不同类型全混合日粮对肉牛生长性能、养分消化及瘤胃发酵的影响

Effects of different types of total mixed ration on growth performance,nutrient digestion and rumen fermentation of beef cattle

文章旨在研究不同类型全混合日粮对肉牛生长性能、养分表观消化率及瘤胃发酵性能的影响。试验将初重为(151.26±2.21)kg的180头肉牛随机分为3组,每组5个重复,每个重复12头。在整个为期20w的饲养试验中,对照组肉牛饲喂象草水平为30%的全混合日粮,T1组饲喂青贮象草水平为30%的全混合日粮,T2组饲喂象草水平为30%的青贮全混合日粮。结果:T2组肉牛11~20w平均日增重及饲料效率均显著高于对照组(P<0.05)。对照组和T1组肉牛0~10w料重比较T2组分别显著降低23.30%和25.25%(P<0.05)。对照组肉牛干物质表观消化率较T1组显著提高15.36%(P<0.05),而对照组和T2组粗脂肪表观消化率较T1组分别显著提高6.35%和5.96%(P<0.05)。T2组肉牛粗蛋白质表观消化率较T1组分别显著提高6.88%(P<0.05)。对照组与T1组肉牛采食后2h氨氮浓度、挥发性脂肪酸和丙酸浓度均显著高于T2组(P<0.05),对照组肉牛采食前瘤胃挥发性脂肪酸和丙酸浓度显著高于T1和T2组(P<0.05)。采食2h后,T2组肉牛瘤胃乙酸浓度及乙酸与丙酸比值均显著高于对照组和T1组(P<0.05)。结论:饲喂发酵全混合日粮可改善瘤胃氮代谢,用含30%青贮象草的全混合日粮或发酵含30%象草的全混合日粮可以替代普通象草全混合日粮,对整个试验期肉牛的生长性能无负面影响。

This experiment was conducted to investigate the effects of different types of total mixed diets on growth performance,nutrient apparent digestibility and rumen fermentation performance of beef cattle.A total of 180 beef cattle with an initial body weight of 151.26±2.21 kg were randomly divided into 3 groups with 5 replicates per group and 12 cattle per replicate.During the entire 20 W feeding experiment,beef cattle in control group were fed a total mixed diet with 30%elephant grass level,those in T1 group were fed a total mixed diet with 30%silage elephant grass level,and those in T2 group were fed a total mixed diet with 30%elephant grass level.Results:The average daily gain and feed efficiency of beef cattle in group T2 at 11~20 W were significantly higher than those in control group(P<0.05).The feed/gain of beef cattle in control group and T1 group at 0~10 W was significantly decreased by 23.30%and 25.25%compared with that in T2 group(P<0.05),respectively.Compared with T1 group,the apparent digestibility of dry matter in control group was significantly increased by 15.36%(P<0.05),while the apparent digestibility of ether extract in control group and T2 group was significantly increased by 6.35%and 5.96%(P<0.05),respectively,compared with T1 group.Compared with T1 group,the apparent digestibility of crude protein in T2 group was significantly increased by 6.88%(P<0.05),respectively.The concentrations of ammonia nitrogen,volatile fatty acid and propionic acid 2 h after feeding in control group and T1 group were significantly higher than those in T2 group(P<0.05),and the concentrations of volatile fatty acid and propionic acid in rumen of control group were significantly higher than those in T1 and T2 groups before feeding(P<0.05).After 2 h of feeding,the acetic acid concentration and the ratio of acetic acid to propionic acid in the rumen of T2 group were significantly higher than those of control group and T1 group(P<0.05).Conclusion:Feeding the fermented total mixed diet can improve the rumen nitrogen metabolism.The total mixed diet containing 30%silage elephant grass or the fermented total mixed diet containing 30%elephant grass can replace the normal elephant grass total mixed diet.There is no negative effect on the growth performance of beef cattle during the whole trial period.