Kim Hyun Sang, Eom Jun Sik, Lee Shin Ja, Choi Youyoung, Jo Seong Uk, Lee Sang Suk, Kim Eun Tae, Lee Sung Sill
Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 52828, Korea.
University-Centered Labs, Gyeongsang National University, Jinju 52828, Korea.
Anim Biosci. 2023 Aug;36(8):1199-1208. doi: 10.5713/ab.22.0486. Epub 2023 Feb 26.
The purpose of this study was to perform a comparative analysis of metabolite levels in serum and milk obtained from cows fed on different concentrate to forage feed ratios.
Eight lactating Holstein cows were divided into two groups: a high forage ratio diet (HF; 80% Italian ryegrass and 20% concentrate of daily intake of dry matter) group and a high concentrate diet (HC; 20% Italian ryegrass and 80% concentrate) group. Blood was collected from the jugular vein, and milk was sampled using a milking machine. Metabolite levels in serum and milk were estimated using proton nuclear magnetic resonance and subjected to qualitative and quantitative analyses performed using Chenomx 8.4. For statistical analysis, Student's t-test and multivariate analysis were performed using Metaboanalyst 4.0.
In the principal component analysis, a clear distinction between the two groups regarding milk metabolites while serum metabolites were shown in similar. In serum, 95 metabolites were identified, and 13 metabolites (include leucine, lactulose, glucose, betaine, etc.) showed significant differences between the two groups. In milk, 122 metabolites were identified, and 20 metabolites (include urea, carnitine, acetate, butyrate, arabinitol, etc.) showed significant differences.
Our results show that different concentrate to forage feed ratios impact the metabolite levels in the serum and milk of lactating Holstein cows. A higher number of metabolites in milk, including those associated with milk fat synthesis and the presence of Escherichia coli in the rumen, differed between the two groups compared to that in the serum. The results of this study provide a useful insight into the metabolites associated with different concentrate to forge feed ratios in cows and may aid in the search for potential biomarkers for subacute ruminal acidosis.
本研究旨在对采食不同精粗比饲料的奶牛所产血清和乳中的代谢物水平进行比较分析。
将8头泌乳期荷斯坦奶牛分为两组：高粗料比例日粮组（HF；意大利黑麦草占干物质日摄入量的80%，精料占20%）和高精料日粮组（HC；意大利黑麦草占20%，精料占80%）。从颈静脉采集血液，并用挤奶机采集乳样。采用质子核磁共振波谱法测定血清和乳中的代谢物水平，并使用Chenomx 8.4进行定性和定量分析。采用Metaboanalyst 4.0进行统计分析，包括学生t检验和多变量分析。
在主成分分析中，两组乳代谢物之间有明显区别，而血清代谢物表现相似。血清中鉴定出95种代谢物，两组间有13种代谢物（包括亮氨酸、乳果糖、葡萄糖、甜菜碱等）存在显著差异。乳中鉴定出122种代谢物，20种代谢物（包括尿素、肉碱、乙酸、丁酸、阿拉伯糖醇等）存在显著差异。
我们的结果表明，不同的精粗比会影响泌乳期荷斯坦奶牛血清和乳中的代谢物水平。与血清相比，两组乳中包括与乳脂肪合成及瘤胃中大肠杆菌存在相关的代谢物数量更多，且存在差异。本研究结果为了解奶牛不同精粗比相关的代谢物提供了有益见解，并可能有助于寻找亚急性瘤胃酸中毒的潜在生物标志物。
