Centre for Ruminant Nutrition and Feed Engineering Research, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Laboratory for Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Centre for International Research On Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Appl Microbiol Biotechnol. 2022 Nov;106(22):7627-7642. doi: 10.1007/s00253-022-12240-2. Epub 2022 Oct 20.
The study was conducted to evaluate the rumen microbiota as well as the milk composition and milk component yields of Holstein cows supplemented with fermented soybean meal (FSBM). Eighteen Holstein cows in their 2nd parity with 54.38 ± 11.12 SD days in milking (DIM) were divided into two dietary groups (CON and TRT) of nine cows per group. The cows in the TRT group received 300 g of FSBM per cow per day in addition to the conventional diet, while each cow in the CON group was supplemented with 350 g of soybean meal (SBM) in their diet daily throughout the 28-day feeding trial. Rumen bacterial composition was detected via 16S rRNA sequencing, and the functional profiles of bacterial communities were predicted. Milk composition, milk yield, as well as rumen fermentation parameters, and serum biochemistry were also recorded. The inclusion of FSBM into the diets of Holstein cows increased the milk urea nitrogen (MUN), milk protein yield, fat corrected milk (FCM), and milk fat yield while the milk somatic cell count (SCC) was decreased. In the rumen, the relative abundances of Fibrobacterota, and Spirochaetota phyla were increased in the TRT group, while the percentage of Proteobacteria was lower. In addition, the supplementation of FSBM to Holstein cows increased the acetate percentage, rumen pH, and acetate to propionate ratio, while the proportion of propionate and propionate % was observed to decrease in the TRT group. The KEGG pathway and functional prediction revealed an upregulation in the functional genes associated with the biosynthesis of amino acids in the TRT group. This enrichment in functional genes resulted in an improved synthesis of several essential amino acids including lysine, methionine, and branch chain amino acids (BCAA) which might be responsible for the increased milk protein yield. Future studies should employ shotgun metagenomics, transcriptomics, and metabolomics technology to investigate the effects of FSBM on other rumen microbiomes and milk protein synthesis in the mammary gland in Holstein cows. KEY POINTS: • The supplementation of fermented soybean meal (FSBM) to Holstein cows modified the proportion of rumen bacteria. • Predicted metabolic pathways and functional genes of rumen bacteria revealed an enrichment in pathway and genes associated with biosynthesis of amino acids in the group fed FSBM. • The cows supplemented with FSBM record an improved rumen fermentation. • Cows supplemented with FSBM recorded an increased yield of milk protein and milk fat.
该研究旨在评估添加发酵豆粕（FSBM）对荷斯坦奶牛的瘤胃微生物群以及牛奶成分和牛奶成分产量的影响。18 头处于泌乳期第 2 胎的荷斯坦奶牛，泌乳天数（DIM）为 54.38±11.12 SD，分为两组（CON 和 TRT），每组 9 头牛。TRT 组的奶牛每天每头额外摄入 300 克 FSBM，而 CON 组的每头奶牛每天在饮食中补充 350 克豆粕（SBM），为期 28 天的喂养试验。通过 16S rRNA 测序检测瘤胃细菌组成，并预测细菌群落的功能谱。还记录了牛奶成分、产奶量以及瘤胃发酵参数和血清生化指标。在荷斯坦奶牛的日粮中添加 FSBM 提高了牛奶尿素氮（MUN）、牛奶蛋白产量、脂肪校正奶（FCM）和牛奶脂肪产量，而牛奶体细胞计数（SCC）则降低。在瘤胃中，TRT 组中 Fibrobacterota 和 Spirochaetota 门的相对丰度增加，而 Proteobacteria 的比例较低。此外，向荷斯坦奶牛补充 FSBM 增加了乙酸的百分比、瘤胃 pH 值和乙酸与丙酸的比值，而 TRT 组中丙酸和丙酸%的比例下降。KEGG 途径和功能预测显示，TRT 组中与氨基酸生物合成相关的功能基因上调。这种功能基因的富集导致几种必需氨基酸（包括赖氨酸、蛋氨酸和支链氨基酸（BCAA））的合成增加，这可能是牛奶蛋白产量增加的原因。未来的研究应该采用 shotgun 宏基因组学、转录组学和代谢组学技术来研究 FSBM 对荷斯坦奶牛其他瘤胃微生物组和乳腺中牛奶蛋白合成的影响。关键点：• 向荷斯坦奶牛补充发酵豆粕（FSBM）改变了瘤胃细菌的比例。• 预测的瘤胃细菌代谢途径和功能基因显示，FSBM 组中与氨基酸生物合成相关的途径和基因富集。• 补充 FSBM 的奶牛记录了改善的瘤胃发酵。• 补充 FSBM 的奶牛记录了牛奶蛋白和牛奶脂肪产量的增加。
