DEVELOPMENT 271 



destroyed by the early stunting resulting from insuffi- 

 cient food. The gains, the amount of food consumed, 

 and the gain in live weight based on each pound of 

 grain consumed is shown in the tables for the various 

 periods of the feeding experiment. (Tables on pages 

 269, 270.) It will be observed from the figures given 

 in these tables that the animal subjected to severe condi- 

 tions of feeding during its early life evidently had a 

 greater capacity for growth, and made better use of the 

 food consumed, than did the animal that received a 

 generous ration during the same period of its life. 

 There can be no question but that under certain con- 

 ditions a significant check to the development of an 

 animal may actually increase the rate of growth during 

 the later periods of its life. 



256. Climate. Small animals like mice and domestic 

 rabbits reared in artificially heated temperatures are 

 noticeably larger than normal size and have less hair on 

 the bodies. Cattle that are well fed and housed in warm 

 barns have much less hair than animals of similar breed- 

 ing that are required to live exposed to the rigors of severe 

 cold weather. 



257. The age factor in animal-breeding. Very large 

 numbers of farm animals are bred and produce offspring 

 while still immature. The use of young sires among 

 all classes of animals is general, but especially is their use 

 common in the breeding of hogs, sheep and cattle. 

 Various opinions exist among breeders as to the good or 

 evil effects which follow this practice. Some of the evil 

 results which it is claimed have followed the long-con- 

 tinued mating of immature animals are, a gradual decrease, 

 in the size of the breed ; weakness of constitution ; loss 

 of prepotency in the transmission of valuable qualities; 



