Productive and reproductive performance and egg quality of laying hens fed diets containing different levels of date pits with enzyme supplementations.

Two experiments were conducted to investigate the effect of phytase and/or multienzymes (protease, amyloglucoidase, xylanase, B-glucanase, cellulose, and hemicellulase) on improving the utilization of date pit (DP) in laying hens. In the first one, DP completely replaced corn in four isocaloric and isonitrogenous diets: (1) DP50 without additives, (2) DP50 + 500 FTU phytase/kg, (3) DP50 + 0.1 % multienzymes, and (4) DP50 + 500 FTU phytase/kg + 0.1 % multienzymes, in addition to the diet without DP. In the second experiment, DP was included at 0 %, 15 %, and 30 % in isocaloric and isonitrogenous diets. Meanwhile, diets containing 15 % and 30 % DP (DP15 and DP30) were fed without or with 500 FTU phytase/kg diet and/or 0.1 % multienzymes. In both experiments, each diet was fed to six groups of five hens housed individually (520 cm(2) per hen) during 30-42 and 28-42 weeks in the first and second experiment, respectively. In the first experiment, productive performance and shell quality of laying hens significantly decreased due to complete substitution of corn, but fertility and hatchability were not affected. Phytase, multienzymes supplementation did not restore laying performance to the control level. The results of experiment 2 indicated that DP could be included in laying hens diets up to 30 % when supplemented with multienzymes.