Negative effects of aflatoxin B1 (AFB1) in the diet on growth performance, protein and lipid metabolism, and liver health of juvenile hybrid grouper (Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂)

Abstract

With the increasing consumption of plant-based ingredients in aquafeeds, aflatoxin B1 (AFB1) contamination has become an issue of concern. This experiment aimed to investigate the effect of dietary AFB1 levels on the growth and liver function of hybrid grouper and the mechanisms involved. Six diets with different AFB1 levels were formulated at concentrations of 0 μgkg−1 (AFB0), seven μgkg−1 (AFB7), 30 μgkg−1 (AFB30), 111 μgkg−1 (AFB111), 445 μgkg−1 (AFB445) and 2230 μgkg−1 (AFB2230). A total of 540 healthy hybrid grouper with an initial weight of 11.59 ± 0.03 g were selected and randomly divided into six groups of three replicates of 30 fish each for a trial period of eight weeks. The results showed that with increasing dietary AFB1 levels, growth performance decreased, feed conversion ratio increased, and serum liver damage indicators increased. Liver section results also showed a significant hepatic inflammatory response and increased liver ROS levels in the high AFB1 dietary dose group. In addition, combined with the expression of critical genes in the liver, it was shown that high dietary AFB1 levels disrupted normal liver lipid and protein metabolism, reduced liver antioxidant capacity, and upregulated liver inflammation-related gene expression.