Goat Manure
GOAT MANURE
Extension Goat Handbook – 1992
This material was contributed from collections at the National Agricultural Library. However, users should direct all inquires about the contents to authors or originating agencies.
R. E. McDowell; Cornell U., Ithaca, NYG.
F. W. Haenlein; U. of Delaware, Newark.
Management and Housing
1 For gardening, goat manure can be a real asset. In their naturally
dry, pelleted state, goat feces are easily handled, stored or directly
applied on vegetables, trees, and flower gardens, as mulch, organic
matter, fertilizer, or just to increase the water holding capacity of
the soil; and goat feces do not normally attract flies or breed
maggots. A daily raking or sweeping of the goat yard keeps the goats
clean and free from parasites; and the garden will soon show its
appreciation.
2 Few research data are available on the value of goat feces or
manure. Of course, it depends on the level of feeding. Thus, high
producing, well fed dairy goats should produce more and better feces
than other goats. In general, 2.0 to 6.00f live weight of goat in
fresh feces weight can be expected. Depending on feed and water intake,
the fresh feces voided per day might weigh between 30, and as much as
1000f the daily dry matter consumed. Dry matter content of goat feces
is be tween 50 and 60ormally; the color depends on the type of
feed. Hard feed kernels, like barley and corn may appear in goat feces,
especially at high levels of feeding, but generally they are masticated
and ruminated much finer and more completely than by calves or cows.
3 Goat feces contain not only feed residues but endogenous substances
from the goat’s intestinal tract too. Swedish research established that
goats excrete daily, regardless of feed type, a minimum of 34g protein,
8g fat and 13g carbohydrates for each kg (2.2 lb) feed dry matter
eaten. This would mean that a 150 lb goat milking a gallon of milk a
day, and been given 7 lbs of feed dry matter daily; this goat would
lose 7/2.2 x 34 = 108g protein daily in her feces, not even accounting
for her milk production and her own maintenance needs. This 108g
endogenous protein loss also translates into a 3.4minimum protein
content in the 7 lb daily feed dry matter to avoid a negative protein
balance for this goat. In comparison, a daily goat ration with a 14
protein content supplies just 445g protein, of which a certain
percentage is always undigestible and a loss to the goat too. This
percentage increases when the crude fiber content of the feed
increases.
4 Goat manure i.e. feces plus bedding and wasted feed, fresh or
usually composted in pens or outside piles can average 10 lb per day
for the above example goat or more, depending on bedding amount, urine
drainage or fermentation losses. This can amount to around 1-1/2 ton of
manure per goat per year or more with a possible composition of 31
dry matter; 1.3itrogen, 1.50001:0000hosphorus (P205), 0.46952:DE9Eotassium
and 2.4
fertilizer asset per goat of at least 1/2 ton dry matter with 15 lb
nitrogen, 17 lb phosphorus, 5 lb potassium and 27 lb lime.
5 For large herds or flocks, disposal of goat manure could have
problems, but in some parts of the world animal wastes serve numerous
useful purposes. In fact, animals are frequently kept beyond their
period of usefulness for the production of milk or work so that they can
provide dung. Approximately 40 percent of the farmers of the world
depend wholly or in part on animal wastes to enhance soil fertility.
Generally, manures do not increase short-term crop yields to the extent
of equivalent amounts of nutrients supplied in refined chemical form.
The differences in yields are, however, with long-term usage. Small
farmers who till land by hand or with chisel type plows prefer manures
over chemical fertilizer because manure enhances the aggregate crumb
structure and soil permeability which aids in cultivation. Marginal
micronutrient deficiencies, which may occur after repeated cropping
with chemical fertilizers, can be prevented with supplementary
applications of manure.
6 The value of manures for soil fertility can be markedly influenced
by handling procedures. At least 50 percent of the nitrogen and 60 to
70 percent of the potassium are found in the urine. Frequently, manure
has a low fertility value due to failure to incorporate the urine, or
the nitrogen is lost through leaching. Eighteen to 20 Mcal of energy
inputs are required to produce one kg of nitrogen fertilizer. Fuel
costs to produce nitrogen have already aroused new interest in research
on storage and handling of manures. Predictions for the future are
that animal wastes will again be viewed more favorably as a useful
resource. Predictions for the future are that animal wastes will again
be viewed more favorably as a useful resource.
7 Fuel
The energy in ruminant manures is rather high (dry cow dung 4.58 to
4.72 kcal per gram) and can be used as efficiently as energy from coal
or oil if appropriate equipment is used. In some cases, dry dung cakes
are preferred over plant residues because of uniformity of heat. India
annually uses 60 to 80 million tons of dry buffalo, cattle, sheep and
goat dung for fuel. In the central plains area where there is no
firewood, per-capita use is as much as one ton per year. In two
instances, the sale of dung cakes to urban centers provided up to 60
percent of the total cash income per rural family. The expected return
per animal per day from the sale of dung cakes is 1.03 rupees or $0.12.
India would need to expend over US $3 billion per year, exclusive of
distribution costs, for coal and oil to replace dung.
8 Pastoral herders, especially nomads, largely depend on cattle,
sheep, or goat manure as fuel for cooking, heating and light. Estimates
are that over 200 million tons of manure are used per year as fuel in
developing countries. Supplies of firewood or charcoal – traditionally
the chief sources of fuel in central Africa fringing the Sahara, the
Andes region of Latin America, the highlands of Central America and
the Caribbean islands – have become scarce or non-existent. In many
areas nearly 20 percent of the total family labor is expended to
gather wood or crop residues for fuel, and the time spent is
increasing. Expenditures by salaried workers for firewood or crop
residues have risen from 15 to 25 percent of income. In Africa and the
Americas, animal manures have not been used extensively as fuel, but
usage will probably increase rapidly in the near future. Over the long
run, methane gas from animal wastes will likely make the greatest
contribution.
9 Methane Gas
During the 1930’s and 40’s, digesters were used rather extensively
in central and northern Europe for producing methane gas, but
production declined to nearly zero when oil became cheap during the
1950’s. Currently there is vast interest in digesters to meet fuel
needs. In 1975, South Korea had 29,000 bio-gas plants and planned to
build another 50,000. India has about 20,000 plants, two-thirds of
which were built since the energy crisis, and plans to build 100,000
more within the next 5 years. Taiwan has a large number of plants and
there are some in Bangladesh and Nepal.
10 The US could obtain nearly 1.0 percent of its energy by 1985 from
renewable resources, and this could increase to 25 percent by 2020 AD.
Of this, methane production is capable of producing about 5 percent by
1985 and 25 percent in 2020. Canada has a similar capability.
11 Fecal material produced by ruminants, particularly buffalo, cattle,
sheep and goats, is an ideal substrate for anaerobic fermentation
because it is already buffered and contains large populations of
methanogenic bacteria. Methane from manure has a value of 5 kcal per
cubic meter which is 71 percent of the energy value of natural gas. It
works well for household use but is difficult to handle in mobile
power. Processing manure through bio-gas plants has the added
advantages of better preservation of fertilizer in some areas where dung
is burned.
12 A major handicap for methane production is capital cost for small
units. Several countries have extensive research programs underway to
reduce construction costs. Even so, the use of bio-gas plants is not
likely to approach anywhere near the level projected, unless prices of
fossil fuels rise to extremely high levels. For the US, it is estimated
that manure from 40 cows will be needed to supply fuel, including
electricity, for an average farm family, but will not replace fossil
fuel to operate tractors, trucks or automobiles. The average Indian
village could potentially accrue high benefits from the use of
digesters, but acceptance will be low because it will deprive
individuals of one, if not their major, source of income. In spite of
limitations, anaerobic fermentation technology will undoubtedly play a
significant role in waste management. For developed countries, units
will be employed on large farms or in conjunction with feedlots where
the cost of production will be in line with other fuels.
13 Adopted from Winrock Report, September 1977, ”Ruminant Products,
More than Meat and Milk,” 17-19; Winrock International Livestock
Research and Training Center, Morrilton, Arkansas.
VIDF 67