438 Report of the First Assistant of the 



At the first change in the ration there was an increase in the total 

 food, in the total digestible nutrients, and in the fuel value. The 

 nutritive ratio was made narrower and the cost of the ration in- 

 creased. There was a slight increase in the milk yield, in the per 

 cent, of fat, and also in the cost of milk and fat production. When 

 carrots took the place of silage in the ration for the third period, 

 there was considerable falling off in the amount of dry matter in 

 the food. There was no decrease in the amount of grain or of hay 

 fed, and the principal changes in the composition of the ration were 

 due to the unwillingness or inability of the cows to eat the quantity 

 of carrots desired. There was little decrease in the amount of 

 digestible protein although considerable in the amount of every 

 other constituent. The fuel value was much lower and the nutritive 

 ratio considerably narrower. The cost of the ration was somewhat 

 reduced. There was a decided falling off in the milk flow — much 

 more than the normal decrease, and the per cent, of each constituent 

 in the milk was less. There was an increase in the food cost of 

 milk and fat. Less water-free food, however, was consumed for an 

 equal production of milk or fat, than during the preceding or follow- 

 ing periods. 



For the third period there was a slight change in the make up of 

 the grain mixture, but almost none in its chemical composition. 

 Corn silage was substituted for the carrots of the preceding period. 

 There was an increase in the amount of dry matter in the food and 

 in the amount digestible of each constituent. The nutritive ratio 

 was made wider and the fuel value much higher. The cost of the 

 ration was a trifle lessened. There followed an increase in the milk 

 flow with but little change in the composition of the milk. The 

 cost of milk was somewhat reduced and also the cost of fat. 



For the first period the greatest daily average milk yield was 39.5 

 pounds and the smallest 12.07 pounds. The highest average per- 

 centage of fat was 6.32 and the lowest 2.98. For the second period 

 the extremes in daily average milk yield were 40.1 pounds and 19.0 

 pounds. The extremes in average percentage of fat were 6.00 and 

 2.95. For the third period the extremes in average milk yield 

 were 34.0 pounds and 17.9 pounds, and in average percentage of fat 

 5.70 and 2.95. For the fourth period the extremes in daily average 

 milk yield were 29.6 pounds and 18.2 pounds, and in average per- 

 centage of fat 5.75 and 2.80. 



Each food used had the composition shown in the following table : 



