UNP-0070 Nutritional Management of Meat Goats
Nutritional Management of Meat Goats
UNP-0070, November 2005,
Julio E. Correa,
Extension Animal Scientist, Associate Professor, Food and
Animal Sciences, Alabama A&M University
Introduction
The meat goat sector is currently the largest of the goat industry
in the United States. The increased demand for goat meat is a
result of a rise in immigrant and ethnic group populations. Primarily
located in the Southwest and Southeast, the meat goat sector has
shown promise of expansion over the past decade, and it continues
to emerge as an alternative animal production system for small
and limited resource farmers.
Meat goat breeds in the United States include the Spanish and
the Boer. The Spanish goat, sometimes called brush or meat goat,
is a mixed breed with widely varying colors and markings. Though
relatively small (75 pounds at maturity), Spanish goats are highly
prolific and can survive with little care. The Boer goat, originally
from the Eastern Cape Province of South Africa, is also prolific
with a kidding rate of 200 percent being common. Because of their
extended breeding season, Boer goats produce three kiddings every
two years. Boer goats, introduced into the United States in 1993,
are white with a red-horned head and Roman nose. Mature bucks
weigh 240 to 380 pounds and mature does weigh 200 to 265 pounds.
Because no market exists for grain-finished goats, producers
in the United States take advantage of low-quality forages and
roughages to provide a product in high demand. In fact, one of
the advantages of goat meat production is that farmers can produce
goats without intensive feeding strategies or systems because
of the goats' unique ability to digest large quantities of fiber
or roughage.
Boer goats are white with a red-horned head and
Roman nose. Mature Boer bucks weigh 240 to 380 pounds. |
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![](Boer.jpg) |
Digestive System
Mature goats are ruminant animals. Their digestive tracts,
which are similar to those of cattle, sheep, and deer, consist
of the mouth, esophagus, four stomach compartments, small intestine,
and large intestine. Following is a brief description of the anatomy
and physiology of the mouth and the stomach compartments of goats.
The digestive tract of goats.
- Esophagus
- Rumen (paunch)
- Reticulum (honeycomb)
- Omasum (manyplies)
- Abomasum (true stomach)
- Small Intestine
- Cecum
- Large Intestine
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![](Goatnumbers.gif) |
Mouth: Like other ruminant animals, goats have no upper
incisor or canine teeth. They depend on the dental pad in front
of the hard palate, lower incisor teeth, lips, and tongue to take
food into their mouths.
Rumen: This is the largest of the four stomach compartments
of ruminant animals. The capacity of the rumen of goats ranges
from 3 to 6 gallons depending on the type of feed. This compartment,
also known as the paunch, contains many microorganisms (bacteria
and protozoa) that supply enzymes to breakdown fiber and other
feed parts. The conversion of the cellulose of feeds to volatile
fatty acids (acetic, propionic, and butyric acids) is the result
of microbiological activities in the rumen. These volatile fatty
acids are absorbed through the rumen wall and provide up to 80
percent of the total energy requirements of the animal. Microbial
digestion in the rumen is the basic reason why ruminant animals
effectively utilize fibrous feeds and are maintained primarily
on roughages.
Rumen microorganisms also convert components of the feed to
useful products such as the essential amino acids, the B complex
vitamins, and vitamin K. Finally, the microorganisms themselves
are digested farther in the digestive tract.
Reticulum: This compartment, also known as the hardware
stomach or honeycomb, is located just below the entrance of the
esophagus into the stomach. The reticulum is part of the rumen
separated only by an overflow connection, the rumino-reticular
fold. The capacity of the reticulum of goats ranges from 0.25
to 0.50 gallons.
Omasum: This compartment, also known as the manyplies,
consists of many folds or layers of tissue that grind up feed
ingesta and remove some of the water from the feed. The capacity
of the omasum of goats is approximately 0.25 gallons.
Abomasum: This compartment is more often considered
the true stomach of ruminant animals. It functions similarly to
human stomachs. It contains hydrochloric acid and digestive enzymes
that breakdown feed particles before they enter the small intestine.
The capacity of the abomasum of goats is approximately one gallon.
As partially digested feed enters the small intestine, enzymes
produced and secreted by the pancreas and small intestinal mucosa
further breakdown feed nutrients into simple compounds that are
absorbed into the bloodstream. Undigested feed and unabsorbed
nutrients leaving the small intestine pass into the large intestine.
The functions of the large intestine include absorption of water
and further digestion of feed materials by the microorganisms
present in this area. The 100-foot-long intestinal canal of goats
has a capacity to hold 3 gallons.
When a goat kid is born, the rumen is small and the abomasum
is the largest of the four stomach compartments. The rumen of
a goat kid represents about 30 percent of the total stomach area,
while the abomasum represents about 70 percent. Hence, digestion
in the goat kid is like that of a monogastric animal. In the suckling
goat kid, closure of the esophageal groove ensures that milk is
channeled directly to the abomasum, instead of entering the rumen,
reticulum, and omasum. When the suckling goat kid starts to eat
vegetation (first or second week of life), the rumen, reticulum,
and omasum gradually develop in size and function.
Nutrients
Energy: Age, body size, growth, level of activity, pregnancy,
lactation, and environment all affect the energy requirements
of goats. Carbohydrates and fats supply most of the energy requirements
of the animal body. Much of the goat's energy comes from the breakdown
of cellulose in roughages and the breakdown of starch and fat
in concentrates. Energy deficiency in goats results in reduced
growth or weight loss, reduced reproductive performance, reduced
milk or fiber production, and reduced resistance to infectious
diseases and internal parasites.
Protein: Protein consists of amino acids that are the
basic units of all body cells. The goat's body requires protein
for growth, reproduction, milk production, disease resistance,
and general maintenance. Mature goats, like other ruminant animals,
rely on rumen microorganisms to synthesize essential amino acids.
Rumen microbes can utilize either nitrogen (N) of feed origin
or nonprotein nitrogen (NPN) to synthesize amino acids and protein
to meet the requirements of the host animal. Microbial protein
and undigested feed protein reaching the small intestine are broken
down to amino acids that are absorbed and utilized by goats. Protein
deficiencies in the diet of goats result in depleted stores in
muscles, retarded fetal development, low birth weights, reduced
growth, and depressed milk production.
Vitamins: Vitamins are organic compounds required in
small amounts by the goat's body. Because all the B vitamins and
vitamin K are synthesized by microorganisms in the rumen and vitamin
C is synthesized in body tissues, mature goats require only dietary
sources of the fat-soluble vitamins A, D, and E. During the grazing
season, goats can obtain sufficient fat-soluble vitamins from
green pastures and plenty of sunlight. Goats can also store an
adequate supply of these vitamins to maintain production for 3
to 4 months.
Symptoms of vitamin A deficiency are associated with abnormal
bone development, low resistance to infections, night blindness,
and birth of abnormal kids. Vitamin D deficiency results in bone
abnormalities, such as rickets, in kids. Vitamin E, a biological
antioxidant, is added to the diet of young nursing kids to prevent
nutritional muscular dystrophy. Selenium, which has a sparing
effect on the vitamin E requirement, is also effective in preventing
nutritional muscular dystrophy in young kids.
Minerals: Many minerals (inorganic elements) are required
by the goat. The major or macrominerals of concern are common
salt (NaCl), calcium (Ca), phosphorus (P), magnesium (Mg), potassium
(K), and sulfur (S). The trace or microminerals involved in goat
nutrition are cobalt (Co), copper (Cu), molybdenum (Mo), fluorine
(F), iodine (I), iron (Fe), manganese (Mn), selenium (Se), and
zinc (Zn). In goat feeding, most minerals are usually added to
mixed feeds. It is also recommended that the Ca: P ratio be kept
at approximately 2:1.
Specific information on the symptoms of mineral deficiencies
and toxicities in goats is scarce. However, these symptoms appear
to be similar to those in sheep. Some symptoms of mineral deficiencies
in goats include reduced feed intake, depressed milk production,
and retarded growth and abnormal bone development in young kids.
Water: Water is the least expensive nutrient and the
largest component of live plant and animal tissue. Environmental
factors, age, growth, pregnancy, lactation, and level of activity
affect the water requirements of goats. Goats obtain water from
their feed, as well as from drinking water, snow, and dew. Because
water carries out important body functions, an adequate supply
of fresh, clean water is critical to goats during their entire
life cycle.
For more information on the recommended dietary nutrient allowances,
obtain a copy of the National Research Council report titled Nutrient
Requirements of Goats, Number 15, 1981. This NRC report can be
obtained from the National Academy Press, 2101 Constitution Avenue,
N.W., Washington, D.C. 20418.
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Goats put the bite on brush. (Photo courtesy
of the Forest Service, USDA) |
Feedstuffs
Goats prefer to eat browse (brushy plants) and can efficiently
digest coarse, fibrous feeds. Hence, goats will consume and effectively
utilize a wide variety of woody and weedy plant species found
on ranges.
Meat goats are raised primarily on unimproved pastures and
rangelands. Meat goats do not need extra feed if they are grazing
on land areas with a variety of brush, weeds, and grass. Additional
feed, however, may be needed in periods of drought or in winter.
The types and amounts of supplemental feed are also dictated by
the functions of the goats.
Aside from pasture and brush lands, dry roughages and forages
are the most economical feeds for meat goats. The use of good
quality hays as supplemental feed for grazing meat goats can compensate
for extremely poor pasture or range conditions while supporting
the profit margins. Legume hays such as alfalfa and clover are
preferred to grass hays, such as bromegrass, orchardgrass, and
timothy, because they are much higher in protein and a variety
of minerals. Good quality legume hay or a mixed legume and grass
hay provide an excellent source of highly digestible nutrients.
The cutting date is the single most important factor affecting
hay quality. As the stage of maturity of the forage crop increases,
the protein content decreases and the fiber content increases.
Good quality hays are those that have been cut earlier and have
more leaves and tender stems. If pasture or range conditions become
adverse and supplemental hay is of poor quality, provide supplemental
concentrates for maximum performance. Cereal grains such as corn,
oats, barley, and wheat, are the common energy ingredients of
concentrate mixtures for goats. Oil meals such as cottonseed meal
and soybean meal are probably the most widely used sources of
protein for goats. Commercial supplements containing other nutrients
such as minerals in addition to protein may be preferable to one
of the oil meals.
Because the cost of grain and meal mixtures is usually high,
feeding supplemental concentrates to meat goats is advised only
during critical periods of their life cycle. The profit margins
do not support intensive feeding strategies using expensive feeds.
Goats prefer woody and weedy plant species. (Photo
courtesy of the Agricultural Research Service, USDA) |
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![](woodyweedy.jpg) |
Feeding
Kids: Newborn kids should be allowed to nurse their
dams to obtain colostrum (first milk). Colostrum contains antibodies
that protect young kids against diseases. At birth, kids are able
to absorb these antibodies effectively. However, the ability to
absorb colostral antibodies decreases within the first 36 to 48
hours of life. To greatly increase the chances of survival, kids
should receive colostrum immediately after birth.
Early forage consumption will lead to early rumen development.
To encourage young kids to consume solid feed at about 2 to 3
weeks of age, fine hay can be offered. Young kids receiving adequate
amounts of milk from their dams do well on good pasture or range.
If pasture or range conditions are poor, however, kids should
have access to good quality hay plus about 0.75 pounds of a grain
mixture daily.
Kids weaned at about 3 to 4 months should be suitable for slaughter
off grass. With the increased population of immigrant and ethnic
groups, particularly Hispanics, the cabrito, or weaned kid, has
become very popular.
![](babygoat.jpg) |
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Young kids receiving adequate amounts of milk
from their dams do well on good pasture or range. |
Replacements: After 4 to 6 months of age, replacement
does and bucks can do well on good pasture or good quality hay
alone. A daily allotment of 0.5 pounds of a concentrate mixture
should lead to ample growth. If the pasture or hay is of poor
quality, however, replacement animals may require 1 to 1.5 pounds
of concentrate per day. If properly fed, replacement goats will
be large enough to breed as yearlings.
Does: Feeding does during a dry period is important
for development of the unborn kids and for obtaining proper body
condition of the does for adequate nutrition of the newborn kids.
The unborn kid develops 70 percent of its birth weight during
the dry period (last 6 weeks of pregnancy). During this period,
does can be maintained on good range or pasture, with only mineral
supplementation needed, particularly salt and phosphorus. However,
if grass is short, a good quality mixed legume and grass hay are
good for feeding. If pasture and hay are poor quality, provide
supplemental feeds such as goat range cubes at the rate of 0.5
to 0.75 pound per head per day. A doe should be in good flesh
but not fat at time of kidding.
Lactating does on good quality range or pasture may require
daily supplementation of 0.5 to 0.75 pounds of grain mixture or
range cubes that contain approximately 20 percent protein. If
the quality of range feed is poor, a higher protein supplement
may be needed at the rate of 0.25 pound per head per day.
If grass is short, a good quality mixed legume
and grass hay is good for feeding. |
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![](goat12.jpg) |
Bucks: Young bucks should be fed in the same manner
as replacement does, but they will require more feed because of
their size. Bucks that are not breeding can do well on good pasture
or good quality hay alone. Supplemental grain or concentrates
should be fed according to the condition of the pasture and the
bucks. During the breeding season, however, grain or supplement
should be provided at the rate of 0.3 to 0.5 pound per head per
day. If the bucks become too fat or inactive, grain can
be withdrawn.
Rotational grazing should be practiced to improve the pastures
and help control internal parasites. Discard moldy feeds, and
make any changes in the diet gradually.
Nutritional Diseases
Enterotoxemia: This condition, also known as overeating
disease, is a toxic reaction to Clostridium perfringens types
C and D. Enterotoxemia is caused by excessive feeding of concentrates
to animals not accustomed to such feeds and sudden access or change
to highly palatable feed. All kids should be given a toxoid vaccination
at about one month of age, followed by a second dose two weeks
later and booster doses every year. All does should be given a
yearly booster toxoid about 3 to 4 weeks before kidding.
Urolithiasis: This condition, also known as urinary
calculi, is characterized by the formation of inorganic masses,
known as calculi, in any part of the urinary tract. When a high
phosphorus level develops in the blood and urine, magnesium and
ammonium phosphate precipitate to form a calculus. This calculus
can pass easily through the urethra of does but not so easily
through the urethra of bucks. Obstruction to the outflow of urine
often results in rupture of the urethra or bladder. Keep the calcium-phosphorus
ratio at approximately 2:1.
Ketosis: This condition, also known as pregnancy disease,
is characterized by an increased concentration of ketone bodies
in the body tissues and fluids. Ketosis occurs when the energy
requirements are met by way of lipid metabolism within the liver,
resulting in an increased production of ketones (acetoacetic acid
and b-hydroxybutyric acid). The condition, which usually appears
in the last 30 days of pregnancy, is caused by a decreased blood
glucose level due to increasing fetal demand and undernourishment.
Ketosis rarely occurs in meat goats. Nevertheless, as a form of
prevention, make certain that goats have clean, fresh water at
all times.
References
Church, D. C. (1993). The ruminant animal:
Digestive physiology and nutrition. Prospect Heights, IL: Waveland
Press, Inc.
Ensminger, M. E. (2002). Sheep and goat science
(6th ed.). Danville, IL: Interstate Publishers, Inc.
Gillespie, J. R. (1998). Animal science. Albany,
NY: Delmar Publishers.
Shapiro, L. S. (2001). Introduction to animal
science. Upper Saddle River, NJ: Prentice-Hall, Inc.
Taylor, R. E. and T. G. Field. (2001). Scientific
farm animal production: An introduction to animal science (7th
ed.). Upper Saddle River, NJ: Prentice-Hall, Inc. Special thanks to Jean Hall Dwyer, Extension
Communications Specialist, for the drawing "The digestive
tract of goats."
For more information, contact your county Extension office. Visit http://www.aces.edu/counties or look in your telephone directory under your county's name to find contact information.
Issued in furtherance of Cooperative Extension work in agriculture and
home economics, Acts of May 8 and June 30, 1914, and other related
acts, in cooperation with the U.S. Department of Agriculture. The Alabama
Cooperative Extension System (Alabama A&M University and Auburn
University) offers educational programs, materials, and equal
opportunity employment to all people without regard to race, color,
national origin, religion, sex, age, veteran status, or disability.
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