Feeding and nutritional value of sweet blue and yellow lupin seed (Lupinus angustifolius L., Lupinus luteus L.) for broiler chicks

In a metabolism trial with a total of 108 broiler chicks the nutrient metabolisability and energy content of the seeds of sweet blue lupins (Lupinus angustifolius L. var. Bordako and var. Borweta) were determined resulting in nutrient metabolisability quotients for organic matter, protein, ether extracts, and N-free extracts of 43% and 50%, 43% and 36%, 69% and 83%, and 46% and 58%, respectively. Energy concentration was calculated as 7.54 MJ AME/kg DM for Bordako and 8.22 MJ AME/kg DM for Borweta. In a 5-week fattening trial with 350 day-old male broiler chicks seeds of sweet yellow lupin (Lupinus luteus var. Borsaja) and of sweet blue lupin (Lupinus angustifolius var. Bordako) were used in isoenergetic and isonitrogenic diets in amounts of 20% and 30%. Feed intake (64.5 g/d without lupin seed) was increased to up to 70 g/d by including lupin seed but growth performance was rather similar for all groups (42.8 g/d; 40.9 g/d for the group 3 with 30% Lupinus angustifolius) resulting in a higher feed expense for the lupin seed diets (up to 1.64 versus 1.51 in the control group). Up to 20% yellow lupin seed can be included in broiler diets in replacement of soybean meal without impairing growth performance and feed-to-gain efficiency, when amino acid supplementation is adjusted. However, 30% yellow lupin seed impaired feed-to-gain efficiency by 9%. The inclusion of 20% blue lupin seed showed the same growth performance as the control, but feed-to-gain efficiency was reduced by 6%.