No toxic effects or interactions between aflatoxin B1 and zearalenone in broiler chickens fed diets at China's regulatory limits

Currently, several countries such as China have established regulatory limits for six major mycotoxins in animal feed. However, these limits are primarily designed for single mycotoxin exposure. Co-contamination with multiple mycotoxins is increasingly common, and simultaneous exposure may lead to additive toxic effects. This study aimed to investigate the effects of individual and combined contamination of aflatoxin B₁ (AFB₁) and zearalenone (ZEA) at China's regulatory limits on the growth performance, oxidative stress, serum biochemistry, immunity indicators, intestinal morphology, liver and kidney histopathology of broilers by incorporating mycotoxin standards into the feed. A total of 432 one-day-old male AA broilers were randomly assigned to four treatment groups, each consisting of six replicates of 18 birds. The control group received a basic diet, while the experimental groups were supplemented with 10 μg/kg AFB₁, 500 μg/kg ZEA, or a combination of both in the basic diet. The experimental period lasted for 35 days. The results revealed no significant differences among the groups in terms of growth performance, oxidative damage markers, serum biochemistry, cytokine levels, intestinal health, or histopathological assessments of the liver and kidneys. Furthermore, no toxic interactions between the two mycotoxins were observed. Taken together, these results suggest that future assessments should take into account the combined toxicological effects of a wider range of mycotoxins to inform the revision and formulation of feed safety standards.