£46 PRODUCTIVE FEEDING OF FARM ANIMALS 
Concentrates.—The common concentrates used on American 
dairy farms are cereals and mill-refuse feeds, starch or glucose ref- 
use feeds, brewers’ and distillers’ feeds, and oil meals, especially 
linseed meal and cotton-seed meal. The amounts of these feeds 
that can be fed to dairy cows with profit will depend upon the price 
of the feeds, the production of the cows, and the prices obtained 
for the dairy products. In general, the carbohydrates of feed 
rations are supplied by farm-grown crops, while nitrogenous feeds 
are largely purchased, except when leguminous crops are grown. 
By the culture of crops of the latter class the amount of protein 
feeds that it will be necessary to purchase will be reduced to a 
minimum. Wheat bran may be partially replaced, nearly ton for 
ton, by carefully-cured alfalfa hay, or by five to six tons of pea- 
i shia 
Fic. 50.—Alfalfa is, as a rule, fed in racks in the corrals (feeding yards) to milch cows in 
the Western States. 
vine silage. Roughly speaking, the cereals may be considered 
of equal feeding value for dairy cows, and of similar value to bran 
or shorts, in rations as ordinarily fed. Cotton-seed meal, gluten 
meal, and linseed meal likewise possess nearly equal value, with the 
first two feeds occasionally ahead. The comparative value of feed- 
ing stuffs depends, however, to a large extent on the combination 
in which they are fed, a starchy feed being of greater value to a 
farmer having a good supply of protein feeds than to one who has 
mainly starchy feeds to select from. The feed-unit system fur- 
nishes a convenient and very satisfactory method of comparing 
. . . 5 
the value of different kinds of feeds for dairy cows (p. 79). 
The quantities of grain feeds fed by American dairy farmers 
vary considerably, from a few pounds to fifteen or more pounds 
