

PROTEIN REQUIRED FOR DAIRY COWS. 169 
4. Lhe period of lactation. A more rational system of grain 
feeding. As has been stated, the recommended rations were fed 
four weeks later than the original rations. The natural shrink- 
age in the milk flow under a uniform unchanged ration would 
theoretically amount to 0.85 pound per cow per day. In this 
connection it should be noticed, however, that the amount of 
grain received by each cow in each herd was not the same in 
the original and recommended rations. In the original rations 
the grain was generally apportioned to the individuals of the 
herd uniformly, although in some cases slightly more grain was 
fed to cows which were fresh, and less to those further along in 
lactation. In many of the recommended rations, however, grain 
was apportioned to the different individuals in the herd accord- 
ing to the milk production, or to the yield of total solids or 
butter fat. It seems reasonable to assume, therefore, that this 
more rational system of apportioning the grain in the recom- 
mended rations had a measurable effect on the milk flow, and’ 
that this in part at least offset the natural shrinkage that other- 
wise would have occurred. 
| CONCLUSION. 
The twenty-one recommended rations were fed to the same 
herds four weeks later than the original rations. The aver- 
age cow, instead of shrinking 0.85 pound daily as she nor- 
mally would have done on a uniform ration, positively gained 
0.25 pound, a total gain of 1.10 pounds of milk per cow per 
day. ‘This increase in milk flow at 2% cents per quart would 
amount to 1.29 cents per cow per day. ‘There was an additional 
‘daily saving of 0.23 cent in food, while the value of obtainable 
manure was 0.5 cent greater, a total daily saving per cow of 
2.02 cents as a result of the substitution of the recommended 
rations for the original. It.seems reasonable to assume, how- 
ever: 
I. That part of this saving was due to an increase in the 
amount of grain fed. 
2. ‘That a decrease in calories in the recommended ration 
when they were above the standard in the original did not de- 
press the ration, but, on the contrary, may have increased the 
effect of the ration. 
13 
