Evaluation of a rapeseed (cv. Tower) meal protein supplement for growing pigs

Abstract

Seventy-two cross-bred castrated male pigs were ted tour experimental diets, either ad lib. or ristricted, from 20 to 90 kg live weight. Experimental diets were based on barley and wheat and contained either SBM or equal proportions of soyabean meal (SBM), meat meal (MM), and ‘Tower’ (Brassica napus) rape seed meal (RSM) on an isonitrogenous basis. Diets containing 8.4% Tower RSM did not depress daily feed intakes, indicating that RSM from a double low cultivar is fully acceptable to growing pigs. Over the growth period 20–55 kg, diets containing either SBM or SBM/RSM and fed in restricted quantities supported similar daily gains, these being superior to those of pigs fed diets containing combinations of MM/RSM or MM/SBM. The SBM and SBM/RSM diets promoted more efficient feed utilisation during the growth period 20–55kg and supported both faster and more efficient weight gains during the growth period 20–90 kg, than a diet containing MM/RSM. Pigs fed the diets ad lib. showed a similar but non-significant rate and efficiency of weight gain. The supplementary protein source had no significant effects on carcass measurements. Carcasses of pigs fed restricted quantities of feed were superior in some traits to those of pigs fed ad lib.