Objective To evaluate the effect of Eucommia ulmoides leaves on the proliferation of probiotics, the inhibitory activity of pathogens and the effect of fermentation broth on the blood biochemical indexes of pregnant sows.

Methods Using Eucommia ulmoides leaves as raw material and the number of viable probiotics as index, different supplemental levels of Eucommia ulmoides leaves (0%, 0.5%, 1%, 2%, 3%, 4%) were investigated within 24～72 h to investigate the effects of lactic acid bacteria (Lactobacillus plantarum, Enterococcus faecalis, Lactobacillus rhamnosus and Bifidobacterium animalis), Bacillus (Bacillus subtilis, Bacillus licheniformis and Clostridium butyricum), and yeast (Saccharomyces cerevisiae boulardii and Saccharomyces cerevisiae) on the proliferation of probiotics. The bacteriostatic activity of probiotic fermentation products from Eucommia ulmoides was evaluated by plate bacteriostatic method and co-culture method. The fermentation broth of 9 kinds of probiotics in 4% Eucommia leaves group was mixed according to the same volume to make the composite probiotic broth of Eucommia leaves. The effect of the broth on the blood biochemical indexes of pregnant sows was measured according to the addition ratio of 1% and feed mix.

Results The total number of lactic acid bacteria probiotics in Eucommia ulmoides leaves showed a trend of significant increase with the increase of added concentration, and the number of lactic acid bacteria decreased with the increase of fermentation time. The addition of leaves of Eutmoia ulmoides had a good effect on the growth of bacillus, showing that the growth of bacillus was significantly promoted at low concentration (0.5%～2%), while the number of viable bacteria decreased slightly at high concentration (3%～4%), but was significantly higher than that of the control group. Eucommia ulmoides leaves had no significant effect on the yeast species at medium and low concentration, but the number of viable bacteria increased significantly at higher concentration, and the number of viable bacteria increased with the increase of culture time. The results of plate inhibition and co-culture showed that the bacterial probiotic fermentation broth of Eucommia ulmoides had a significant inhibitory effect on bacteria and fungi, while the yeast fermentation broth of Eucommia ulmoides had a better inhibitory effect on fungal pathogens. Most of the biochemical indexes of blood of pregnant sows were better than those of control group.

Conclusion Eucommia ulmoides leaves can significantly increase the number of intestinal probiotics, and the fermentation fluid has an inhibitory effect on pathogenic bacteria, and the inhibitory effect is dependent on concentration and fermentation time. Eucommia ulmoides leaves can significantly increase the number of intestinal probiotics, and the fermentation fluid has an inhibitory effect on pathogenic bacteria, and the inhibitory effect is dependent on concentration and fermentation time.