170 STORRS AGRICULTURAL EXPERIMENT STATION. 
3. The addition of protein to the ration shows to best ad- 
vantage, as measured by increased milk flow, when the orig- 
inal rations carried less than 1.5 pounds of protein. But in 
these rations there is an increase of grain as well as of protein, 
and the increased milk flow of these cows may be attributed 
in part to the increase in grain. 
4. An assumption that the calculated natural shrinkage in 
milk flow ordinarily occurring as the period of lactation ad- 
vances under uniform unchanged rations was offset by the ad- 
dition of protein to the recommended rations is not warranted. 
In Table 80, division C, seven herds of ninety-four cows re- 
ceived on an average only 0.17 pound increase in protein in the 
recommended rations. This small increase of protein is attended 
by the average milk flow. Division B, which received an in- 
crease of four times as much protein, made a greater shrinkage 
than did division C. 
5. The food cost of the recommended rations is 0.23 cent 
less than the cost of the original rations. Ordinarily the addi- 
tion of protein to a ration will increase the cost of the ration, 
as protein foods are the most expensive. ‘The lessened cost of 
the recommended rations over the original is effected by feed- 
ing a smaller amount of nutrients. The 28,240 calories in the 
original rations cost 19.43 cents, or at the rate of 0.69 cent per 
1,000 calories, while the 27,170 calories in the recommended 
rations cost 19.2 cents, or at the rate of 0.71 cent per 1,000 cal- 
ories. If the excess of calories in the original rations (1,070) 
were not needed, the cost might have been reduced 0.74 cent 
(1,070 X .69) without affecting the milk flow. In this case the 
original rations would have cost a half cent less than the recom- 
mended ones. 
6. The assumption does not seem to be warranted, there- 
fore, that the food cost of a quart of milk was materially dif- 
ferent in the original and recommended rations, although the 
latter contained more protein. 
7. The net cost of a quart of milk was less with the recom- 
mended than with the original rations on account of the greater 
value of the estimated obtainable manure. 



