THE FATTENING ANIAIAL. 197 



animals. Animals when first confined, and supplied 

 with fattening food, generally increase largely in 

 weight during the first few weeks, after which the rate 

 of increase diminishes to a considerable extent. 



The proportion of nitrogenous matter in the fatten- 

 ing increase is very small, the albuminoid ratio of the 

 increase varying from 1 : 19 to 1 : 22 (p. 110). The 

 proportion of lean to fat can be influenced to only 

 a limited extent by the character of the feeding. In 

 the case of a rapidly growing young animal, a diet 

 supplying an abundance of albuminoids will produce 

 a much larger increase of nitrogenous tissue (lean) 

 than a diet rich in carbohydrates and fat. Very 

 young pigs fed liberally on separated milk, with some 

 barley meal and bran, will yield much leaner pork and 

 bacon than similar pigs receiving barley meal and 

 potatoes without milk. When, however, we are 

 dealing with fully-grown animals, as oxen, the increase 

 obtained during fattening is chiefly fat, whatever may 

 be the albuminoid ratio of the diet. 



Many years ago scientific men believed that albu- 

 minoids and fat were the only constituents of food 

 which contributed to the formation of animal increase ; 

 the carbohydrates were supposed to produce heat in 

 the body, but not fat. As a consequence of this belief 

 the nutritive value of foods was supposed to be chiefly 

 determined by the proportion of albuminoids, or 

 «' flesh formers," which they contained. This idea of 

 the limited function of carbohydrates has been dis- 

 proved by an abundance of experimental evidence. 

 Nevertheless, the impression of the great preponderat- 

 ing value of albuminoids for the production of animal 

 increase still remains in the minds of many agricultural 



