EXPERIMENT STATION BULLETINS. 



229 



While the composition of the grain ration was fixed in the office of 

 the Farm Department of the Experiment Station, the amount to be fed 

 each day to each cow was left to the judgment of the expert herdsman. 

 This plan was inevitable. No cow wants day after day the same 

 amount of food nor even the same mixture. When thQ weather is cold 

 and keen, her appetite is more vigorous, even if she is kept in a rela- 

 tively warm but well ventilated barn, than on a warm and murky day. 

 The proportion of coarse fodders to grain may profitably be increased 

 on such occasions. The quantity, therefore, both of the coarse fodders 

 and of the grain feed and by-products was left entirely to the judgment 

 of the man who fed the cows and who adjusted the quantity to the 

 milk yield and the condition of the bowels. 



In formulating the standard daily ration the cows were grouped 

 into three lots, those weighing approximately 1,000 pounds, those weigh- 

 ing about 1,400 pounds, and cows not giving milk. From the data 

 furnished by the weights of feed and of milk and butter fat yielded, 

 the amount of dry matter, digestible protein, digestible carbohydrates 

 and digestible fat were calculated. 



The records showed the amount of fat secreted by the cows. The 

 table below shows the average daily fat yield secured from the consump- 

 tion of the ration by the cows under experiment. There is also given 

 the average month in the period of lactation and the average weight 

 of the cows. , 



M. A. C. STANDARD RATIONS. PER 1000 LIVE WEIGHT. 



1,000 pound cows 

 1,200 pound cows 

 Dry cows 



Average 

 Weight. 



lbs. 



9828 

 1,396.68 

 1,373.5 



The nutritive ratio of the standard ration suggested for the thousand 

 pound cows is 1 : 7.1, that of the larger cows 1 : 7.21, and that of the 

 cows in the very late*st months of the period of lactation is much wider, 

 being 1 : 8.53, 



The tables from which these feeding standards were derived, con- 

 clusively demonstrate the limitations of the use of the feeding stan- 

 dards. They show that it is entirely wrong to assume as Wolff does 

 to set up a stated amount of dry matter and of protein as correct for a 

 cow of given weight, or to graduate the amount of dry matter and of 

 protein, which a cow should receive, by her live weight alone. One cow 

 has a greater capacity to consume, digest, assimilate, and economically 

 utilize food than another of the same weight. Again, the same cow re- 

 quires a difterent amount of dry matter at one time than at another. 

 In the early months of the period of lactation, when her yield is at the 

 maximum, she requires a much larger amount of feed than later, when 

 the draft upon her body of milk constituents is lessened by the smaller 

 yield. Take the case of a certain Guernsey cow, Aida II, for instance. 

 In January, 189G, although weighing but 915 pounds, her daily yield 



