Effects of dietary vitamin E on the quality of table eggs enriched with n-3 long-chain fatty acids

Because of the proposed cardioprotective benefits of n-3 fatty acids and vitamin E, a trial was carried out to investigate the possibility of enriching eggs with n-3 fatty acid and vitamin E added to the hen's diet. One hundred ninety-two Hy-Line Brown hens, 39-wk-old, were divided into eight groups: four groups received the basal diet supplemented with 3% lard and four doses of dl-alpha-tocopheryl acetate (0, 50, 100, and 200 ppm), whereas the diets of the other groups were supplemented with 3% of fish oil and the same doses of vitamin E. The performances of the hens and egg weights were not affected either by the type of lipid supplement or by the vitamin level. The treatment with fish oil caused a dramatic increase (P < 0.01) of all n-3 fatty acids of the yolk, particularly EPA (19.53 vs. 0.74 mg/egg) and DHA (143.70 vs. 43.66 mg/egg), and an appreciable decrease of arachidonic acid (25.54 vs. 67.72 mg/egg). The different levels of dietary vitamin E slightly affected the fatty acid composition of the yolk. Yolk alpha-tocopherol increased linearly as dietary dl-alpha-tocopheryl acetate increased (P < 0.01) from the control level of 90.93 microg/g of yolk to 313.84 microg/g of yolk when 200 ppm were added to the hen diets. Twenty-eight days of storage at room temperature (20 to 25 C) did not alter the yolk fatty acid profile, and, moreover, the levels of vitamin E remained still very close to those observed in fresh egg.