PERFORMANCE AND MOLECULAR RESPONSES TO GLUCOSE SUPPLEMENTATION OF MEAT-TYPE CHICKENS RAISED UNDER THERMONEUTRAL OR HEAT STRESS ENVIRONMENT

Heat stress (HS) impairs the performance of broiler chickens by reducing feed intake, suppressing protein synthesis and subsequently reducing carcass yield. The expression of intestinal nutrient transporters and kidney aquaporins (AQPs) are affected by HS. A 2x2 factorial design was used to evaluate the effect of glucose supplementation (Glu-Supplementation) on the performance and carcass parameters of broilers raised under thermoneutral (TN) or HS condition. Factors included glucose supplementation (0 and 6%) and temperature (250C and 350C). The treatments were TN-0% glucose (TN0); TN-6% glucose (TN6), HS-0% glucose (HS0) and HS-6% glucose (HS6). Heat was applied d28 to d35. Glu-Supplementation improved carcass yield, Pectoralis major and drumstick proportions in heat stressed-chickens. Under HS, Glu-Supplementation upwardly expressed monosaccharide (GLUT1 and GLUT5), fatty acid (FATP1, FABP6), and amino acid (rBAT, b0,+AT, SNAT2, and SNAT7) transporters; and downwardly expressed kidney AQPs1,2 and 3. Glu-supplementation provided extra-energy and possibly, molecular precursors for enhancing protein synthesis.