Effects Of Adding Low-level Condensed Tannin On The Fermentation Quality Of Silage Fireball And The Rumen Fermentation Of Yanbian Yellow Cattle In Vitro

The purpose of this experiment was to investigate the effects of adding low-level condensed tannin on fermentation quality of silage wildballs,rumen fluid indicators of Yanbian yellow cattle,and their microbial flora.In the first experiment,the experiment uses fresh and mature wildfire balls as raw materials,and adds different doses of tannin for silage fermentation to study the effect of low-level condensation tannins on the quality of wildfire balls.The experiment was divided into four groups.CK group was the control group without adding tannin.The experiment group added tannin 0.2%,0.4%and 0.6%respectively.Each group had six repetitions.After silage for 60 days,all indexes were analyzed.The results showed that adding tannin in different proportion to the field fireball silage could improve the sensory score,reduce the pH of silage,increase the content of lactic acid,reduce the content of acetic acid and butyric acid,increase the content of crude protein in the field fireball,reduce the content of yeast and aerobic bacteria in the silage,and the T3 group with 0.6%tannin was the best.In the second experiment,four Yanbian Yellow Cattle with a mean body weight of 445.25 ± 38.52 kg and similar parity were selected to install a permanent rumen fistula to provide rumen fluid.The fireball forage of silage field was fermented in vitro for 48 hours according to the experimental design of Experiment 1.The pH,NH3-N content,total gas production,volatile fatty acid content of rumen fermentation were measured at 3 h,6 h.9h,12h,24 h and 48 h respectively,and the degradation rate of dry matter and crude egg white were calculated.Investigate the effect of low-level condensation tannin silage field fireball on rumen fluid index of Yanbian yellow cattle.The results showed that the pH value,the total gas production,the NH3-N content,the propionic acid content,the butyric acid content,the dry matter degradation rate and the crude protein degradation rate could be reduced by adding low-level condensed tannin silage field fireball,and the T3 group with 0.6%tannin was the best.In Experiment 3,we collected the rumen fluid from Experiment 2 and extracted the total DNA of bacteria.After PCR amplification,we used Illumina Hi Seq 2500 sequencing platform for high-throughput sequencing to explore the effect of adding low-level condensed tannin silage field fireball on the rumen microflora of Yanbian yellow cattle.The results showed that the addition of low-level condensed tannin silage field fireball did not change the composition of the whole rumen microflora of Yanbian yellow cattle,had no adverse effect on the rumen microbial abundance of Yanbian yellow cattle,and had a positive effect on the in vitro fermentation microbial diversity of Yanbian yellow cattle.In the aspect of rumen microbial composition,the dominant microflora at the level of each phylum were Firmicutes,Bacteroidetes and Proteobacteria and Prevotella-l at the level of each genus.The increase of Bacteroidetes abundance in the middle and later stage of Yanbian Yellow Cattle fermentation by adding low-level condensed tannin silage fireball had a positive effect on the degradation and digestion of starch and plant cell wall polysaccharides.The addition of low-level condensed tannin silage field fireball in the fermentation of Yanbian yellow cattle can inhibit the Gram-positive bacteria and the microbial abundance of cellulosic substances,which may be the reason why condensed tannin can inhibit the degradation of cellulosic substances.In conclusion,the addition of low-level condensed tannin in the field fireball of silage has strong protein binding ability and antibacterial activity,and can reduce the degradation of protein,improve the fermentation quality of the field fireball of silage,promote the in vitro fermentation of Yanbian yellow cattle,improve the degradation rate of dry matter,reduce the degradation rate of protein,and do not change the overall composition of rumen microbial flora,which has a great impact on microbial diversity It has a positive effect on inhibiting the activity of Gram-positive bacteria and the microbial abundance of cellulosic substances.