茶皂素对奶牛瘤胃原虫区系的影响

Effects of Tea Saponin on Rumen Protozoa Flora of Dairy Cows

本研究旨在研究茶皂素对奶牛瘤胃原虫区系的影响。选取12头健康荷斯坦奶牛[体重(550±30)kg,产奶量35 kg/(头·d),胎次2~4],随机分为4组,每组3头,均饲喂基础饲粮,分别于晨饲前灌服0(对照)、20、30、40 g/(头·d)的茶皂素。试验期49 d,其中预试期14 d,正试期35 d,正试期内每7 d于晨饲前1 h用口腔采样器采集瘤胃液。采用聚丙烯酰氨凝胶电泳(DGGE)结合18S r DNA序列分析技术研究瘤胃原虫区系的变化。结果表明:1)添加茶皂素可以选择性地抑制瘤胃中原虫的生长。2)与对照组相比,30、40 g/(头·d)茶皂素组的丰富度指数和香农多样性指数都显著降低(P<0.05),优势度指数显著增加(P<0.05),但是均一性指数无显著变化(P>0.05);茶皂素显著减少了瘤胃中前庭亚纲内毛目的原虫数量。综上所述,饲粮中添加30、40 g/(头·d)茶皂素均可抑制奶牛瘤胃原虫的生长,并且降低瘤胃原虫的多样性。

The objective of this study was to research the effects of tea saponin on rumen protozoa flora of dairy cows.Twelve healthy Holstein dairy cows[body weight was（550±30） kg） milk yield was35 kg/（head·d）;2 to 4 parities]were randomly allocated to one of four groups with 3 cows per group.Tea saponin[0（control）,20,30 and 40 g/（head·d）]was perfused to cows before morning feeding.The experiment lasted for 49 d with 14 d of adaptation period and 35 d of formal test period.Rumen fluid was collected by mouth sampler at 1 h before morning feeding every 7 d during formal test period.Denaturing gradient gel electrophoresis（DGGE） combined with 18 S rDNA sequence analysis technique was used for rumen protozoa flora analysis.The results showed as follows：1） tea saponin could selectively inhibit protozoa growth.2）Compared with control group,richness index and Shannon index in 30 and 40 g/（head·d） tea saponin groups were significantly reduced（P〈0.05）,and dominance index was significantly increased（P〈0.05）,but evenness index was not significantly different among groups（P〉0.05）;tea saponin could significantly reduce rumen Vestibuliferia Entodiniomorphida protozoa number.In conclusion,dietary supplementation of 30 and40 g/（head·d） tea saponin can inhibit protozoa growth in rumen of dairy cows,and reduce the diversity of rumen protozoa.