50 BULLETIN 1388, U. S. DEPARTMENT OF AGRICULTURE 
tive. Good pastures, according to careful estimates of farmers in 
this area, will care for from two to three milk cows per acre for seven 
months, reducing the quantity of hay fed during the pasture season 
by two-thirds. Pastures are not only economical for all the different 
classes of livestock produced, but they contribute much to the health 
and contentment of the animals. Whether or not it will pay to 
supplement pastures with other feeds must be left to the business 
judgment of the farmer, based on records. Cows producing heavily 
will profit by some grain. A small quantity of dry roughage at 
night is usually desirable for producing dairy cows while on pasture. 
The quantity of feed required by different classes of livestock will 
be determined by the class of animals and whether they are fed for 
maintenance or production. Animals to be maintained, such as idle 
work stock and dry cows, need only enough to maintain their bodies 
without losing weight. The quantity to feed animals for production 
or those being fitted for market depends a great deal upon the ability 
of the animal to respond economically to additional quantities of 
feed. A dairy cow, particularly, must be fed as an individual. She 
is so contituted that she can digest and assimilate about double the 
quantity of food necessary to maintain her body. 
Sometimes it is difficult to determine which succulent feeds can 
be produced most economically on a particular farm. This can be 
partly determined from the replacement value of succulent feeds in 
Table 24. According to this table, it would require approximately 
25 tons of squash or 20 tons of rutabagas to replace the feeding 
value of a 10-ton yield of corn silage. Knowing this, and knowing 
requirements of labor, materials, and equipment involved in the pro- 
duction of each crop, the Yakima Valley farmer who is handicapped 
in the growing of corn on account of wireworms or alkali will be able 
to decide more definitely which succulents can be produced most 
economically on his farm. 
Many of the simple rules for the successful feeding of livestock 
are given in a publication issued by the Bureau of Animal Industry 
of the United States Department of Agriculture. It is Miscellane- 
ous Circular No. 12, entitled "A Handbook for Better Feeding of 
Livestock," and the price is 5 cents, which should be sent in cash 
(not stamps) to the Superintendent of Documents, Government 
Printing Office, Washington, D. C. 
PRINCIPLES GOVERNING CHOICE OF CROPS AND LIVESTOCK 
From the information presented on preceding pages, the following 
principles may be deduced which farmers in the area should bear in 
mind when selecting and adjusting farm enterprises to meet conditions 
existing on their farms : 
(1) Variations in a farmer's resources influence the selection 
of enterprises and the returns from farming. 
(2) Markets and marketing conditions vary for different farm 
products. 
(3) Farm enterprises vary in their demand upon the resources 
of the farmer. 
(4) Nonmarketable resources must be used when and where 
they are available. 
