LAUSR

Abstract This experiment was conducted to study the effects of γ-amino butyric acid (GABA) on growth performance, blood biochemical indices and intestinal morphology of yellow-feathered broilers exposed to a high temperature environment. One hundred and forty four, 28-day-old male yellow-feathered broilers were separated into 2 groups with 6 replicates and 12 birds per replicate. The two experimental groups included: control group, which fed the basal diet, and GABA supplemented group, which fed the basal diet supplemented with 100 mg/kg GABA. After 7 days of feeding experimental diet at 26 °C, birds were fed the experimental diet and exposed to a high temperature environment at 35 °C and 60% RH for 14 days. Results revealed that average daily gain (ADG, p = .004) and average daily feed intake (ADFI, p = .003) of the GABA group were higher than control group, feed: gain ratio (F/G; p = .023) and mortality (p = .042) were lower than control group. The serum levels of glucose (GLU; p = .016), total cholesterol (T-CHO; p = .001), and low density lipoprotein (LDL; p = .001) as well as the activities of aspartate-aminotransferase (AST; p = .008), lactate dehydrogenase (LDH; p = .042) and creatine kinase (CK; p = .032) of the GABA group were lower than control group, while villus length (p = .016) of jejunum was higher than control group. In conclusion, adding 100 mg/kg GABA to diet can improve growth performance, reduce serum intracellular enzyme activities, protect the organs and intestinal morphology of yellow-feathered broilers exposed to a high temperature environment during 36-49 days of age. Highlights GABA improves growth performance of yellow-feathered broilers exposed to a high temperature environment. GABA protects the intestine of yellow-feathered broilers exposed to a high temperature environment.