Dairy Herd Improvement Notes, August, 1972

              Coopero'ive -­New
Mexico S'ale Un ive rsity
August , 1972
With all the talk about animal waste disposal systems, did you ever stop to think
about the tons of waste material that the dairy cow converts into very tasty nut­ritious
food?
Wastes, in this sense, are materials that are factory by - products that would be
difficult disposal problems if cows did not eat them. For the cows, however, these
are edible beneficial foods. The list is long: millrun from flour manufacture,
pulp and molasses from sugar manufacture , citrus pulp from fruit juice production ,
potato waste , oilseed meals , cannery wastes, brewery wastes, cottonseed hulls, mill
screenings, molasses from wood pulp , and many others.
The t onnage is tremendous. Still further amounts could be used if necessary. The
ruminant can digest wood fibers in small amounts and in large amounts when the lignin
is removed. At present prices, wood fibers wit'hout lignin cost about 50% more than
comparable cereal grain feeds.
The cow, in America, consumes about 50% roughage- - material such as alfalfa hay, silage
and grass--that humans cannot digest efficiently. In some areas of the world , the
sale diet of the cow will be roughage.
Of the 50'. non- forage portion of the cows' feed, not more than half would be edible
by humans. The other fraction would include one or more of the many waste products
mentioned above.
This leaves a balance of about a ton of edible cereal grains that each cow eats
yearly . In turn, the average cow produces five or Six tons of very nutritious milk
and gives birth to a calf weighing almost 100 pounds. On a calorie basis, she
produces JUSt about as much energy as milk as she eats as edible cereal grains .
On a quality of food basis, the cow is ahead. The total nutrient balance in milk
is near perfect . The cereal grains contain small quantities of incomplete protein .
Milk protein contains all of the essential amino acids needed in the body in large
Milk is very high in calcium and phosphorus. Cereals are low. Milk suppl:les 75-801.
of the total calcium in the human diet.
The cow can even use inorganic materials like urea and l ime~ tone to make milk pro­tein
and calcium that are then nutritious human foods . The reason that the cow can
eat these waste products while humans cannot is the ruminant stomach or rumen.
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director, .nd tho U. S. O.p.nm .... of "ricuhu ... «,oper.nne.