Indexed on: 15 May '09Published on: 15 May '09Published in: Poultry science
The effects of maternal n-6 and n-3 fatty acid (FA) supplementation on hatched chick tissue FA profile, antioxidant status, and ex vivo eicosanoid production by the cardiac tissue were investigated. Eggs with low, medium, and high levels of n-3 FA were obtained by feeding Cobb breeder hens were fed a corn-soybean meal-based diet containing 3.5% sunflower oil (low n-3), 1.75% sunflower oil plus 1.75% fish oil (medium n-3), or 3.5% fish oil (high n-3). Total n-3 FA in the yolk ranged from 1.8, 10.3, and 13.3% for low, medium, and high n-3 eggs, respectively (P < 0.001). Total long-chain (>20 C) n-6 FA in the egg yolk were 7.4, 2.1, and 1.3 for low n-3, medium n-3, and high n-3 eggs, respectively (P < 0.001). No differences were observed in total fat content of the eggs, which was 33.3, 31.6, and 31.9% for low n-3, medium n-3, and high n-3 eggs, respectively (P > 0.05). Hatchability for the low, medium, and high n-3 eggs was 89, 85, and 83%, respectively (P > 0.05). The total lipid content of chick liver, heart, brain, and lungs can be placed in the following descending order: liver > brain > heart > lung and was not affected by egg FA (P > 0.05). Total n-3 FA were higher in the tissues of medium and high n-3 chicks than in the tissue of low n-3 chicks (P < 0.05). There was no effect of egg FA on docosahexaenoic acid (22:6n-3) in the heart of low, medium, and high n-3 chicks (P > 0.05). There were no differences in total glutathione, glutathione peroxidase, glutathione reductase, or superoxide dismutase activities in the tissues of chicks from low n-3, medium n-3, and high n-3 eggs (P > 0.05). The medium n-3 and high n-3 chicks had lower catalase activity in the heart than did the low n-3 chicks (P = 0.013). The TBA reactive substances were significantly lower in the liver of high n-3 chicks than in that of low and medium n-3 chicks (P < 0.05). Heart tissue prostaglandin E(2) concentration was higher in low n-3 chicks than in those hatched from medium or high n-3 eggs (P < 0.05). Heart tissue thromboxane A(3) was lowest in low n-3 chicks (P < 0.05). There was no effect of yolk FA on ex vivo prostaglandin E(3) or thromboxane A(2) production in cardiac tissue (P > 0.05). These results indicate that modulating egg yolk n-3 FA enhances tissue n-3 FA and reduces proinflammatory cardiac eicosanoid production without affecting hatchability.