USES OF FEED BY ANIMALS 



37 



Feeding Standards. The Wolff standards were brought to the 

 attention of American farmers in the seventies, and, mainly through 

 the publication of Armsby's " Manual of Cattle Feeding," in 1880, 

 they became quite generally known here as " the German feeding 

 standards." They were modified in 1897 by Lehmann, another 

 German scientist, and ten years later Kellner proposed a new set of 

 standards, based on contents of digestible protein and "starch 

 values "; i.e., the amounts of different nutrients or feeds equivalent 

 to one pound of starch for the production of body fat by mature 

 fattening steers. These and similar standards suggested by Armsby 

 are the latest contributions to this subject. In order that students 

 may become familiar with the two methods of determining the 

 requirements of different farm animals, we shall give in this book 

 both sets of standards, known as the Wolff-Lehmann and the Armsby 

 standards, based respectively upon digestible components of feeds 

 and the digestible true protein and energy values, measured in 

 therms. 4 



Wolff-Lehmann Standards. The feed requirements for dif- 

 ferent farm animals of average body weights, according to these 

 standards, are as follows: 



Feed Requirements per 1000 Pounds Live Weight. Wolff-Lehmann 



As all the main feeding stuffs in this country, like corn and com 

 products, oats, mill feeds, oil meal, hay, etc., are relatively high in 

 fat, there is no danger that the rations will not contain sufficient 

 amounts of this component; it does not, therefore, call for special 

 consideration, and has generally been merged with the carbohydrates 

 in this book, according to its carbohydrate equivalent (by multiply- 

 ing with 2.25, see p. 46). Stated in this manner, the Wolff-Leh- 



4 One therm is the amount of heat required to raise the temperature of 

 1000 kilograms of water 1 degree C. (see p. 45). 



