Influence of lupin and faba bean on growth performance and nutrient digestibility in starter diets for broilers.

The effects of lupin and faba bean on growth performance, nutrient digestibility and gastrointestinal tract development of broilers fed starter diets were examined in a 21-day trial. Five diets based on soybean meal (SBM) or 100 or 200 g/kg Australian-grown lupin or faba bean were formulated and pelleted at 75°C. A total of 320, one-day-old male broilers (Ross 308) were allocated to 8 replicates per treatment, 8 birds per replicate. On d-21, birds from each replicate were euthanised, and ileal digesta was collected for nutrient digestibility. Pellet durability index, and hardness were lowest in diets containing 200 g/kg lupin or faba bean. Over the whole trial period, birds fed lupin diets had greater (P< 0.05) weight gain than those fed faba bean or SBM diet. Feed intake was lowest (P< 0.05) in faba bean, and feed conversion ratio (P< 0.05) poorest in birds fed SBM. Coefficient of apparent ileal digestibility (CAID) of nitrogen was greatest (P< 0.05) in grain legume diets, except that 100 g/kg faba bean was not different from SBM. The CAID of starch was greatest (P< 0.05) in lupin diets. Relative weight of gizzard and proventriculus of birds fed 200 g/kg faba bean, and 100 or 200 g/kg lupin diets were greater (P< 0.05) than those fed SBM diet. Gizzard and proventriculus weight of birds fed 100 g/kg faba bean were not different from birds fed SBM. These findings show that inclusion of lupin or faba bean up to 200 g/kg in broil er starter diets improved nutrient utilization and growth performance.