EXPERIMENT STATION BULLETINS. 277 



and by October the cow bad made the phenomenal yields of 11,314.71 

 pounds of milk and 553.06 pounds of fat. It would have been sheer 

 folly to measure her feed during the early months of her period of lacta- 

 tion by any standard based upon live weight alone or derived from the 

 average feeding of average cows. 



Still more remarkable is the consumption of dry matter and protein 

 of College Fogis 11 during the winter of 1895-90. Here we have a cow 

 that weighed in January but 880 pounds, who was gaining in live 

 weight because still young and who was turning out regularly nearW 

 2 pounds of butter a day. She required on the average for a whole 

 month over 32 pounds of dry matter per thousand pounds of live weight 

 per day, containing 2.75 pounds of protein. The cow weighed but 880 

 pounds, and this 880 pounds was made up largely of digestive organs, 

 lungs and udder. In proportion to her live weight she co">l consume 

 and economically utilize a very much larger amount of feed than could 

 an animal with a massive frame and relatively small per cent of viscera 

 and udder. 



A study of the tables shows conclusively that an expert feeder vari^, 

 the size of the ration, not according to the weight of the cow aloue 

 or primarily, but according to her capacity to receive and her ability 

 to yield, and that, with the same cow, the ration is modified as the 

 period of lactation advances, to conform to the requirements of the 

 system. 



What is true of the dry matter is true of the digestible protein. 

 Where a cow is secreting a large amount of milk containing from one 

 to as high as two and one half pounds of dry casein per day, her food 

 must be relatively much richer in protein than when she has not this 

 demand upon her system to supply. The food requirements of the sys- 

 tem to sustain the vital functions remain comparatively constant. To 

 these requirements is superadded, in the periods of greatest milk yields, 

 the demand for the butter and cheese in the milk. Protein is required 

 not only to supply the casein of the milk, but to insure that active 

 vitality of the whole nervous system which is involved in butter pro- 

 duction. A farther discussion of the subject is not necessary to prop- 

 erly emphasize the fact that not only must a larger, but a richer ration 

 as well, be given to a cow when giving a large yield than when com- 

 parative! v drv. 



As to the digestible fat, economic considerations demand that such 

 a combination of foods be made, to furnish the requisite dry matter 

 and protein, as will furnish at the same time fully .89 pounds of digesti- 

 ble fat per day for the smaller cows. But no definite amount of fat 

 can be prescribed in the ration, first, because the word fat in this con- 

 nection includes within its meaning many dissimilar substances. A 

 pound of digestible fat derived from silage or green fodder is a very 

 different thing from a pound of digestible fat derived from linseed meal 

 or any of the by-products. Again, using the feeding stuffs grown upon 

 the farm for the largest practicable share of the ration it would be 

 difficult to propose an economical combination that would not furnish 

 more digestible fat than the standard of either Wolff or Woll calls for. 



It is evident from a consideration of all the facts in the case, that 

 a standard ration cannot be used as a fixed rule in determining the 



