Methionine mitigates aflatoxicosis in quail chicks by improving gut microbiota, immunity, and meat quality

This study aimed to investigate the effects of dietary methionine (Met) supplementation on performance, immunity, and meat quality in growing Japanese quail exposed to aflatoxin B1 (AFB1)-contaminated diets. Nine experimental diets were formulated, incorporating three levels of dietary Met (5.0, 6.0, and 7.0 g/kg) and three levels of AFB1 (0.0, 2.5, and 5.0 mg/kg) in a completely randomized design and fed from d 8 post-hatch to d 35 of age. The results revealed that increasing dietary Met levels significantly improved body weight gain (BWG; P < 0.001), feed conversion ratio (FCR; P < 0.001), and feed intake (FI; P < 0.001), while counteracting the negative effects of AFB1 on these performance parameters. Dietary Met supplementation also exerted a protective effect against elevated hepatic enzyme levels (AST, P < 0.001; ALT, P < 0.001; ALP, P = 0.001; and LDH, P < 0.001) and serum uric acid levels (P < 0.001) induced by AFB1. Furthermore, dietary Met enhanced humoral immunity responses by increasing antibody production against sheep red blood cell antigen (P < 0.001) and hemagglutination inhibition response (P < 0.001), mitigating the AFB1-induced immune impairment. Meat quality parameters, including pH (P = 0.04), drip loss (P < 0.001), and malondialdehyde concentration (P < 0.001), were significantly influenced by the interaction between dietary Met and AFB1. Lastly, dietary Met supplementation effectively counteracted AFB1's detrimental effects on ileal lactic acid bacteria populations (P < 0.001). In conclusion, dietary Met supplementation shows promise as a nutritional intervention to alleviate the harmful effects of AFB1 exposure in Japanese quail, particularly in improving food quality and overall health.