Effect Of Dietary Buckwheat Straw Level On Growth Performance, Blood Biochemical Indexes, Rumen Fermentation Indexes And Microflora In Sheep

Buckwheat was a rare medicinal and edible crop in nature,it had a high nutritional value and medicinal value.Buckwheat was rich in plant hormones,which could improve the level of endogenous hormones in the blood,with the promotion of animal growth and reproductive performance.At present,the use of buckwheat was mainly concentrated in fruits and extracts,the exploit and utilization of its straw and the possibility as coarse fodder was rarely reported.Ruminant could use the feed of cellulose,protein and other substances for the body to provide fermentation Energy,the production performance was a large extent dependent on the rumen microbial flora digestion and rumen fermentation regulation.Therefore,the effects of different diets of buckwheat straw level on the growth performance,serum biochemical,rumen fermentation and microbial diversity were studied in this experiment.Expt.l was carried out to influence of buckwheat straw on growth performance and serum biochemical indicators.A total of 30 hybrid 5-month-old Dorper(♂)xSmall Tail Han sheep(♀)F1 male lamb sheep weighted 25 kg were randomly devided into 5 groups.The control group was fed a basal diet,and the experimental groups,including A,B,C and D were fed experimental diet with the buckwheat straw replacing corn straw in basal diet of 13.75%,27.5%,41.25%and 55%,respectively.The results were as follows:(1)Compared with control group,the ADG and ADFI in group 27.5%was significantly increased,whereas the food/gain was significantly decreased(P<0.05).The ADG and ADFI in groups 42.25%and 55%was significantly decreased,and the food/gain was significantly increased(P<0.05).(2)Compared with the control group,the blood glucose level of the experiment groups was significantly decreased(P<0.05),and the urea nitrogen content in the 27.5%,41.25%and 55%groups was significantly decreased(P<0.05).The total protein content in the 27.5%and 55%groups was significantly increased(P<0.05),and the total antioxidant capacity was significantly higher in the 13.75%group than the control group(P<0.05).The 27.5%and 55%groups were significantly decreased in the creatine jubase(P<0.05).The activity of alanine transferase in the 55%group was significantly higher than the control group(P<0.05).Expt.2 was carried out to influence of buckwheat straw on rumen fermentation and main digestive enzymes’ activities.The content of TVFA and MCP in group 27.5%was significantly increased compared with the others groups(P<0.05).Compared with the control group,content of TVFA,NH3-N and MCP was significantly decreased in group 55%(P<0.05),and the pH was significantly increased(P<0.05).(3)Activities of carboxymethyl cellulose,xylanase,pectinase and filter paper enzymes were significantly increased in group of 27.5%compared with other groups(P<0.05).The activities of protease was decreased in experiment groups compared with control group(P>0.05).Expt.3 was carried out to influence of buckwheat straw on rumen bacterial diversity and microbial structure.The number of the tags and OTUs in the experiment groups was decreased compared with the control group.The Chaol index,Ace index,Shannon index and Simpson index in the 27.5%,41.25%and 55%groups were significantly decreased than the control group at the level of 0.03(P<0.05),it was indicated in these levels,the bacterial diversity was decreased,the microbial structure was tend to be simplified.On the level of phylum,the content of Firmicutes(75%)was highest in the group 27.5%,and the content of Bacteroidetes(15%)was the lowest(P<0.05).On the contrary,the group 55%had the highest content of Bacteroidetes(79%)and the lowest content of Firmicutes(16%).On the level of family,the group 27.5%possessed significantly higher content of Ruminococcaceae and lachnospiraceae,but its content of Prevotellaceae was significantly decreased(P<0.05).Compared with other groups,the group 55%had the highest content of R24-7(P<0.05),but the content of Ruminococcaceae,lachnospiraceae,Veillonellaceae and Prevotellaceae was significant decreased(P<0.05).In summary,the addition 27.5%of the buckwheat straw in diets significantly increased the daily gain and daily feed intake of the sheep;increased the antioxidant capacity in the serum;increased the content of volatile fatty acids,microbial protein and ammonia nitrogen in the rumen of sheep;Cellulase activity promotes the growth of cellulosic flora.Under the condition of this study,it was suggested that the addition level of buckwheat straw in diet is 27.5%.