白酒糟和发酵白酒糟对西门塔尔杂交牛瘤胃发酵参数和微生物区系的影响

Effects of distiller's grains and fermented distiller's grains on rumen fermentation parameters and microflora of Simmental hybrid cattle

本试验旨在研究不同比例白酒糟和发酵白酒糟替代饲粮中粗料对西门塔尔杂交公牛(西门塔尔牛×本地黄牛)瘤胃发酵参数和微生物区系的影响,采用2×3双因素试验设计。选取49头体重相近[(491.35±48.32)kg]、健康状况良好的西门塔尔杂交公牛,随机分为7组,每组7头牛。对照组饲喂基础饲粮,处理组分别饲喂用20%,40%和60%白酒糟和发酵白酒糟以粗料形式替换基础饲粮中皇竹草配制的全混合日粮,预饲期15 d,正饲期60 d。结果显示:(1)发酵白酒糟组丙酸、丁酸、异丁酸、异戊酸以及总挥发性脂肪(VFA)酸含量显著高于白酒糟组(P<0.05);酒糟添加水平对乙酸、丙酸、异丁酸、异戊酸、总挥发性脂肪酸含量以及乙丙比均有显著影响(P<0.05);酒糟类型和酒糟添加水平对瘤胃挥发性脂肪酸浓度无显著交互作用(P>0.05)。(2)发酵白酒糟组瘤胃微生物蛋白显著高于白酒糟组(P<0.05);酒糟添加水平对pH、氨态氮及微生物蛋白均有显著影响(P<0.05);酒糟类型和酒糟添加水平对微生物蛋白(MCP)有显著的互作效应(P<0.05)。(3)酒糟类型及添加量对微生物多样性及丰度无显著影响且酒糟类型与酒糟添加量之间不存在交互作用(P>0.05)。(4)门水平上,优势菌门均为拟杆菌门和厚壁菌门,其中发酵白酒糟组放线菌门丰度显著低于白酒糟组(P<0.05);属水平上,优势菌属均为普雷沃氏菌属。40%替代组和60%替代组中拟杆菌属BS11丰度较20%替代组显著降低;40%和60%发酵白酒糟替代组瘤胃球菌属2丰度较对照组显著升高(P<0.05)。各处理组其他几种菌属丰度差异不显著(P>0.05)。综上所述,发酵白酒糟对西杂牛瘤胃NH3-N的代谢和MCP的合成效果优于白酒糟。发酵白酒糟更有利于改善瘤胃发酵方式。白酒糟和发酵白酒糟对西杂牛瘤胃微生物门水平上的两种主要优势菌门(拟杆菌门、厚壁菌门)丰度无显著影响。发酵白酒糟和白酒糟用量较高时,发酵白酒糟维持西杂牛瘤胃微生物多样性更加有利,且能促进普雷沃氏菌属的生长和繁殖。

The objective of this study was to evaluate the effects of different replaced levels of distiller's grains(WDG)and fermented distiller's grains(FWDG)on rumen fermentation parameters and microflora of simmental hybrid cattle.The experiment was designed with a 2×3 factorial arrangement.For this purpose,49 healthy fattening cattle with similar body weigh[(491.35±48.32)kg]were selected and divided into 7 groups with 7 cattle in each group.The 7 groups included a control group whose cattle were fed with a basal diet,and 6 experimental groups that were fed with TMR whose Pennisetum sinese in the roughage were replaced with 20%,40%and 60%distiller's grains or fermented distiller's grains in the basal diet,respectively.The pre-trial period took 15 days and the formal experimental period lasted for 60 days.The result showed as follows:(1)The contents of propionic acid,butyric acid,isobutyric acid,isovaleric acid and total volatile fatty acids(VFA)in the FWDG group were significantly higher than those in the WDG group(P<0.05);Statistically significant effects were detected on the contents of acetic acid,propionic acid,isobutyric acid,isovaleric acid,total volatile fatty acids and the ratio of ethylene to propylene to adding different levels of distiller’s grains(P<0.05);There detected no interaction between different types and proportion of substitution of distiller’s grains on the concentration of rumen VFA(P<0.05).(2)The rumen microbial protein in the FWDG group was significantly higher than WDG group(P<0.05);It showed significant effect on pH,ammonia nitrogen and microbial protein when adding different level of distiller’s grains and there exists significant interaction between different types and proportion of substitution of distiller’s grains.(3)The type and amount of distiller's grains had no significant effect on microbial diversity and abundance,and there was no interaction between the type and adding level of distiller's grains(P>0.05).(4)The dominant phyla in each group were Bacteroidetes and Firmicutes,and the abundance of Actinomycetes in the FWDG group was significantly lower than that in the WDG group(P<0.05);the dominant genus of each group was Prevotella.The abundance of Bacteroides BS11 in 40%and 60%replacing groups was significantly lower than that in the 20%replacing group(P<0.05);the abundance of Ruminococcus_2 in 40%and 60%replaced of FWDG group was significantly higher than that in the control group(P<0.05);there observed no significant difference in the abundance of other bacteria among the treatment groups(P>0.05).Under the conditions of this study,fermented distiller’s grains were superior to distiller’s grains in the metabolism of rumen NH3-N and the synthesis of MCP in Simmental hybrid cattle.Fermented distiller’s grains were more conducive to improving the rumen fermentation mode.Fermented distiller’s grains and distiller’s grains were used in higher amounts,fermented distiller’s grains were more beneficial to maintaining the diversity of rumen microorganisms in Simmental hybrid cattle,and promote the growth and reproduction of Prevotella.