Effect of dietary aflatoxin B1 on growth, fecundity and tissue accumulation in gibel carp during the stage of gonad development

A 24-week feeding trial was conducted to evaluate the effect of dietary aflatoxin B1 (AFB1) on growth, physiological responses, histological changes, fecundity and accumulation in gibel carp (Carassius auratus gibelio) during the stage of gonad development. Triplicate groups of gibel carp (initial body weight 57.6 ± 0.1 g) were fed with three semipurified diets (Diets 1 to 3) designed to contain 0, 20, and 2000 μg AFB1 kg− 1 diets (determined level was 3.3, 22.3, and 1646.5 μg AFB1 kg− 1 diet, respectively). The results showed that, after 24 weeks of AFB1 exposure, there was no significant difference in final body weight between AFB1 exposure groups and the control group. No external changes, unusual behavior or significant difference in mortality were observed in the fish fed with AFB1. There were no significant differences in feeding rate (FR), specific growth rate (SGR) or feed efficiency (FE) between the control and experimental groups. Fish fed with various levels of AFB1 showed no significant differences in activities of serum alanine aminotransferase (ALT), and aspartate aminotransferase (AST) compared to the control group. No significant histological lesions in hepatopancreas and midgut were identified between the control and increasing AFB1 treatments. However, gonadosomatic index (GSI), absolute brood amount (AF), relative brood amount (RF) and oocyte diameter in the groups fed the diets with AFB1 were significantly lower than the control group. AFB1 accumulation in fish ovaries and muscles increased significantly as the AFB1 concentration increased in diets. AFB1 in muscles in all the groups were all below the safety limitation of 5 μg kg− 1 wet weight. These results indicate that AFB1 exposure up to approximately 2000 μg AFB1 kg− 1 diet showed no evident effect on growth and liver function of gibel carp, but it would do harm to fecundity of the fish.