20 



PRINCIPLES OF FEEDING FARM ANIMALS 



from 24 to 42 per cent. As these percentages increase, those for the 

 other components decrease ; e.g., the water contents in the body of a 

 steer decrease from 66 to 49 per cent, in sheep from 67 to 43 per 

 cent, and in swine from 58 to 44 per cent. In all cases except 

 where the animals are very fat, their bodies consist of more than 

 one-half water; the body of a lean animal or a fat calf (as of all 

 young animals) is made up of nearly two-thirds water. As the 

 animal grows toward maturity, and especially during fattening, the 

 proportion of water in its body tissue becomes generally smaller, 

 and that of fat increases. This is because the increase in body 



10 



20 50 40 50 60 70 



90 100 



STEER, WELL FED 

 HALF FAT 

 FAT 



FAT CALF 



SHEEP, LEAN 



WELL FED 

 HALF FAT 

 FAT 

 VERY FAT 



SWINE, WELL FED 

 FAT 



FAT 

 PROTEIN 



ASH 

 WATER 



Fia. 6. Composition of live animals less contents of stomach and intestines, in per cent. 



weight of animals with increasing age or during fattening is com- 

 posed of more dry matter and less water than when the animal is 

 young or has not been fattened, and not because the fat replaces the 

 water in the body tissues (Fig. 6). 



The composition of the increase of live weight in fattening 

 has been calculated by Lawes and Gilbert for steers, sheep, and hogs. 

 They found that if a steer, for example, gained 100 pounds during 

 fattening, these 100 pounds would be composed, on the average, as 

 follows : 



Water, 23.8 pounds, and total dry matter, 76.2 pounds, made up of: 



Fat, 67.8 pounds, 



Protein, 7.3 pounds, 



Ash, 1.1 pounds. 



While lean animals consist of nearly two-thirds water and less 

 than one-tenth fat, the increase in body substance during fattening 



