Zhang Lei, Shen Hong, Zhang Jiyou, Mao Shengyong
Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China.
Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China.
Front Vet Sci. 2023 Mar 2;10:1106834. doi: 10.3389/fvets.2023.1106834. eCollection 2023.
Our objective was to investigate the contribution of the rumen microbiome on the individual milk fat percentage (MFP) of Holstein dairy cows under the same nutritional and management conditions. From 92 early lactation dairy cows, the top 10 with the highest MFP (HF; = 10) and the last 10 with the lowest MFP (LF; = 10) were selected for the study. As a result, the milk 10, 12 C18:2 content was significant lower in the HF group than that in the LF group ( < 0.001). The rumen acetate to propionate ratio was significant higher in the HF group than that in the LF group ( = 0.035). According to the results of 16S rRNA gene sequencing, a minor but significant difference existed between the groups ( = 0.040). Three genera of the family Lachnospiraceae and four genera of the order Bacteroidales were identified to be the biomarkers for the LF group and HF group in the LEfSe analysis, respectively. Three microbial modules enriched by the family Lachnospiraceae were positively related to the milk 10, 12 C18:2 content ( > 0.60, < 0.05). According to the results of shotgun metagenome sequencing, three kinds of linoleic acid (LA) isomerase genes were present in the gene pools of the rumen microbiome. Among them, the relative abundance of LA isomerase (BBI) was higher in the HF group than that in the LF group ( = 0.007). Three metagenome-assembled genomes (MAGs) with LA isomerase genes were positively correlated to the milk 10, 12 C18:2 content ( > 0.40, < 0.05). Furthermore, all of these three MAGs were found to be able to produce lactate. Taken together, these results indicate that the increased relative abundance of microbial population with the -10 biohydrogenation pathway within the rumen microbiome contributes to the decrease of MFP the increase of rumen 10, 12 C18:2 production. This study provides a new perspective for the development of measures for improving the milking performance of dairy cows.
我们的目标是研究在相同营养和管理条件下，瘤胃微生物群对荷斯坦奶牛个体乳脂率（MFP）的影响。从92头早期泌乳奶牛中，挑选出MFP最高的前10头（HF；n = 10）和MFP最低的后10头（LF；n = 10）用于本研究。结果显示，HF组牛奶中10,12 C18:2含量显著低于LF组（P < 0.001）。HF组瘤胃乙酸与丙酸比值显著高于LF组（P = 0.035）。根据16S rRNA基因测序结果，两组之间存在微小但显著的差异（P = 0.040）。在LEfSe分析中，分别鉴定出毛螺菌科的三个属和拟杆菌目的四个属为LF组和HF组的生物标志物。毛螺菌科富集的三个微生物模块与牛奶中10,12 C18:2含量呈正相关（r > 0.60，P < 0.05）。根据鸟枪法宏基因组测序结果，瘤胃微生物群基因库中存在三种亚油酸（LA）异构酶基因。其中，HF组中LA异构酶（BBI）的相对丰度高于LF组（P = 0.007）。三个具有LA异构酶基因的宏基因组组装基因组（MAG）与牛奶中10,12 C18:2含量呈正相关（r > 0.40，P < 0.05）。此外，发现这三个MAG均能够产生乳酸。综上所述，这些结果表明瘤胃微生物群中具有-10生物氢化途径的微生物种群相对丰度增加，有助于MFP降低和瘤胃10,12 C18:2产量增加。本研究为制定提高奶牛挤奶性能的措施提供了新的视角。
