30 PRINCIPLES OF FEEDING FARM ANIMALS 



it may rank next to water. Fat cattle contain about 16 per 

 c^t^ fat sheep abouFT^ per cent" and fat hogs about 14 

 ^er cent of protein. Thin cat_tle co ntain approximately 20 

 per cent j^thin sheep about 15 per cent, and thin hogs about 

 15 per cent of protein. The fat calf and fat lamb contain 

 about 20 per cent and 12 per cent of protein, respectively. 

 I n genera j^_the_ fatter the animal, the lower is the per ce nt 

 of protein. Thus cattle usually contain more protein than 

 sheep and hogs. It may be noted also that the protein 

 content of the animal varies difectly with the water and ash 

 content because considerable quantities of these two classes 

 of compounds are always found associated with the proteins. 

 As shown by Figure 1 , the percentage of protein in the body 

 decreases slightly mth increasing maturity. 



Carbohydrates. — The animal body contains a very small 

 per cent of carbohydrates in the form of glycogen or " animal 

 starch," as it is sometimes called. It is stored up especially 

 in the liver which ordinarily contains from 1 to 4 per cent 

 and in smaller amounts in the muscles. There is also a small 

 amount of glucose in the blood and muscles. In the ordinary 

 analysis of the animal body, the amount of carbohydrates is 

 not determined. 



Composition of Increase in Body Weight. — Jlie ^feed ing 

 of meat-produ cing animals usuallv has as its primary ob]^ 

 the increng^ nffJTpjnHyw^ight of thp flnimnl The increase 

 in body weight also is the primary object of feeding all 

 growing animals. Gain in body weight is due ordinarily 

 to one or both of two factors, growth and fattening . 



Growth consists of an_incr£as£_jQf the striicjiiral com- 



^■~ - — ■ — - — ~ 



ponents of the body, chiefly by cell mult iplication, resultm g 

 in^ ^n liTaizc and w e ight . Inasmuch as the dry substance 



