Further evaluation of proteins for the growing chicken by the carcass retention method

In this study are reported further net protein values (SPV) of protein sources used either commercially or in the laboratory with the growing chicken. A dehulled soya meal was a better protein source than non‐dehulled meal. Dried beef prepared in the laboratory gave one of the highest NPV yet determined in our laboratory. When a commercial fish or meat meal was used as a supplement to a maize‐soya‐lucerne protein combination, the former protein significantly improved the KPV of the mixture, whereas the latter did not. Safflower protein, when supplemented with the limiting amino‐acids, methionine and lysine, supported excellent growth but the XPV was much inferior to those of other proteins that supported equivalent growth.