POOR PERFORMANCE OF BROILERS FED DIETS CONTAINING SOYBEAN-MEAL AS THESOLE PROTEIN-CONCENTRATE

Broiler chickens fed diets containing soyabean meal as the sole dietar y protein concentrate consistently showed poor growth in a number of f eeding trials. Soyabean meal processed in Australia gave inferior perf ormance to soyabean meal processed in the U.S.A. Growth was improved a t similar dietary energy and protein concentrations by replacing appro ximately 25% of the soyabean meal with either sunflower meal, cottonse ed meal or rapeseed meal but not by supplementing the soyabean meal di et with lysine, methionine and cystine. The responses of broilers to t he soyabean meal diet were unaffected by the cereal component of the d iet and the beneficial responses observed when sunflower meal replaced part of the soyabean meal were not related to the amino acid composit ion or digestibility of the diets.