Composition of Animal Body. 73 



the water in the animal's body. It is shown that 63 out of every 

 100 pounds live weight of the fat calf ' a body is water. With the 

 half-fat ox, this is materially reduced, and with the fat ox it 

 amounts to 45.5 per cent. Thus we learn that considerably more 

 than half the body weight of the calf, and nearly half that of the 

 fatted ox is water. In extra-fat sheep the water content falls to 

 35.2 pounds, the lowest of all farm animals, while for the fat pig 

 it is 41.3 pounds for each 100 pounds. On the average, for all 

 animals studied, 49 pounds in every 100 of body weight is water. 

 The supreme importance of this neutral fluid to the animal sys- 

 tem is strikingly brought out by these figures. 



103. Composition of the increase while fattening. — Lawes and 

 Gilbert's researches furnish data showing that the process of 

 fattening is really what the term implies — the layiug-on of 

 fat. During fattening the percentage of total dry matter in 

 the body is considerably increased, and the fatty matter accu- 

 mulated is much greater than the nitrogenous substance. The 

 increase during fattening of moderately fattened oxen will con- 

 tain scarcely more than 1.5 per cent, of mineral matter, 8 per 

 cent, of nitrogenous substance, and 65 per cent, of fat, the total 

 dry substance put on during fattening ranging from 70 to 75 per 

 cent. The remainder of the increase is water. If steers grow 

 as well as fatten, there may be more mineral matter and nitrog- 

 enous substance, less fat and more water in the added growth, 

 than just reported. In such case about two-thirds of the increase 

 is dry substance and one-third water, while if the steer is mature, 

 the added weight while fattening consists of as much as three- 

 fourths dry substance and one-fourth water. 



Studies of sheep lead to the conclusion that the increase during 

 fattening will contain not less than 2 per cent, of mineral matter 

 and frequently more — a decided increase over the ox, due largely 

 to the growth of wool during fattening. Of the added weight of 

 sheep during fattening, from 70 to 75 per cent, may be fat. 



While fattening, the pig adds scarcely any mineral matter to the 

 body, and rarely more than 7.5 per cent, of nitrogenous substance, 

 the fat forming as much as 70 per cent, of the tacrease. Of the 

 gain in weight made by the pig during fattening, about 75 per 

 cent, is dry matter and 25 per cent, water. The increase of less 



