Effects of γ-aminobutyric acid on growth performance, immune function, and serum biochemical indexes of broilers.

The experiment aims to explore the impact of varying proportions of γ-aminobutyric acid (GABA) on the growth performance, immune function, and serum biochemical indexes of broilers. The trial employed a randomized block design, a total of 1 200 one-day-old broilers were divided into four groups with six replicates per group and 50 broilers per replicate. The broilers were fed diets supplemented with 0, 10, 20 and 40 mg/kg GABA, respectively. The trial lasted for 21 days. The results showed that compared with Group I, Group IV showed an extreme reduction in the feed-to-gain ratio (F/G) (P<0.01), and there was a significant increase in average daily feed intake (ADFI) and average daily weight gain (ADG) (P<0.05). The thymus index, bursa index, and the serum levels of immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), and interferon-γ (IFN-γ) in Group IV were all significantly elevated (P<0.05). The serum leptin (Lep) levels in all experimental groups were significantly decreased (P<0.05). The levels of serum growth hormone (GH), insulin-like growth factor 1 (IGF-1), albumin (ALB), and high-density lipoprotein (HDL) in Group III and Group IV were significantly increased, while the levels of total cholesterol (TC) and triglycerides (TG) were significantly reduced (P<0.05), and the urea nitrogen (BUN) content showed an extreme decrease (P<0.01). The total protein (TP) and globulin (GLB) content in Group IV, as well as the levels of cholecystokinin (CCK) and the activity of alanine aminotransferase (ALT), were significantly reduced (P<0.05). The study suggests that the addition of 40 mg/kg GABA in the feed can enhance broilers' appetite, promote protein deposition in the body, regulate growth and development, and strengthen the immune system. [ABSTRACT FROM AUTHOR]