THE FEEDS 



331 



Hughes' has, however, shown tliat corn alone is an ade- 

 quate diet for adult pigeons for maintenance for at least one 

 year. The protein deficiency in corn seems to be due to the 

 poor cjuahty rather than to the quantity, h'or corn which 

 usually contains about 1) ])er cent protein will produce a very 

 slight growth even when all the other necessary dietary 

 factors are present in sufficient amounts. A diet containing 

 this amount of protein in the form of milk albumen as shown 

 l)y Osl)orne and Mendel- will ]jraduce a niaximimi growth. 

 This protein deficiency in corn is imdoubtedly due to the 

 high per cent of zein, a ]:)rotein which contains neither lysin 

 nor tryptophan, and which is incapable of supporting life. 



Fig. 1 



White Leghorn coekerel at eight months' of age which liad Ijeen fed only 

 corn and salt mixture. (After Hutihes.) 



Corn is the best liked grain that is fed to poultry in the 

 Middle West. Yellow corn imparts a deeper color to the 

 yolk of eggs than wheat or oats and produces yellow flesh as 

 a fattening ration. It carries more of fat soluble A than the 

 white corn. It also tends to make \\hite birds creann* 

 in color. 



^ ]vansas Technical Bulletin, No. .^. 



^ Journal of Biological Chemistry, yol. x.xiv. 



