Abstract

    The purpose of this study was to assess the effect of canola and soybean oils on egg production and cholesterol in layers. for this purpose. 15 experimental units (8 layers per experimental unit) were randomly allotted to 5 dietary treatments (3 experimental units/treatment) containing 2,5% canola oil, 5% canola oil, 2.5% soybean oil, 5% soybean oil and control without any oil (all five rations were isocaloric and isonitrogenous) for a period of9 weeks. Effect of these treatments on production parameters including egg production, egg mass, weight gain, feed intake and feed conversion ratio and egg quality parameters including shell thickness, albumen quality, yolk index, egg cholesterol level and yolk fatty acid composition were studied. The results indicated that the effect of canola and soybean oils on egg production and egg mass was non-significant. Significantly (P<0.05) less yolk cholesterol was found in hens fed diets containing oils compared with the control. Palmitic fatty acid content and total saturated fatty acids (SFA) content decreased as oils percentage increased. Total Polyunsaturated fatty acids (PUFA) content was significantly (P<0.01) greater in canola and soybean oil fed hens eggs than the control diet fed hens eggs. Addition of 5% canola oil to the diet resulted in yolk omega-6:omega-3 PUFA being significantly lower (P<0.01) than those of the control diets.

Keywords: Egg production, egg mass, weight gain, egg cholesterol, fatty acids, omega-6 PUFA, omega-3 PUF A