Feeding Standards — Calculating Rations. 



117 



Digestible nutrients required daily by a 1100-lb. cow yielding 25 lbs. of If 

 per ct. milk. 



In the above there is first set down the maintenance allowance 

 for the 1000-lb. cow, increased by one-tenth because this cow 

 weighs 100 lbs. more than the standard; this is 0.77 lb. crude pro- 

 tein, 7.7 lbs. carbohydrates, and 0.11 lb. fat, all digestible. The 

 previous table shows the daily nutrient allowance for each lb. of 

 4 per ct. milk to be 0.047 lb. crude protein, 0.23 lb. carbohydrates, 

 and 0.018 lb. fat, all digestible. Since this cow is yielding 25 lbs. 

 of milk daily, the foregoing numbers multiplied by 25 are placed 

 in the second line of the table. Thus it is shown that the pro- 

 duction of 25 lbs. of 4 per ct. milk calls for 1.18 lbs. of crude pro- 

 tein, 5.75 lbs. of carbohydrates, and 0.45 lb. of fat, all digestible. 

 Adding these nutrients to those for maintenance, we have prac- 

 tically 2 lbs. (1.95 lbs.) of digestible protein, 13.5 lbs. (13.45 lbs.) 

 of digestible carbohydrates, and 0.6 lb. (0.56 lb.) of digestible 

 fat as the quantity of digestible nutrients required daily to prop- 

 erly nourish a 1100-lb. cow when giving 25 lbs. of 4 per ct. milk 

 daily. 



V. Kellner^s Starch Values and Feeding Standards. 



Careful and laborious investigations, conducted by Kellner and 

 Zuntz by means of a modern respiration apparatus and by Armsby 

 by means of a respiration calorimeter, have shown that the total 

 quantity of digestible nutrients in a feeding stuff is not the true 

 measure of its feeding value, as is assumed in the Woltt'-Lehmann 

 feeding standards. These investigators have found that to deter- 

 mine the actual net value of any given feeding stuff to the animal 

 it is necessary to deduct the energy expended in the work of mas- 

 tication, digestion, and assimilation from the total available energy 

 furnished by the digestible nutrients in the feeding stuff. (70) 



141. Kellner's starch values. — As a result of his investigations 

 concerning the net values of feeding stuffs to the animal, Kell- 

 ner has formulated a feeding standard based upon what he calls 



