文献类型： 外文期刊

作者： Liu, Hu ¹ ; Ran, Tao ¹ ; Zhang, Chengfu ³ ; Yang, Wenzhu ⁴ ; Wu, Xiukun ⁵ ; Degen, Allan ⁶ ; Long, Ruijun ² ; Shi, Zunji ¹ ; Zhou, Jianwei ¹ ;

作者机构： 1.Lanzhou Univ, Coll Pastoral Agr Sci & Technol, Ctr Grassland Microbiome, State Key Lab Grassland Agroecosystems, Lanzhou, Peoples R China

2.Lanzhou Univ, Coll Ecol, Int Ctr Tibetan Plateau Ecosyst Management, Lanzhou, Peoples R China

3.Tibet Acad Agr & Anim Husb Sci, Inst Anim Sci & Vet, State Key Lab Barley & Yak Germplasm Resources & G, Lhasa, Peoples R China

4.Agr & Agrifood Canada AAFC, Lethbridge Res & Dev Ctr, Lethbridge, AB, Canada

5.Chinese Acad Sci, Northwest Inst Ecol Environm & Resources, Lanzhou, Peoples R China

6.Bengur Univ Negev, Blaustein Inst Desert Res, Wyler Dept Dryland Agr, Desert Anim Adaptat & Husb, Beer Sheva, Israel

关键词： yaks; rumen bacterial community; Qaidam cattle; low protein diet; energy levels

期刊名称：FRONTIERS IN MICROBIOLOGY （ 影响因子：6.064； 五年影响因子：6.843 ）

ISSN：

年卷期： 2022 年 13 卷

页码：

收录情况： SCI

摘要： The yak (Bos grunniens), an indigenous bovine on the Qinghai-Tibetan plateau (QTP), is reported to digest low quality forage to a greater extent and to require less protein and energy for maintenance than the introduced Qaidam cattle (Bos taurus). Ruminal bacteria play a major role in feed degradation, and therefore, we hypothesized that ruminal bacteria composition would differ between yaks and cattle, and confer an advantage to yaks for poor quality diets. To test our hypothesis, we determined the ruminal bacteria profiles, rumen fermentation parameters, and enzyme activities in these bovine species consuming a low-protein diet differing in energy level. Six castrated yaks (155 +/- 5.8 kg) and 6 castrated Qaidam cattle (154 +/- 8.0 kg) were used in two concurrent 4 x 4 Latin square designs with 2 additional animals of each species in each period. The animals were offered a low-protein diet of 70.4 g/kg dry matter (DM) and one of four metabolizable energy levels, namely 6.62, 8.02, 9.42, and 10.80 MJ/kg. Ruminal pH, concentrations of ammonia-N and total volatile fatty acids (VFAs), the molar proportion of acetate, and the ratio of acetate to propionate (A:P) were greater (P < 0.05), whereas the molar proportion of propionate was lesser (P = 0.043) in yaks than in cattle. With increasing dietary energy level, ruminal pH, the molar proportion of acetate and the ratio of A:P decreased linearly (P < 0.05), whereas, the concentration of total VFAs, molar proportions of propionate, butyrate, iso-butyrate, and iso-valerate and concentration of ammonia-N increased linearly (P < 0.05). The relative abundance (RA) of Firmicutes increased linearly (P < 0.01), whereas, the RA of Bacteroidetes decreased linearly (P < 0.001) with increasing energy level in both bovine species. The RAs of Prevotella and Rikenellaceae_RC9_gut_group decreased linearly (P < 0.05) with increasing energy level in both yaks and cattle. The RAs of fibrolytic (e.g., Rikenellaceae_RC9_gut_group), and H-2-incorporating (e.g., Quinella) bacteria were greater (P < 0.05) in yaks than in cattle. We concluded that the two bovines differ in ruminal bacterial profiles and rumen fermentation parameters, and confer an advantage to yaks over cattle in consuming a low protein diet with differing energy level.