全混合日粮中添加百脉根对肉牛瘤胃内环境的影响OA

To explore the effects of adding the leguminous forage Lotus corniculatus to total mixed ration on rumen of beef cattle,30 healthy Simmental crossbred beef cattle with similar body weight were randomly divided into 3 groups(10 cows per group),namely the control group(fed with basal diet),treatment 1(2%of Lotus corniculatus in dry matter of alfalfa was added to the diet)and treatment 2(4%of Lotus corniculatus in dry matter of alfalfa was added to the diet).Rumen pH,total nitrogen content,ammonia nitrogen content(NH3-N)and the contents of rumen protein-degrading bacteria and cellulose-degrading bacteria were measured at 0 h before morning feeding and 3,6,9 and 12 h after morning feeding for each group after 90 days.The results showed that adding Lotus corniculatus to the diet could increase rumen pH.The total nitrogen concentration in treatment 1 and treatment 2 was slightly lower than that in the control group from 3 to 9 h after feeding.Except at 3 h post-feeding,the NH3-N concentrations in the control group,treatment 1 and treatment 2 were 11.88-16.38,13.03-14.46 and 12.80-14.52 mg/100 mL,respectively,at the other time points.The urea nitrogen concentrations in the rumen of the 3 groups of beef cattle were similar.From 3 to 6 h after feeding,the protein nitrogen concentration in rumen fluid of the control group was higher than that of treatment 1 and treatment 2.The number of rumen protein-degrading bacteria in treatment 1 and treatment 2 was significantly lower than that in the control group(P<0.05).In conclusion,adding Lotus corniculatus to the diet can improve rumen nitrogen metabolism,inhibit the growth of protein-degrading bacteria,thereby inhibiting the fermentation and degradation of protein in the rumen and improving the utilization efficiency of feed protein.This study provides a reference for the application of Lotus corniculatus in ruminant feed.