Effects Of Hainanmycin On Rumen Fermentation, Methanogenesis And Microbialflora

The aim of this study was to investigate the effects of different levels of supplementation with Hainanmycin on rumen fermentation, methane production and micro flora in vitro and make sure to effect the methane production and the type of rumen fermentation.The results showed that the addition of Hainanmycin could inhibit significantly the gas production (P<0.05). At each time point incubation in vitro, the different levels of supplement with Hainanmycin and monensin reduced significantly when compared with the control (P<0.05). The gas production of the 10mg/kg Hainanmycin supplementation in the diet could be lower than other levels (P<0.05). At 24h incubation in vitro, the gas production was inhibited quadratically (P<0.05). The results showed that Hainanmycin could inhibit activated aerogen, the 10 mg/kg Hainanmycin supplementation obvious reduced.The methane production was inhibited quadratically by the addition of Hainanmycin in the diet (P<0.05). At the same time, Hainanmycin inhibited the methane production by the fermentation time. And the methane production could reach the lowest level theoretically when the supplementation level of Hainanmycin was 7.2mg/kg.The different levels of supplement with Hainanmycin and monensin increased significantly the pH with the control (P<0.05) during the fermentation in vitro. It showed that Hainanmycin could change the pH. At 24h incubation in vitro, pH enhanced linearly remarkably as the inclusion level of Hainanmycin increased (P<0.05). Compared to the control, the 10 mg/kg Hainanmycin supplementation in the diet increased the pH by 4%.The addition of Hainanmycin could inhibit significantly and the concentration of ammonia nitrogen (P<0.05). At 24h incubation in vitro, ammonia nitrogen was inhibited quadratically by the addition of Hainanmycin in the diet (P<0.05). Compared the control, Hainanmycin supplementation groups reduced partly the ammonia nitrogen 6.45%,12.03%,12.21%.The addition of Hainanmycin had significantly no effect on VFA (P<0.05). At 24h incubation in vitro, acetate reduced linearly remarkably as the inclusion level of Hainanmycin increased (P<0.05). And the concentration of propionate increased (P<0.05). Butyrate and A/P decreased significantly (P<0.05). Hainanmycin could reduce acetate and increase propionate during the rumen fermentation, than changed the type of rumen fermentation.The different levels of supplement with Hainanmycin in the diet could affect significantly the percentage of total bacterial 16SrDNA of ruminococcu flavefaciens, fungi and protozoa. But the addition of Hainanmycin groups had no difference. The percentage of total bacterial 16SrDNA of ruminococcu flavefaciens, fungi were inhibited quadratically (P<0.05), protozoa changed linearly, and methanogen and ruminococcus albus were not altered by the treatment.The addition of Hainanmycin in the diet changed significantly rumen bacterium structure. The bands of DGGE fingerprint changed significantly by the fermentation time. The bands 6 had always existed in the experimental group and control. After adding Hainanmycin, the band 5 gained the dominant position. The band 4 in the control disappeared after 16h fermentation in vitro and in the experimental group existed with the dominant position after 12h. The band 3 had disappeared adding Hainanmycin after 12h fermentation in vitro, but it existed in the control. Then the band 1and 2 had losed the dominant position.The analysis of dominant sequence bands showed that the dominant band 6 always appeared similarity highest Ruminobacter amylophilus. The bands 2,4,5 was Uncultured rumen bacterium. The band 6 stood for Ruminobacter amylophilus. Hainanmycin inhibited the band 3 bacteria which stood for B.fibrisolvens.The analysis of similarity of bands in DGGE fingerprint showed that micro flora in the sample of rumen liquid similarity index is 62%-94%. Overall, the experimental groups of Hainanmycin formed a clusterâ… , and the control formed a clusterâ…¡.It was concluded that the supplementation with Hainanmycin in the diet could influence ruminal fermentation pattern, inhibit the methane production, and affect micro flora significantly in vitro.