Effects Of Fibrolytic Enzymes, Isobutyrate Or Their Combination On Ruminal Development In Calves

For study the effects of fibrolytic enzymes, isobutyrate or their combination on ruminal development in dairy calves, we select3630-day-old male Holstein calves with similar weight and well developed, randomly divided into four groups for the feeding trial. Experimental group’s diet was basal diet added with fibrolytic enzymes (1.83g/d, containing filter paper activity160FPU and xylanase activity4000IU), isobutyric acid (6g/d), the control group fed basal diet only. Slaughtered after measuring size and weight of the calves before morning feeding at45,60and90days of age respectively, Collect rumen fluid, rumen tissue,measure rumen fermentation, rumen enzyme activity, the quantitative expression of cellulolytic bacteria flora, the expression of rumen functional gene, the morphological change of Rumen The results showed that:(1) Effects on body weight:the weight of calves with isobutyrate added diet and diet mixed added with isobutyrate and fibrolytic enzymes was high than the that with basal diet and diet added with fibrolytic enzymes (P<0.05); On60days age, the weight of mixed added group was significantly higher than the control group and isobutyrate added group (P<0.05); The weight of isobutyrate added group was significantly higher than the control group (P<0.05). On90days age, the weight of mixed added group was significantly higher than the control group (P<0.05).(2) Effects on body size:On45days age, the size of the group added only with fibrolytic enzymes has no significant change with that of the control group (P>0.05); The Body length, chest depth, rump length of the group added only with isobutyrate was significantly higher than the control group (P<0.05). There also has a significantly increase on body height, body length, chest width, chest depth, rump length of mixed added group than the control group (P<0.05).(3) total VFA, acetic acid of the experimental group was significantly higher than the the control group (P <0.05); Despite of90days age group added with fibrolytic enzymes, ammonia nitrogen concentrations were significantly lower (P<0.05).(4) The activity of rumen CMC, xylanase enzyme, paper enzyme, cellobiase of experimental group was significantly higher the control group (P<0.05).(5) The major rumen cellulolytic bacteria flora quantitative expression of experimental group was significantly increased than the control group (P<0.05).(6) The results showed that:Add fibrolytic enzymes to the diet of calves has no significant effects on rumen cellulolytic development of (P>0.05). Rumen tissue morphogenesis growth (except for the thickness of the outer cuticle) increased significantly after adding isobutyrate to the diet of calves.(7) Adding isobutyrate to the calves’ diet significantly influenced the functional gene of rumen (P <0.05)(except for the INSR and HMGCS1of Anterior ventral blind sac of rumen).Mixed added group was also significantly higher than the control group (P<0.05)(except for the INSR and HMGCS1of Anterior ventral blind sac of rumen). For the effects of ruminal developmentMixed, added group was better than single added group.