不同添加剂处理全株玉米青贮对奶牛瘤胃发酵参数和菌群结构的影响

Effects of Whole Corn Silage Treated with Different Additives on Rumen Fermentation Parameters and Bacterial Community Structure of Dairy Cows

本试验旨在研究不同添加剂处理的全株玉米青贮对奶牛瘤胃发酵参数和菌群结构的影响。选取2~4胎、泌乳期、体重、产奶量相近的健康荷斯坦奶牛80头,随机分为4组,每组20头,分别饲喂用无添加剂(CK组)、有机酸制剂(OA组)、菌制剂(LAB组)、菌酶复合制剂(LABE组)处理的全株玉米青贮饲粮,试验期共70 d,其中预试期10 d,正试期60 d。结果表明:1)与CK组相比,试验组奶牛的干物质采食量均有所提高,但差异不显著(P>0.05),OA组、LAB组、LABE组产奶量分别提高了4.5%、1.1%、5.4%(P<0.05)。2)不同添加剂处理的全株玉米青贮对瘤胃内pH、氨态氮/总氮(NH3⁃N/TN)、总挥发性脂肪酸(TVFA)、丁酸含量和乙酸/丙酸的影响不显著(P>0.05),LABE组乙酸含量极显著高于OA组和LAB组(P<0.01),LABE组丙酸含量显著高于OA组和LAB组(P<0.05)。3)4组间Chao1、Observed species、Shannon、Simpson指数均差异极显著(P<0.01),且各指数均为LABE组>OA组>LAB组。4)试验组奶牛瘤胃液厚壁菌门(Firmicutes)相对丰度均高于CK组,变形菌门(Proteobacteria)相对丰度均低于CK组,但差异不显著(P>0.05)。试验组梭菌属(Clostridium)相对丰度极显著低于CK组(P<0.01),CK组类普雷沃氏菌科下一属(YRC22)相对丰度极显著低于3个试验组(P<0.01),LAB组和OA组颤螺旋菌属(Oscillospira)相对丰度显著高于CK组(P<0.05),与LABE组差异不显著(P>0.05)。由此可见,不同添加剂处理全株玉米青贮能够影响奶牛瘤胃微生物多样性,对瘤胃菌群具有一定调节作用,且菌酶复合制剂效果最佳。

This experiment was conducted to evaluate the effects of whole corn silag with different additives on rumen fermentation parameters and microbial community structure of dairy cows.A total of 80 healthy Holstein cows were randomly divided into 4 groups of 20 cows in each group,the whole corn silage was without addi⁃tives(CK group),with organic acid(OA group),bacteria(LAB group)and bacteria⁃enzyme complex(LABE group)for 70 days,of which the pre⁃feeding period was 10 days and the formal period was 60 days.The results showed as follows:1)dry matter intake of cows in the experimental groups was increased,but the difference was not significant(P>0.05).Milk production of OA group,LAB group and LABE group in⁃creased by 4.5%,1.1%and 5.4%,respectively(P<0.05).2)There was no significant difference in rumen pH,ammonia nitrogen/total nitrogen(NH3⁃N/TN),total volatile fatty acid(TVFA)contents,acetate/propi⁃onate of whole corn silage treated with different additives(P>0.05).The acetate content of LABE group was significantly higher than that of OA group and LAB group(P<0.01).The content of butyrate of LABE group was significantly higher than that of OA group and LAB group(P<0.05),but not significantly different from CK group(P>0.05).3)The Chao1,observed species,Shannon,and Simpson indexes of the four groups were significantly different(P<0.01),and the indexes were LABE group>OA group>LAB group.4)The rel⁃ative abundance of Firmicutes in rumen fluid of experimental groups was higher than that of the CK group,and the relative abundance of Proteobacteria was lower than of the CK group,but there was no significant differ⁃ence(P>0.05).The relative abundance of Clostridium of the experimental group was significantly lower than that of the CK group(P<0.01),and the next genus YRC22 in the CK group was significantly lower than that in the three experimental groups(P<0.01),the relative abundance of Oscillospira of the LAB and OA groups was significantly higher than that of the CK group(P<0.05),but not significantly different from the LABE group.In conclusion,the whole corn silage treated with different additives can affect the rumen microbial di⁃versity of dairy cows,and has a certain regulatory effect on rumen flora,and the compound preparation of bac⁃teria enzyme is the best.