Metabolic and Microbiota Response to Arginine Supplementation and Cyclic Heat Stress in Broiler Chickens

The risk of suffering from heat stress (HS) and its multifaceted physiological consequences is extremely high for fast-growing broilers. Among the myriad nutritional strategies tried so far to help heat-stressed broilers, very little attention has been paid to the biological role of arginine and its dietary supplementation. Therefore, the main aim of this study was to assess the response of broilers to arginine supplementation and cyclic HS, with a focus on liver, pectoral muscle, and blood metabolic profiles and the cecal microbiota.For the cacal microbiota analysis one-day-old male Ross 308 broilers (n = 48) were randomly assigned to one of two experimental groups: the control group (CON) was given a commercial diet in mash form and the treated group (ARG) was fed CON diet supplemented with crystalline L-arginine. The same birds were also grown under two different environmental conditions: one group was constantly kept at thermoneutral (TN) conditions, while the other was kept at TN conditions until D34 and subjected to cyclic HS from D35 onwards (~34 C from 9:00 AM to 6:00 PM).