Composition of Animal Body. 



77 



As a natural result of the larger consumption of food, the pig 

 increases in weight more rapidly than the sheep or ox. Not only 

 is the rate of increase more rapid, but the increase yielded by the 

 pig is also far greater in proportion to the food consumed, as 

 plainly appears from the lower division of the table. The pig, 

 with its very large consumption of food, has, in fact, to spend a 

 smaller proportion of it on heat and work, and has a larger sur- 

 plus to store as increase. Of 100 pounds digested organic 

 matter, the fattening ox spends about 77 for heat and work, the 

 sheep 74, and the pig 57. The upper division of the table shows, 

 however, that in a given time a pig converts a much larger 

 amount of food into heat and work than either the sheep or ox. 

 This greater consumption probably represents the internal work 

 performed in lay ing- on increase. The pig, with its rapid feeding 

 and high rate of increase, is undoubtedly the most economical meat- 

 making machine at the farmer's disposal. The returns of sheep 

 lie between those given by oxen and pigs, being, however, much 

 nearer the former than the latter. The German experiments 

 place the sheep below the ox as an economic producer of increase, 

 instead of above it, as in the Bothamsted statistics just quoted. 

 The difference is probably due to the different breeds of animals 

 under experiment. 



106. Nitrogen and ash in carcasses of farm animals. The table 

 shows the quantity of nitrogen, and principal ash constituents, in 

 the fasted live weight of animals analyzed at Eothamsted. 



Ash constituents and nitrogen in 1,000 pounds of various animals, 

 based on live fasted weight, including contents of stomach and 

 intestines Lawes and Gilbert. 



