e r e d p ro la p s e o f th e u te r u s .
About th r e e days a f t e r im p la n ta tio n , a l l g i l t s showed extrem e sw e llin g
o f th e e x te r n a l g e n i t a l i a which n e v er r e tu r n e d to norm al a n e s tr u s co n d i­
t i o n d u rin g th e t r i a l .
A ll g i l t s and barrow s showed mammary developm ent
— ^6 —
and t e a t grow th, b u t th e e f f e c t was g r e a te r w ith th e g i l t s .
Renewed sex-
d e s ir e and a b i l i t y f o r e r e c tio n was e v id e n t i n th e b a rro w s, ^ s p e c ia lly
th o s e im p la n te d i n th e s c r o t a l c a v ity .
W oehling e t a l . (195>1) im p la n te d 12 mg. s t i l b e s t r o l p e l l e t s in to
th e r e a r f la n k o f w ean lin g p ig s , and re p e a te d th e p ro c e s s tw e lv e weeks
l a t e r . - No s i g n i f i c a n t d if f e r e n c e s were found f o r a v erag e d a i l y g a in ,
fe e d e f f i c i e n c y , fe e d consum ption, d r e s s in g p e rc e n ta g e , eye m uscle
m easurem ent, o r back f a t th ic k n e s s .
There was a h ig h ly s i g n i f i c a n t
d if f e r e n c e i n s e e d in e s s o f th e f r e s h b e l l y , compared to th e c o n tr o l
g ro u p s.
R ep ro d u ctiv e o rg an s showed d e f i n i t e ev id en ce o f horm onal stim u­
la tio n .
P earso n e t a l . (19!?2) conducted two ex p erim en ts to d e te rm in e e f f e c t s
o f s t i l b e s t r o l im p la n ts on c e r t a i n c h a r a c t e r i s t i c s o f sw in e.
I n E x p eri­
ment I , l a s t i n g 10? d a y s, 25 mg. p e l l e t s were i n j e c t e d a t th e b eg in n in g
and end o f th e f i r p t m onth.
p e l l e t s w ere im p la n te d .
At th e end' o f two m onths, two more 25 mg.
I n E xperim ent I I , a 50 mg. p e l l e t was im p lan ted
a t th e b eg in n in g o f th e t r i a l *
Im p lan ts d id n o t m a t e r i a l l y a f f e c t g a in s
o f g i l t s o r b a rro w s, b u t a p p a r e n tly c a u s e d a g ro w th -d e p re ssin g a c tio n
upon young b o a r s .
Feed e f f i c i e n c y was u n a ffe c te d , as w ere d re s s in g p e r ­
c e n ta g e , th ic k n e s s o f back f a t , c a r c a s s g ra d e , and te n d e r n e s s o f m eat.
E a tin g q u a l i t i e s o f meat from b o a rs w ere n o t improved*
Andrews e t a l . (I9h9 a and b ) f i r s t r e p o r te d r e s u l t s o f s t i l b e s ­
t r o l fe e d in g on w e th er la m b s.
amount o f f e e d .
C o n tro l and t r e a t e d groups g o t th e same
Lambs t r e a t e d w ith 12 o r 2k mg. o f s t i l b e s t r o l g ained
0 .5 0 pounds p e r head d a i l y , w h ile th e c o n tr o ls g ain ed 0*35 pounds p e r
— 57 —
head.
Treated anim als required 31 p ercen t le g s corn per hundred pounds
o f g a in .
Carcass grades were somewhat h ig h er in th e c o n tr o l groups.
Rope e t a l . (1950) o b ta in e d h ig h ly s i g n i f i c a n t d if f e r e n c e s i n r a t e o f
g a in i n fa v o r o f lambs im p la n te d w ith one 15 mg. p e l l e t p e r lam b.
Jordan (1950) im planted 12 mg. p e l l e t s in both fou r and e ig h t
month old- fe e d e r lam bs.
gain fo r each t r i a l .
p ercen t r e s p e c t iv e ly .
There was a s ig n if ic a n t in c r e a se in ra te o f
Feed per 100 pounds o f gain was reduced 16 and 21
There was l i t t l e d iffe r e n c e in d a ily fe e d consumed,
but tr e a te d lambs were e a s ie r to keep on f u ll,.f e e d than were th e c o n tr o ls .
There was no s ig n if ic a n t d iffe r e n c e in ca rca ss grades between tr e a ted
and c o n tr o l lambs o f four months age, but tr e a te d lambs e ig h t, months o f
age were' o f a low er grade than th e corresponding groups.
R e s u lts o f l a t e r work u s in g s 't i l b e s t r o l im p la n ts on fe e d e r lambs
a g re e w ith th e ev id en ce a lr e a d y p r e s e n te d .
Mean e t a l . (1 9 5 3 )J .Andrews
and Beeson (1953)3 Jo rd an and BeI l (1952)3 and O1Mary e t a l . (1952)
o b ta in e d s i g n i f i c a n t l y in c re a s e d r a t e o f g a in and s i g n i f i c a n t l y in c re a s e d
fe e d e f f i c i e n c y .
C arcass q u a l i t y f o r t r e a t e d anim als was lo w e re d .
S til-
b e s t r o l low ered fe e d c o s ts and s l i g h t l y lo w ered s e l l i n g p r ic e i n some
c a s e s , b u t a g r e a t e r p r o f i t p e r lamb was r e a l i z e d .
B e ll e t a l . .(19514-) showed t h a t no b e n e f i t was d e riv e d from a second
15 mg. im p la n t made 70 days a f t e r an o r i g i n a l im p la n t on f e e d e r lambs i n
a com m ercial f e e d l o t .
Of 517 lambs on e x p erim en t, tw e lv e lambs were l o s t
from p ro la p s e o f th e rectum and from ex cess s w e llin g and in flam m atio n
i n th e r e c t a l o r p e r i n e a l r e g io n s .
im p la n te d p e l l e t s .
A ll th e s e an im als h ad r e c e iv e d two
The c o n d itio n resem b led symptoms o f u r in a r y c a l c u l i .
— 58 —
I t was th o u g h t t h a t th e h ig h in c id e n c e o f p ro la p s e was due to s t r a i n i n g
r e s u l t i n g from d i f f i c u l t y o f u r i n a t i o n ,
Clegg e t a l , (1955) found anim als w eig h in g from 20 to 60 pounds
re sp o n d ed th e same to s t i l b e s t r o l im p la n ts .
s ig n ific a n tly in a l l c ase s.
p e l l e t s w ere em ployed.
R ate o f g a in was in c re a s e d
E f f e c ts were th e game when 12 mg. o r 36 mg.
Range groups on n a tiv e range g ra s s o r i r r i g a t e d
la d in o c lo v e r and mixed g ra s s p a s tu r e d id a s w e ll a s g ro u p s on g r a in and
h ig h q u a l i t y ro ughage.
. S e v e ra l r e c e n t t r i a l s have in v e s t ig a te d th e m e rits o f fe e d in g s t i l ­
b e s t r o l i n th e r a t i o n , a s opposed to th e im p la n t m e th o d .■ H ale e t a l .
(195U) u sed l e v e l s o f - s t i l b e s t r o l from 0 ,5 to 1200 meg. p e r pound o f
r a t i o n i n s i x in d iv id u a l fe e d in g t r i a l s .
I n f i v e o f th e s ix t r i a l s a
re sp o n se i n w e ig h t g a in was o b ta in e d a t ox n e a r th e 2 .0 meg. l e v e l .
a l l s i x t r i a l s , th e re sp o n se was 19 p e r c e n t o v er th e c o n t r o l s .
For
At
l e v e l s betw een 3 ,0 meg. and 600 m eg., no c o n s is te n t re sp o n se was n o te d ,
b u t q u ite o f te n a d e p re s s in g a c tio n was fo u n d .
The 600 meg. and 1200
meg. l e v e l s in c r e a s e d w e ig h t g a in s 20 p e r c e n t and 28 p e r c e n t re s p e c tiv e ly over th e c o n t r o l s , b u t th e s e r e s u l t s w ere n o t v e r i f i e d i n two group
fe e d in g t r i a l s .
I n th e s e t r i a l s , s t i l b e s t r o l fe d o r a l l y d id n o t ap p ear
to have an a p p re c ia b le e f f e c t on c a r c a s s q u a l i t y .
M easurement o f c e r t a i n
sec o n d a ry sex o rgans o f w e th e rs and u t e r i n e measurement on a lim ite d
number o f ewe lambs showed t h a t th e s t i l b e s t r o l e x e rte d p h y s io lo g ic a l
a c tiv ity .
1
Jo rd a n e t a l , -(1955) fe d s t i l b e s t r o l o r a l l y a t 0ol m g., 0 .5 m g.,
and 1 .5 mg. p e r lamb d a i l y , w ith no s i g n i f i c a n t e f f e c t on r a t e o f g a in .
- 59 Lambs fe d the 0*1 mg. and 0 .5 mg. l e v e l s produced c a rc a sse s th a t graded
h igh er than th e c o n tr o ls , Trhile lambs on the 1 .5 mg. l e v e l produced
c a rc a sse s equal to that' o f the c o n tr o ls . . Other lambs g iv en s t i l b e s t r o l
im plants gained s ig n if i c a n t ly f a s t e r than th e c o n tr o ls but produced
low er y ie ld in g or grading c a r c a s se s.
H a le ■e t a l . (1955) f e d s t i l b e s t r o l t o w e th er lambs a t a p p ro x i­
m a te ly 2 .0 mg. p e r head d a i l y i n a f a t t e n i n g r a t i o n . R ate o f g ain was
t
in crea sed 22 p ercen t over a c o n tr o l group. Feed consumption was not
'■-consistently, in c r ea se d , and carca ss q u a lity was a ffe c te d o n ly s l i g h t l y .
S t ilb e s t r o l fe d a t 3 .6 mg. per head d a ily f a i l e d to g iv e as s a t is f a c t o r y
r a te o f gain as did s t i l b e s t r o l fe d a t th e low er l e v e l s . .
C lose examina- '
t io n o f the anim als showed c e r ta in changes in e x te rn a l appearance sim ila r
to th o se n o tic e d w ith s tilb e s tr o l-im p la n te d lambs, in c lu d in g enlarged
prepuce, mammary developm ent, .and edema o f the anal area .
Summary ■
Research data com piled during the l a s t decade by experim ent s ta tio n s'
and commercial fe e d e rs throughout the U nited S ta te s have shown th at s t i l ­
b e s tr o l i s e f f e c t i v e in o b ta in in g c e r ta in d e sir e d e f f e c t s when used in
liv e s t o c k r a tio n s or when a p p lied subcutaneously in p e l l e t form .
In
p o u ltr y s t i l b e s t r o l i s g e n e r a lly used in im plant form and r e s u lt s in
in c r ea se d growth r a te and a b e tte r q u a lity c a r c a s s.
In f in is h in g b eef
c a t t l e , s t i l b e s t r o l i s used v e r y e x t e n s iv e ly a t low l e v e l s in th e d a ily ■
r a tio n .
Gains and fe e d e f f ic ie n c y are improved, and c a rca ss c h a r a c te r is­
t i c s are not ad v ersely a f f e c t e d .
The drug i s probably more e f f e c t iv e
upon fa tte n in g c a t t l e than upon animals on pasture a lo n e .
I
- 60 S t ilb e s t r o l work w ith swine has not produced s a t is f a c t o r y r e s u lt s .
Rate o f gain and fe e d e f f i c i e n c y are not in crea sed s ig n if ic a n t ly ,;
Un­
d e s ir a b le ca rca ss c h a r a c t e r is t ic s and.unfavorable sid e e f f e c t s such a s
p rolap se o f th e uterus may r e s u lt from th e u se o f s t i l b e s t r o l on swine,
S t il b e s t r o l was f i r s t used on sheep in th e p e l l e t im plant form.
In alm ost a l l experim ents, r a te o f gain and fe e d e f f ic ie n c y are improved.
Feed consumption i s not u s u a lly a f f e c t e d .
Carcass q u a lity i s d e f in it e ly
low ered, p a r t ly because o f a la c k o f s u f f i c ie n t f a t coverin g over the
sh o u ld er s.
On a commercial f e e d - lo t b a s is , p ro la p se o f the u teru s and
rectum o f ewe and w ether lambs r e s p e c t iv e ly have occurred-.
More recen t
work u sin g s t i l b e s t r o l in sm all d a ily do’b es in the r a tio n in d ic a te s
t h is method o f s t i l b e s t r o l supplem entation may in c r ea se r a te o f g a in '
and fe e d e f f ic ie n c y w ithout unfavorably a f f e c t in g ca rca ss q u a lity .
** Si. •*
E f f e c t o f F eeding T h io n r a c il and T h y ro p ro te in to Farm Animaip
S e c re to ry a c t i v i t y o f th e th y r o id g la n d I s r e g u la te d b y an i n t e r ­
a c tio n and b a la n c e betw een th e th y r o id hormone and th y r o tr o p h in from th e
a n te rio r p itu ita r y .
There a re s e v e r a l c h e m ic a l compounds known t h a t can
cau se a h y p o th y ro id c o n d itio n i n man and a n im a ls.
th e s e g o itr o g e n ic compounds i s t h i o u r a c i l ,
The m ost p o te n t o f
I n some unknown way, th e s e
compounds i n t e r f e r e w ith th e s y n th e s is o r u t i l i z a t i o n o f th e th y ro id
hormone, io d o th y ro g lo b u lin .
A ccording to T u rn er (1 9 1 $ ), ev id en ce fa v o rs
th e th e o ry t h a t norm al s y n th e s is o f io d o th y ro g lo b u lin i s lo w e re d , cau sin g
.a n in c r e a s e d o u tp u t o f th y r o tr o p h in from th e " a n t e r i o r p i t u i t a r y ,
Thyro­
tr o p h in s tim u la te s growth o f s e c r e to r y e p ith e liu m o f th e th y r o id g lan d ,
and m o b iliz e s io d o th y ro g lo b u lin s to r e d i n th e th y r o id g la n d . • As t h i s
su p p ly i s e x h a u ste d , th e m e ta b o lic r a t e o f th e anim al d e c li n e s .
V ario u s d e g re es o f h y p e rth y ro id ism can a lso b e produced b y i n t r o ­
ducing i n t o an anim al sm all amounts o f an io d in a te d c a s e in o r io d in a te d
p r o t e i n p ro d u c t.
A ccording to B la x te r (±9k9) io d in a te d c a s e in was p re ­
p a re d f i r s t i n Germany s h o r t l y b e fo re th e s t a r t o f W orld War I I .
The
p ro d u c t was found to .c o n ta in v a r ia b le amounts o f th e same compound s e c re ­
t e d by th e th y r o id g la n d .
American and B r i t i s h w orkers im proved th e
io d in a tio n p ro c e s s so t h a t th e th y r o i d a l p o te n c y o f io d in a te d c a s e in i s
many tim e s t h a t o f d r ie d th y r o id g la n d .
O th er p r o te in s such a s serum
g lo b u lin , serum album in, and egg album in have been s u c c e s s f u lly sub­
s t i t u t e d f o r c a s e in as a s t a r t i n g m a t e r i a l .
I o d in a te d c a s e in i s p ro ­
duced com m ercially i n th e U n ited S ta te s and s o ld under th e r e g i s t e r e d
tr a d e name uP rotam one. u
T his p ro d u c t w i l l w ith s ta n d th e r a t h e r h ig h
— 62 —
te m p e ra tu re s o f cubing e n co u n te re d i n fe e d p r e p a r a tio n and does n o t lo s e .
I
■'
i t s p o te n c y d u rin g s to r a g e . P a l a t a b i l i t y of fe e d s i s u n a ffe c te d by th e
a d d itio n o f "Protamo'ne."
Much o f th e e a r l y work u s in g t h i o u r a c i l was done on r a t s .
When '
t h i o u r a c i l i s a d m in is te re d t o grow ing r a t s , Astwood (I9h3)t MacKenzie and
MacKenzie (1 9 ^ 3 ), grow th i s red u ced .
S e c re tio n o f th e th y r o id gland i s
.
i n h i b i t e d and b a s a l m e ta b o lic r a t e i s lo w e re d . •
Kempster and T urner ( I 9I4.5D fe d c h ic k s a r a t i o n c o n ta in in g 0 ,2 p e r­
c e n t t h i o u r a c i l f o r s ix te e n days b e g in n in g a t te n weeks o f a g e .
The
grow th r a t e , a s t h e i r work shows, i s n o t a f f e c t e d b u t m ark et grade i s
im proved.
When th e same l e v e l i s fe d f o r t h i r t y - s i x d a y s, f e e d r e q u ir e ­
ment p e r pound o f g a in i s in c r e a s e d , growth r a t e d e c re a se d , and m arket
g rad e g r e a t l y im proved.
Andrews and S c h n e tz le r (19I4.6 ) fe d t h i o u r a c i l a t
s im ila r l e v e l s to c h ic k s betw een s i x and f o u r te e n weeks o f a g e .
Growth
r a t e was red u ced s l i g h t l y , b u t m arket grade and f a t d e p o s itio n were
s i g n i f i c a n t l y in c r e a s e d .
"
D e tw ile r and Andrews (1930) f e d b r o i l e r s t h i o u r a c i l as 0 .1 3 p e r c e n t'
o f th e r a t i o n to b r o i l e r s and in a d d itio n im p la n te d a 6 m g .•s t i l b e s t r o l
p e l l e t su b c u ta n e o u sly i n th e neck from th e n in th th ro u g h th e tw e lf th
week o f ag e.
T his tr e a tm e n t r e s u l t e d i n maximum g a in s , f e e d e f f ic ie n c y ,
and m arket q u a l i t y .
T h io u ra c il o r s t i l b e s t r o l fe d alone c o n s is te n tly
im proves c a r c a s s q u a l i t y , b u t th e co m b in atio n o f th e two i s s u p e r io r to
e i t h e r a lo n e .
a l l tr e a tm e n ts .
F a t d e p o s itio n and d r e s s in g p e rc e n ta g e w ere in c re a s e d in
D e tw ile r and Andrews (1930) su g g e st t h a t th e le n g th o f
tre a tm e n t and dosage l e v e l s p ro b a b ly c o u ld b e re d u c e d . -
- 63E vidence o f th e e f f e c t s o f th io iy r a c il and r e l a t e d compounds i n fe e d
e f f i c i e n c y by hogs i s c o n tr a d ic to r y .
Van Der N o tt e t a l . (I9k7)>
M cM illen d t a l . (19L 7), and Muhrer e t a l . (±9h7) found t h i o u r a c i l i n ­
c re a s e d f e e d e f f i c i e n c y o f sw in e.
Beeson e t a l . (l9li-7) and Acevedo e t
a l . (I9l|.8) r e p o r te d o p p o s ite r e s u l t s .
The p e rio d o f grow th o f th e
anim al when su p p le m e n ta tio n i s perfo rm ed a p p ea rs to be an im p o rta n t
fa c to r,
Ih e n t h e d rug i s g iv en o n ly d u rin g th e l a s t few weeks o f the
fe e d in g p e rio d i n sw ine, th e r e i s u s u a ll y a s i g n i f i c a n t l y im proved
economy o f g a in .
Jo h n sto n e t a l . (19l|.6) o f t h e U n ited S ta te s D epartm ent o f A g ric u l- .
t u r e , s tu d ie d th e i n t e r a c t i o n o f te m p e ra tu re and t h i o u r a c i l upon c a rc a s s
c h a r a c t e r i s t i c s , r a t e o f g a in , and fe e d e f f i c i e n c y o f h o g s.
At teim-
p e r a tu r e s n e a r £0° F , tre a tm e n t w ith t h i o u r a c i l r e s u l t e d in d e crea se d ,
th ic k n e s s o f back f a t and in c r e a s e d p e rc e n ta g e o f p r o t e i n i n th e hams.
L iv e rs and th y r o id s w ere l a r g e r i n anim als t r e a t e d a t 90° F. and 5>0° F.
th a n i n th e c o n tr o l anim als,, b u t d if f e r e n c e s in th e s i z e o f th e s e organs
was g r e a te r a t th e .lower te m p e ra tu re .
R ate o f g a in was in c r e a s e d a t th e
lo w er te m p e ra tu re , b u t n o t a t th e h ig h e r te m p e ra tu re .
D iffe re n c e s i n
economy o f fe e d u t i l i z a t i o n ap p eared t o be g r e a te r betw een t r e a t e d
p ig s and th e c o n tr o ls a t £0° F . th a n b etw een t r e a t e d an im als and c o n tr o ls
a t 90° F .
E f f e c ts o f h y p e rth y ro id ism i n r e l a t i o n to l a c t a t i o n in d a ir y c a t t l e
and o th e r p h a se s o f anim al p ro d u c tio n h a s been c o m p reh en siv ely review ed
by B la x te r e t a l . (19U 9).
He r e p o r ts t h a t w ith in a li m i t e d ran g e th e
p e rc e n ta g e in c r e a s e i n m ilk y ie ld i s ro u g h ly p r o p o r tio n a l to th e dosage
- 6h -
o f th yrop rd tein j f a t percentage in c r e a se s a ls o , th e in c r e a se usuallyappearing a t low er dosage l e v e l s than th e in c r e a se in m ilk y ie ld .
Milk
from cows fe d io d in a te d p r o te in i s s a fe and n u t r it ip n a lly adequate. ■
Because th y ro p ro tein supplem entation in c r e a se s th e b a sa l m etabolic
r a t e , n u tr ie n t in tak e must be in c r ea se d to avoid rath er sev ere lo s s e s in
body w e ig h t.
Some experim ents show th a t a h igh er in ta k e o f n u tr ie n ts
w ith ou t supplem ental th y ro p ro tein in c r e a s e s m ilk production as much a s
does a h igh er n u tr ie n t in ta k e p lu s th e th y ro p ro tein .
I t i s g e n e r a lly thought th a t io d in a te d p r o te in can be p r o fita b ly
used o n ly during p erio d s o f m ilk s c a r c it y , and then o n ly fo r a p eriod o f
approxim ately two months.. and o n ly in commercial h erd s.
Use o f io d in a ted
p r o te in i s not considered d e sir a b le in pure bred breeding h erd s.
Use o f t h io u r a c il and th y ro p ro tein on b e e f c a t t le has been lim ite d
to a few s t u d ie s .
Andrews and B ullard (l9l|.0) p a r t ia l ly thyrodectom ized
b e e f s t e e r s and found r a te o f gain was in crea sed g r e a tly during the f i r s t
s i x to e ig h t p o sto p e r a tiv e w eeks.
to normal a f t e r 10 to 12 w eeks.
The r a te o f gain grad u ally decreased
I t was unknown how much o f the in crea sed
r a te o f gain was due to removal o f the gland and how much was due sim ply
to regain o f w eight l o s t during th e o p e r a tio n .
Some o f the in c r ea se was
a ttr ib u te d to absence o f the th y r o id .
Beeson e t a l . (iplj.?) fe d th io u r a c il t o y e a r lin g s t e e r s at 2 .0 :gm., '
U.O ;gm., and 6*0 gm. per s t e e r d a ily .
a t the two lower l e v e l s .
Rate o f gain was in c r ea se d s l i g h t l y
D ressing p ercentage and amount o f carcass f i n i s h
was improved, but n ot s ig n if i c a n t ly .
K line e t a l . (1914.9) fed. t h io u r a c il to s te e r s a t 0 ,2 p ercen t o f the
— 6^ —
g r a in r a t i o n .
Thig l e v e l caused a d e c re a se i n consum ption o f g ra in mix­
t u r e and an in c r e a s e i n roughage consum ption.
c re a s e d and fe e d c o s ts w ere lo w ered .
a ffe c te d .
Feed e f f i c i e n c y was i n ­
R a te o f g ain was n o t s i g n i f i c a n t l y
C arcass q u a l i t y was n o t a f f e c t e d o v er a lo n g fe e d in g p e rio d ,
b u t c a r c a s s g ra d e s o f tw o -y e a r-o ld h e i f e r s ap p eared to be s l i g h t l y im­
p ro v ed d u rin g a s h o r t fe e d in g p e r io d .
Some -work.has b een done on r a t e o f in ta k e o f g o itr o g e n ic compounds
i n t o th e body» ,ELi e t a l . (I9ij,8) s tu d ie d a b s o rp tio n and e lim in a tio n of
t h i o u r a c i l i n c a lv e s and g o a ts fo llo w in g o r a l and su b cu tan eo u s a d m in is tra ­
tio n s .
Maximum b lo o d plasm a t h i o u r a c i l c o n c e n tra tio n s o c c u rre d i n b to
8 h o u rs a f t e r o r a l a d m in is tr a tio n o f 0 .1 gm. a n d .0 .2 gm.. p e r kg, o f body
w e ig h t and a f t e r 2 to !(.'hours’ fo llo w in g subcutaneous a d m in is tr a tio n .
These r e s u l t s in d i c a t e slo w er r a t e s o f a b s o r p tio n th a n w ith n o n ru m in an ts.
Maximum b lo o d plasm a l e v e l s i n t h e c h ick e n may b e re a c h e d w ith in 30
m in u tes a f t e r a d m in is tr a tio n o f t h i o u r a c i l .
I n th e g o at and c a l f , plasm a
l e v e l s were a p p ro x im a te ly p r o p o r tio n a l t o dosage l e v e l s .
S in g le doses
g iv e n s u b c u ta n e o u sly r e s u l t e d i n a p p ro x im a te ly tw ice th e plasm a t h i o u r a c i l
c o n c e n tra tio n s a s th e same dosage given o r a l l y .
E s s e n t i a l l y uniform
b lo o d plasm a t h i o u r a c i l l e v e l s were m a in ta in e d w ith a d m in is tr a tio n s made
a t 12 h our i n t e r v a l s .
The d rug was p r a c t i c a l l y e lim in a te d th ro u g h th e
u r in e w ith in 2li h o u rs a f t e r c e s s a tio n o f a d m in is tr a tio n .
S e v e ra l w o rk ers have t e s t e d th e e f f e c t s o f t h i o u r a c i l on th e more
im p o rta n t economic c h a r a c te r s i n sh eep .
Andrews e t a l . (I9 b 7 ) t r e a t e d
lam bs w ith l e v e l s o f 0.18 gm,, 0.3 3 gm ., and 0.5L gm. o f t h i o u r a c i l p e r
lamb d a i l y .
There was no s i g n i f i c a n t e f f e c t on t o t a l g a in i n w e ig h t, a l ­
— 66 —
though r a t e o f g a in was s l i g h t l y l e s s i n a l l l o t s r e c e iv in g t h e d ru g .
At
1*1$ gm. p e r head d a ily , th e lam bs showed . s i g n i f i c a n t l y re d u c e d fe e d con­
sum ption and r a t e o f g a in .
At l e v e l s o f 0 .1 8 gm. a n d .0 .3 3 gm. th e c a r c a s s
q u a l i t y improvement approached s ig n if ic a n c e .
F a t d e te rm in a tio n s o f th e
e n t i r e c a r c a s s e s were n o t made, b u t i t was a p p a re n t t h a t cod and i n t e r n a l
f a t d e p o s itio n w ere in c r e a s e d .
o c cu rs i n t r e a t e d p o u l t r y .
A .s im ila r in c r e a s e i n f a t d e p o s itio n
T h io u ra c il and th io u r e a a t a l l l e v e l s fe d
produced h ig h ly s i g n i f i c a n t i n c r e a s e s 'i n th y r o id w e ig h ts .
Feed r e q u ir e ­
m ents p e r pound o f g a in w ere n o t a f f e c t e d by t h i o u r a c i l u n t i l in ta k e ex­
ceeded th e 0 .3 3 gm. l e v e l , b u t th e r e was a te n d e n c y f o r th e g ro ss
e f f i c i e n c y to be re d u c ed as l e v e l s o f t h i o u r a c i l and th io u r e a were i n c re a s e d .
B a rric k e t a l . (±9h9) a d m in is te re d t h i o u r a c i l i n th e fe e d a t 0 .21
gm. and 0 .3 9 gm. p e r lamb d a i l y d u rin g th e w in te r f a tte n in g p e rio d o f
19k6-k7, and a t. th e r a t e o f 0 Jj.2 gm. and 0 .6 3 gm. d u rin g th e fo llo w in g
w in te r .
T h e ir r e s u l t s showed no s i g n i f i c a n t e f f e c t on t o t a l g a in , fe e d
•e f f i c i e n c y , c a rc a s s y i e l d , o r c a r c a s s g ra d e .
P r o p y lth io u r a c il was giv en
i n th e fe e d a t 0 .0 3 gm. p e r iamb d a i l y d u rin g th e f i r s t w in te r .
s i g n i f i c a n t e f f e c t s were re c o rd e d .
Again no
T h y ro p ro te in was given, i n th e fe e d
d u rin g th e second w in te r a t th e r a t e o f 0.£ 2 gm. and I . OL gm. p e r lamb
d a i l y w ith no s i g n i f i c a n t e f f e c t .
Feed consum ption was re d u c ed somewhat
by t h i o u r a c i l a t th e 0 .3 9 gm. to 0.6 3 gm. l e v e l s and was s tim u la te d some­
w hat by th y r o p r o te in a t b o th th e Oa$2 gm, and l.O L gm. l e v e l s . • T hyroid
g la n d s from th e th y r o p r o te in t r e a t e d an im als were found to b e in a c tiv e *
T hyroid g lan d s from lambs fe d 0 .2 1 to 0 ,6 3 gm. o f t h i o u r a c i l , and 0,03
- 6? gm. o f p ro p y l t h i o u r a c i l showed no more ev id en ce o f s tim u la tio n th a n th o se
from c o n tr o l anim als and were n o t in c re a s e d i p s i z e .
The a u th o rs con­
c lu d ed from th e r e s u l t s o f t h i s experim ent t h a t th e r e was no ad v an tag e
i n u s in g t h i o u r a c i l o r th y ro p n o te in f o r f a t t e n i n g w e ste rn fe e d e r lam bs. ■
B a rric k e t a l . (l95>0) s tu d ie d th e p h y s io lo g ic a l e f f e c t o f t h i o u r a c i l
and o th e r drugs on w e th e r 'Ia n b s .
T h io u ra c il p u t i n th e r a t i o n s o f fe e d e r
.lambs a t l e v e l s below 1 .0 gm. p e r lamb p e r day r e s u l t e d i n marked s tim u la ­
t i o n o f th e th y r o id g lan d d u rin g o n ly one o u t o f th r e e y e a r s .
'In th e one
e f f e c t i v e t r i a l , th y r o id s o f lambs re c e iv in g as l i t t l e as 0.1 8 gm.
t h i o u r a c i l p e r lamb d a ily w ere ,fiv e tim e s h e a v ie r th a n c o n tr o l lambs and
showed d e f i n i t e h i s t o l o g i c a l evidence o f s tim u la tio n .
caused d e f i n i t e s tim u la tio n q f th e th y ro id s '.
T h io u rea a ls o
I n two o f t h e th r e e y e a r s ,
th e th y r o id g lan d s from lambs g e ttin g 0*2 to 0 .6 gm. t h i o u r a c i l d a ily
w ere s m a lle r th a n th o s e from c o n tr o l lam bs, and h i s t o l o g i c a l l y th e glands
from t r e a t e d and c o n tr o l a n im als w ere v e ry s im ila r .
T h io u r a c il given
o r a l l y by c a p s u le o r t a b l e t a t le v e l s up to 1 .0 gm. p e r lamb d a i l y f o r
H O days produced v e ry l i t t l e e f f e c t .
At th e 3 .0 gm. l e v e l th e glands
e n la rg e d i n s iz e and showed d e f i n i t e h i s t o l o g i c a l ev id en ce o f s tim u la tio n .
O ra l a d m in is tr a tio n o f 1*0 gm. th io u r e a t a b l e t s p e r lamb d a i l y caused
m arked s tim u la tio n o f th e g la n d a n d . s e r io u s ly lim it e d fe e d consum ption
and r a t e o f g row th.
P ro p y l t h i o u r a c i l g iv en o r a l l y i n t a b l e t form a t 0 .1 gm. d a ily d id
n o t s i g n i f i c a n t l y , a f f e c t th e th y r o id g la n d .
The gland was s tim u la te d ,
how ever, when 1 .0 gm. p e r head d a i l y was g iv e n f o r t h r e e w eeks.
T h y roid g la n d s o f lam bs r e c e iv in g 0*5 gm. to 1 ,0 gm. th y r o p r o te in
- 68 p e r head d a i l y were l a r g e r th a n th y r o id s from c o n tr o l lam bs o r th io u r a c .il
t r e a t e d lam bs. ■ H is to lo g ic a ll y , th e g lan d s were e a s i l y d e te c te d by t h e i r
g e n e r a l app earance o f i n a c t i v i t y i,'
Blood plasm a c h o le s te r o l was in c re a s e d 30 p e r c e n t t o h.0 p e rc e n t as
a r e s u l t o f a d m in is te rin g t h i o u r a c i l o r th io u r e a a t r a t e s a s low a s 0 .6
gm. p e r head d a i l y .
A marked in c r e a s e i n c h o le s te r o l l e v e l was n o tic e d
when th e lambs w ere lo s in g w e ig h t, r e g a r d le s s o f th e t h i o u r a c i l t r e a t ­
m ent.
V itam in A l e v e l s i n b lo o d plasm a o f lambs i n d ry l o t w ere n o t
a f f e c t e d by t h i o u r a c i l . . I n one e x p erim en t, i n -mhich lambs t r e a t e d w ith
t h i o u r a c i l were p u t on g re e n p a s tu r e fo llo w in g a d ry l o t fe e d in g t r i a l ,
th e in c r e a s e i n blo o d plasm a V itam in A. l e v e l s was s i g n i f i c a n t l y l e s s th a n
th e in c r e a s e w hich o c c u r r e d .in the c o n tr o l a n im a ls,
At t h i o u r a c i l le v e l s
to 3 .0 gm. p e r h e a d d a ily , hem oglobin, e ry th ro c y te c o u n ts , and le u k o cy te
c o u n ts were n o t a f f e c t e d .
L a b a rth e e t a l . (±9h9) fe d R am b o u illet ewes a l f a l f a hay, ground
o a ts , and c o tto n s e e d meal p lu s "Protamone" a t 0 .3 gm., 1 ,0 gm ., and 1 .3
gm. p e r ewe d a i l y .
Wool p b s e rv a tio n s w ere made.
A ll sheep produced more
wool under c o n tr o lle d e x p e rim e n ta l c o n d itio n s th a n d u rin g t h e p re v io u s
y e a r on a ra n c h .
A nimals on th e two h ig h e s t le v e l s o f th y r o p r o te in p ro ­
duced 1 3 p e r c e n t and 10l|. p e r c e n t more wpol r e s p e c tiv e ly th a n d id th e
c o n tr o l l o t .
Ewes on th e lo w e st l e v e l o f drug produced 16 p e rc e n t l e s s
w ool th a n d id th e c o n tr o l ew es.
There was no a p p re c ia b le d if f e r e n c e in
f i b e r le n g th , d ia m e te r, o r g re a s e p e rc e n ta g e .
A s tu d y o f t h e pathw ay ta k e n by th y r o p r o te in in to th e body was made
— 69 —
by Campbell e t al« (1950)..
R a d io a c tiv e th y r o p r o te in uras a d m in is te re d i n '
s o lu tio n , in tr a v e n o u s ly , o r a l l y , and th ro u g h ru m e n ,' sm all i n t e s t i n e , and
cecal fis tu la s .
When given in tr a v e n o u s ly i n sh eep , n e a r ly a l l ra d io ­
a c t i v i t y had d is a p p e a re d from th e b lo o d w ith in seven h o u rs ,
H ighest
l e v e l s o f b lo o d r a d i o a c t i v i t y w ere o b ta in e d fo llo w in g o r a l or.rum en
a d m in is tr a tio n a b o u t 10 h o u rs fo llo w in g tre a tm e n t.
A c t i v i t y was l e s s
when a d m in is tr a tio n was made i n th e sm all i n t e s t i n e ; th e r e was p r a c t i c a l l y
no a b s o rp tio n from th e cecum.
F ollow ing a b s o rp tio n i n t o th e b lo o d stre am ,
p a r t o f th e th y r o p r o te in was i n th e form o f r a d io a c tiv e th y ro x in e and p a r t
was p r e s e n t as d iio do ty r o s in e an d o th e r io d in e - c o n ta in in g compounds.
Summary
T h io u r a c il and o th e r s im ila r compounds w i l l i n h i b i t hormone p ro ­
d u c tio n o f th e th y r o id g la n d .
When g iv e n to p o u ltr y and swine d u rin g
o n ly th e l a s t few weeks o f th e f a t t e n i n g p e r io d , th e r e i s u s u a lly a
s i g n i f i c a n t improvement i n economy o f g a in . . in c r e a s e d f a t d e p o s itio n
u s u a ll y o c c u rs i n p o u ltr y .
R e s u lts w ith b e e f c a t t l e and sheep have been i n c o n s i s t e n t .
Some
w orkers b e lie v e t h a t when o p tim a l c o n d itio n s f o r a d m in is tr a tio n o f th e
drug have been e s ta b lis h e d , i t s u se may have some m e rit upon th e s e two
a n im a ls.
T h y ro p ro te in compounds have been u sed e x te n s iv e ly i n d a i r y c a t t l e ,
t o in c r e a s e m ilk and m ilk - f a t p ro d u c tio n .
The compounds a re e f f e c t iv e
i n acco m p lish in g th e s e g o a ls , b u t u n d e s ir a b le s id e e f f e c t s t h a t accompany
th e u se o f th y r o p r o te in compounds may s e v e r e ly l i m i t t h e i r a p p lic a tio n .
I n p o u ltr y , th y r o p r o te in c o n s i s t e n t l y r e s u l t s i n a c c e le r a te d f e a th e r
- 70 grow th o f c h ic k s .
I t s e f f e c t on body g ro w th , egg p ro d u c tio n , and o th e r
f a c t o r s i s v a r i a b l e and n o t c o n c lu s iv e .
When th y r o p r o te in i s given a t c e r t a i n l e v e l s to sh eep , wool p ro ­
d u c tio n i s s tim u la te d .
- 71 OBJECTIVES
The p u rp o se o f t h i s ex p erim en t was to s tu d y th e e f f e c t s o f c e r t a i n
d ru g s on t h e r a t e o f g a in , fe e d e f f ic ie n c y , and c a r c a s s q u a l i t y o f w ether,
lambs fe d a f a t t e n i n g r a t i o n .
T reatm en ts in c lu d e d co m b in atio n s o f thyro-r
p r o t e i n o r t h i o u r a c i l w ith s t i l b e s t r o l ' g iv e n o r a l l y i n th e r a t i o n , and
s t i l b e s t r o l g iv e n su b c u ta n e o u sly as q p e l l e t im p la n t.
72 PROCEDURE
T h i r ty - th r e e w h ite f ace lambs o f R e m b o u ille t, Columbia, and Targhee
b re e d in g w ere random ized by b re e d and w e ig h t i n t o e le v e n l o t s o f th re e
anim als e a c h .
Average w eig h t f o r t h e e n t i r e group vuas 8 0 .pounds, w ith a
ran g e o f £8 to 97 pounds.
The lambs were k e p t i n th e pens f o r a p p ro x im a te ly one week b e fo re
th e t r i a l b e g a n .
On Depember 13, th e i n i t i a l w eig h ts w ere ta k e n , and
a n im als i n pens se v e n , e i g h t , and n in e were g iv e n s t i l b e s t r o l p e l l e t s
su b c u ta n e o u sly below th e l e f t e a r .
A fte r December 1 3, each pen o f th r e e an im als was fe d 0 of> pounds o f
soybean m eal d a i l y s p r in k le d o v er th e g r a i n m ix tu re .
The m eal f o r some
p en s s e rv e d as a c a r r i e r f o r th e t h i o u r a c i l , th y r o p r o te in , and s t i l b e s ­
t r o l as w e ll as f u r n is h in g some p r o t e i n .
The d e sig n o f th e experim ent
i s shown i n T able I .
A c o n c e n tra te m ix tu re o f o n e - th ir d whole o a ts , o n e - th ir d whole b a r­
l e y , and o n e - th ir d d r ie d m o lasses b e e t p u lp was o ff e re d each d ay in
amounts w hich th e lam bs would c le a n up.
lib itu m to each pen o f sh e e p .
A lf a lf a hay was s u p p lie d ad
S a lt was a v a il a b le I n each pen a t a l l
tim e s .
Lambs i n each pen w ere s u p p lie d w a te r i n a wash tu b .
T h is method
was s a t i s f a c t o r y e x ce p t d u rin g p e rio d s o f e x tre m e ly c o ld w e ath e r, a t
w hich tim e s th e w a te r was fro z e n e x c e p t f o r a few hours each day im­
m e d ia te ly fo llo w in g a d d itio n o f more w a te r ,.
Rowe v e r, t h e la c k o f w a te r
d u rin g c e r t a i n p e rio d s o f th e d ay a p p a r e n tly had no e f f e c t on th e lam b s.
There was some v a r i a t i o n i n pen s fz e among th e e le v e n l o t s .
L o ts
- 73 I th ro u g h .6 had i d e n t i c a l pen s iz e s ,, a l l b e in g lo c a te d i n t h e same wing
o f th e sheep b a rn .
L ots 7 th ro u g h 11 were a l l fe d i n a d i f f e r e n t w ing.
The s iz e o f th e s e pens v a r ie d , b u t, I n g e n e r a l, th e pens were l a r g e r .than
th o s e o f th e f i r s t s ix l o t s ,
At th e end o f th e t r i a l , one lamb from each l o t was s la u g h te re d .
Each lamb k i l l e d was in te rm e d ia te i n w ean in g .w eig h t f o r i t s r e s p e c tiv e
l o t ; c a r c a s s e s o f t h e s la u g h te re d lambs were graded,-
The th y r o id , p i t u i ­
t a r y , and a d re n a l g la n d s were rem oved, and t h e i r r e s p e c tiv e s iz e s and
volumes d eterm in ed
T able I .
E x perim ental D esign, W eight G ain s, and G rain Consumption D ata o f Lamb F a tte n in g T r i a l .
S tilb e s tro l
I mg. ( o r a l)
L ot and R a tio n No.
I
T h y ro p ro te in ,
.0 .5 gm. d a i l y
T h io u r a c il,
.0.5) gm. d a i l y
T h io u r a c il,
I gm. d a i l y
X
2
S t i l b e s t r o l ( o r a l)
0.5> mg. I mg. 2 mg.
3
I
3
6
Im p lan t - •
12 mg.
18 mg.
7
X
C o n tro l
8
9
10
X
X
X
82 .7
1 2 0 .0
8 2 .7
115.3
11
%
Average Weig h ts ( l b s . )
In itia l
F in a l
Gain p e r lamb
D a ily Gain
Feed Consumption
p e r lamb
Feed Consumption
. p e r Cwt. Gain
77.0
1 0 2.3
2 3 ,3
4 .3 6
7 8 .0
1 0 3 .0
2 7 .0
0 .3 8
82.3
103.3
23.0
0 .3 2
78.3
111.3
3 3 .0
0 . 1*6
7 9 .0
1 0 7 .0
7 9 .0
1 1 2 .7
28 .0
3 3 .7
0 . 1*0 0.1*7
8 0 .3
1 23.3
1*2 .6
0 .6 0
37 .3
0 .3 3
3 3 .6
0 .3 0
81.3
99.3
79.3
1 02.3
1 8 .0
23.0
0 .2 3 . 0 .3 2 .
H it. 3
113.3
131.3
1 6 6 .0
11*0.3
170.3
1 7 6 .3
1 6 7 .3
1 3 3 .0
132.0
1 3 8 .3
1*3 2 .6
U27.0
370.9
3 0 3 .0
301.0
33U.1
1*11*.3 . 1*1*9.1
1*33.1*
733.3
602.2
1
1
- 7f> ~
RESULTS MD DISCUSSION
Very soon a f t e r th e t r i a l began, i t became obvious t h a t c e r ta in
drug supplem ents w ere u n p a la ta b le to th e lam b s.
I n g e n e r a l, th e l o t s
r e c e iv in g t h i o u r a c i l a te a s l i t t l e o f th e supplem ent a s p o s s i b l e .
It
ft
was. im p o s sib le t o a c c u r a te ly weigh back th e re fu s e d supplem ent a s i t
was alw ays m ixed w ith f i n e b e e t p u lp m a t e r i a l .
I t was e s tim a te d t h a t
lambs i n L ot 3 a te ab o u t o n e - h a lf th e supplem ent o f f e r e d , w h ile th o se
i n L ots 2 , 8, 9, and 10 a te somewhat m ore.
T h is f a c t o r d id n o t a f f e c t
consum ption o f th e c o n c e n tr a te , how ever, a s th e lambs v e ry e f f e c t i v e l y
s o r te d o u t th e g r a in k e rn e ls and th e l a r g e r b e e t p u lp p a r t i c l e s .
g r a in was w a ste d i n the* th io u p a c il- f e d l o t s .
Some .
T his lo s s was e stim a te d and
com pensated f o r i n com puting fe e d e f f ic ie n c y f i g u r e s .
Hay consum ption av erag ed a p p ro x im a te ly l . b pounds p e r h ead d a ily ,
n o t in c lu d in g w eighback.
v a ry g re a tly .
Hay consum ption betw een tr e a tm e n ts d id n o t
The c o n tro l'la m b s (L ot .11) a te t h e l e a s t .
The e x p e rim e n ta l d e s ig n , fe e d consum ption, and w e ig h t g a in s o f th e
f a t t e n i n g lam bs a re shown i n T able I ,
The lambs weighed an av erag e o f
80 pounds a t th e s t a r t and HO pounds a t th e end o f th e sev e n ty -o n e day
fe e d in g p e r io d . ' G ains o f th e lambs d u rin g th e t r i a l w ere s u b je c te d to
a n a ly s is o f v a ria n c e Snedecor (I9 lt6 ),
There was a h ig h ly s i g n i f i c a n t
(PO.Ol) d if f e r e n c e among tr e a tm e n t g a i n s .
Lambs i n Lot 7 (12 mg, s t i l -
b e s t r o l im p la n t) g a in e d th e f a s t e s t (0 ,6 0 pounds p e r d a y ).
Lambs in
Lot 10 (l.O gm. t h i o u r a c i l p e r head d a ily ) g a in e d th e s lo w e s t (0 ,2 5
pounds p e r head d a i l y ) .
Lambs i n Lot I r e c e iv e d 0 ,5 gm. th y r o p r o te in and I 6O mg. s t i l b e s t r o l
- 76 d a i l y i n th e r a t i o n .
Lambs o f Lot 2 re c e iv e d 0 .5 gm. t h i o u r a c i l and 1 .0
gm. s t i l b e s t r o l i n th e same way.
A lthough th e r e was a s l i g h t d i f f e r e n c e '
i n r a t e o f g a in and fe e d e f f i c i e n c y betw een an im als o f L o ts I and 2, t h i s
d if f e r e n c e m ight be due to c h a n c e .
I t i s a ls o p o s s ib le t h a t th e s t i l ­
b e s t r o l may have had an i n t e r a c t i n g e f f e c t , masking th e d if f e r e n c e t h a t
w ould have r e s u l t e d i f th y r o p r o te in and t h i o u r a c i l had been compared
a lo n e .
The e f f e c t s o f 0 .5 and 1 .0 gm. o f t h i o u r a c i l p e r h ead d a ily , when
b o th tr e a tm e n ts c o n ta in e d 1 .0 mg. s t i l b e s t r o l p e r head d a ily , were com­
p a re d i n L o ts 2 and 3 .
R e s u lts fa v o re d th e lo w er le v e l o f t h i o u r a c i l f o r
fe e d e f f i c i e n c y , b u t d if f e r e n c e s were s m a ll.
S t i l b e s t r o l i n t h e fe e d a t 0 .5 , 1 .0 and 2 .0 mg. p e r head d a i l y was
g iv en t o L o ts U, 5> and 6 r e s p e c t i v e l y .
R e s u lts a re n o t c o n s is te n t,
p ro b a b ly due to in d iv id u a l v a r i a t i o n and t h e s m a ll number o f anim als in .
each tr e a tm e n t.
However, a l l th e lambs g iv en s t i l b e s t r o l o r a l l y had
h ig h e r r a t e s o f g a in th a n th e c o n tr o l lam bs.
Lambs i n b o th L ots '8 and 9 re c e iv e d 0 .5 gm. t h i o u r a c i l p e r head
d a i l y , b u t L ot 9 lambs re c e iv e d an 18 mg, s t i l b e s t r o l im p la n t, compared
t o a 12 mg. im p la n t in L ot 8 .
I n r a t e o f g a in th e r e was o n ly a v ery
s l i g h t d if f e r e n c e , w hich co u ld e a s i l y have been due to c h a n c e .
Feed
e f f i c i e n c y d a ta in d ic a te d somewhat g r e a t e r d if f e r e n c e s , s u g g e s tin g th a t
th e 12 mg. im p la n t o f s t i l b e s t r o l was more d e s ir a b le th a n th e 18 mg.
im p la n t.
Animals i n b o th L ots 9 and 10 re c e iv e d 0 .5 gm. o f t h i o u r a c i l p e r
head p e r day, b u t t h o s e . i n L ot 10 d id n o t r e c e iv e th e 18 mg, s t i l b e s t r o l
- 77 im p la n to
I t i s q u ite e v id e n t t h a t th e 18 mg. s t i l b e s t r o l p e l l e t a f f e c te d
r a t e o f g a in .
i n L ot 1 0 .
Lambs o f Lot 9 g a in ed e x a c tly tw ice as f a s t as d id th o se
Feed e f f ic ie n c y was a ls o more fa v o ra b le when th e s t i l b e s t r o l
p e l l e t was added.
Lambs i n L ot 11 ( c o n tr o ls ) g a in ed an a v e ra g e o f 0 .3 2 pounds p e r d ay ,
and consumed 602 pounds o f fe e d p e r hundredw eight o f g a in . -Lambs in L o ts
I and 2 had a v e ry s im ila r r a t e o f g a in , b u t consumed h$3 and L|27 pounds
o f fe e d p e r hundredw eight o f g a in r e s p e c t i v e l y .
Lambs o f L ot 3 were
s l i g h t l y b e t t e r i n fe e d e f f i c i e n c y th a n th e c o n tr o l lam b s.
Lambs i n L ots
U, £ , and 6 a p p a r e n tly b e n e f ite d from o r a l in ta k e o f s t i l b e s t r o l .
R ates
o f g a in f o r lambs i n th e s e t h r e e l o t s w ere 0 .^ 6 ,. O.UO, and 0.1*7 pounds p e r
day, and fe e d consum ption p e r hundredw eight o f g a in was S03, £01, and
pounds r e s p e c t i v e l y .
L ot 7 anim als re c e iv e d o n ly a 12 mg. s t i l b e s t r o l
im p la n t and had th e h ig h e s t r a t e o f g a in (0»60 pounds p e r d a y ) and fe e d
e f f i c i e n c y (Ull* pounds o f fe e d p e r hundredw eight o f g a in ) o f a l l t r e a t ­
m ents i n th e e x p e rim e n t.
A d d itio n o f t h i o u r a c i l (L ot 8 ) , o r a d d itio n o f
t h i o u r a c i l .and a l a r g e r s t i l b e s t r o l im p la n t (L ot 9 ) , r e s u l t e d i n a low er
r a t e o f g a in (0 .5 3 and 0 .5 0 r e s p e c tiv e ly ) th a n th e low er l e v e l o f
s t i l b e s t r o l p e l l e t a lo n e .
Lambs i n L ot .10 ( t h i o u r a c i l o n ly ) w ere th e only a n im a ls whose p e r ­
form ance was d e f i n i t e l y i n f e r i o r t o th e c o n tr o l lam bs.
R ate o f g a in was
0 .0 7 pounds p e r d a y l e s s and fe e d consum ption p e r hundredw eight o f gain
was 131 pounds more th a n f o r th e c o n tr o l g ro u p .
One lamb from each l o t was s la u g h te re d a t th e end o f th e t r i a l .
The in s p e c tin g v e t e r i n a r i a n condemned th e c a r c a s s o f th e lamb from Lot 7
- 78 becau se o f in flam m a tio n o f th e i n t e s t i n e s .
The abnorm al c o n d itio n o f th e
condemned lamb a p p a r e n tly was n o t c au sed by th e drug giv en i n th e fe e d in g
tria l.
The re m a in in g c a r c a s s e s w ere g rad ed b y a two-man com m ittee.
I t was n o tic e d t h a t t h e p e l t s w ere u n u s u a lly d i f f i c u l t to remove from
lam bs r e c e iv in g th e s t i l b e s t r o l im p la n t tr e a tm e n ts .
D ata w ere re c o rd e d on w eig h ts and s i z e s o f th e p i t u i t a r y , th y ro id ,
and a d re n a l g la n d s .
T able I I ,
These d a t a and th e c a r c a s s , g ra d e s a re p re s e n te d i n
I n g e n e ra l th e lam bs were n o t e x c e s s iv e ly f a t .
A p a rtia l
e x p la n a tio n o f t h i s c o n d itio n m ig h t be t h a t th e lambs w ere q u ite m ature
when th e t r i a l b eg an .
Also th e t r i a l was somewhat b r i e f , • I t should be
n o te d t h a t th e lamb s la u g h te re d from th e c o n tr o l l o t g rad ed average
c h o ic e , w hich was th e h ig h e s t grad e g iv e n any c a r c a s s .
Because o f o n ly
one c a r c a s s o b s e rv a tio n p e r l o t , i t would be unwise to a t t a c h to o much
s ig n if ic a n c e to th e c a r c a s s g rades o b ta in e d .
I n exam ining th e d a ta o f t h i s t r i a l , i t sh o u ld be remembered t h a t
o n ly th r e e anim als w e re .u se d w ith each tre a tm e n t.
T h e re fo re , i t i s
c o n c e iv a b le t h a t r e s u l t s o b ta in e d i n t h i s t r i a l may v a ry c o n s id e ra b le i n
com parison t o r e s u l t s o f an ex p erim en t i n w hich l a r g e r numbers of anim als
a re u s e d .
I n a f u tu r e t r i a l o f t h i s n a tu re i t would be d e s ir a b le to
su p p ly th e t h i o u r a c i l i n a d i f f e r e n t form th a n was u sed i n t h i s e x p e ri­
m ent.
A 't h i o u r a c i l - f i l l e d c a p s u le g iv en d a i l y would in s u r e th e in ta k e
o f a known amount o f th e d ru g .
I n d iv id u a l fe e d in g o f a n im a ls , o r e ls e
u s in g more anim als p e r pen w ould in c r e a s e a c c u ra c y .
U sing an im als o f
more u n iform s i z e , and fe e d in g them f o r a lo n g e r p e rio d th a n was used
i n t h i s t r i a l would be d e s i r a b l e .
T able I I ,
S la u g h te r D ata o f Lambs (One Animal p e r L o t) ,
S tilb e s tro l
I . mg. ( o r a l)
l o t and R a tio n Nb.
I -
2
T h y ro p ro te in j 0 .5 gm.X
T h io u r a c ilj 0 .5 gm.
T h io u r a c ilj I gm.
S t i l b e s t r o l .. ( o r a l )
0 .5 mg. I mg. 2 mg.
3
0 .6 0
0 .5
7
C o n tro l
8
9
10
X
X
X
.
11
0 .6 8
h ig h
good
h ig h
good
av.
good
conav.
demned good
low
good
av.
good
av.
choice
0 .7 6
1 .0
0 .6 5
o .5
0 .7 5
0 .7
0 .9 2
1 .0
1 .0 7
1 .0
1 .1 9
1 .2
0.62
0 .9
1 ,5
I.U
1 .5
1 .7
1 .3
1 .6
1 .7
1 .7
lo s t
lo s t
lo s t
lo s t
0 .7
1 .0
lo s t
lo s t
1 .8
. 1 .8
1 .6
1 .9
1 .7
1 .7
l.l
l.l
0 .7
0 .6
lo s t
lo s t
lo s t
lo s t
lo s t
lo s t
1 .7
1 .0
lo s t
lo s t
1 .5
2 .0
1 .5
1 .2
1 .3
1 .5
1 .5 1 .5
1 .7
1 .2
1 .8
1 .9
lo s t
lo s t
i.U
1 .7
1 .7
I.U
1 .9
1 .9
I.U
I.U
1 .3
1 .3 .
1 .6
1 .5
1 .3
1 .5
i.U
1 .2
1 .9 ■
2.-0
2 .1 . . 2 .0
1 .8
2 .5
1 .9
2 .0
1 .7
2 .0
lo s t
lo s t
0 .7 0
O .U
1 .2
1 .1
1 .5
i.U
A drenal ( r i g h t )
W eight, gm s.^
Volume, c c .
1 .2
1 .1
A d re n a l' ( l e f t )
W eight, gms.
Volume, c c .
i.U
i.U
T hyroid ( l e f t )
. W eight, gms.
Volume, c c .
6
Impla nt.
18 mg.
X
o .u
T hyroid ( r i g h t )
. W eight, gm s.,
Volume, c c .
5
X
low
C arca ss Grade (One a v .
' av .
... Lamb p e r L o t)
good, choice. good
E ndocrine Glands
P itu ita ry
W eight, gms.
Volume, c c .
U
12 mg
0 .8 1
0 .8
1 .2
1 .1
"■
.
80 SUMMARY
E leven l o t s o f th r e e w ether lambs each w ere hand f e d , a c c o rd in g to
a p p e t i t e , a r a t i o n o f equal- p a r t s whole o a ts , whole b a r le y , and d rie d
m o lasses b e e t p u lp , p lu s a l f a l f a h ay .
V a ria b le s in c lu d e d com binations
o f th y r o p r o te in , t h i o u r a c i l , o r s t i l b e s t r o l in c o rp o ra te d i n soybean
m eal, and s t i l b e s t r o l p e l l e t s im p la n te d su b q u ta n e o u sly .
Soybean m eal c o n tain in g - t h i o u r a c i l a lo n e , o r soybean meal c o n ta in in g
t h i o u r a c i l i n co m b in atio n w ith s t i l b e s t r o l was n o t r e a d i l y consumed,
a p p a r e n tly b ecau se p a l a t a b i l i t y was a f f e c t e d .
There was a h ig h ly s i g n i f i c a n t d if f e r e n c e (P<e0 l) i n g a in s p e r lamb
among l o t s .
D a ily g a in s p e r la m b 'ra n g e d from 0 o2fp t o 0 ,6 0 pounds p e r
d ay ,
A 12 mg. s t i l b e s t r o l p e l l e t im p la n t gave th e h ig h e s t r a t e o f g a in
and b e s t f e e d e f f i c i e n c y o f any tre a tm e n t t e s t e d .
The same s i z e im p la n t
p lu s t h i o u r a c i l g iv e n o r a l l y le s s e n e d d a i l y g a in s b y 0 .0 7 pounds p e r day.
Three d i f f e r e n t l e v e l s o f s t i l b e s t r o l g iv e n o r a l l y r e s u l t e d i n
in c r e a s e s o f 0,11;, 0 .0 8 , and 0 »15> pounds p e r day r e s p e c t i v e l y i n r a t e o f
g a in .
Feed e f f ic ie n c y was im proved 99# 101, and 68 pounds r e s p e c tiv e ly
p e r hundred pounds o f g a in .
O ral in ta k e o f s t i l b e s t r o l w ith e i t h e r th y r o p r o te in o r t h i o u r a c i l
in c r e a s e d fe e d e f f i c i e n c y , b u t d id n o t a f f e c t r a t e o f g a in .
The o n ly tr e a tm e n t d e f i n i t e l y i n f e r i o r t o th e c o n tr o l group was
t h i o u r a c i l by i t s e l f i n th e g r a in m ix tu re .
C arcass g rad es were o b ta in e d on one anim al from each l o t .
c a s s e s were n o t f a t .
The c a r ­
The c o n tro l anim al graded av erag e c h o ic e , th e
81 h ig h e s t o f a l l e le v e n lo ts *
The p i t u i t a r y , a d r e n a l, and th y r o id g la n d s were removed.
A fte r
w eig h t and volume d a ta w ere re c o rd e d , th e g lan d s were p re s e rv e d f o r f u tu r e
h is to lo g ic a l s tu d ie s .
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T erre
E l i , R. E ., K. J . O lson, and E. P . R ein ek e. 1914.8» A b so rp tio n and E lim in ­
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J o u r.
Jo rd a n , P . S ., R. M. Jo rd a n , and H. G. Groom. 1955. E f f e c t o f S t i l b e s t r o l ,
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J o u r. Anim. S c i. 11:795» ■
K em pster, H, L. and C. W. T u rn e r. 19L5* The E f f e c t o f Feeding T h io u rac i l on th e F in is h in g o f New Hampshire B r o i l e r s . P o u ltr y S c i. 2kt9hK lin e , E. A ., M. E. Ensm inger, T. J . Cunha, W. W. Heinemann, and'W. E.
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.
T h ay er, R. H ., R. G. Ja a p , and R. P e n q u ite . 191*5»
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T u rn e r, C. D. 191*8,
d e lp h ia , Penn.
G eneral E n d o crin o lo g y .
F a tte n in g Chickens by
W. B.. Saunders Co.
P h ila ­
Vander H oot, C, ¥ . , Rv R. R eece, and W, C. S k e lle y . 19l*7» The E f f e c t o f
T h io u r a c il i n th e R a tio n o f Growing Swinev J o u r. Anim. S c i. 6 :1 2 .
W oehling, J . L ,, G. D. W ilson, R. H. Grummer, R. W. Bray, and L. E. C asid a.
1951* E f f e c ts o f S t i l b e s t r o l and T e s to s te ro n e P e l l e t s Im p lan te d in to
Growing F a tte n in g P ig s . J o u r. Anim. S c i. 1 0 :8 8 9 .
118856
U1 cTATF IlNtVERSITY LIBRARIES
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The e f f e c t o f Aureomycin in
p e lle t e d or whole grain creep
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