The combined influence of dietary flaxseed variety, level, form, and storage conditions on egg production and composition among vitamin E-supplemented hens.

Trial 1 tested the effects of ground vs whole flaxseed at dietary levels of 5, 10, or 15% compared to a corn-soybean or fish oil control on egg production of Leghorn hens over a period of 8 wk. Dietary flaxseed decreased feed consumption, weight gain, and egg weights compared to the control diets; however, flaxseed and fish oil significantly improved egg production (88.9 and 93.0%, respectively) compared to the control (83.1%). Incorporation of linolenic acid (C18:3n-3) into the egg increased linearly as the level of dietary flaxseed increased (2.31, 4.18, or 6.83% of the yolk fatty acids for 5, 10, and 15% flaxseed diets, respectively). In Trial 1, flaxseed and fish oil significantly increased percentage white and decreased percentage yolk compared to the control treatment but had no effects on egg cholesterol. Trial 2 was a factorial design of varieties of flaxseed (brown vs golden), types (ground vs whole), levels of dietary vitamin E (27 vs 50 IU/kg), and feed storage temperatures (4 vs 21 C) fed to hens for 6 wk. Brown flaxseed significantly increased egg weight and egg production compared to the golden variety. There was no difference in whole vs ground flaxseed for measured production variables. Vitamin E (50 IU) significantly improved egg production (96.1 vs 94.3%) compared to 27 IU. Storage temperature of flaxseed did not significantly affect any production variables. In conclusion, dietary flaxseed can be safely added whole to layer diets up to 15% without any detrimental effects on hen-day egg production. Levels of 10 to 15% flaxseed yield eggs with 4 to 7% yolk n-3 fatty acids, respectively, making these eggs rich sources of n-3 fatty acids.