Effects of oxidized feed on productivity, plasma oxidative stress, and meat quality of broilers

Abstract High environmental temperature due to climate change can accelerate oxidation of feed during storage and preparation. Oxidized feed can cause elevated oxidative stress in live birds, resulting in decreased productivity and meat quality of broilers. The study was aimed to determine effects of feed containing oxidized oil on growth performance, plasma oxidative stress, and breast meat quality of broilers. Male broilers (192; Cobb500) at 21 days old were randomly allotted to 32 pens (8 pens/treatment) and raised for 21 days. The birds were fed feed containing fresh (Control) or oxidized corn oil (5%, Peroxide Value:140) with or without vitamin E (500 IU/kg feed) supplementation. Growth performance, oxidative stress markers in plasma collected at Day 42, and quality parameters of breast meat harvested at Day 43 were determined. Data were analyzed using proc glm and means were compared using Tukey’s studentized range (HSD) test. Oxidized feed and/or vitamin E supplementation did not affect growth performance and plasma DNA and protein oxidation. Oxidized feed significantly increased lipid oxidation and reduced total antioxidant capacity in plasma (P < 0.05) and, interestingly, dietary vitamin E made them worse (P < 0.05), indicating that oxidized lipids in feed can induce oxidative stress in live birds and vitamin E may act as a pro-oxidant in highly oxidized conditions. Although they did not affect sensory and functional properties of chicken breast meat, oxidized feed significantly increased lipid oxidation in cooked meat (P < 0.05) but dietary vitamin E considerably inhibited its development (P < 0.05), indicating that oxidized oil and vitamin E in feed can be accumulated in muscle and act as a pro- and anti-oxidants in meat, respectively. The results suggested that oxidized oil in feed can increase oxidative stress in live birds and susceptibility of breast meat to lipid oxidation, and dietary vitamin E can improve its oxidative stability.