Effect of Vitamin E Supplementation on Oxidative Stress Markers in Layers During Peak Production in Imo State, South East Nigeria

Peak egg production in commercial laying hens is associated with heightened oxidative stress due to accelerated metabolic activity and increased free radical generation. This study assessed the effect of dietary vitamin E supplementation on oxidative stress markers in laying hens during peak production at a commercial farm in Imo State, South East Nigeria. One hundred and twenty Isa Brown layers at twenty-four weeks of age were divided into four groups receiving 0, 100, 200, and 400 IU of vitamin E per kilogram of feed for eight weeks. Blood samples were collected biweekly and serum assayed for malondialdehyde, superoxide dismutase, catalase, and glutathione peroxidase activities using spectrophotometric techniques. Vitamin E supplementation at 200 and 400 IU/kg significantly reduced malondialdehyde concentrations and elevated antioxidant enzyme activities compared to the unsupplemented control. Egg production percentages were highest in the 200 IU/kg group, suggesting an optimal supplementation threshold beyond which additional antioxidant capacity does not translate to further production gains. Feed intake and body weight were not significantly affected by vitamin E level. These findings support the targeted use of vitamin E in commercial laying operations to mitigate oxidative stress and sustain egg production efficiency under the hot-humid conditions characteristic of Imo State. Keywords: vitamin E, oxidative stress, laying hens, peak production, South East Nigeria.