Protein Nutrition
Dan Morrical
Iowa State University
515-294-2904
morrical@iastate.edu
What is Protein
Amino acid chain
What is AA
polypeptide that contains N
Essential and non essential
methionine and lysine
Protein Uses
Milk
Growth
Wool
Maintenance
Metabolic Fecal Nitrogen
Dermal Loss
Endogenous Urinary Protein
Protein Requirements
Expressed as Crude Protein
because CP = 6.25 X % N
example would be alfalfa hay
18.8% crude protein = 3% N
Protein Requirements
Varies with
Stage of production
Level of production
Composition of lamb gain
Ewes 9-15 % CP
Lambs 11-20% CP
Protein Sources
Intake
protein
Microbial
protein
Intake Protein
Undegraded (UIP)
Degraded (DIP)
Intake Protein
Ingredient
Corn
Alfalfa hay
SBM
CGM
DDG/S
P.Blood meal
Urea
% CP
7.5
14-22
43
60
27
83.7
281
%UIP
40
15
40
60
62
80
0
Value of Protein Sources for UIP
% CP
Grass Pasture
Alfalfa Hay
Dehydrated Alfalfa
Corn
SBM 44, Solvent
SBM 44, Expeller
CGM
Blood Meal
Fish Meal
6-20
16-24
16-18
8.5
44
43
60
85
60
% UIP
10
15
20
40
25
50
40
80
40-80
UIP
Conc. %
2
2.7
3.4
3.6
11
21.5
24
68
24-48
Intake Protein Quality
Urea versus SBM
Quality is determined by how
well the AA composition
matches animal needs.
Biological value
Microbial Protein Quality
Biological
Value
.66
Microbial Protein Yield
TDN intake x .13
40-80 % total protein
Rumen N
requirement
9-13% CP diet
Maximizing Microbial Protein Yield
Energy: Protein Ratio
TDN
Concentration
% CP
50%
7.8
65%
9.8
80%
12.1
.13 lbs microbial crude protein/lb TDN
Protein Nutrition
Why do we care?
Deficiency reduces production
depressed forage digestion
Excess increases main.,
$$$$$ and
environment
NPN Precautions
<1/3 of total protein intake
must have fermentable energy
increases need for S
Using information
Protein needs with
Alfalfa hay versus corn stalk
Corn stalks always need
supplemental protein
Alfalfa hay seldom needs
supplemental protein
Iowa Hay Quality Survey
Hay type
Grass
1st cut
all others
Mixed
1st
2nd
3rd
Legumes
1st
2nd
3rd
Crude protein
Ave. Range
11.6 (6-20)
15.2 (12-19.7)
TDN
Ave. Range
55.7 (47-67)
61.8 (57-70)
13.9
16.8
18.3
(8-22)
(10-22)
(11-23)
56.1
59.6
62.4
(41-69)
(47-70)
(49-73)
16.9
18.3
19.9
(10-22)
(14-22)
(13-23)
56.7
57.7
59.4
(48-69)
(45-68)
(47-70)
New Sheep NRC
Protein Requirements set based
off of % UIP
More UIP the lower the total
protein requirement
Using information
Very high producing animals
may need supplement UIP.
ex. Ewes rearing triplets
Economics
escape protein is expensive
Is extra production
worth cost?
Example lactation rations
8 pound yield
Ewe Alfalfa
Wt
hay
Corn
150
5.0
2.5
175
5.8
2.5
200
7.0
2.0
225
7.75
1.75
250
9.0
1.25
Hay is:
Premium grade
22% CP
60% TDN
175 RFV
Full fed
No weight loss
Energy and Protein vs. Yield
M
i
l
k
Y
i
e
l
d
8
1.86 TDN 2.35 TDN
7
1.28 TDN
6
5
4
3
2
1
0
.37
.52
.66
.83
.83
.93
.93 1.10
Protein Intake, ewes losing weight
Milk Yield Results from Additional Protein
Protein Source
Urea
Nutmeal
Soybean Meal
Meat & Bone Meal
Lineseed Meal
Fish Meal
Blood Meal
Protein Added
.18 lbs.
.44 lbs.
.29
.88
.88
.88
1.32
1.32
1.32
145 lb. ewes rearing twins fed
base diet 2.67 TDN 11.6% CP
Gonzalez et al. 1982
0
0
0
0
0
.55
.74
Cheap protein sources
cost/t
soybean meal $260
ddgs
cgf
cgm
alfalfa hay
$135
$120
$485
$160
cost/lb
cost/
lb cp
$.13
$.27
260/(2000*.48)
$.0675 $.25
$.06
$.33
$.24
$.40
$.08
$.44
Cheap protein sources
soybean meal
cost/lb
CP
$.27
cost/lb
UIP
$.90
ddgs
cgf
cgm
alfalfa hay
$.25
$.33
$.40
$.44
$.45
$1.10
$.67
$2.93
Questions?
Feeding ewes
Weight loss 2-6 weeks of lactation
Test hays
Sort by production levels
Lactation phase is highest need
Supplementation on crop residue
Never feed protein tubs