可溶性糖部分取代淀粉抑制奶牛瘤胃trans-10氢化路径的效果和机理

有效抑制采食高精料饲粮奶牛瘤胃中的trans-10氢化路径是在保证高产的同时提高乳脂含量和乳脂品质的关键。为了研究可溶性糖能否作为一种可替代能源在提供能量的同时抑制奶牛瘤胃trans-10氢化路径进而改善乳脂合成，本项目拟在高精料饲粮条件下，首先利用人工瘤胃发酵系统，比较研究不同可溶性糖部分取代淀粉对瘤胃发酵模式和trans-10氢化路径的影响，筛选对trans-10氢化路径抑制效果最好的可溶性糖种类；然后用所选的可溶性糖进行动物试验，进一步研究可溶性糖部分取代淀粉对奶牛瘤胃trans-10氢化路径和乳脂合成的影响，并借助高通量测序和多平台定量代谢组学技术分别研究可溶性糖对的瘤胃微生物区系和代谢产物的影响，从瘤胃发酵模式、瘤胃微生物区系和瘤胃代谢产物多个角度，阐明可溶性糖部分取代淀粉抑制奶牛瘤胃trans-10氢化路径的效果和机理，为可溶性糖在奶牛生产中的应用提供参考和理论依据。

Effectively inhibition of the trans-10 biohydrogenation pathway in the rumen of dairy cows receiving high-concentrate diets is critical to support high milk yield and simultaneously increase milk fat content and milk fat quality. To investigate whether sugar could be used as an alternative energy source that inhibits rumen trans-10 biohydrogenation pathway and therefore improves milk fat synthesis, this project will firstly use an artificial rumen in vitro study to compare the effects of replacing starch in a high-concentrate diet with different sugars on the inhibition of rumen trans-10 biohydrogenation pathway and rumen fermentation pattern. The sugar that has the best inhibiting effect on the trans-10 biohydrogenation pathway will be chosen and then used in an in vivo study. The effects of sugar on rumen trans-10 biohydrogenation pathway and milk fat synthesis will be further studied in the in vivo study, and the deep sequencing technique and the multiple platforms quantitative metabolomic analysis will be used as well to evaluate the effects of sugar on rumen microbial ecosystem and rumen metabolomics. All the parameters from rumen fermentation pattern, rumen ecosystem and rumen metabolomics will be used to elucidate the mechanism of the inhibition of sugar on rumen trans-10 biohydrogenation pathway, so as to provide evidence and theoretical basis for the utilization of sugars in dairy production.