THE DEVELOPMENT OF ANIMALS 79 



of bone will be below what is normal and likewise relative 

 strength in the same. 



The relation between strength and cleanness of bone in 

 horses and grasses grown on soils of limestone formation 

 has long been noticed. The same may also be said of the 

 relation between a corn diet and deficiency of bone develop- 

 ment both in quantity and strength, in growing and fatten- 

 ing swine, but more particularly during the growing period. 

 It has been noticed that when a brood sow is fed exclusively 

 on a corn diet during the period of gestation, the pigs are 

 deficient in size at birth and have small bones. The corn 

 does not furnish the dam with enough of the elements of 

 bone making material. 



It has also been proved by experiment that swine fed 

 on corn alone during the growing period have bone develop- 

 ment inadequate in quantity and quality. This of course 

 is adverse to large and robust development, since a small 

 framework of bone and similar muscular development are 

 more or less intimately associated. It has also been observed 

 that swine reared chiefly on corn and fattened on the same 

 go down on their limbs much sooner than those fed on 

 foods which supply an ample amount of bone making 

 material. It has furthermore been observed that sheep 

 largely reared on alfalfa and red clover develop large 

 frames covered by a corresponding amount of muscle. 



But increase in bone development beyond what is 

 normal is not produced by feeding foods to an animal pos- 

 sessed of more ash than is necessary for normal develop- 

 ment. In other words an animal may be fed bone making 

 materials much in excess of its needs, and yet the pro- 

 duction of bone will stop at that point of development 

 which is normal for the breed or at least which is normal 

 for the individual as determined by inheritance. But in- 

 crease in bone development may be attained beyond what is 

 normal for the breed by feeding food relatively rich in. the 

 materials for making bone, aided by selection. In other 



