effects of rice bran and phytase supplementation on performance, egg quality, and biochemical parameters of comercial hy-line hens

rice bran (rb) is a major by-product, produced from the rice milling process. this study was conducted to evaluate the performance, egg quality, and blood biochemical parameters of 288 hy-line laying hens fed diets with rice bran and commercial microbial phytase natuphos®5000. the experiment was a 4×2 factorial one with four rb levels (0, 5, 10, and 15%) by two phytase levels (0 and 5000 ftu/kgdiet). these diets were fed to experimental groups from 30 up to 42 week old. the results indicated that there were no significant phytase effects or rice bran levels, on hen-day egg production, feed intake, egg mass, yolk index, egg shell weight, egg shell thickness, haugh unit, specific gravity, and shell weight/surface area compared with control group. inclusion of the rb or phytase in laying hens diets did not significantly influence biochemical parameters (cholesterol, triglyceride, uric acid, glucose, total protein and albumin), and cholesterol in yolk. the results suggested that supplementing 5000 ftu/kgdiet of phytase enzyme for layers resulted in no further improvement; it was also indicated that use of rb at a dietary level is beneficial to the laying hens industry, up to 15% in iran. moreover, since the price of rb was cheaper than other major ingredients, dietary inclusion of rice bran (rb) would be beneficial.