Protein levels in practical diets for bacon pigs

Abstract

1. The performance and profitability of growing-fattening bacon pigs on two diets, A and B, were compared in farm-scale trials at five centres involving a total of 94 pigs. Diet A contained normal amounts of white-fish meal, middlings and barley meal. Diet B was a cheap low-protein diet containing 90–95% barley meal and no wheat offals.2. The average crude protein contents of the diets were: diet A, weaner meal 17·2%, fattener meal 14·1% and diet B 14·8% and 12·1% respectively.3. The pigs on diet A had a daily live-weight gain 1·26 lb. and a food conversion ratio of 3·38 lb.; corresponding figures for the pigs on diet B were 1·22 lb. and 3·49 lb.The food costs of the pigs on diet B were lower by 10s. 10d. per pig; although the grading of these pigs was slightly poorer, the ultimate profit was 7s. 10d. greater per pig than for diet A.4. At a sixth centre, decorticated groundnut meal was used in diet B instead of soya bean meal; this had a marked adverse effect on the performance of the pigs and the profit was 18s. 3d. less per pig than for diet A.