体外产气法研究丁酸梭菌对瘤胃发酵特性的影响OA北大核心CSTPCD

The purpose of this experiment was to study the effects of different levels of Clostridium butyricum supplementation on the gas production,fermentation parameters,and nutrient digestibility in TMR diet by in vitro gas production method,so as to determine the appropriate amount of Clostridium butyricum supplementation in beef cattle diet.Holstein steers with permanent fistula were selected as rumen fluid donors and TMR as culture substrate.The control group(CON group)only contained the culture substrate,while the Clostridium butyricum test group added Clostridium butyricum with the concentrations of 2 × 108(CB1 group),4 × 108(CB2 group),6 × 108(CB3 group),8 × 108(CB4 group)and 10 × 108 CFU/kg(CB5 group)on the basis of the culture substrate,with six replicates at each level.The results showed that the in vitro gas production of CB1 group was significantly lower than that of other groups when the fermentation time was 2 h and 4 h(P＜0.05).When the fermentation time was 12 h,the in vitro gas production of CB3 group,CB2 group,CB4 group,and CB5 group was significantly higher than that of CON group and CB1 group(P＜0.05).The pH value in each experimental group were significantly lower than those in CON group(P＜0.05),while the content of ammonia nitrogen(NH3-N)was significantly higher than that in CON group(P＜0.05),and there was no significant difference among the experimental groups(P＞0.05).The concentrations of acetic acid,propionic acid,and total acid in CB3 group,CB4 group and CB5 group were significantly higher than those in CON group(P＜0.05).Isobutyric acid content in CB1 group,CB2 group and CB3 group was significantly higher than that in CON group(P＜0.05).Dry matter digestibility(DMD)and neutral detergent fiber degradation(NDFD)of each experimental group were significantly higher than those of CON group(P＜0.05).The degradation rate of acid detergent fiber(ADFD)in CB2 group was significantly higher than that in CON group(P＜0.05).The study indicates that the addition of Clostridium butyricum can increase gas production,NH3-N,acetic acid,propionic acid,total volatile acid content and DMD.The suitable addition of Clostridium butyricum is 6 × 108 CFU/kg.