霉菌毒素分解酶对奶公牛生长性能和瘤胃发酵的影响

Effects of Mycotoxin Clastic Enzyme Addition on Growth Performance and Rumen Fermentation in Dairy Bulls

为研究霉菌毒素分解酶(MCE)对奶公牛生长性能、养分消化率、瘤胃发酵、瘤胃酶活和微生物菌群的影响,本试验选择26月龄、体重(763±12.3)kg、装有瘤胃瘘管的荷斯坦公牛8头,采用4×4重复拉丁方设计,4个处理组分别在试验牛饲喂基础日粮中补充0、10、15、20 g/d MCE,试验分4个阶段,每阶段包括10 d预试期和10d正试期。结果表明:与0g/d和20g/dMCE组相比,10、15g/dMCE组的平均日增重、总挥发酸浓度、乙酸摩尔百分比以及乙酸/丙酸比值提高,耗料增重比降低(P<0.05),瘤胃pH降低(P<0.05);与0 g/d MCE组相比,日粮添加15、20 g/d MCE提高了干物质和有机物消化率(P<0.05);与0 g/d MCE组相比,日粮补充15 g/d MCE提高了中性洗涤纤维与酸性洗涤纤维的消化率,降低了瘤胃氨态氮浓度(P<0.05);与0 g/d MCE组相比,10、15 g/d MCE组瘤胃内总细菌、黄色瘤胃球菌、产琥珀酸丝状杆菌和溶纤维丁酸弧菌的数量,以及瘤胃纤维二糖酶、羧甲基纤维素酶和木聚糖酶的活性均提高,瘤胃蛋白酶活性降低(P<0.05)。结果提示,日粮补充15 g/d MCE能显著改善奶公牛生长性能、瘤胃发酵和养分消化率。

The aim of this study was to investigate the influences of mycotoxin clastic enzyme(MCE)addition on growth performance,rumen fermentation,microbial enzymatic activity and microbiota in dairy bulls.Eight Holstein bulls with permanent rumen fistulas were selected and divided into four groups using a 4×4 repeated Latin experimental design.Bulls were fed a basic diet,four treatments were supplemented with 0,10,15,and 20 g/d of MCE,respectively.Experiment included four periods and each period continued for 20 days including 10 days of adaptive phase followed by a 10-days of data and sample collection period.The results showed that supplementation of MCE at 10 and 15 g/d increased average daily gain,total VFA content,molar percentage of acetate and the ratio of acetate to propionate,improved feed conversion ratio,and reduced the rumen pH compared with 0 and 20 g/d of MCE(P<0.05).Apparent digestibility of dietary dry matter and organic matter increased with supplementation of MCE at 15 and 20 g/d compared with 0 g/d(P<0.05).Apparent digestibility of dietary neutral detergent fiber and acid detergent fiber increased,whereas rumen ammonia nitrogen concentration reduced with supplementation of MCE at 15 g/d compared with 0 g/d of MCE(P<0.05).Copies of total bacteria,R.flavefaciens,B.fibrisolvens and F.succinogenes as well as the ruminal activities of cellobiase,carboxymethyl cellulase and xyranase increased(P<0.05),while ruminal protease activity reduced with supplementation of MCE at 10 and 15 g/d compared with 0 g/d of MCE.In conclusion,dietary MCE supplementation at 15 g/d significantly improved average daily gain,rumen fermentation and nutrient digestibility of dairy bulls.