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 ”; ¢.¢., 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.* 
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.—W olff-Lehmann 
* 
Digestible 
Dry Aut 
matter, -. |Carbohy- live 
pounds oan dratos, wonntia ratio, 1: 
Fattening steers, first period..... 30 2.5 15.0 5 6.5 
Milch cows, yielding 22 pounds 
milk daily ................ 29 2.5 13.0 5 5.7 
Fattening sheep, first period..... 30 3.0 15.0 5 5.4 
Horses, medium work.......... 24 2.0 11.0 6 6.2 
Fattening swine, first period..... 36 4.5 25.0 7 5.9 
As all the main feeding stuffs in this country, like corn and corn 
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- 
“One therm is the amount of heat required to raise the temperature of 
1000 kilograms of water 1 degree C. (see p. 45). 
