Screening of Fermentation Conditions for Liver-Protecting Tablets Residues and Their Effect on the Slaughtering Performance of Brolier Chickens

In order to optimise the solid-state fermentation process of liver tablet dregs and evaluate its feed application value, Bacillus subtilis Bu412 was used as the strain. This was achieved by optimising the water content, temperature, time and inoculum amount by one-way test, and by detecting the changes of saponins and other active ingredients. One hundred and twenty 7-day-old white-feathered broilers were selected and randomly divided into the control group and 1%, 3% and 5% fermented dregs group to determine the slaughtering performance and HE staining to observe the liver and kidney morphology. The results demonstrated that the optimal process was identified as a water content of 60%, a temperature of 30°C, a duration of 72 hours, and an inoculum of 20%. The study revealed a significant increase in polysaccharides and polyphenols (P<0.05) and a decrease in saponins and flavonoids following fermentation. While no significant differences (P>0.05) were observed in the slaughter rate indices of the feeding group, they did exhibit higher values compared to the control group. Furthermore, the morphology of liver and kidney tissues was found to be normal. This finding indicates that the optimised fermentation process enhances the content of polysaccharides and polyphenols in the dregs, which is safe and has the potential to be valuable as a feed additive for broiler chickens. Furthermore, it provides a foundation for the effective utilisation of Chinese medicine dregs and the research and development of alternative-resistant feeds.