茶皂素对奶牛瘤胃发酵及瘤胃微生物区系的影响

本试验旨在研究茶皂素对奶牛瘤胃发酵及瘤胃微生物区系的影响。试验选用12头健康状况良好,体重相近的荷斯坦奶牛,随机分为4组,均饲喂基础饲粮,各组分别灌服0(对照)、20、30、40 g/d茶皂素,茶皂素与水混匀灌服,进行预试期14 d,正试期35 d的饲养试验。正试期期间每隔7 d,在晨饲前1 h用口腔采样器采集瘤胃液测定瘤胃发酵指标,用实时定量PCR(qRT-PCR)法测定瘤胃微生物含量。结果表明:1)与对照组相比,茶皂素显著降低了瘤胃液p H(30、40 g/d组)、氨态氮的浓度(20、30、40 g/d组)(P0.05),但均未超过正常范围值;茶皂素显著提高了微生物蛋白(30、40 g/d组)、丙酸(20、30、40 g/d组)和丁酸浓度(20、30、40 g/d组)(P0.05),30 g/d组的微生物蛋白浓度提高了20.20%;但茶皂素对总挥发性脂肪酸和乙酸浓度的影响不显著(P0.05)。2)与对照组相比,茶皂素各组的瘤胃液原虫、溶纤维丁酸弧菌含量均显著降低(P0.05),甲烷菌、白色瘤胃球菌、产琥珀酸丝状杆菌、黄色瘤胃球菌、真菌含量没有显著变化(P0.05)。综上所述,补饲茶皂素改善了奶牛瘤胃发酵模式,并显著影响了奶牛瘤胃微生物区系,30 g/d的剂量对奶牛较为适宜。

Effects of Tea Saponin on Rumen Fermentation and Rumen Microflora of Dairy Cows

This experiment was conducted to study the effects of tea saponin on rumenfermentation and rumen microflora of dairy cows. Twelve healthy Holstein cows with similar weight were used, and randomly divided into four groups, all were fed a basal diet and drenched with 0 ( control) , 20, 30 and 40 g/d of tea saponin in different groups. Tea saponin and water were mixed for drenching. Pre experimental period went 14 days, and the trial period went 35 days. Rumen fluid was collected with oral sampler at 1 h before morning feeding every 7 days during the trail period for determination of rumen fermentation parameters and rumen microorganisms (real?time quantitative PCR method). The results showed as follows: 1) compared with control group, tea saponin significantly reduced rumen fluid pH (30 and 40 g/d groups), ammonia nitrogen concentration (20, 30 and 40 g/d groups) (P<0.05), which were not exceeded the normal range values, but significantly in?creased microbial protein (30 and 40 g/d groups), propionic acid (20, 30 and 40 g/d groups) and butyric acid concentrations (20, 30 and 40 g/d groups) (P<0.05), and microbial protein concentration of 30 g/d tea saponin group increased 20. 20%; however, tea saponin did not significantly affected total volatile fatty acid and acetic acid concentrations ( P>0.05) . 2) Compared with control group, the contents of rumen fluid proto?zoa and Butyrivibrio fibrisolvens of tea saponin groups were significantly decreased ( P<0.05) , but no signifi?cant changes on methanogens, Ruminococcus albus, Fibrobacter succinogenes, Ruminococcus flavefaciens and fungi contents were found ( P>0.05) . In conclusion, the supplementation of tea saponin can improve the pat?tern of rumen fermentation and has a significant effect on rumen microbial flora, and the optimal level for dairy cows is 30 g/d.