تاثیر سطوح مختلف خرده برنج در جیره بر عملکرد و خصوصیات تخم مرغ در مرغ های تخمگذار لگهورن

     Broken rice (BR) is one of the important by-products of rice production, which is produced in large scales in northern provinces of Iran. An experiment was conducted to investigate the effect of different levels of BR on egg quality and performance of laying hen, with 5 levels of BR (0, 10, 20, 30 and 40%) in a completely randomization design (CRD) on 90  Hy-line W36 egg-type laying hens for 84 days in 5 treatments and 6 replicates with 3 hens in each replicate. During the experiment, performance (feed intake, egg production, egg weight, egg mass and feed conversion ratio), blood parameters (Triglycerides, cholesterol, HDL, LDL and glucose), egg quality characteristic (Egg white height, thickness, strength and shell weight, yolk and egg index, egg score, haugh unit, yolk color and yolk cholesterol content), and body weight  of laying hen were measured. In this experiment, the effect of BR was not significant on feed intake, white height, thickness, strength and shell weight, yolk and egg cholesterol content, but it significantly decreased egg yolk color. Increasing of BR in diets caused significant rising in cholesterol and glucose concentration in week 6, and it also increased blood cholesterol, LDL and glucose concentration in the end of the experiment (P<0.05). Increasing BR level in diets significantly increased egg mass, egg production, egg weight, feed conversion ratio and body weight in the end of the experiment (P<0.05). The result of the present experiment indicated that utilization of BR up to 40 % had not any adverse effect on egg production, egg weight and feed conversion ratio and body weigh of laying hens.