عنوان مقاله [English]
نویسندگان [English]چکیده [English]
The present study was carried out to investigate the effects of different levels of canola meal eithr with or without phytase addition on laying hen's performance. A number of 288 layer hens (the strains of Hy-line W36) at the 60th week of age, selected as based on the same egg production percentage and body weight were, assigned to a factorial arrangement with a completely randomized design of 18 treatments (each treatment in 4 replicates). The factors included 6 levels of canola meal replacements (0, 20, 40, 60, 80 and 100%) and 3 methods of enzyme addition namely: 1-without enzyme 2-with enzyme (rations balanced with nutrient’s derived from the enzyme accounted for in feed formulation and 3-with enzyme and derived nutrients from the enzyme not taken into account in formulating the ration. The experiment was performed in three 28 day periods. The results indicated that feed intake was not affected by canola meal and enzyme and it was not affected by the interaction between enzyme and canola meal either. Phytase and canola meal addition to layer diet had no significant effect on mass egg production. Egg weight was affected by different levels of canola meal (P<0.01). The effect of interaction between phytase supplementation and canola meal in diet was significant on egg weight (P<0.05). Egg mass didn’t affect by canola meal, phytase and their interaction (P>0.05).There were no significant effects of different levels of canola, enzyme and their interaction on body weight changes, soft and cracked shell egg percentage and FCR (P>0.05). The effect of canola meal and phytase on toe ash as well as its Ca and P content was significant (P<0.01).