微生物饲料添加剂对固原黄牛生长性能和瘤胃微生物区系的影响

Effects of Microbial Feed Additives on Growth Performance and Rumen Microflora of Guyuan Yellow Cattle

本试验旨在研究微生物饲料添加剂对固原黄牛生长性能和瘤胃微生物区系的影响。本研究选取12月龄固原黄牛56头(公母各占1/2),随机分为对照组和试验组,每组公母牛各2个重复,每个重复7头公(母)牛。对照组饲喂不含微生物饲料添加剂的全混合日粮(TMR),试验组在对照组饲粮的基础上添加2 g/kg微生物饲料添加剂。预试期7 d,正试期60 d。结果表明:1)虽然试验组全期(第1~60天)平均日增重(ADG)与对照组差异不显著(P>0.05),但在试验后期(第31~60天)试验组ADG较对照组显著提高了19.05%(P<0.05)。2)试验组中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的表观消化率分别比对照组显著提高了4.00%和12.11%(P<0.05)。3)试验组瘤胃液中乙酸(AA)、丙酸(PA)、丁酸(BA)含量较对照组分别极显著提高了56.36%、200.00%、150.00%(P<0.01),pH较对照组显著提高了2.71%(P<0.05),而异丁酸(IA)含量则较对照组显著降低了20.00%(P<0.05)。4)对瘤胃液中微生物区系的分析表明,与对照组相比,试验组厚壁菌门(Firmicutes)的相对丰度有升高趋势,而拟杆菌门(Bacteroidetes)的相对丰度有降低趋势;试验组不动杆菌属(Acinetobacter)、嗜冷杆菌属(Psychrobacter)、乳球菌属(Lactococcus)、束毛球菌属(Trichococcus)和类芽孢杆菌属(Paenibacillus)的相对丰度有升高趋势,而假单胞菌属(Pseudomonas)、土壤芽孢杆菌属(Solibacillus)、丛毛单胞菌属(Comamonas)和沃氏黄杆菌属(Wautersiella)的相对丰度有降低趋势。这些瘤胃菌属与ADG、ADF和NDF表观消化率及瘤胃液中AA、PA、IA、BA含量和pH均存在一定的相关性。由此可见,在固原黄牛TMR中添加2 g/kg微生物饲料添加剂可通过调控瘤胃微生物区系提高其生长性能及NDF和ADF的表观消化率。

This experiment was conducted to study the effects of microbial feed additives on growth performance and rumen microflora of Guyuan yellow cattle. Fifty-six 12-month-old Guyuan yellow cattle(half male and half female)were selected and randomly divided into control and experimental groups. Each group had 4replications,and 7 male or female cattle in each replication. The cattle in the control group were fed a total mixed ration(TMR)without microbial feed additives,and those in the experimental group were fed the TMR supplemented with 2 g/kg microbial feed additives. The pre-experimental period was 7 d,and the formal experimental period was 60 d. The results showed as follows:1)even though average daily gain(ADG)was insignificantly different between control and experimental groups during the whole experimental period(days 1 to60)(P>0.05),the ADG in the experimental group was 19.05% higher than that in the control group during the later period of experiment(days 31 to 60)(P<0.05). 2)Compared with the control group,the neutral detergent fiber(NDF)and acid detergent fiber(ADF)apparent digestibility in the experimental group was significantly increased by 4.00% and 12.11%(P<0.05),respectively. 3)Compared with the control group,the acetic acid(AA),propionic acid(PA)and butyric acid(BA)contents in rumen fluid in the experimental group were extremely significantly increased by 56.36%,200.00% and 150.00%(P<0.01),respectively,and the pH was significantly increased by 2.71%(P<0.05),but the isobutyric acid(IA)content was significantly decreased by 20.00%(P<0.05). 4)The analysis of microflora in rumen fluid showed that the relative abundance of Firmicutes in the experimental group was increased,while the relative abundance of Bacteroidetes was decreased compared with the control group. The relative abundances of Acinetobacter,Psychrobacter,Lactococcus,Trichococcus and Paenibacillus in the experimental group were increased;while the relative abundances of Pseudomonas,Solibacillus,Comamonas and Wautersiella were decreased compared with the control group. The relative abundance of those rumen bacterial genus had some correlations with ADG,ADF and NDF apparent digestibility,and AA,PA,IA,BA contents and pH in rumen fluid. It is concluded that adding 2 g/kg microbial feed additives to TMR for Guyuan yellow cattle can improve growth performance and increase NDF and ADF apparent digestibility through regulating rumen microflora.