


PROTEIN REQUIRED FOR DAIRY COWS. 165 
(C) Lower division.— With eleven herds of one hundred and 
fifty cows, the recommended ration contains 2,410 less calories 
(calories decreased when above 27,000), 0.3 pound more grain, 
and less roughage. ‘The gain in milk is 0.29 pound. 
The gain in (C) of 0.20 pound of milk is a little larger than 
the average gain of all the herds, although the calories are 
decreased twice as much as the average of all. 
The conclusion seems to be warranted, therefore, that the 
lowering of the recommended rations to the extent of 1,070 
calories did not depress the milk flow (Table 77). Or, to put it 
another way, the milk flow from the recommended rations would 
not have been larger if the former supply of calories had been 
maintained. 
2. The effect of increase of grain on milk flow.—Zuntz and 
Lehman report that the work of chewing the food and digesting 
it, in the case of the horse, may represent a considerable portion 
of the nutrition of the food. ‘The effort of chewing hay repre- 
sents 11.2 per cent. and in the case of oats 2.8 per cent. of the 
total energy yielded by the food (Henry’s Feeds and Feeding, 
page 29). 
‘According to Wolff’s experiments, 2.5 pounds of good 
meadow hay have an equal nutritive value to 1.5 pounds of oats, 
if the digestible crude fiber be included in both cases.’’* ‘There 
are 1.19 pounds of digestible nutrients in 2.5 pounds of hay, and 
0.91 pound of digestible nutrients in 1.5 pounds of oats. 
Henry has shown that 475 pounds of skim milk are equiva- 
lent to 100 pounds of corn meal for pig feeding (Henry’s Feeds 
and Feeding, page 572). 
There are 78.9 pounds of digestible nutrients in 100 pounds 
of corn meal, and 37.9 pounds of digestible nutrients in 475 
pounds of skim milk. One pound of nutrients in skim milk is 
worth twice as much, therefore, as one pound in corn meal. - 
The same principle is illustrated in horse feeding. When 
work is heavy, the proportion of grain to roughage is increased; 
and when labor is lessened, the roughage may be increased, and 
the grain decreased. 
*Ldw. Jahrb., xxIv., p. 267. 
