Effects Of Exogenous Enzymes On Rumen Fermentation And Digestion And Metabolism Of Nutrients In Weaning Lambs

The purpose of this study was to investigate the effects of exogenous enzyme types and levels on the digestion and metabolism of ruminal nutrients and related blood biochemical parameters in weaning lambs.In vitro fermentation method was used to screen the suitable dosage of cellulase,alpha amylase,neutral protease and the mixture of the three.The weaning lamb digestive metabolism experiment was conducted on the basis of this.Through its comprehensive effect on the fermentation index,the nutritional regulation effect of exogenous enzymes on weaning lambs was explored to improve the digestion metabolism and to provide a theoretical basis for better application of exogenous enzymes to increase the digestive metabolism and production performance of weaning lamb.Test 1 In vitro fermentation test,selection of appropriate levels of exogenous enzymesSelecting three single enzymes of neutral protease,alpha amylase and cellulase as the raw material of the exogenous enzyme preparation,three single enzyme treatment groups were designed,and each treatment group was set at three levels;one compound enzyme treatment group was set;A control group?without any enzyme preparation?was set up.The in vitro culture was performed at time points of0,1,2,4,8,12,24,48,and 72 hours,and the pH,NH₃-N concentration,mycelium protein content,and volatile fatty acid?VFA?concentration,neutral protease,alpha amylase and cellulase activity in fermentation broth were measured at each time point.The results showed that the optimum proportion of exogenous enzyme levels were respectively cellulase 13000IU/kg concentrate+protease 13000IU/kg concentrate+amylase 14000IU/kg concentrate,amylase 30000IU/kg concentrate,protease 300000IU/kg concentrate,cellulase 30000IU/kg concentrate.Test 2 Effect of Exogenous Enzymes on Nutrient Metabolism and Blood Biochemical Indexes of Weaning LambsThe purpose of this study was to investigate the effects of different exogenous enzymes on the blood biochemical indexes and nutrient digestibility of weaned lambs in corn soybean meal diets.25 weaned lamb aged 2 months with similar weight were randomly divided into 5 groups?Group I:control group,basal diet;group II:basal diet+cellulase+amylase+protease;group III:basal diet+amylase;group IV:basal diet+protease;group V:basal diet+cellulase?,each group of 5sheep,to study the effects of different kinds of exogenous enzymes on the blood biochemical indexes and nutrient digestibility of weaned lambs.The results showed that the average value of the experimental group II aspartate aminotransferase,total protein,urea nitrogen and creatine kinase,lactate dehydrogenase is higher than that of control group.Compared with the control group,the content of albumin increased,and the exogenous digestive enzyme had little influence on the content of alanine aminotransferase,globulin and glucose.The feed intake of the lambs in group II,group III and group V was significantly lower than that in the control group?P<0.01?;The intake of lambs in test group IV was significantly lower than that in control group?P<0.05?;The digestibility of NDF in group II and group III was significantly lower than that in control group?P<0.05?;The digestibility of ADF in experimental group III was significantly lower than that in control group?P<0.01?.In conclusion,Under the condition of this experiment,the addition of exogenous enzyme affected the intake of lamb;Exogenous amylase significantly or significantly decreased the digestibility of NDF and ADF;compound amylase significantly reduced NDF digestibility;The addition of exogenous digestive enzymes to the diets of weaned lambs showed no significant effect on their blood biochemical parameters and nutrient digestibility.Adding compound enzyme preparation has certain influence on blood biochemical indexes.