USES OF FEED BY ANIMALS— FEEDING STANDARDS 51 



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. The complete 

 standards are given in Part IV, at the beginning of the chapters 

 on the feeding of the various classes of farm animals. In the fol- 

 lowing pages only typical feeding standards for different animals 

 are presented. 



Wolff-Lehmann Standards. — The feed requirements for dif- 

 ferent farm animals of average body weights, according to these 

 standards, are as follows: 



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 carbohy- 

 drates in this book, according to its carbohydrate equivalent (by 

 multiplying with 2.25, see p. 46). Stated in this manner, the 

 Wolff-Lehmann standards become very simple and are as easily 

 applied as any standard so far proposed for farm animalsi. Modifi- 

 cations of the Wolff-Lehmann feeding standards for dairy cows, 

 fattening cattle, horses, sheep and pigs have been proposed by 

 Henry-Morrison,* which aim to bring these in accord with the 

 results of late American investigations in stock feeding. ( 



The nutritive ratio of a feed (or- a ration) is the proportion 

 between the digestible protein and the sum of the digestible carbo- 

 hydrates and fat contained therein. The fat is changed to its 

 carbohydrate equivalent by multiplying with 2.25, because it has 

 2.25 times as high heat value as similar amounts of carbohydrates. 

 For example, the nutritive ratio is expressed as 1 : 6.5 ; meaning that 



'"Feeds and Feeding," 15th Ed., p. 669. 



