Effect of enzyme supplementation on the nutritional value of raw, autoclaved, and dehulled lupins (Lupinus albus) in chicken diets.

The effects of adding crude enzyme preparations to diets containing raw, autoclaved, and dehulled lupin seeds on the performance of broiler and Leghorn chicks (7 to 21 days) were evaluated in five experiments. In the first experiment, enzyme addition (combination of Energex-carbohydrase, Bio-Feed Pro-protease, and Novozyme-alpha-galactosidase) to a diet containing 70% raw lupins improved the weight gain and feed to gain ratio of broiler chicks by 18 and 10%, respectively. The relative intestinal length and gizzard weight also were reduced by enzyme treatment. In the second experiment, the optimum concentration of enzymes was determined in diets containing 50% raw lupins. Bio-Feed Pro at 3% increased weight gains by 24% and the feed to gain ratio by 11%, whereas a combination of three enzymes at .10% of each yielded respective improvements of 18 and 9%. In Experiment 3, the AME and protein digestibility of dehulled lupin seeds were increased by 18 and 7% compared with those for raw seeds. Autoclaving (20 min) significantly (P < .05) improved chick performance and AME and protein digestibility of raw seeds. In the fourth experiment, autoclaving (15 min), dehulling, and a combination of both improved weight gains by 11, 15, and 8% and feed to gain ratios by 4, 11, and 6%, respectively. Enzyme addition improved the performance of birds fed raw, but not autoclaved lupin diets. In the fifth experiment, dehulling and enzyme treatment but not autoclaving (20 min) improved the performance of birds fed diets containing 50% lupins. The relative weight of gizzard was reduced by both treatments but that of the pancreas was affected only by enzyme treatment. Overall, enzyme supplementation of raw lupin diets considerably improved chick performance. Dehulling of lupins also improved chick performance with results for autoclaved lupins being inconsistent.