Comparative study on the effects of feeding canola and soybean oils on egg production and cholesterol in commercial layers

摘要

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 percent canola oil, 5 percent canola oil, 2,5 percent soybean oil, 5 percent soybean oil and control without any oil (all five rations were isocaloric and isonitrogenous) for a period of 9 weeks. Effect of thesetreatments 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 controldiet fed hens eggs. Addition of 5 percent 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.