The study on the impact of indoleacetic acid on enhancing the ability of the rumen's original microecology to degrade aflatoxin B1.

Aflatoxin B1 (AFB1) poses a serious threat to the health of cattle and is strictly monitored in their diets. Rumen microorganisms in cattle have the ability to degrade AFB1, but this capability is limited. Enhancing the degradation capacity of the original rumen microecology for AFB1 is a novel approach. From a molecular perspective,indoleacetic-3-acid (IAA) promotes the expression of cytochromes, which can improve the degradation of AFB1. Therefore, this study aims to investigate the impact of different concentrations of IAA on the degradation of AFB1 by the rumen microecology. Experiments used rumen fluid from three adult cows as donors, and the cows were all fed the same total mixed ration. Rumen fluid was collected from these three cannulated cows before morning feeding to prepare in vitro fermentation fluid. The experiments used a completely randomized design, with each treatment repeated four times. The results showed that as the fermentation time increased, the content of AFB1 gradually decreased, with a degradation rate of up to 75.73% after 24 h. AFB1 altered the rumen fermentation pattern, with a significant reduction in the content of acetic acid (P<0.05) and a significant decrease in the acetic acid to propionic acid ratio (P<0.05). It also affected the rumen microecology, causing a significant reduction in the abundance of Ruminococcus amylophilus, Prevotella ruminicola, and Fusobacterium succinogenes (P<0.05). In addition, this study found that with the increase in the amount of IAA added, the content of AFB1 in the rumen gradually decreased. IAA enhances the degradation capacity of the original rumen microecology for AFB1, and the addition of IAA alleviates the impact of AFB1 on Ruminococcus amylophilus, Prevotella ruminicola, and Fusobacterium succinogenes in the rumen (P<0.05). Moreover, the addition of IAA can promote the stability of the rumen microecology, with significantly higher acetic acid and acetic acid to propionic acid ratios in the fermentation fluid compared to the non-added group (P<0.05). In summary, the addition of IAA can improve the degradation capacity of the rumen microecology for AFB1, providing a new solution for alleviating the impact of AFB1 on animal health.