Replacement of soyabean meal with dehydrated lupin seeds in pig diets

Abstract

One hundred and twenty pigs with an initial weight of 11.6 kg ± 2.2 kg were given one of five isonitrogenous, isocaloric diets to evaluate lupin seeds as a protein supplement. The treatments replaced soyabean meal (SBM) with dehydrated lupin seeds ( L. alhus cultivar ‘Ultra’) at 0, 25, 50, 75 and 100% of the supplementary protein in barley-based diets. Starter pigs (10–20 kg) given the 25% lupin diet (25% L) had similar growth rates and consumed more feed ( p < 0.05), relative to those given the 0% lupin diet (0% L). However, there was a linear decrease in feed intake and weight gain of starter pigs with higher concentrations of lupins in the diet ( P < 0.05). This may have been due to the high fibre levels in the lupin seeds. Increasing levels of lupin seeds adversely affected the feed efficiency and bodyweight gain of grower pigs (21–50 kg) ( P < 0.05), but not feed intake. Finisher pigs (51–95 kg) given the 100% L or 0% L had similar feed intakes and bodyweight gains; however, increasing levels of dietary lupin seeds adversely affected feed efficiency ( P < 0.05). Dressing percentage, lean yield class value and commercial grade index of pigs were not affected by the amount of lupin seeds in the diet. Lupin seeds included at 6% of the diet (25%L) for starter pigs, 12% of the diet (75% L) for grower pigs and 9% (75% L) for finisher pigs gave a growth performance similar to those obtained with the barley-based diet containing SBM as the sole source of supplemental protein. Therefore, lupin seeds have potential as a protein source in diets for pigs, particularly grower and finisher pigs.