Xie Yunyi, Sun Huizeng, Xue Mingyuan, Liu Jianxin
Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China.
Ministry of Education Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou, 310058, China.
Anim Microbiome. 2022 Mar 8;4(1):19. doi: 10.1186/s42523-022-00170-3.
Rumen microbial composition and functions have vital roles in feed digestion and fermentation and are linked to feed efficiency in cattle. This study selected Holstein cows, which are high in both milk protein content and milk yield, to analyse the relationship between the rumen microbiota and residual feed intake (RFI). Eighteen multiparous lactating cows were divided into low RFI (LRFI, high efficiency, n = 9) and high RFI (HRFI, low efficiency, n = 9) groups to investigate the differences in microbial composition and functions.
The relative abundances of butyrate producers, including the Clostridium, Butyrivibrio, Eubacterium and Blautia genera, were higher in HRFI cows than in LRFI cows (P < 0.05). Four carbohydrate metabolic pathways (glycolysis/gluconeogenesis, pentose phosphate pathway, fructose and mannose metabolism, and butanoate metabolism) and one energy metabolism pathway (methane metabolism), were more abundant in HRFI animals (P < 0.05). Quorum sensing and DNA replication pathways were more abundant in HRFI cows. For CAZyme profiles, 14 out of 19 genes encoding carbohydrates-deconstructing enzymes were more abundant in HRFI cows (P < 0.05). Seven Lachnospiraceae species associated with carbohydrate metabolism and quorum sensing may contribute to the difference in feed efficiency. Moreover, the LRFI cows had lower abundances of Methanosphaera (P < 0.01), Methanobrevibacter ruminantium (P = 0.09) and methanogenesis functions (P = 0.04).
The rumen microbiota of low-efficiency cows has stronger abilities to degrade carbohydrates and produce methane, and quorum sensing pathways could also be associated with differences in feed efficiency. This study provides a deeper understanding of the microbial ecology of dairy cows with different feed efficiencies and highlights the possibility of modulating the rumen microbiome or microbial functions to improve the feed efficiency of dairy cows.
瘤胃微生物组成和功能在饲料消化和发酵中起着至关重要的作用，并且与奶牛的饲料效率相关。本研究选择了乳蛋白含量和产奶量均较高的荷斯坦奶牛，以分析瘤胃微生物群与剩余采食量（RFI）之间的关系。将18头经产泌乳奶牛分为低RFI（LRFI，高效率，n = 9）和高RFI（HRFI，低效率，n = 9）组，以研究微生物组成和功能的差异。
包括梭菌属、丁酸弧菌属、真杆菌属和布劳特氏菌属在内的丁酸盐产生菌的相对丰度在HRFI奶牛中高于LRFI奶牛（P < 0.05）。四种碳水化合物代谢途径（糖酵解/糖异生、磷酸戊糖途径、果糖和甘露糖代谢以及丁酸代谢）和一种能量代谢途径（甲烷代谢）在HRFI动物中更为丰富（P < o.o5）。群体感应和DNA复制途径在HRFI奶牛中更为丰富。对于碳水化合物活性酶（CAZyme）谱，19个编码碳水化合物解构酶的基因中有14个在HRFI奶牛中更为丰富（P < 0.05）。七种与碳水化合物代谢和群体感应相关的毛螺菌科物种可能导致饲料效率的差异。此外，LRFI奶牛中甲烷短杆菌（P < 0.01）、反刍兽甲烷短杆菌（P = 0.09）和甲烷生成功能（P = 0.04）的丰度较低。
低效奶牛的瘤胃微生物群具有更强的碳水化合物降解和甲烷产生能力，群体感应途径也可能与饲料效率差异有关。本研究为深入了解不同饲料效率奶牛的微生物生态学提供了依据，并突出了调节瘤胃微生物组或微生物功能以提高奶牛饲料效率的可能性。
