MEAT SCRAPS VERSUS SOYBEAN PROTEINS AS A 

 SUPPLEMENT TO CORN FOR GROWING CHICKS 



By A. G. Philips, Chief in Poultry Husbandry, R. H. Carr, Associate in Nutrition, 

 and D. C. Kennard, Assistant in Poultry Husbandry, Purdue University Agri- 

 cultural Experiment Station 



The proteins found in natural feed stuffs vary greatly in their nutritive 

 value as well as in their solubility and in the proportions of the different 

 amino acids which they are capable of yielding. The cereal grains con- 

 tain most of the important amino acids but apparently in many cases in 

 proportions unsuitable to promote growth and development. McCollum 

 and his coworkers ^ have shown that the cereal grains, although they 

 have a low biological value as compared to milk, have a remarkable value 

 as supplementary sources of amino acids for certain vegetable proteins. 

 It is thought that the value of com proteins in producing growth has been 

 somewhat underestimated. This may be due to the fact that one of the 

 proteins (zein) which is usually present in a considerable amount, lacks 

 two important amino acids (lysin and tryptophane), and the young 

 animal fed on corn is incapable of appreciable growth on the only pro- 

 teins remaining (glutelin, globulins, and albumins). Data obtained by 

 R. H. Carr and coworkers^ would seem to indicate that the amount of 

 zein in mature corn is somewhat overestimated, and hence that the other 

 proteins present were probably largely responsible for the consistent 

 growth which was secured with chicks fed on corn containing less than lo 

 per cent proteins fortified with ash and with fat-soluble vitamines. The 

 proteins of meats are credited with having a high value in producing 

 growth, but their relative efficiency as compared with vegetable protein 

 is not so well understood. The proteins of soybean are usually con- 

 sidered of excellent quality, ^ but their biological value is thought to be 

 of the same order as that of corn and oats. 



Most of the work done so far in measuring the biological value of pro- 

 teins from various sources has been conducted on the rat or the pig, 

 because these animals have many points of advantage for laboratory 

 investigations. The growing chick has been used by some investigators, 



>McCoLLUM, E. v., SiMMONDs, N. and Parsons, H. T. supplbmentary relationships betwbbn 

 THE PROTEINS OP CERTAIN SEEDS. In Jour. Biol. Chem., V. 37, no. I, p. 155-178, 7 charts. 1918. Bibliog- 

 raphy, p. 177-178. 



'Spitzer, George, Carr. R. H., and Epple, W. F. soft corn— its chemical composition and 

 NITROGEN distribution. In Jour. Amer. Chem. Soc., v. 41, no. 8, p. 1212-1221. 1919- 



' Daniels, Amy I,., and Nichols, Nell B. the nutritive valub op the soybean. In Jour. Biol. 

 Chem., V. 32, no. i, p. 91-102. 1917- 



Journal of Agricultural Research, Vol. XVHI, No. 7 



Washington, D. C. Jan. 2, 1920 



th (391) Key No. Ind.-7 



