Evaluation of Anti-oxidant and Anti-inflammatory Effects of Brown Seaweed (Sargassum sp.) on Barki Sheep Exposed to Environmental Heat Stress or Challenged with Bacterial Endotoxin

Abstract

The heat stress is the most potent environmental stressor for livestock in tropical/subtropical regions. It induced splanchnic tissue hypoxia and intestinal oxidative damage leading to endotoxemia and systemic inflammation. The present study aimed to evaluate/compare the modulatory effects of consuming two different doses of the Egyptian brown seaweeds "Sargassum latifolium" (2% and 4% of the diet) for 40 consecutive days on some physiological and immunological alterations in Barki male sheep (Ovis aries) exposed to the environmental heat stress or challenged twice with the commercially prepared bacterial lipopolysaccharides (LPS, 1.25 g/kg body weight, injected intravenously on the 28th day and the 35th day of the experimental period). The results of the present study showed that the diet containing Sargassum latifolium (especially 4%) modulated significantly (P<0.05-0.001) almost all changes shown in the heat-stressed (HS) and LPS-challenged sheep including the increase in the thermo-respiratory response (skin and rectal temperatures and respiration rate) and the resulted hyperglycemia, dyslipidemia, anemia, and systemic inflammation (blood leukocytosis, the elevation in the erythrocyte sedimentation rate, and the increase in serum proinflammatory cytokines and heat shock protein-70 concentrations). In addition, it improved significantly (P<0.05-0.001) the body-weight gain and kidney functions in the HS sheep, as well as the systemic antioxidant defense system (blood total antioxidant capacity and the activities of enzymic antioxidants) in both HS and LPS-challenged sheep, and protected the animals from the risk of atherosclerosis and oxidative tissue damage. In conclusion, feeding sheep with the diet containing 4% of the Egyptian Sargassum latifolium was safe and suitable for animal nutrition, as well as efficiently alleviated the harmful effects of both the environmental heat stress and the challenge with the bacterial endotoxin in Barki sheep through improving the animal antioxidant defense system and regulating the thermo-respiratory and inflammatory responses.