CHAPTER XII 



INCREASE 



Increase. In previous chapters it was assumed, for simplicity, 

 that the live weight of the animal remained constant. Any 

 system of feeding which resulted in a diminution of the weight 

 would, of course, be unspeakably bad. We have, therefore, 

 only to consider those circumstances and conditions under 

 which it may increase. These are briefly, (i) pregnancy of 

 females, (2) growth of young animals from birth to adolescence, 

 (3) fattening of adults. The increase of weight of any given 

 animal might of course be due to more than one of these 

 causes ; and it has to be kept in view that the animal might 

 also be doing work or producing milk at the same time. In 

 this way very complicated questions might, and do, sometimes 

 arise. The most important is that of the fattening of young 

 (growing) animals. It is convenient, however, for purposes 

 of study, to consider each of the cases separately in the first 

 instance. It is scarcely necessary to remark that the phenomena 

 are not exactly the same for different kinds of animals cattle, 

 sheep, and pigs. 



Any increase in the live weight of an animal indicates an 

 addition to the mass of its body, i.e. of the quantity of matter 

 in it, and the matter so added must be derived from the food 

 and water consumed. The constituents of the maintenance 

 ration are not available for this purpose, for they are all disposed 

 of in other ways. The increase in live weight must, therefore, 

 be derived from additional food added to the maintenance 

 ration for the purpose. 



The maintenance rations required by any given animal, 

 under known conditions, can be approximately calculated by 

 the formulae (p. 128). In order to find out how much addi- 

 tional food is required for increase of any kind, obviously, 



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