Effects of betaine on biological functions in meat-type ducks exposed to heat stress

Heat stress in hot seasons is a major problem in poultry production, particularly in humid areas. The aim of this study was to determine the pharmacodynamics of betaine on the blood and cecal short chain fatty acid profile in meat-type ducks exposed to heat stress. Three-hundred-sixty meat-type ducks (Anas platyrhynchos domesticus) were randomly allocated into 4 treatments: C (heat stress control without betaine), T1 (700 ppm betaine), T2 (1,000 ppm betaine), and T3 (1,300 ppm betaine). Each treatment had 6 replicated pens with 15 meat-type ducks per pen. The study was conducted for 42 days. Our findings revealed that the betaine group had higher body weight gain compared to the control group under heat stress (P < 0.05). Betaine supplementation resulted in more significant improvement in hematological indicators such as RBCs and platelet counts than the heat stress control group (P < 0.05). Under the heat-wave environment, supplementation of betaine manifested a significant decrease in blood pH (P < 0.05) but not in electrolytes (Na+, K+ and Cl-) and gas concentration. The concentration of short chain fatty acids (SCFA) in the cecum was higher than the control under heat stress conditions. The total SCFA, acetic acid, and propionic acid production was higher in the betaine supplemented groups compared to the heat stress control group (P < 0.05). Results showed that betaine supplementation has beneficial effects in meat-type ducks under heat stress on short chain fatty acid levels, blood biochemical parameters, and body weight.