Effects Of Succinate Supplementation On Digestion And Metabolism,Rumen Fermentation And Micro Flora Structure Of Tan Sheep

In this experiment,the effect of dietary succinic acid on digestive metabolism,rumen fermentation and microflora structure of Tan sheep was initially investigated in order to provide new ideas for improving the production performance of Tan sheep.A total of thirty-six 5-month-old ram lambs,weighing about 33 kg,in good physical condition,healthy,and disease-free,were allotted into 4 treatment groups with 6 replicate per treatment and 3 lambs per replicate.A single-factor experimental design was used to study the effects of adding 0,0.5%,1%and 2%succinic acid on the digestive metabolism and rumen fermentation of Tan sheep,and the effects of adding 0,0.5%,1%and 2%succinic acid on the structure of rumen flora of Tan sheep by 16S rRNA high-throughput sequencing technology.The results of the experiment were as follows:Experiment 1:Effect of dietary succinic acid supplementation on digestion and metabolism of Tan sheep.The results of nutrient digestibility showed that compared with the control group,the apparent digestibility of neutral detergent fiber of Tan sheep diet was significantly increased（P<0.05）,and the apparent digestibility of acid detergent fiber was increased significantly（0.05≤P<0.1）,but the addition of succinic acid had no significant effect on the apparent digestibility of Tan sheep diet（P>0.05）.The nitrogen metabolism results showed that compared with the control group,the total utilization of fecal nitrogen,deposited nitrogen and nitrogen did not differ significantly（P>0.05）,and the fed nitrogen and digested nitrogen increased in test group Ⅰ and test group Ⅲ compared with the control group（0.05≤P<0.1）.Nitrogen digestibility was significantly increased in test group Ⅱ and test group Ⅲ compared to the control group（P<0.05）.Experiment 2:Effect of dietary succinic acid supplementation on rumen fermentation parameters and enzyme activity in Tan sheep.The results of fermentation parameters showed that the pH value of the rumen decreased significantly（P<0.05）,and the ammonia nitrogen concentration was significantly reduced（P<0.01）.The concentrations of Acetic,Propionic,Butyric and Total volatile fatty acid were significantly higher compared with the control group（P<0.01）,while the Acetic/Bropionic were significantly lower than that of the control group（P<0.05）.The enzyme activity test group Ⅱ was highest with the increase of the concentration of succinate.Compared with the control group,there was a significant increase in rumen cellulase activity in the test group（0.05<P<0.1）,while the rumen α-amylase activity of the test group Ⅲ was lower than that of the control group,but the difference was not significant（P>0.05）.The enzyme activities of the rumen lipase and protease were higher than that of the control group,but there was no significant difference（P>0.05）.Experiment 3:Effect of dietary succinic acid supplementation on the rumen bacterial flora structure of Tan sheep.The results showed that dietary addition of succinate altered the species composition and coverage of the rumen microbial community in Tan sheep.Sequenced and analyzed the rumen contents of Tan sheep using 16S rRNA sequencing,and obtained the differential taxon based on the screening criteria of LDA>2.0 and P<0.01,from phylum to genus,30 units with significant differences in relative abundance were selected among the four groups in this trial,among,the control group significantly differentiated 12 rumen microorganisms,the main enrichment is Desulfovibrio,Desulfovibrionales,Desulfovibrionaceae under proteobacteria There were four significantly different ruminal microorganisms in test group I,the main enrichment is TM7 and TM7₃ at the TM7 phylum level.Test group Ⅱ had seven significantly different rumen microorganisms,the main enrichment are Pseudomonadales under the Proteobacteria and Sphaerochaetales,Sphaerochaeta,Sphaerochaetaceae under the Firmicutes.There were 7 significantly different ruminal microorganisms in the test group Ⅲ,the main enrichment were Pseudomonadaceae,Pseudomonadaceae_Pseudomonas,Bifidobacteriales,Bifidobacterium,Bifidob acteriaceae under proteobacteria.In conclusion,the addition of succinate improves the digestibility of cellulose and nitrogen,improves the body’s digestive capacity,improves the rumen pH and volatile fatty acids,reduces ammonia nitrogen,changes the differential rumen microorganisms to enhance the rumen digestion and fermentation function,and maintains the rumen health.