As previously indicated, meat goats must depend almost solely on forages to meet
their nutritional needs if they are to be economically viable. Forages commonly utilized
are grasses, browse, weeds, forbs, and, seasonally, small grains, hays, and silages.
With rare exception, all these plants contain usable protein, energy, minerals and
vitamins in useful measure. It should be emphasized that goats actually prefer to
browse on brush rather than on grass, commonly taking about 60% browse and 40% grass
in mixed plant populations.
Since goats are particularly adept at selecting the most nutritious plants (and within
plants, the most nutritious portions), they may do reasonably well on grazing areas
considered poor to fair by man and cow alike if, of course, the amount of herbage
is adequate. Like other animals, however, goats respond quite favorably to increased
quality/quantity of feedstuffs. Public perceptions to the contrary, goats cannot
in fact economically turn low quality vegetative matter into meat and milk. Successful
managers know this; novices may not last long enough to learn it.
Composition of Forages
The composition of forages commonly eaten by goats varies widely. For information
on their composition, see Table 1. In practical grazing situations, goats consume
an ever-changing combination of these feedstuffs with selection reflecting seasonal
availability's and relative palatability's. The daily dry matter intakes of mature
goats range between 3-5% of body weight, occasionally higher. The actual quantity
of feedstuffs eaten per day will be influenced by physiological needs, palatability,
dry matter content, digestibility, and rate of passage from the rumen.
As one compares the protein, total digestible nutrients (TDN) and mineral values
of forages shown in Table 1, several points become apparent. First, legumes such
as alfalfa, cowpea, lespedeza and vetch are higher in protein and calcium than non-legumes
such as bermudagrass, bluestems, johnsongrass, sudangrass and lovegrass, either as
grazing or as hay crops; their TDN values, however, are fairly comparable. Secondly,
forages consumed by grazing, due to animal selection, are higher quality then hay
from the same field. Thirdly, roughages are relatively higher in calcium than in
phosphorus, while feed grains generally have more phosphorus than calcium. The mineral
needs of meat goats are such that a need for phosphorus supplementation is much more
likely than a need for extra calcium except perhaps during early lactation. Fourthly,
protein and TDN levels of individual roughages are dependent on several variables,
among them: age of the plant, soil fertility, rainfall, harvesting procedures, storage
conditions, and variety. However, maturity (age) of the forage crop is the single
greatest influence of quality.
Note that the protein and TDN contents of most browse plants are quite comparable
with those of more traditional southern forages. As noted before, goats are particularly
adept at selecting the most palatable parts of browse plants; fortunately, palatability
is generally associated with lower fiber, higher protein and increased digestibility.
Spring growth is typically the most palatable and therefore has the highest nutrient
value. Browse plants, particularly those grown in forested areas, may produce significantly
less quantity of forage per acre than native or improved pastures, but initial quality
of browse may be a compensating consideration. Pine and oak forest understory brush
is a variable mixture of plants, many of which are good sources of protein and TDN
for meat goats.
To evaluate the usefulness of pasture and browse plants for meat goat enterprises,
it would be helpful to know their average annual yields per acre in addition to their
protein and TDN content. Unfortunately, such data are scarce and, in any case, yields
can vary very widely across time and place. Thus, it is very difficult to answer
basic management questions concerning grazing density (head/acre), optimum grazing
pattern (frequency and duration), and needs for supplemental feeding (protein, energy
and minerals). For novice goat owners, the experiences of goat-owning neighbors are
likely to be the best guidelines available.
Several rules of thumb for grazing can be typically applied, e.g., 6 mature goats
equal 1 cow on native or improved pastures or 10 goats equal 1 cow on browse or understory
brushy areas. As a practical matter, goat owners have rotationally grazed 10-12 goats
per acre of good wheat pasture and 12-15 (occasionally more) goats per acre on alfalfa
pastures. Producers have also reported grazing densities of 2-3 head per acre on
good native pastures and 1-2 head per acre of brushy fields (go-back land). Texas
rangelands typically require 3 to 4 acres per goat. These general stocking rates
emphasize the advantage of the humid southeast over the traditional areas of goat
Opinions are many and varied when discussing forage quality. The use of many different
terms used in describing forage quality further complicates this topic, especially
when discussing hay. For example, the color of a hay bale is frequently suggested
as an indicator of the quality of the hay as a feedstuff, but hay color has almost
no relationship to animal performance. This is the basis of an important fact: the
only true measure of forage quality is animal performance. Quality is important only
because it relates to animal performance.
Plants are made up of cells which are composed of cell walls and the contents within
the cell walls. The intracellular contents can be assumed to be near 100% digestible,
and digestibility does not change as the plant ages or grows. However, the chemical
makeup of cell walls does change as the plant grows. With aging, the fiber content
increases as a percent of the total plant. One complication is that there are several
types of fiber in plants, and they can vary greatly in digestibility. We use the
term increasing fiber to mean decreasing digestibility. Lignin, a fiber which is
basically indigestible, increases rapidly as the plant matures, particularly if it
begins reproductive growth.
Digestibility and Fiber Analysis
Digestibility can be viewed as a simple balance. If an animal is fed 10 pounds of
dry hay and four pounds of dry manure is produced, then the hay is 60% digestible.
The more digestible the forage, the more energy the animal obtains from the forage.
Currently most laboratories chemically determine the percent Acid Detergent Fiber
(ADF) and/or Neutral Detergent Fiber (NDF) to predict the energy content, TDN, metabolizable
energy, and/or net energy. NDF is a chemical estimate of the plant cell wall content
of a forage, and ADF is the cell wall content minus a cell wall component called
hemicellulose. As a plant matures the cell wall content increases as a percent of
the total plant cell. Plant cell walls are much less digestible than other parts
of the cell (intracellular contents), accordingly, as the cell wall component of
the cell increases with maturity, digestibility or quality of the forage decreases.
Thus, a forage with a low NDF or ADF content is higher in quality than one with a
high NDF or ADF content.
NDF is closely associated with total potential intake of the forage by an animal
while ADF is more closely related to digestibility of the forage. Therefore, both
values are used in predicting forage quality. Generally, most laboratories are using
NDF or ADF along with crude protein (CP) content to predict the overall quality of
forage samples. (A further quality factor in forages is the mineral content; this
aspect of quality is justifiably receiving more attention now than in the past.)
In general, as crude protein increases in a forage, livestock perform better (i.e.,
gain more weight, produce more milk, etc.). Thus, there is a reasonably good relationship
between forage quality and CP content. However, there are several problems with CP
as a predictor of animal performance. The first is the concept of first limiting
nutrient. Put simply, if an animal is deficient in energy, any amount of protein
in excess of requirements will do little to increase performance. The excess protein
can be converted to an energy source by the animal, but this is a very expensive
way to meet energy requirements. For example, if an animal has a crude protein requirement
of 12%, then a forage with 15% CP will do little to increase performance. As always
there are exceptions, which here concern some relatively difficult concepts involving
amino acid (the building blocks of protein) balance, rumen protein bypass, and the
relationship between higher protein and energy in forages. Although protein content
of forages is important, energy is often more of a concern.
Forage Quality Components
The next step in understanding forage quality is to achieve a more thorough understanding
of where the quality components of a forage are located in the plant. Previously,
forage quality was discussed as it related to chemical assays and plant cellular
components; but how does this relate to the whole plant and its parts? In general,
most usable nutrients in a plant, at least the aboveground parts, are in the leaves
rather than in the stem. This is true of both grasses and broadleaf species, such
as bermudagrass, tall fescue, alfalfa, clovers, dewberry/blackberry briars, honeysuckle,
and kudzu. Further, the older or more mature the plant, the more this is true. For
example, an alfalfa plant may analyze 31% ADF and 18% CP, but if the leaves and stems
were separated and analyzed, the leaves might be 23% ADF and 26% CP, while the stems
might be 37% ADF and 11% CP. This is the basis of the expression "manage for leafiness."
Therefore, the leaf/stem ratio of a forage is a reasonably good indicator of forage
quality. As the leaf/stem ratio increases (i.e., more leaf), the quality of the forage
Another factor involved in the feeding value of forage is the presence of anti-quality
components. We deal with many of these factors. The alkaloids produced by the endophytic
fungus of tall fescue are an example of one common anti-quality factor. Cattle performance
on tall fescue has often been poorer than what was predicted or expected based on
CP, TDN, etc., because of these alkaloids. Unfortunately the effect(s) of the tall
fescue endophyte on goats is unknown at present. Prussic acid and high nitrates in
summer annuals are more examples of anti-quality components, as is tannin content
in lespedeza. Therefore, when anti-quality components are present in a forage plant,
chemical assays to predict performance will usually overestimate the actual animal
Principles of Forage Management
"Manage for maximum leaf production to maximize forage quality." This rule of thumb
has been used for years. The principles that make this true are the bases for successful
grazing management. When used, this principle typically refers to forage grasses,
alfalfa, and other forage legumes such as lespedeza, clover, and birdsfoot trefoil.
However, the principle holds true for herbaceous forbs (weeds?) such as pigweed,
and brushy species such as blackberry briars.
Although goats are basically browsing animals, with preferred diets that are more
similar to deer than cattle or sheep, most goat production in the region will involve
grass based forage systems. For that reason the following discussion is based on
forage grasses, but the principles would be the same for forbs, legumes, and brushy
species. Only the location of the growing points and the way leaves form and grow
would be different.
The basic unit of forage production is a tiller, which is composed of the leaf blade
and sheath, stem, and seedhead. Tillers grow from the base up, and new leaves are
pushed up through surrounding sheaths of older leaves. The last leaf to emerge is
the flag leaf. The flag leaf precedes the emergence of the seedhead and is recognized
by its peculiar orientation, generally parallel to the ground. Most forage grasses
will produce between 5 and 10 leaves per tiller.
However, not all tillers become reproductive and produce a seedhead. Seedhead production
varies from species to species and seasonally within species. Tall fescue makes a
good example. Spring growth tillers, in response to cold temperatures and day length,
produce seedheads while fall growth tillers generally remain vegetative. Bahiagrass,
on the other hand, produces seedheads throughout its growing season (grievously so
in a home lawn).
Individual tillers are relatively short-lived. New tillers originate from growing
points or basal buds, a form of specialized plant tissue. If growing points are removed
by grazing or cutting, no more tillers are produced. Most of the forage grasses,
which have evolved under grazing, have basal buds at or slightly below the soil surface
while broadleaf plants, including many of the brushy browse species preferred by
goats have buds or growing points above ground.
Influence on Forage Quality
As the grass tiller changes from vegetative growth (leaf production) to reproductive
growth (seedhead production) the plant goes through rapid physiological changes.
Typically the plant attempts to place its seedhead up high so the seed can be dispersed
over a wide area - it is trying to reproduce itself. This is seen as the stem elongates,
called jointing in small grains. To hold the seedhead up the stem must become more
rigid, stronger, stiffer, and tougher. These words indicate that digestibility or
forage quality is decreasing. Fibers in the stem are being converted from more digestible
forms to lignin the most indigestible form. The process of fiber conversion is occurring
in all forages as they mature or age, even if the individual tiller does not become
If the tiller is producing a seedhead, several other changes are occurring in the
plant. Since all the leaves have already been produced by that tiller, the nutrients
to fill the seed have to come out of these leaves. These nutrients include protein,
minerals, and carbohydrates such as starches and sugars. The bottom, or oldest leaves
on the tiller are the first to have nutrients translocated to the seedhead. When
growing a grain crop, such as grain sorghum or wheat, we speak of the bottom leaves
as 'firing.' The leaves are, in fact, senescing or dying. The translocation of nutrients
is a great process when producing grain such as corn, wheat, or grain sorghum. Contrarily,
most grass seed (including grain sorghum and the small grains, and especially the
forage grass seeds) are relatively indigestible when fed whole and are generally
passed out the rear of the animal and are useful only to birds!
This gives us two management principles then to help keep forage quality high. One
is to harvest, graze or cut for hay, before seedheads are produced. The second is
to utilize the forage in a way that maximizes the leaf:stem ratio.
Influence on Forage Quantity
On a per tiller basis, forage quantity increases as new leaves emerge. In general,
maximum dry matter yield per tiller will occur sometime between flag leaf and flowering.
Keep in mind that the plant must flower before the seed is formed so we are talking
about the time before grain filling, soft dough, etc. However, maximum digestible
nutrient yield almost always occurs at flag leaf, or before seedhead emergence.
While yield per acre does increase as tillers grow, yield mainly increases as the
number of tillers per acre increases. New tillers are produced in response to several
actions. Generally, removal of top growth will stimulate tillering, as long as the
basal bud is protected. Proper fertility is needed for maximum tiller development
as is reasonable moisture.
Energy, in the form of carbohydrates stored in roots and the lower stem bases, is
used by the plant to develop new tillers. The new tiller uses this stored energy
to 'feed' its new growth until it develops enough leaf area to produce its own energy
or food. After that time the depleted energy in the roots is replaced. Depleted root
energy reserves will slow new tiller development; therefore, proper defoliation management
to keep root energy reserves replenished will maximize new tiller development and
increase yield per acre.
In most forage grasses some sunlight needs to strike the basal bud to initiate new
tiller development. This principle is the reason yield per acre can actually decrease
if the defoliation period is too long. The grass actually mulches itself so to speak.
Heavy growth does not allow sunlight to the growing points, bottom leaves are senescing,
seedheads are forming, and, with no defoliation at all, total yield per acre decreases;
and forage quality goes to pot.
This gives us two management principles to increase yield. Do not defoliate so frequently
that root energy reserves are not replenished (stated another way, allow the forage
plant time to grow with no grazing so that energy is moved to and stored in the roots).
The second principle is to defoliate before the plant becomes decadent and few new
tillers are being produced. This usually coincides with seedhead formation, and/or
as a good percentage of the bottom leaves are senescing.
From the above discussion it should now be obvious that you can not have both maximum
yield and best quality. However, the fact that yield increases with time (maturity)
and forage quality decreases with time does give us a management principle to meet
goat nutrient requirements. A meat goat producing 5 lbs milk/day, or weaned doeling
gaining 0.25 lbs/day must consume vegetative forage to meet these production requirements;
thus a producer will not be able to produce maximum tonnage of forage.
At the other end of the spectrum are your bucks and dry does. These animals can do
just fine on older more mature pastures, or hay that was cut late. The nutrient requirements
of these classes of livestock are lower and therefore the pasture can be managed
for a higher yield; it is also possible to feed the hay that was put up after it
was too mature.
Understanding tiller growth and development is the key to proper defoliation manage-ment.
Pastures should be grazed and hay can be cut to produce the desired or needed forage
quality, through an understanding of the influence that defoliation has on forage
quality and yield.
Application to Grazing Management
Grazing management is the application of basic plant and animal science principles
to obtain the needed animal nutrition - quality and quantity - while maintaining
the long term productivity or health of your pasture. You do this by controlling
the intensity and frequency of forage plant defoliation. Intensity refers to the
degree of defoliation, usually thought of as a stubble height. It is easy to visualize
in a hay field, you cut the forage to a certain level, say leaving a 3 inch stubble
in the field. Animal grazing can be manipulated to also leave a certain stubble height
in the field. Frequency refers to how often a forage plant is grazed.
Since we speak in terms of controlling intensity and frequency of defoliation by
controlling animal access to forage, we can reasonably refer to a controlled grazing
system. The system uses cross fences to subdivide an area into multiple paddocks.
Animals are rotated from one paddock to another to provide forage of a needed quality,
depending on the class of animal (dry does, young growing animals, etc.).
To develop a grazing system then the manager must know the number of grazing systems
needed, the size of an area to put into a grazing system, the number of paddocks
per system, the time to keep animals confined to one paddock, and the time to complete
one rotation through all paddocks. There are no set answers to these questions, as
a matter of fact some folks might consider the answer somewhat tacky. Producers,
based on overall management objectives, the forage base on hand, and the information
and principles presented in this handbook, have to design it themselves.
Your operation has a specific forage base at present; stocking rates for cattle are
probably known and this will allow you to make a good estimate of goat carrying capacity.
Your local county Extension office has information on grazing systems that can help
you apply the principles described in this Handbook. A short, brief summary: put
your goats on young forage to meet their nutritional needs, graze the paddock uniformly
by adjusting goat numbers or by adjusting paddock size, move (rotate) them when they
have defoliated the area to a desired stubble height and before they start grazing
regrowth (replace root energy reserves), rotate back to the first paddock before
it has become too mature to meet goat nutritional requirements.
Keep in mind that continuous grazing is a form of grazing management and it can meet
certain production management objectives, particularly if the goat enterprise is
just supplemental to a cattle or other operation.
Application to Brush and Weed Control
As mentioned previously goats actively prefer several plants that are considered
weeds in typical Southeastern pastures; e.g., dewberry/blackberry briars, thistles,
honeysuckle, kudzu, etc. By using the principles discussed earlier you can control
unwanted weed and brush species in your pastures. Use the goats to defoliate the
undesirable species frequently, grazing off growing points, and intensively enough
to deplete root energy reserves! This will usually require fairly high stocking rates.
The primary management objective should be to control brush and weeds. Typically
goats used for this purpose, as heavily as they are needed, will not perform well
in terms of weight gain, milk production, or quickness of rebreeding. It is thought,
but not experimentally proven, that goats can be used to suppress weeds in a pasture
without the severe decrease in performance. This would be accomplished by adjusting
stocking rates, and the intensity and frequency of defoliation of the target weed
species. This process should be helped by the goats preference for most weeds. However,
not all weeds are readily consumed by goats (e.g. Carolina horsenettle) and other
means of weed control may have to be integrated into the management plan.
A final warning here; most of the brush/weeds that goats prefer are fairly nutritious,
some more than the pasture grass. Properly utilized the weeds will produce reasonable
goat performance. If you do indeed control the weeds with goats, you may find that
you wish you had some of them back. Decide your objectives and manage the forage
base (which may include the weeds) accordingly. Proper utilization of the brush/weeds
so as not to kill them may result in under utilization of the forage grasses, due
to goat browsing preferences.