PLANT CHARACTERISTICS RELATED TO FEEDING
PREFERENCE BY BLACK· TAILED DEER
M. A. RADWAN, Pacific Northwest Forest and Range Experiment Station, USDA Forest Service, Olympia, Washington 98502
G. l. CROUCH, Pacific Northwest Forest and Range Experiment Stotion, USDA Forest Service, Olympia, Washington 98502
Abstract: Six plant species of known preference by black-tailed deer (Odocoileus /wlIlioIJIIS coltlmbia­
nus) were used to evaluate several factors thought to influence preference . Factors studied included
chemical composition, in vitro fermentation of dry matter and cellulose, and effects of essential oils
and water and methanol extracts on rumen microbial activity in vitro . Chemical analyses revealed
considerable differences among species in all constituents; but, with the exception of moisture which
was generally higher in the more preferred species, tissue cOl1lponents did not show any consistent rela­
tionship to preference . Fennentations of cellulose but not of dry matter were more closely related to
preference than chemical composition and provided a good general indication of species preference .
Similarly, the overall effects of oils and extracts on rumen activity suggested different preference rating
for the species, but results of the water extracts most closely approximated the established preference order .
J. WILDL. MANAGE. 38(11:32-41
Like other herbivores, black-tailed deer
oils and individual terpenes isolated from
show definite selectivity in their feeding.
plants (Nagy et al. 1964, Oh et al. 1967 ) .
Thus, the animals have often been observed
Most
to prefer different parts of plants (Brown
marily concerned with the nutritive value
1961:68-69, Oh et al. 1970:24 ) and to dis­
investigations,
however,
were
pri­
of deer foods and included only proximate
criminate among and within species (Cowan
analyses which did not allow for determina­
1945:1.31-137, Brown 1961:63-76, Crouch
1966, Miller 1968:144-148, Oh et al. 1970:
24) . In addition, preference has been
tion
shown to vary by location and even on the
influencing forage preferences of deer.
same area during different seasons (Miller
1968:144-148, Brown 1961:69, Crouch 1966:
472-474, Crouch 1968:548, Oh et at 1970:
24 ) .
of many
individual
chemical com­
pounds. Much detailed work, therefore, is
still needed to better understand factors
In the Pacific Northwest,
(Pseudotsuga menziesii)
Douglas fir
is utilized by deer,
and in many areas intensive browsing seri­
ously retards reforestation. Efforts to COll­
Studies designed to identify factors influ­
trol browsing require an understanding of
encing relative preference of animals for
the role of Douglas fir in deer diets and its
plants can provide information for formulat­
relative preference among associated spe­
ing better management programs for both
cies. In this study, therefore, we evaluated
animal and plant resources. Many workers,
several factors suspected to affect prefer­
therefore, have attempted to identify such
ence using Douglas fir and five associated
factors by studying chemical composition
species of known preference to black-tailed
and digestibilities of deer foods (Hellmers
deer during the dormant season. \Ve deter­
1940, Einarsen 1946, Gastler et al. 1951, Bis­
mined
sell et al. 1955, Bissell and Strong 1955,
nonnutritional
Taber and Dasmann 1958:84-107, Brown
studied fermentabilities of the tissues and
1961:83-89, Dietz et al. 1962, Short et al.
1966 ) . Other investigators have studied ef­
fects on deer microbial activity of essential
32
conce ltrations of nutritional and
chemical
compound
.and
effects of their essential oils and extracts on
rumen microbial activity in vitro.
We gratefully acknowledge the coopera-
J. Wild!. Manage. 38(1) :1974
PLANT CHARACTERISTICS AND DEER FEEDING PREFERENCE
tion of personnel of the Oregon Game Com­
mission, Corvallis, Oregon, for use of the
Cedar Creek deer enclosure at the Tilla­
mook Burn to obtain the necessary plant
material and deer.
MATERIALS AND METHODS
Plants and deer were obtained during
February 1969 in or near a 340-acre deer
enclosure at the Tillamook Burn in north­
west Oregon. The area has been previously
desclibed by Crouch ( 1968:543) .
Plant Material
Six shrub and tree species were used in
all work except in experiments designed to
study effects of essential oils and plant ex­
tracts on cellulose fennentability by rumen
micro-organisms where only three species
were evaluated. Arranged in decreasing or­
der of deer preference during the winter
( Crouch 1966) , the species were: cascara
(Rhamnus purshiana) , red whortleberry
(Vaccinium parvifalium.) (commonly known
as red huckleberry in the Pacific Northwest),
Douglas fir, hazel (Carylus califarnica), red
alder (Alnus rubra), and vine maple (Acer
circinatum) .
Three composite twig samples were col­
lected from each species during the winter.
Collections were made in early morning
when deer commonly feed. All sample
plante; were selected from a 10-acre area of
similar elevation, slope, aspect, soil series,
and vegetational composition. Each sample
was taken from 10 to 20 plants selected at
random, and consisted of the terminal 3
inches of twig tissue produced the past sea­
son which was growing within the reach of
•
Radwan and Crouch
33
mination of moisture; total phenols, leuco­
anthocy.anins, and flavonols; paper-chro­
matographic separation of sugars; steam­
distillation of essential oils; and preparation
of water and methanol extracts. Remaining
tissue was dried to constant weight at 65 C,
ground to 40 mesh in a Wiley mill, and
stored in closed containers at - 15 C until
used.
Chemical Analysis
Moisture was determined by drying to
constant weight in a forced-air oven at 65 C,
and ash in the ground tissue was estimated
by heating in platinum crucibles at 500·-550
C for 4 hours.
Total available carbohydrates were ex­
tracted and hydrolyzed with 0.2N H2S04
( Smith et a1. 1964) , and resulting sugars
were estimated as glucose ( Hassid 1.937) .
Sugars were extracted in Soxhlet apparatus
with 80-percent ethanol, and portions of the
extracts were subjected to sugar determina­
tions before and after hydrolysis ( Hassid
1937) . Quantities of reducing and total
sugars and those of nonreducing sugars were
calculated as glucose and sucrose equiva­
lents, respectively. Additiomil portions of
the ethanol extracts were partitioned be­
tween water and chloroform to remove
lipids and chlorophyll. Aqueous phases
were evaporated to dryness and residues
taken up in distilled water. Sugars in the
resulting extracts were separated by two­
dimensional chromatography on Whatman
No. 1. paper ( Block et a1. 1958) . The paper
was developed in the short direction with
liquid phenol:water ( 4: 1 by volume) con­
taining 0.04-percent 8-hydroxyquinoline and
deer. Samples were individually sealed in
then in the long direction with the upper
glass containers and brought to the labora­
phase of n-butanol:acetic acid:water (25:6:
tory in a portable cooler.
Fresh twig tissue was chopped into small
25 by volume) . Sugars on the developed
chromatograms were located with aniline­
pieces. Subsamples were taken for deter-
diphenylamine-phosphate
J. Wildl. Manage. 38(1) :1974
spray
reagent
I
I
I
t!
34
•
PLANT CHARACTERISTICS AND DEER FEEDING PREFERENCE
(Block et a!. 1958: 194). Identification of
resulting spots was made from their R,
values and by co-chromatography with
authentic compounds.
Analyses of other tissue components were
made as follows: total nitrogen by the mi­
cro-Kjeldahl technique, calcium by a titri­
metric method, and crude fat from loss in
tissue weight after extraction with ether in
Soxhlet apparatus (Horwitz 1970); acid­
detergent fiber and acid-detergent lignin
according to Van Soest (1963); cellulose by
the method of Crampton and Maynard
( 1938:391); magnesium by the magnesium
ammonium phosphate method (Chapman
and Pratt 1961: 136); phosphorus according
to the colorimetric method of Fiske and
Subbarow (1925); and total phenols, flavo­
nols, and leucoanthocyanins obtained by ex­
traction in Soxhlet apparatus with 80 per­
cent methanol, by the techniques of Swain
and Hillis (1959).
All analyses were made in duplicate on
each of the three replicate samples.
Fermentability Determinations
Fermentabilities of dry matter and cellu­
lose were estimated by an in vitro rumen
fermentation technique.
Determinations
were made on ovendried tissue and on cel­
lulose. Solka-Floc (produced by Brown
Co., Berlin, New Hampshire; mention of
chemical companies and their products does
not represent endorsement by the Forest
•
Radwan and Crouch
through four layers of cheesecloth. The
fluid was immediately gassed with CO2
while maintained at 39 C, and, after allow­
ing food particles and associated micro-or­
ganisms to settle for about 1 hour, the fluid
in the bottom layer was withdrawn for use
as inoculum. Time lapse between shooting
the deer and inoculating the fermentation
vessels was approximately 3.5 hours.
Preparation of Essential Oils and Plant
Extracts.-Red whortleberry, Douglas fir,
and red alder were the only species investi­
gated because oil content of the other spe­
cies was very low.
In preliminary experiments, essential oils
varied among tissues of Douglas fir, alder,
and whortleberry, in that order. Different
amounts of tissue from each species, there­
fore, were used to prepare the required
volumes of oil. Tissues, mixed with mini­
mum amounts of distilled water, were steam­
distilled at atmospheric pressure for 4 hours.
Distillates were saturated with NaCl and
the oils extracted with ether. Oils were then
isolated by drying the extracts over anhy­
drous Na2S04 and removing the ether by
evaporation.
Water extracts were prepared by homoge­
nizing 60 grams of tissue with three 30-ml
portions of distilled water in a blender.
Homogenates were squeezed through two
layers of cheesecloth, centrifuged, and the
supernatant made up to 120.ml with dis­
tilled water.
Service or by the U.S. Department of Agri­
Methanol extracts were obtained by Soxh­
culture) was used as the cellulose source in
let extraction of 25 grams of tissue with
investigating effects of essential oils and
methanol. Extracts were filtered and made
water and methanol extracts on rumen mi­
up to 250 ml with methanol.
crobial activity.
Rumen Sou rce .-Rumen fluid was ob­
Fermentation Conditions.-The in vitro
technique used was essentially that outlined
tained from deer collected shortly after
by Kutches et a!. (1970:431). Each fermen­
dawn near the Tillamook Burn enclosure.
tation was conducted in triplicate on sub­
The inoculum was prepared by squeezing
strates of 0.8 gram of plant tissue or 0.4
rumen contents from freshly sacrificed deer
gram of Solka-Floc in 100-ml lipless beakers
J. Wildl. Manage. 38 (1) : 1974
PLANT CHARACTERISTICS AND DEER FEEDING PREFERENCE '
Table
1.
Radwan alld Crouch
35
Concentration of selecled chemical constituents in the fresh Iwig tissues of six different browse species in the
winter.
Plant species"
Chemical
constituent
Moisture
Ash
Calcium
Magnesium
Phosphorus
Total nitrogen
Total available
carbohydrates
Total sugars
Reducing sugars
Nonreducing sugars
Crude fat
Acid-detergent fiber
Acid-detergent lignin
Cellulose
Total phenols
Leucoanthocyanins
Flavonols
Whortleberry
(percent)b
Douglas fir
(percent)b
,Hazel
(percent)b
58.48w
1. 88w
0.65w
0.13w
0.07yz
0.51y
54.52wx
1.38xy
0.44xy
0.06y
0. 06z
0. 45y
57. 85w
l. 11z
0.22z
0.10x
0.10x
0.59x
51.31x
1. 51x
0. 48wx
0. 11wx
0. 07yz
0.48y
52. 56x
1.14yz
0.28yz
0. 10x
0. 12w
0. 75w
45.58y
1. 38xy
0.45xy
0.D7y
0. 08y
0. 45y
5.89wx
2.35yz
1.73z
0.59w
1. 32z
15.01z
4. 8 . z
8.75y
1.28z
0.08z
0.53y
5.01xy
3. 11wx
3. 04x
0.09xy
1.20z
22.68y
8. 67x
12.85x
1.93xy
0.21x
0. 61y
6.19w
3.69w
3.66w
0.01y
4.37x
12.64v
6.72y
6.90z
2. 31x
0.35w
1.43w
4. 48xz
2. 41xyz
2. 29y
0.11wxy
1.16z
25.03x
11.42w
13.15x
1.47yz
0. 14y
0. 92x
6. 30w
3.00xy
3. 01x
0,01y
6.65w
15.72z
7.94xy
8.50y
4. 73w
0.14y
0. 51y
4.00z
1. 83z
1. 44z
0.38wx
2. 73y
28. 61w
7. 70xy
17.63w
0.51v
0. 02v
0. 10z
Cascara
(percent)b
Red alder
(percent)b
Vine maple
(percent)b
•
I
I
I
•
-----,----
deer (Crouch 1966).
• Arranged from left to rigbt in descending order of preference by black-tailed
b Values are averages of three composite samples from 10 to 20 plants each. Means within each chemical constituent
followed by the same letter (s) designation do not differ significantly at the 5 percent level. To convert to dryweight basis, multi ly by 2.41, 2.20, 2.37, 2.05, 2.11, and 1.84 for cascara, whortleberry, Douglas fir, hozel, alder,
and maple, respectlvely.
fitted with gas release valves. The buffer­
nutrient solution for each vessel was 25 ml
of CO2-saturated McDougall's solution
(1948: 106) containing 22 mg urea, and the
inoculum was 8 ml of rumen fluid. Also,
in the Solka..Floc experiments different
amounts of essential oils and plant extracts
were added. In the methanol-extract runs,
extracts were first dried to remove the sol­
vent and then remaining solutes were sus­
pended in the buffer-nutrient solution. Pre­
pared vessels were finally swept with CO2,
stoppered, and incubated at 39 C. After fer­
mentation for 48 hours, microbial activity
was stopped by adding 2 ml of 2N H2S04 to
each vessel. Appropriate unfermented con­
trols were included in each run to correct
results.
cibles (porosity C) and dried to constant
weight at 65 C for determination of remain­
ing dry matter. Cellulose in the residual
material was then estimated by the method
of Crampton and Maynard (1938:391).
Fermentation percents were calculated from
losses of dry matter and cellulose as com­
pared to unfermented controls. These cal­
culations were based on the assumption that
materials which passed through pores of the
crucibles were digested (Church and Peter­
sen 1960:82). Also, in the Solka-Floc ex­
periments, the fermented cellulose was used
as the criterion for rumen microbial activity
as affected by the oils and plant extracts
added.
Dry Matter and Cellulose Fermentabili­
Data were subjected to analysis of vari­
ance, and means were separated according
to Tukey's test as required (Snedecor 1961).
ties.-Following fermentation, samples were
filtered and washed in sintered glass cru­
J. Wildl. Manage. 38(1) :1974
Statistical Analysis
i
I
t
PLANT CHARACTERISTICS AND DEER FEEDING PREFERENCE
36
RESULTS
Chemical Composition
Concentrations of several chemical con­
stituents in twig tissues, summarized in Ta­
ble 1, are expressed on a fresh-weight basis.
\Ve believe that this method of calculation
which allows comparisons of the constitu­
ents' levels as the animal would encounter
them in feeding is more appropriate in
preference studies than calculation on dry­
weight basis which is usually followed in
nutritional investigations ( Radwan and
Campbell 1968: 108). However, for com­
parison with other data, the results can be
easily converted to a dry-weight basis (see
footnote b, Table 1).
Moisture.-The average moisture content
for all species was approximately 53 per­
cent. \Vater, therefore, was a major com­
ponent in twigs of all species during the
winter; it exceeded total dry matter content
in all species but vine maple. In general,
moisture was high in cascara, Douglas fir,
and whortleberry, medium in .alder and
hazel, and low in maple. Moisture contents,
therefore, were higher in the tissues of the
more preferred species.
Minerals.-Ash content ranged from 1.11
percent in Douglas fir to 1.88 percent in cas­
cara. Significant differences were also
found among the species in Ca, Mg, and P,
and in the CalP ratio. Thus, Ca ranked
highest in cascara and lowest in Douglas fir.
Magnesium was also highest in cascara, but
lowest in whortleberry; and phosphorus was
highest in alder and lowest in whortleberry.
In addition, the CalP ratio was closest to
the optimum for deer (Maynard and Loosli
1962:126) in alder and Douglas fir, and
highest at 9:1 in cascara.
Nitl Ogen .-Total nitrogen ranged from a
high of 0.75 percent in alder to a low of 0.45
percent in maple and whortleberry. For
comparison with other data, these amounts,
'
•
Radwan and Crouch
on a dry-weight basis, are equivalent to ap­
proximately 9 and 6 percent crude protein,
respectively. In all species, crude protein,
therefore, was slightly above the minimum
requirement for black-tails proposed by
Einarsen (1946:311).
Available Carbohydrates.-Total avail­
able carbohydrates averaged about 5 per­
cent in the tissues. They were highest in
alder and Douglas fir, medium in cascara
and whortleberry, medium-low in hazel, and
lowest in maple. Also, in all species, avail­
able carbohydrates constituted a major com­
ponent of organic matter and contained a
high proportion of sugars.
Reducing sugars predominated in all spe­
cies; nonreducing sugars contributed only
an average of 7.3 percent to the total sugar
content. Trends of reducing sugars were
similar to those of total sugars. Thus, con­
centrations were highest in Douglas fir, high
in whortleberry and alder, medium in hazel,
and low in cascara and maple.
Glucose, fructose, sucrose, and traces of
raffinose were detected by chromatography
in all species. In addition, trace amounts of
stachyose were found in cascara, alder, and
maple. Among reducing sugars, glucose
predominated in all species; it was followed
by fructose which occurred in much smaller
amounts. Sucrose was the principal non­
reducing sugar-.highest amounts were in
cascara and maple, and the lowest concen­
trations were in Douglas fir and alder.
Crude Fat.-Highest concentrations of
crude fat were in alder (6.65 percent) fol­
lowed by Douglas fir. Lowest level at 1.16
percent was in hazel.
Fiber, Lignin, and Cellu lose
The acid­
.-
detergent fiber, representing the acid in­
soluble cell-wall materials (Van Soest 1965:
835), was, as expected, the highest of the
measured organic constituents in all species.
Also, the fiber fraction in all species was
J. Wild!. Manage. 38(1) :1974
PLANT CHARACTERISTICS AND DEER FEEDING PREFERENCE '
composed of more cellulose than lignin.
Fiber and cellulose trends were similar,
with maple containing the highest and
Douglas fir the lowest levels. Lignin, on the
other hand, was highest in hazel and lowest
in cascara.
Phenols.-Leucoanthocyanins and flavo­
nols are astringent phenols (Joslyn and
Goldstein 1964: 199-200) ; and total phenols
estimate tannins. Alder and Douglas fir
contained high levels of total phenols and
astringent materials, and lowest concentra­
tions of all phenolics were found in maple.
Results of chemical analyses, therefore,
indicate considerable variations among spe­
cies in all constituents. However, except for
moisture which was generally higher in the
more preferred species, tissue components
did not show any consistent relationship to
preference.
Fermentations of Dry Matter and Cellulose
Ranges of in vitro fermentations by rumen
micro-organisms were 12.8 to 25.0 percent
for dry matter and 2.9 to 24.1 percent for
cellulose (Table 2) . Dry matter and cellu­
lose fermentabilities were highest in cas­
cara, and lowest in alder and Douglas fir,
and alder and maple, respectively. In addi­
tion, fermentations of cellulose were con­
sistently lower than those of dry matter in
all species.
The observed preference order of the spe­
cies was not indicated by fermentations of
their dry matter. Cellulose results, on the
Table
2.
In vitro
RadllJall and Crouch
fermentabilities
of browse
37
plant tissues
by black-tailed deer rumen micro-organisms.
In vitro fermentabilityb
Specieso.
Cascara
vVhortleberry
Douglas fir
Hazel
Red alder
Vine maple
Dry matter
( percent)
Cellulose
(percent)
25. 0\V
14.0yz
12,.8z
17. 1x
13. 1yz
15. 4xy
24. 1\V
10. 3x
10. 9x
8.1y
3. 1z
2. 9z
n Arranged in descending order of preference
by black­
tailed deer (Crouch 1966).
b Detemlined hy in vitro fermentation technique. Values
are means of three detenninntions and means within col­
umns followed by the same letter designation do not differ
significantly at the 5 percent level.
rumen microbes fermented about one-third
of the cellulose substrate. Microbial activity,
however, was affected. when oils and ex­
tracts were present, and effects varied with
the level and source of added materials.
At the lowest level, whortleberry oil sig­
nificantly stimulated microbial activity, but
oils from Douglas fir and alder were essen­
tially without effect. As the amount of oils
added was increased, microbial activity was
significantly decreased. However, the level
of Douglas fir oil required to produce the
first significant inhibition was greater than
that of the other two species. In addition,
alder oil was consistently more inhibitory
than that of whortleberry.
'Vater extracts of alder inhibited micro­
bial activity at all levels, and inhibitions
increased with the increase in the amounts
added.
Extracts of whortleberry did not
other hand, were more closely related to
significantly
preference, although fermentations did not
lowest or highest concentrations but pro­
distinguish between all species.
affect
fermentation
at the
moted activity at the 2-ml level. Also, re­
sults of Douglas fir were similar to those of
Effects of Essential Oils and Tissue Extracts
Fermentations of Solka-Floc cellulose in
whortleberry at the low concentrations, but
the highest level was inhibitory.
the presence of increasing amounts of essen­
Contents of the methanol extracts of
tial oils and plant extracts are summarized
Douglas fir and alder were similar in their
in Table 3. Without oils or extracts, deer
effects on rumen activity at all levels. They
J. WildI. Manage. 38(1) :1974
1
J
38
PLANT CHARACTERISTICS AND DEER FEEDING PREFERENCE
•
Radwan and Crouch
Tobie 3. Effects of essential oil!, water extracts, and methanal extracts from different plont species an cellulose fermenta·
by black·tailnd deer rumen micro·organisms in vitro.
tian
Oil or
extract
added to
substrate"
(ml)
i�
l
Source of oil or extractb
_._---- --------
Douglas fir
Red whortleberry
Fermentation
(percent)'
Relative
fermentation
(percent) ,
Fermentation
(percent) ,
35.Bw
46 .4x
17.3 Y
IB.3 Y
100. 0
129.6
4B.3
5 1. 1
0. 0
1. 0
2. 0
,1. 0
35. B x
36. 8 x
47. 7w
36. 4 x
100. 0
102 .B
13 3.2
101.7
0.0
1.0
3. 0
5 .0
3 8.2w
34.9w
2 7.3 x
17 .6 Y
100.0
II.
Ill.
9 1. 4
7 1.4
46. 0
._---
Fennentation
(percent)'
Relative
fermentation
(percent ) '
---
-
Essential oils
35. Bw
39.1w
40. 4w
36.2 w
9. Bx
100. 0
109 ,2
112. B
101. 1
27. 4
35.8w
33.Bw
9.6 x
2. 4Y
100. 0
94. 4
26.9
6 .7
Water extra ct
35. Bx
35.2 x
46.6 w
2 1.6 Y
100. 0
9 B.3
13 0. 1
6 0.3
35.Bw
32.9 wx
3 1. 0wx
2 8. 1x
100. 0
9 1. 9
86.5
7B.4
38.2 w
25.3 x
14.2 Y
5. 1z
JOO.O
1.
0. 00
0.02
0. 06
0. 10
0.2 0
Relative
fermentation
(percent) ,
Red alder
--------------
Methanol extract
3 B.2 w
100.0
2 4. B x
6 4.7
15 .6 Y
40.7
7. 1 z
IB.5
66.2
3 7.3
13.2
• Oils and extmets' were obt.ined, respectively, by steam ..distillation and extraction with water or methanol, and Solki!­
Floc served as substrate.
b Relative preference by black-tailEd deer: red whortleberry > Douglas fir> red alder (Crouch 1966).
'Fermclllability was determined by in vitro fermentation technique and volues are means of three detcrnlinations.
Withh, ench of the three scctions of the tahle, means within columns followed by the same letter designation do not
diffe]' significantly at the 5 percent level.
were always inhibitory, and inhibitions be­
came progressively stronger with increases
in t.n. e volumes added. VvVhortleberry ex­
tracts, on the other hand, were inhibitory
only at the higher concentrations. Inhibi­
tions were stronger at the highest level but
were always less potent than those pro­
duced by Douglas fir or alder at the same
concentrations.
In general, the overall effects of the oils
and extracts on rumen microbial activity
indicated different preference ratings for
the three species, depending upon the ma­
terials used. These ratings according to oil,
water, and methanol data were, respec­
tively, as follows:
Douglas fir > whortle­
berry> alder, whortleberry > Douglas fir
> alder, and whortleberry> Douglas fir
=
alder. Results of the water-extracts ex.peri­
ment, therefore, provided the best approxi­
mation of the established preference order
among the three species.
DISCUSSION
The comparative analyses reported here
show considerable differences in chemical
composition among the six plant species
studied. The differences, however, did not
reveal a consistent chemical basis for the
observed deer preference for the species.
For one or more of the different constituents
we determined, our results are in agreement
with conclusions of some earlier studies
(Gastler et al. 1951 : 355, Ullrey et a1. 1967:
451-452, Oh et al. 1970:24-25, Torgerson
and Pfander 1971 : 229) . On the other hand,
J. Wild!. Manage. 38(1) :1974
PLANT CHARACTERISTICS AND DEER FEEDING PREFERENCE
•
Radwan and Crouch
39
the same data do not support findings of
other investigations (Mitchell and Hosley
1936:26, Swift 1948:110, Powell and Box
1966:214, Reynolds 1967:908) . This incon­
sistency is probably due to differences in
methods of analyses, species analyzed and
season of their collection, and kinds of deer
studied. It is also possible that determina­
tions of specific compounds not possible by
proximate analysis or methods employed
here are required for a more consistent rela­
tionship to preference. Such determinations
have indicated that, in ruminants, the palat­
ability and digestibility of plants were in­
fluenced by composition of their essential
oils (Oh et al. 1967, Oh et a1. 1968) . More
recently, another study reported the associa­
tion of chlorogenic acid with susceptibility
of different Douglas fir clones to browsing
by black-tailed deer (Radwan 1972) .
Fermentations of dry matter and cellulose
were not related to chemical composition of
the species. In addition, cellulose fermen­
tations were more closely related to prefer­
ence than those of dry matter. The cellulose
data, therefore, provided a good general in­
dication of species preference. Using a
manometric technique, Longhurst et a1.
( 1968) evaluated several plant species and
found a general positive correlation be­
tween fermentability and palatability. This
the species studied here. This was probably
due to comparisons of the same amounts of
oil regardless of actual concentrations oc­
curring in the different species. Clearly,
such comparisons which have been used in
all oil-rumen studies cannot yield accurate
information when more than one plant spe­
cies is evaluated, especially when the spe­
cies vary appreciably in their oil content.
For future in vitro studies, therefore, more
equitable comparisons should be based up­
on the oil content of the species under
investigation.
Effects of water and methanol extracts on
rumen microbes differed from one another
and from those of oils. Differences were ob­
viously due to dissimilarities in composition
of the three materials--in general, oils were
mostly terpenoids and extracts contained
various substances including nutrients such
as sugars and amino acids. It was not pos­
sible, therefore, to determine whether inhi­
bitions obtained with extracts resulted from
competition by rumen microbes for nutri­
ents over the cellulose substrate ( EI-Shazly
et al. 1961) or by direct action of digestive
inhibitors. Nevertheless, results demonstrate
how plant extracts might be used in evaluat­
ing different plant species. Indeed, water
extracts, as used in this study, provided con­
siderably better indication of species prefer­
relationship, however, has not always been
ence than oils. Most probably, the balance
consistent with deer (Ullrey et a1. 1967:454,
between chemical entities contained in wa­
Torgerson and Pfander 1971:227) or sheep
ter extracts played an important role in de­
(Van Soest 1965:842) .
Responses of rumen microbes to different
ciding this finding. Further work must be
levels of various ess ntial oils were gener­
evaluation of the usefulness of such extracts
ally similar to those reported earlier (Nagy
in ranking different plant species can be
et a1. 1964, Oh et a1. 1967, Oh et a1. 1968,
made.
carried out, however, before a complete
Oh et a1. 1970, Radwan 1972) . Although
differential effects of oils enabled us previ­
LITERATURE CITED
ously to distinguish between clones of
BISSELL, H.
JAMES.
Douglas fir ( Radwan 1972) , the technique
did not accurately rate preference among
J. Wildl. Manage. 38(1) :1974
B. HARRIS, H. STRONG, AND F.
1955 . The digestibility of certain
natural and artificial foods eaten by deer in
California. California Fish Game 4 1(1):57-78.
D.,
40
PLANT CHARACTERISTICS AND DEER FEEDING PREFERENCE
AND H. STRONG.
1955. The crude pro­
tein variations in the browse diet of California
deer. Ca1ifomia Fish Game 41(2):145-155.
BLOCK, R.J.,:E. L. DURRUU, AND G. ZWEIG. 1958.
A manual of paper chromatography and paper
electrophoresis. 2nd ed. Academic Press, Inc.,
New York. 710pp.
BROWN, E. R. 1961. The black-tailed deer of
western Washington.
Washington Dept.
Game, BioI. Bull. 13. 124pp.
CHAPMAN, H. D., AND P. F. PRATT. 1961. Meth­
ods of analysis for soils, plants, and waters.
Diy. Agric. Sci., Univ. of California, Riverside.
309pp.
CHURCH, D. C., AND R. G. PETERSEN. 1960. Effect
of several variables on in vitro rumen fern1en­
tation. J. Dairy Sci. 43(1):81-92.
COWAN, I. MeT. 1945. The ecological relation­
ships of the food of the Columbian black­
tailed deer, Odocoileus hemionus columbianus
(Richardson), in the coast forest region of
southern Vancouver Island, British Columbia.
Ecol. Ionogr. 15( 2):109-139.
CRAMPTON, E. W., AND L. A. MAYNARD. 1938.
The relation of cellulose and lignin content to
the nutritive value of animal feeds. J. NutI'.
15(4):383-395.
CROUCH, G. L. 1966. Preferences of black-tailed
deer for native forage and Douglas-fir seed­
lings. J. Wildl. Manage. 30(3):471-475.
1968. Forage availability in relation to
browsing of Douglas-fir seedlings by black­
tailed deer. J. Wildl. Manage. 32(3):542-553.
DIETZ, D. R., R. H. UDALL, AND L. E. YEAGER.
1962. Chemical composition and digestibility
by mule deer of selected forage species, Cacha
La Poudre range, Colorado. Colorado Dept.
Game and Fish Tech. Pub!. 14. 89pp.
EINARSEN, A. S. 1946. Crude protein detelmina­
tion of deer food as an applied management
technique. Trans. N. Am. Wildl.· Conf. 11:
309-312.
EL- SHAZLY , K., B. A. DEHORlTY, AND R. R. JOHN­
SON. 1961. Effect of starch on the digestion
of cellulose in vitro and in vivo by rumen mi­
croorganisms. J. Anim. Sci. 20( 2):268-273.
FISKE, C. H., AND Y. SUBBAROW. 1925. The
colorimetric detern1ination of phosphorus. J.
BioI. Chern. 66( 2):375-400.
GASTLER, G. F., A. L. MOXON, AND \IV. T. McKEAN.
1951. Composition of some plants eaten by
deer in the Black Hills of South Dakota. J.
Wildl. Manage. 15(4): 352-357.
HAS SID, W. Z. 1937. Determination of sugars in
plants by oxidation with ferricyanide and ceric
sulfate titration. Ind. Eng. Chern. (Anal. ed.)
9( 5):228-229.
HELL1>1ERS, H.
1940. A study Of monthly varia­
tions in the nutritive value of several natural
---,
I!
I
I
'"
!
I
1
I
•
RaduJan alld Crouch
winter deer foods. J. Wildl. Manage. 4( 3):
315-325.
HORWITZ, W., ed. 1970. Official methods of
analysis of the Association of Official Analyti­
cal Chemists. 11th ed. Assoc. Off. Anal.
Chern., Washington, D. C. 1015pp.
JOSLYN, M. A., AND J. L. GOLDSTEIN. 1964.
Astringency of fruits and fruit products in rela­
tion to phenolic content. Adv. Food Res. 1 3:
179-217.
KUTCHES, A. J., D. C. CHURCH, AND F. L. DURYEE.
1970. Toxicological effects of pesticides on
rumen function in vitro. J. Agric. Food Chem.
18(3):430-433.
LONGHURST, W. M., H. K. OH , M. B. JONES, AND
R. E. KEPNER. 1968. A basis for the palat­
ability of deer forage plants. Trans. N. Am.
Wildl. Nat. Resour. Conf. 33:181-189.
MAYNARD, L. A., AND J. K. LOOSLI.
1962. Ani­
mal nutrition. 5th ed. McGraw-Hill Book
Company, Inc., New York. 533pp.
McDOUGALL, E. I. 1948. Studies on ruminant
saliva. I. The composition and output of
sheep's saliva. Biochem. J. 43(1):99-109.
MILLER, F. L.
1968. Observed use of forage and
plant communities by black-tailed deer. J.
Wild!. vlanage. 32( 1): 142-148.
MITCHELL, H. L., AND N. W. HOSLEY. 1936. Dif­
ferential browsing by deer on plots variously
fertilized. Black Rock For. Pap. 5:24-27.
NAGY, J. G., H. W. STEIl';}lOFF, AKD C. 11'1. \VARD.
1964. Effects of essential oils of sagebrush
on deer rumen microbial function. .J. ·Wild!.
Manage. 28( 4) :785-790.
OH, H. K., M. B. JOXES, AKn \\'. M. LONGHUHST.
1968. Comparison of rumen microbial inhibi­
tion resulting from yarious essential oils iso­
lated from relatively unpalatable plant species.
Appl. Microbiol. 16(1) :39-4,1.
--- , T. SAKAI, M. B. Jmms, AND W. M. LOKG­
HURST.
1967. Effect of various essential oils
isolated from Douglas-fir needles upon sheep
and deer rumen microbial activity. Appl. Mi­
crobiol. 15(4):777-784.
OH, J. H., M. B. JONES, W. M. LONGHURST, AND
G. E. CONKOLLY. 1970. Deer browsing and
rumen microbial femlentation of Douglas-fir
as affected by fertilization and growth stage.
For. Sci. 16(1):21-27.
POWELL, J.., AND T. \IV. Box. 1966. Brush man­
agement influences preference values of south Texas woody species for deer and cattle. J. Range Manage. 19(4):212-214. RADWAN, M. A. 1972. Differences between Doug­
las-fir genotypes in relation to browsing pref­
erence by black-tailed deer. Can. J. For. Res.
2(3):250-255.
---, AND D. L. CA1>IPBELL.
1968. Snowshoe
hare preference for spotted catsear flowers in
J. Wildl. Manage. 38(1) :1974
PLANT CHARACTERISTICS AND DEER FEEDING PREFERENCE
western Washington. J. Wild!. Manage. 32
(1):104-108.
REYNOLDS, H. G. 1967. Chemical constituents
and deer use of some crown sprouts in Arizona
. chaparral. J. For. 65(12):905-908.
SHORT, H. L., D. R. DIETZ, AND E. E. REMMENGA.
1966. Selected nutrients in mule deer browse
plants. Ecology 47(2): 222-229.
SMITH, D., G. M. PAULSEN, AND C. A. RAGUSE.
1964. Extraction of total available carbohy­
drates from grass and legume tissue. Plant
Physio\. 39(6) : 960-962.
SNEDECOR, G. W. 1961. Statistical methods ap­
plied to experiments in agriculture and biology.
5th ed. Iowa State University Press, Ames.
534pp.
SWAIN, T., AND W. E. HILLIS. 1959. The phenolic
constituents of P(unllS domestica. 1. The quan­
titative analysis of phenolic constituents. J.
Sci. Food Agric. 1O(1):63-B8.
SWIFT, R. "V. 1948" Deer select most nutritious
forages. J. Wild!. Manage. 12(1): 109-110.
TABER, R. D., AND R. F. DASMANN. 1958. The
•
Radwan and Crouch
41
black-tailed deer of the chaparral. Its life
history and management in the north coast
range of California. California Dept. Fish
Game, Game Bull. 8. 163pp.
TORGERSON, 0., A ND "V. H. PFANDER. 1971. Cel­
lulose digestibility and chemical composition
of Missouri deer foods. J. Wild\. Manage. 35
( 2):221-231.
ULLREY, D. E., W. G. YOUATT, H. E. JOHNSON,
L . D. FAY, AND B. E. BRENT. 1967. Digest­
ibility of cedar and jack pine browse for the white-tailed deer. J. Wildl. Manage. 31( 3): 448-454. VAN SOEST, P. J. 1963. Use of detergents in the
analysis of fibrous feeds. II. A rapid method
for the determination of fiber and lignin. J.
Assoc. Off. Agric. Chern. 46(5):829-835.
. 1965. Symposium on factors influenc­
ing the voluntary intake of herbage by rumi­
nants: Voluntary intake in relation to chemi­
cal composition and digestibility. J. Anim. Sci.
24( 3) : 8 34-843.
---
Accepted 12 October 1973.
Repz'oduced from THE JOURNAL OF WILDLIFE MANAGEMENT,
Vol. 38, No. 1, January 1974,
by the Forest Service, U.S. Department of Agriculture,
for official use
J. Wildl. Manage. 38(1) :1974 GPO 990·585
About this file: This file was created by scanning the printed publication. Some mistakes introduced by scanning may remain.