Combined Effects of Cyclic Heat Stress, Dietary Induced Oxidative Stress and Different Levels of Antioxidant on Gut Fermentation Activity and Mucosal Morphology in Broiler Chickens

The gastrointestinal tract of broilers is susceptible to oxidative stress induced by heat stress (HS) and diet, which can be mitigated by the supply of exogenous vitamins and antioxidants. The aim of this study was to compare the extent of the effects of cyclic HS, and high levels of polyunsaturated fatty acids (PUFA) (HP) on gut health. It also aimed to investigate whether additional supplementation with vitamins E, C and selenium (HA) is required to support gut health under these conditions. In the present study, 192 one-day-old male Ross 308 broilers were randomly divided into eight experimental groups. Exposure to HS and HP significantly (p < 0.001) decreased villus height and villus-to-crypt ratio in the duodenum, while no differences were observed in the jejunum and ileum. In addition, oxidative stress in the liver, indicated by increased malondialdehyde (MDA) levels, was increased in the HP groups (p < 0.0001), while the HA groups had a positive effect on lowering MDA levels. The results confirm that cyclic HS and HP induce oxidative stress that damages the structure of intestinal morphology and that supplementation with HA could be a potential approach to mitigate the negative effects of these stressors.