An assessment of the nutritive value of vegetable protein meals for growing pigs using Silcock available lysine values

Abstract

The effects on the growth performance of pigs and the total and Silcock available lysine content of diets were studied when an equal amount of protein from rapeseed meal and soyabean meal, either expeller or solvent extracted, was included in diets based on wheat and meat and bone meal and fed in restricted amounts to 32 pigs from 20 to 45 kg liveweight. The total and available lysine content of the proteins and diets decreased in the order: solvent extracted soyabean meal, expeller extracted soyabean meal, expeller extracted rapeseed meal, solvent extracted rapeseed meal. The growth rates and food conversion ratios of pigs varied in the same order, and average growth rate and average food conversion were significantly correlated to both total lysine (r2 = 0.910, r2 = 0.918 respectively) and available lysine (r2 = 0.998, r2 = 0.998 respectively) in the diet. The weights of the thyroid glands of pigs fed either rapeseed meal were significantly greater than those of pigs fed the soyabean meals.'Pigs fed solvent extracted soyabean meal had more lean in their hams than pigs fed other supplements.