Effects Of Defaunation On Ruminal Microbes And Digestibility Of Feed In Sheep With Different Ratio Of Concentrate To Roughage

The aim of current research was to study effects of ruminal microorganisms and their interactions on feed digestion,rumen fermentation parameters,fibrolytic enzyme activity,amylolytic enzyme activity and ruminal digesta passage rate on condition of different concentrate to roughage ratio(2:8 and 5:5,respectively) by defaunation in sheep for pursuing the reasonable suggestion in order to improve the utilization of feed in rumen and reduce the cost of production.Two trials were carried out and each trial included 6 healthy male Inner Mongolia sheep with weight about 35kg and aged near 1.5 years.sheep were randomly assigned into two groups( contrast and treatment).Sheep of treatment were isolated.In trial 1(concentrate to roughage ratio was 2:8)treatment group,sheep were defaunation.Then two groups were sampling at the same time.The same way was used in trial 2 (concentrate to roughage ratio was 5:5)When the ratio of concentrate to roughage was 2:8,after defaunation the number of bacteria and amylolytic bacteria significantly increased (P<0.05),the number of fungi and cellulolytic bacteria was not changed a lot (P>0.05).The digestibility of dry matter (concentrate) was increased significantly(P<0.05) and the digestibility of DM,neutral detergent fiber and acid detergent fiber (roughage) were significantly decreased (P<0.05),but the ruminal digesta passage rate was nor changed.Defaunation significantly increased (P<0.01) the activity of amylase, significantly decreased (P<0.05) activity of CMCase,FPA and pectinase,but had little effect on xylanase.Meanwhile the concentration of NH3-N was decreased significantly (P<0.05) and pH value was unchanged after elimination of protozoa. Although there was no significance in concentration of total volatile fatty acid and acetate, the concentration of propionate and butyrate significantly increased (P<0.05) and decreased (P<0.05),respectively.When the ratio of concentrate to roughage was 5:5,defaunation resulted in the significant increase(P<0.05) in populations of amylolytic bacteria and the significant decrease (P<0.01) in cellulolytic bacteria,respectively.However,no significance was observed in fungi and total bacteria. The digestibility of dry matter (concentrate) was increased significantly(P<0.05) and the digestibility of DM,NDF,ADF(roughage) and ruminal digesta passage rate were not affected by defaunation. Defaunation significantly increased (P<0.05) the activity of amylase, significantly decreased (P<0.05) activity of CMCase and FPA,but had little effect on pectinase and xylanase.After elimination of protozoa, pH value and concentration of NH3-N decreased significantly(P<0.01and P<0.05, respectively).Meanwhile the concentration of total VFA,butyrate,acetate and propionate significantly increased(P<0.05).