EXPERIMENT STATION BULLETINS. 231 



tions remain comparatively constant. To these requirements is super- 

 added, in the periods of greatest milli 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 production. A farther discussion 

 of the subject is not necessary to properly 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 comparatively dry. 



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 as the same time fully .89 pounds of digestible 

 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 connec- 

 tion includes 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 stufl;s grown upon the farm for the 

 largest practicable share of the ration it would be difiicult to pro- 

 pose any economical combination that would not furnish more digesti- 

 ble 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 

 amount or kind of feeding stuffs that should be given a certain cow at 

 a certain time. It can supplement and partially guide the judgment of 

 the feeder, but it cannot take the place of judgment and experience. 



A sufficient number of records are not submitted in the third divi- 

 sion of the table, which gives the food consumption of the cows nearly 

 dry, to warrant the statement of a definite conclusion. In each case 

 there is a very evident increase in live weight, as there should be, when 

 cows are approaching parturition. The fact that our cows gained regu- 

 larly in live weight is good, but perhaps insufficient evidence that the 

 ration here suggested is sufficient basal ration representing the amounts 

 of dry matter and digestible nutrients required by the cow to sustain 

 the vital functions. 



Recognizing the just limitations of the application of the feeding 

 standard the daily ration of 23..57 pounds of dry matter 2.06 pounds of 

 digestible protein, 12.50 pounds of digestible carbohydrates and .89 

 pounds. of digestible fat is suggested by the College herd, for cows in 

 the third and fourth month of the period of lactation giving a good yield 

 of milk. A knowledge of the feeding standard and the methods of com- 

 puting rations is by no means all that there is of skillful cow feeding. 

 That art is one which cannot be acquired without long experience in 

 the stable, and one which involves the exercise of well trained powers 

 of observation and, above all, well ripened judgment. 



It is evident that the standard ration takes no cognizance of the rela- 

 tive money values of the various feeding stuffs. The practical feeder 

 has to approach the question of what shall constitute his ration very 

 largely from that side. He considers primarily not what combinations 

 of food will cause his herd to yield the most butter, but what combina- 

 tions he can bring together most economically, and by what combina- 



