Studies With Corn-Soya Laying Diets

NUMEROUS workers have reported acceptable levels of egg production from pullets fed corn-soya type laying diets containing less than the 15 percent of protein recommended by the National Research Council (1960); Thornton et al. (1957), Waibel and Johnson (1961), and Bray and Gesell (1961). An appraisal of the above reports indicated that corn-soya type diets formulated to contain 12 percent of protein were marginal for meeting the amino acid needs of laying pullets. With the exception of the recent reports of Johnson and Fisher (1959) and Waibel and Johnson (1961), few data are available concerning the comparative performance of pullets at successive intervals during the laying year when fed diets containing marginal and adequate levels of protein. The findings of Bray and Gesell (1961) suggest that seasonal trends in temperature, as they affect feed consumption and, hence, protein intake, may influence the relative performance of pullets fed diets containing marginal …