Interactive effects of glutamine and gamma-aminobutyric acid on growth performance and skeletal muscle amino acid metabolism of 22–42-day-old broilers exposed to hot environment

Abstract

The present experiment was conducted to investigate the interactive effects between dietary glutamine (Gln, 0 and 5 g/kg) and gamma-aminobutyric acid (GABA, 0 and 100 mg/kg) on growth performance and amino acid (AA) metabolism of broilers under hot environment. A total of 360 22-day-old Arbor Acres male chickens were randomly assigned to five treatment groups under thermoneutral chamber (PC, 23 °C) and cyclic heat stress (HS, 30-34 °C cycling) conditions. Compared with the PC group, cyclic HS decreased (P < 0.05) daily weight gain (DWG), daily feed consumption (DFC), the concentrations of Gln, glutamate (Glu), and GABA, and the activities of glutaminase and glutamic acid decarboxylase (GAD) in breast muscle at 28, 35, and 42 days, while it increased (P < 0.05) the activities of glutamine synthetase (GS) and gamma-aminobutyric acid transaminase (GABA-T) at 28, 35, and 42 days. Dietary Gln and GABA improved (P < 0.05) DWG and DFC of broilers under cyclic HS during 28-42 days. In breast muscle, the Gln supplementation increased (P < 0.05) the concentrations of Gln (28, 35, and 42 days), Glu (28, 35, and 42 days), and GABA (42 days) and the activities of glutaminase (28, 35, and 42 days) and GAD (28, 35, and 42 days) but decreased (P < 0.05) GS activities at 28, 35, and 42 days and GABA-T activities at 28 days. The addition of GABA increased (P < 0.05) the concentrations of Gln and Glu and activities of glutaminase and GAD, while it decreased (P < 0.05) GABA-T activities at 28, 35, and 42 days. Significant interactions (P < 0.05) between Gln and GABA were found on breast skeletal muscle Gln concentrations, glutaminase activities, GS activities at 28 and 35 days, and DWG, GABA concentrations, and GABA-T activities at 28, 35, and 42 days in broilers under cyclic HS. In conclusion, the present results indicated that the interactions of exogenous Gln and GABA could offer a potential nutritional strategy to prevent HS-related depression in skeletal muscle Gln and GABA metabolism of broilers.

Mechanism of continuous high temperature affecting growth performance, meat quality, and muscle biochemical properties of finishing pigs

“…In addition, many genes related with lipid metabolism such as FABP3, LPL, SCD, DECR, and LPINI were downregulated, which decreased the fat synthesis and deposition. High temperature also increased pH value and decreased the content of glycogen in muscle, which is consistent with Hu et al [15]. The shear force in feed-restricted group is greater compared to the control group, because of the lower intramuscular fat.…”

The effect of fermented buckwheat on producing l‐carnitine‐ and γ‐aminobutyric acid (GABA)‐enriched designer eggs

“…Compared with l ‐carnitine, the GABA content in normal forage was already high, thus it was unclear whether the added GABA (additional 47 mg GABA kg −1 feed compared with the control group) in the diet of the treatment group was transferred significantly. There has been no research on the transfer of GABA from feed to eggs, but it has been previously reported that consumption of a diet with supplemented GABA increased the concentration of GABA in breast muscle of broilers under heat stress . This report is indirectly related to our current research finding that GABA may have been transferred into the eggs.…”

Corticosterone-Mediated Physiological Stress Alters Liver, Kidney, and Breast Muscle Metabolomic Profiles in Chickens

“…Therefore, glutamine is designated as a conditionally essential amino acid during periods of stress [ 57 , 58 ]. Studies have shown the glutamine supplementation in broilers was associated with improved growth, carcass characteristics, and overall meat quality while under stress [ 57 , 59 ]. Under stress conditions, there is a depletion of glutamine [ 59 ], as was observed in breast muscle of birds administered ethanol in the current study, suggesting that ethanol can lead to a decrease in breast meat quality.…”