COMPOSITION OF ANIMAL INCEEASB 109 



cheese the annual loss will be about 28 lbs. of nitrogen, 

 7 lbs. of phosphoric acid, and 1 lb. of potash. If only 

 butter is sold the loss of nitrogen and ash constituents 

 will be quite insignificant. 



In a fat ox about 60 per cent, of the fasted Hve 

 weight will be butcher's carcase ; in a fat sheep about 

 68 per cent. ; in a fat pig (fatted for pork) 83 per 

 cent. The proportion of carcase increases consider- 

 ably during fattening. Thus the carcase in the store 

 sheep killed at Kothamsted averaged 53'4, in the fat 

 sheep 58'6, and in the very fat sheep 64'1 per cent, of 

 the fasted live weight. 



When a lean animal is fattened the larger part of 

 the increase in live weight is carcase. It was found 

 at Eothamsted that in the case of sheep passing from 

 the ** store " to the ** fat " condition, increasing in 

 weight from 102 lbs. to 155 lbs., about 68 per cent, 

 of the increase was carcase. With *'fat" sheep 

 passing into the "very fat" state, increasing from 

 144 lbs. to 202 lbs. live weight, the proportion of car- 

 case in the increase was about 77 per cent. With a 

 fattening pig, increasing from 103 lbs. to 191 lbs. live 

 weight, the proportion of carcase in the increase was 

 found to be 91 per cent. 



The composition of the increase of an animal varies 

 much under different circumstances. The increase of 

 a young growing animal will contain much water, nitro- 

 genous matter, and ash ; while the increase of an 

 adult fattening animal will consist chiefly of fat. It 

 follows that a smaller amount of food is needed to 

 produce a pound of increase under the former than 

 under the latter conditions. 



The percentage composition of the increase of oxen. 



