草本植物混合物对肉牛瘤胃发酵和营养物质消化率的影响

Effects of herb mixture on rumen fermentation and nutrient digestibility in beef cattle

文章旨在评估日粮添加草本植物混合物对肉牛瘤胃发酵、氮平衡和养分表观消化率的影响。试验选择平均初始体重为(434±48.2)kg的肉牛48头,根据体重随机分为4组,每组4个重复,每个重复3头牛。对照组饲喂基础浓缩饲料和牧草,T1~T3分别在浓缩料添加100 g/d柠檬草、100 g/d柠檬草+10 g/d薄荷粉及100 g/d柠檬草+10 g/d薄荷粉+40 g/d大蒜粉。结果:各组肉牛粗饲料、浓缩料和总采食量相似(P>0.05),分别稳定在7.1~7.5、2.1~2.2和9.3~9.6 kg/d。T1组蛋白质消化率最高,T3组蛋白质消化率最低(P<0.05)。对照组氨氮、尿素氮浓度较T2和T3组分别提高了21.93%、24.59%和36.73%、41.05%(P<0.05)。与对照组相比,T1~T3组瘤胃原生动物数量分别降低了26.92%、38.46%和35.90%(P<0.05)。对照组尿氮排泄量较T1和T3组分别提高了55.92%和67.01%(P<0.05),T2组氮吸收率最高,分别较T2和T3组提高了4.31%和5.01%(P<0.05),而T1和T3组氮沉积率较对照组和T2组分别提高了25.30%、19.19%和20%、14.15%(P<0.05)。结论:柠檬草联合薄荷或大蒜粉使用可以降低瘤胃原生动物数量和甲烷产量,提高丙酸产量及氮利用量,但对瘤胃发酵特性和养分利用无负面影响。

The aim of this study was to evaluate the effects of dietary herbal mixtures on rumen fermentation,nitrogen balance and nutrient apparent digestibility in beef cattle.Forty-eight beef cattle with an average initial weight of(434±48.2)kg were selected and randomly divided into four treatments according to their weight,with four replicates for each treatment and three cows for each repeat.The control group was fed basic concentrated feed and herbage,and T1~T3 groups were fed concentrated feed with 100 g/d lemongrass,100 g/d lemongrass+10 g/d mint powder,and 100 g/d lemongrass+10 g/d mint powder+40 g/d garlic powder.Results:the rouse,concentrate and total intake of beef cattle in each group were similar(P>0.05),and were stable at 7.1~7.5,2.1~2.2 and 9.3~9.6 kg/d,respectively.The digestibility of T1 group was the highest and that of T3 group was the lowest(P<0.05).The concentrations of ammonia nitrogen and urea nitrogen in the control group were 21.93%,24.59%,36.73%and 41.05%higher than those in the T2 and T3 groups,respectively(P<0.05).Compared with the control group,the number of rumen protozoa in the T1~T3 group decreased by 26.92%,38.46%and 35.90%,respectively(P<0.05).The urinary nitrogen excretion of the control group was 55.92%and 67.01%higher than that of the T1 and T3 groups,respectively(P<0.05).The nitrogen absorption rate of the T2 group was the highest,which was 4.31%and 5.01%higher than that of the T2 and T3 groups,respectively(P<0.05).The nitrogen deposition rate of the T1 and T3 groups was 25.30%,19.19%,20%and 14.15%higher than that of the control group and T2 group,respectively(P<0.05).Conclusion:lemon grass combined with mint or garlic powder can reduce the number of protozoa and methane production in the rumen,increase the yield of propionic acid and the amount of nitrogen,but have no negative effect on rumen fermentation characteristics and nutrient utilization.