140 Pork Production 



per cent greater than for the pigs fed corn alone. This 

 greater strength was not due to bone of larger apparent 

 size, but to a thicker bone- wall and a denser structure 

 of the bone itself. The figures show that the circum- 

 ference of the bones was not affected by the ration, but 

 the weight, thickness of wall, and percentage of mineral 

 matter present was very markedly affected. The addition 

 of 25 per cent of shorts to a corn ration would appear to 

 have little effect on the strength or composition of the 

 bone produced when compared with corn alone. This 

 result seems reasonable in view of the fact that shorts 

 contain a relatively small amount of mineral matter, 

 particularly calcium. Other studies by Burnett and 

 similar studies by Carlyle 1 and Forbes 2 have given 

 results which confirm those here reported. 



This experiment supplies emphatic evidence of the 

 deficiency of corn as a bone-building feed. Chemical 

 analyses have made it known that this is chiefly due to 

 the extremely small amount of calcium or lime contained. 

 The practical effect of adding tankage or skim-milk was 

 not only to supply needed proteins, but also to furnish 

 the calcium and other inorganic elements in which corn 

 is so notoriously lacking. Although this experiment 

 does not prove directly that the feeding of corn alone 

 causes pigs to go off on their feet and legs, it supplies 

 very strong indirect evidence that this may be the case. 

 Other factors affect the ability of a hog to stand square 

 and strong on his legs and feet, but that the quality or 

 composition of the rations fed has an important influence 

 in supplying strength or weakness cannot be questioned 

 seriously. To develop a breeding herd noted for good 



1 Wis. Exp. Sta. Bull. 104. 



2 Ohio Exp. Sta. Bulls. 213 and 283. 



