Effects of lipid sources and different levels of zinc on fatty acid profile and cholesterol egg yolk, antioxidant status and some blood parameters of laying hens

One of the issues that has created much concern about consumption of eggs is cholesterol and saturated fatty acids of that.
This experiment was conducted to evaluate effects of lipid sources and different levels of zinc on fatty acid composition and cholesterol of egg yolk, antioxidant status and some blood parameters of laying hens in a completely randomized design with factorial arrangement (3*4) with 12 treatments.
Treatments consisted of 4 percentages of different fat sources, including soybean oil, fish oil, tallow and different zinc levels of 100, 200 and 300 ppm and the control group.
The highest level of oleic acid in egg yolk was observed at tallow diets with the level of 300 ppm zinc (P The results of this study indicated that in the diets of tallow and soybean oil, oleic acid of egg yolk increased by adding zinc and highest glutathione peroxidase activity was observed in the diet of soybean oil and level of 200 ppm zinc.