عنوان مقاله [English]
نویسندگان [English]چکیده [English]
A 70-days experiment was conducted to investigate the effects of natural zeolite (clinoptelolite) on the performance of commercial laying hens. 288 Hy-Line W36 strain laying hens (50 weeks old) were allotted to 6 dietary treatments including basal diet as control and basal diet supplemented with 1, 2, 3, 4 and 5% zeolite that were fed ad -libitum throughout the experiment. Experimental diets for the 6 treatments were prepared to be iso-caloric and iso-nitrogenous. A completely randomized design with six treatments, eight replicates of six birds per replicate was used at this experiment. Daily feed intake (DFI), feed conversion ratio (FCR), egg production, egg weight, egg white quality, eggshell quality (thickness and percentage) and body weight changes were measured during the experiment. Results of this experiment showed that DFI, FCR, egg production and egg abnormality were not significantly (P>0.05) affected by zeolite supplementation. Zeolite supplementation significantly increased egg weight, eggshell thickness and live body weight gain of the hens. Dietary zeolite significantly decreased haugh unit of the eggs. In conclusion, natural zeolite significantly improved egg weight and eggshell quality, decreased haugh unit and live weight gain, and had no significant effects on other parameters.