Deer may eat some grass but it's not very common. Most times people see them eating in a yard or golf course and think the are eating grass but that's not the case most times. They are picking out other plants like clover instead. Read this study...is interesting

Wildlife Management Handbook V-A 1

White-tailed Deer Competition with Goats, Sheep, Cattle

and Exotic Wildlife

W. E. Armstrong

Texas Parks and Wildlife Department

Hunt, Texas

Deer management is a relatively simple process. If Bites of plants that these animals consumed were recorded

you can grow deer foods, you can grow deer. By by species at weekly intervals over a year's period of time.

understanding deer food habits in relation to livestock food The same animals were then taken to a pasture that was

habits, the land manager can manipulate both livestock heavily grazed by cattle, sheep and goats at a rate of one

and deer numbers to grow more deer foods. AU per 8 acres. This pasture also contained white-tailed

Kinds of Forages

Today's rangelands are capable of producing a given

quantity of forage. This forage can broadly be divided into

three groups—forbs, browse and grass.

Forbs are best defined as broadleaved flowering

plants which most people call weeds. Although many are

perennials or biennials, most are annuals. Forbs are

generally seasonal with the greatest abundance being in

the spring, depending on local rainfall patterns. As a

group, they are high in protein. Examples of forbs are

velvet bundleflower, mat euphorhia, Dakota verbena and

knotweed leafflower.

Browse plants are shrubby or woody plants. They are

deeper rooted, more drought-resistant plants than most

forbs or grasses. As a group, they are lower in protein than

forbs. Examples of browse plants would be hackberry, live

oak, Texas oak and guayacan.

Grasses are those plants with long narrow leaves,

jointed stems, flowers in spikelets and a seedlike fruit.

Most of the major grasses are perennial and lower in

protein than forbs. Examples of grasses would be little

bluestem, Indiangrass, Texas wintergrass, johnsongrass

and fescuegrass.

Food Habits of White-Tailed Deer

and Domestic Livestock

Many food habit studies of white-tailed deer have

been conducted throughout the state of Texas. Several of

these studies were concerned not only with the food habits

of white-tailed deer, but also with the competitive effects

of domestic livestock on white-tailed deer food habits.

In the 196Os, the Kerr Wildlife Management Area

conducted a series of studies to determine the food habits

of white-tailed deer, domestic sheep, Angora goats and

cattle under three different grazing conditions. In this

study, a tame deer, sheep, goat and cow were taken to a

96-acre exclosure that had not been grazed by domestic

livestock or deer for a period of 6 years prior to the study.

deer. The experimental animals' food habits were recorded

in this pasture. The third pasture to which the animals

were taken contained only white-tailed deer. Deer

numbers in this pasture were at saturation level. Bites of

food by these animals were also recorded in this pasture.

The results of these bite studies were then totaled.

Comparisons were made between the heavily grazed

pasture, the deer-only pasture and the exclosure. In the

exclosure, when given a free choice of what it wanted to

eat, the white-tailed deer preferred forbs when they were

available. As forbs became unavailable in the summer and

fall, the white-tailed deer began to shift its diet to browse.

Grass never accounted for more than 15 percent of the

deer's diet, even in the heavily grazed pasture where forbs

and browse were in short supply and competition for food

was severe.

Just as deer were primarily forb eaters, so were sheep.

But as forbs began to disappear in the summer and fall, the

sheep began to eat both grass and browse. In the heavily

grazed pasture, grass accounted for the major portion of

the sheep's diet.

Goats were primarily browsers, taking some forbs

when available. In the exclosure, when given a free choice

of plant species, goats did not consume a large quantity of

grass. In the heavily grazed pasture, goats did consume a

larger quantity of grass than deer but were still primarily

browse eaters.

Cattle in the ungrazed exclosure preferred grass,

taking some forbs and browse. During the winter, cattle on

the Kerr Area took a surprisingly large amount (73

percent) of liveoak, which is an evergreen. In the heavily

grazed pasture, cattle were primarily grass eaters.

Analysis of the bite study data suggests that cows,

sheep and goats can survive on three classes of forage,

whereas the white-tailed deer readily utilizes only two

classes of forage (forbs and browse). This is not to say that

deer do not eat grass. Bite studies on the Texas

Agricultural Experiment Station at Sonora indicate that

deer will utilize as much as 20 percent grass in their

V-A 2 Wildlife Management Handbook

diets on those occasions when grass is in a "lush" or rapid 3. a pasture that was being grazed by domestic

state of growth. On the Experiment Station, this was livestock at a rate of one AU per 16 acres.

primarily johnsongrass and cane bluestem, following 11

inches of rain in July. However, grasses only accounted for

8 percent of the deer's total yearly diet. As grasses matured

and became more coarse, deer began to avoid them.

Deer Digestion

Studies of deer digestion by Short indicate that deer

do not digest coarse fibered plants as readily as low

fibered plants. In addition, it has also been determined that

browse plants high in oil content inhibit the "fermentation"

process in deer. Domestic livestock are more efficient in

digestion of these plants. It is not unusual to find deer

which have "starved" with a paunch full of grass.

Effects of Competition for Food

on White-tailed Deer

Evidence of the effects of competition by domestic

livestock on white-tailed deer were also studied on the

Agricultural Experimental Ranch at Sonora. Deer

populations were monitored on pastures that were

continuously stocked at heavy, moderate and light grazing

rates. Deer numbers were greatest in the lightly stocked

pastures as opposed to the heavily stocked pastures. In

pastures stocked with goats, sheep or cattle, the fewest

deer were found in the heavily grazed sheep pasture (one

deer to 40 acres) as well as the goat pasture (also one deer

to 40 acres). Light grazing with sheep only produced one

deer per 20 acres. Light grazing with goats produced one

deer per 32 acres. One deer per 15 acres and one deer per

7.3 acres were recorded in the heavily and lightly stocked

cattle only pastures, respectively.

The deer were avoiding those areas in which domestic

livestock were depleting browse and forb populations.

Classes of livestock coupled with stocking rates influence

forb and browse production. This in turn influences deer

carrying capacity.

Food Habits of Exotics

Food habit studies have also been conducted with

axis, silo and fallow deer, as well as with blackbuck

antelope and aoudad sheep. These were conducted on the

Kerr Area and the results are in the process of being

published. The study utilized the animal bite method. Food

habits were studied in three different pastures under three

different grazing conditions. Grazing conditions were:

1. a non-grazed pasture in which no livestock or

deer had been grazed for a minimum of 15 years

prior to the study,

2. a pasture containing white-tailed deer only (at

carrying capacity), and

Results of these studies indicate that these major

exotics can effectively utilize three classes of forage. As

far as food habits are concerned, they are either "sheep" or

"goats" in deer clothing. That is, they prefer forbs or

browse but are able to shift their diets to grass without

apparent signs of malnutrition.

Effects of Exotic Competition

As an extension of this study, six sika deer and six

white-tailed deer were placed in a 96-acre pasture. No

hunting or predation occurred in the pasture. Sika deer and

white-tailed deer increased to 27 and 18, respectively, on

96 acres before competition for food became severe.

White-tailed deer at this time decreased to six animals.

Sika deer increased to 32 during the same period. By the

ninth year of study, there were 59 sika deer and no whitetailed

deer alive in the pasture.

A similar study was carried out with axis deer and

white-tailed deer with similar results. Populations of axis

and white-tailed deer reached peaks of 16 axis and 15

white-tailed deer before competition for forbs and browse

became severe. White-tailed deer populations decreased

to three animals at the end of the study while axis

populations were at 16 animals in 96 acres.

In both cases, exotics and white-tailed deer depleted

a food supply causing losses in white-tailed deer. Exotics

shifted their diets to grass, survived and reproduced. By

maintaining grazing pressure on white-tailed deer foods,

exotics depleted white-tailed deer foods from the pasture.

Loss of foods resulted in losses of white-tailed deer.

Conclusions

Conclusions drawn from the studies conducted on

food habits of white-tailed deer, domestic livestock and the

major exotics found in Texas suggest that white-tailed

deer are able to utilize a more narrow range of plants

(plants low in cellulose fiber or low in oils) than either

domestic livestock or exotics.

Sheep are competitive with white-tailed deer primarily

for the higher protein forbs, while goats compete

with deer for the more stable drought-resistant browse.

Cattle on properly stocked ranges are the least competitive

with white-tailed deer. No conclusions were drawn on the

effects exotics have on domestic livestock although it

seems obvious that many exotics would be highly

competitive with domestic livestock, especially goats.

Our ranges only produce a given quantity of forbs and

browse. If a given range will produce enough

Wildlife Management Handbook V-A 3

forbs or browse to produce 100 animals and if 90 of them result will be small, stunted deer with poor antler

are goats and 10 are white-tailed deer, then the 10 white- development, low fawn production and frequent die-offs.

tailed deer will have adequate diets and grow into healthy

animals. If 90 are white-tailed deer and 10 are goats, then

all will be healthy animals.

The problem comes when we overstock our ranges support a given number of animals. By analyzing the

with domestic livestock as well as white-tailed deer. competition for forages available and adjusting both

White-tailed deer, which are not as competitive as the domestic livestock, exotic and native deer numbers to this

domestic livestock, will suffer from malnutrition. The forage, we can produce healthy, good quality, high

In conclusion, our ranges are capable of producing a

given quantity of forage comprised principally of forbs,

browse and grasses in varying amounts. This forage will

producing animals.

Appendix I

The following is a list of some of the more preferred food items in the white-tailed deer diet. Since browse plants are

the more stable range plant in the deer's diet (not as weather related as forbs), browse plants are good indicators of deer

range. Adequate forb production should release grazing pressure on browse. Heavy dependence on browse in the spring and

early summer indicates an overpopulation of forb or browsing animals. This, in turn, inhibits good deer production.

Selected South Texas forage plants:

Pricklypear cactus

Mesquite mast

La coma

Granjeno

Catclaw acacia

Desert lantana

Lime pricklyash

Guayacan

Allthorn castela

Texas silverleaf

Texas colubrina

Perennial lazy daisy

Kidder dosedaisy

Dayflower sp.

Prostrate euphorbia

Selected Rolling Plains forage plants:

Mistletoe

Indianmallow

Pricklypear

Woollybucket bumelia

Common mesquite (mast)

Spreading sida

Gray goldaster

V-A 4 Wildlife Management Handbook

Appendix I (continued)

Selected East Texas forage plants:

Alabama supplejack

White ash

Yaupon

Blackberry

Greenbriar

Kentucky virburnum

Georgia holley

Honey locust

Selected Edwards Plateau forage plants:

Texas oak (Spanish oak)

Liveoak

Post oak

White shin oak

Woollybucket bumella

Hackberry

Greenbriar

Elm

Flameleaf sumac

Grape sp.

Velvet bundleflower

Knotweed leafflower

Prickly lettuce

Southwest bedstraw

Mat euphorbia

Four-o'clock sp.