RESEARCH NOTES 623 FURTHER EVIDENCE FOR AN UNIDENTIFIED GROWTH FACTOR REQUIRED BY THE POULT1

Several investigators have reported that the growth of poults is improved by the inclusion of a source of the "animal pro-tein " factor in the ration, Scott et al. (1948) concluded that the poult has higher requirements than the chick for both the "animal protein " factor and factor S. McGinnis et al. (1949) reported that turkey poults fed a soybean meal-cereal grain turkey diet responded to a commercial fermentation product, where-as no response was obtained from a liver preparation containing vitamin Bi2. Simi-lar results have more recently been re-ported by Stokstad et al. (1950), in studies involving the use of aureomycin fermenta-tion mash. The results of the experiments presented here further demonstrate that vitamin B12 alone cannot adequately supplement a poult starting ration con-taining soybean meal as the primary source of protein. Day-old Beltsville White poults of mixed sex were reared to 5 weeks in electrically heated batteries with raised wire screen floors. Two lots of poults, located so as to eliminate positional effects, were subjected to each treatment in each experiment. The basal ration used in the first ex-periment contained 34.8 percent yellow corn, 58.0 percent soybean meal (expeller), 5.0 percent steamed bone meal, 1.25 percent limestone, 0.5 percent iodized salt, 0.5 percent cod liver oil (3000 A