Long-term effects of feeding flaxseeds on hepatic lipid characteristics and histopathology of laying hens.

The long-term effects of dietary flaxseed and tocopherols on hepatic and blood plasma lipids, fatty acids, tocopherols, hepatic TBA reactive substances, and histopathology of Brown Leghorn hens were investigated. Thirty-two-week-old ISA Brown Leghorn hens (n = 120) were kept in cages and were fed 1 of the 3 corn-soybean meal-based diets, a control diet (no flax) or a 10% flax diet with or without 100 IU of tocopherols, until the hens were 64 wk of age. Feeding diets with 10% flaxseed reduced hepatic and plasma fat content, hepatic triglycerides, total number of fat vacuoles, and number of cells with 75% or higher lipid infiltration in hepatocytes (P < 0.05). Addition of tocopherols to the 10% flax diet increased hepatic and plasma tocopherol content. A significant reduction in hepatic TBA reactive substances was observed in the hens supplemented with the basal diet with 10% flax and 100 IU of tocopherols (P < 0.05). Feeding diets containing flaxseed resulted in an increase in the content of alpha-linolenic (18: n-3) and docosahexaenoic acids (22:6n-3), with a concomitant reduction in monounsaturated and saturated fatty acids in the hen liver and plasma. Overall, long-term feeding of hens with flax led to a reduction in liver and plasma lipids and reduced hepatocellular infiltration. Inclusion of tocopherols may be needed to reduce lipid oxidation products in the liver of flax-fed hens. However, tocopherol supplementation had no effect on hepatocellular lipid infiltration or liver total lipid or triglyceride content.