Aflatoxin B1 (AFB1) is a derivative of the difuranocoumarin class, which is most toxic and harmful. In livestock production, exposure to AFB1 has been demonstrated to induce growth retardation, immune dysfunction, and increased mortality in livestock and poultry species, including cattle, sheep, pigs, chickens, and ducks, thereby posing a significant constraint to sustainable animal husbandry practices. Current review article focuses on the toxic mechanisms of AFB1 in animals, including oxidative stress, apoptosis, and autophagy. Integrated high-throughput sequencing analysis and experimental investigations have demonstrated that dietary AFB1 intake compromises immune cell function, consequently enhancing the susceptibility of livestock and poultry to pathogenic infections. Animal experiments reveal that AFB1 exerts immunotoxicity (immunosuppression and immunostimulation). However, the specific mechanisms underlying AFB1-induced immunotoxicity remain unclear. This review provides a detailed summary of the known types of aflatoxins (AFs) and the transformation processes of their various metabolites. To sum up, this review comprehensively reviews the immunotoxic mechanisms of AFB1 in livestock and poultry, establishing a theoretical framework to guide early diagnosis, immunomodulatory interventions, and feed toxin mitigation strategies in veterinary clinical practice.

To Cite This Article: Cui R, Pan A, Wang T, Liang Y and Yu HF 2025. Aflatoxin B1 in animals: metabolism and immunotoxicity. Pak Vet J. http://dx.doi.org/10.29261/pakvetj/2025.207