Dietary soluble flaxseed oils as a source of omega-3 polyunsaturated fatty acids for laying hens

The present study investigated the effect of dietary soluble flaxseed oil (SFO), as a source of omega-3 polyunsaturated fatty acids, on the fatty acid composition of egg yolk and various indices including laying performance, egg quality, nutrient composition of eggs, egg stability upon storage, and serum characteristics in laying hens. A total of 210 52-week-old Hy-Line Brown laying hens were assigned to one of 5 experimental diets. A corn-soybean meal-based control diet was mixed without or with SFO to reach the concentrations of 0.2, 0.4, 0.6, and 0.8% in diets and fed for 4 wk. Dietary SFO did not affect laying performance and egg quality. Increasing dietary SFO linearly increased the pH of yolk at 7, 14, and 28 d following storage at room temperature (P < 0.05). Malondialdehyde contents in egg yolks were quadratically increased (P < 0.05) at 0, 7, and 21 d following storage as the inclusion levels of SFO increased in diets. A significant increase (P < 0.05) in total omega-3 polyunsaturated fatty acids and docosahexaenoic acid, but not α-linolenic acid and eicosapentaenoic acid, was deposited in egg yolks at 2 and 4 wk following the SFO feeding. Finally, dietary SFO did not affect serum parameters such as total cholesterol, triglyceride, high-density lipoprotein cholesterol, and nitric oxide. It is concluded that adding SFO into the diets of laying hens can be an efficient strategy to enrich the omega-3 polyunsaturated fatty acids, including docosahexaenoic acid in eggs.