110 Feeds and Feeding. 



The table shows that according to Wolff's teachings a 1000-lb. 

 ox at rest, neither gaining nor losing in weight, requires for 1 day 's 

 maintenance 18 lbs. of dry matter containing the following diges- 

 tible nutrients : 0.7 lb. crude protein, 8.0 lbs. carbohydrates, and 0.1 

 lb. fat, with a nutritive ratio of 1 : 11.8. Tho the ox is resting, work 

 is still being performed ; the beating of the heart, mastication, diges- 

 tion, standing, breathing — all the manifestations of life in fact — 

 imply internal work and call for energy and for repair material. 



When the animal is growing, fattening, giving milk, or doing ex- 

 ternal work, a larger quantity of nutrients must be supplied than 

 for maintenance, as the table shows. For the cow yielding 22 lbs. 

 of milk daily, the standard calls for the following quantities of the 

 several digestible nutrients: Crude protein 2.5 lbs., carbohydrates 

 13.0 lbs., and fat 0.5 lb. These have a nutritive ratio of 1 : 5.7, 

 which is much narrower than for the ox at rest. In his effort to 

 attain the proper standard Wolffs reasoned that, since pasture grass 

 is the natural food of the dairy cow, the nutritive ratio of such 

 grass might most properly serve as the chosen standard. 



III. Calculating Rations for Farm Animals. 



We have now advanced to a point where the tables of nutrients 

 and the feeding standards can be put to use in calculating rations 

 for farm animals according to the Wolff-Lehmann standards. 



134. Ration for a steer at rest.— In Example Tables III and IV 

 we have the data for calculating the feed required to maintain a 

 1000-lb. ox at rest in his stall when neither gaining nor losing in 

 weight. If for the trial ration it is decided to feed 10 lbs. of corn 

 stover and 10 lbs. of oat straw for roughage, then the calculations 

 for dry matter and digestible nutrients would be as given below: 



Corn stover 



In 100 

 pounds 



Dry matter 59.5 • 



Crude protein 1.4 - 



Carbohydrates 31.2 



Fat.... 0.7 



Oat straw 



Dry matter 90.8 - 



Crude protein 1.3- 



Carbohydrates 39.5- 



Fat 0.8 - 



' Farm Foods, Eng. ed., p. 224. 



