Leguminous seeds on substitutes of soybean meal in poultry diets

Abstract

The use of leguminous seeds (peas, faba beans and lupin seeds) in broiler feeding is quite possible with a correction of their low sulfur amino acid content. When they are introduced in the diets at levels between 20 and 35 %, they already constitue a good protein source substituting to soybean meal. The metabolisable energy content and nitrogen digestibility of peas and faba beans are increased by thermal and mecanical treatments. For laying hen feeding, peas can be largely used and can provide 30 % of the total nitrogen content of the diet. Peas are also favourable to the egg flavor. The possible use of faba beans is limited to 7 % of the diet by the vicin and convicin content of the seed which reduces egg weight. Faba beans have a slightly favourable effect on egg albumen quality but tend to increase the blood spots incidence. The limit for lupin introduction in layer diets is around 10 % ; at a higher level, a tryptophan deficiency can appear. Among the three considered seeds, lupin is the most concerned by this problem due to its high total protein content.