奶绵羊与奶牛乳成分与泌乳期血清代谢组比较分析

Comparative analysis of milk composition and serum metabolomics between dairy ewes and cows during lactation

通过对绵羊奶与牛奶乳成分及泌乳期奶绵羊和奶牛血清代谢组进行分析,旨在探究两个物种乳成分差异及潜在调控机制。在分娩后第90天分别采集6只奶绵羊与奶牛奶样与血液样本,通过乳成分分析仪对两个物种进行乳常规成分分析,并通过非靶向代谢组学对血清代谢物进行比较分析。结果发现,绵羊奶中乳脂、蛋白质、酪蛋白、固形物和非乳脂固形物均显著高于牛奶(P<0.05),乳糖无明显差异(P>0.05)。对血清进行代谢谱分析,共检测到1 615种代谢物,对其中486种进行了注释,根据条件筛选鉴定出412种差异代谢物。对差异代谢物进行通路(Kyoto Encyclopedia of Genes and Genomes,KEGG)富集分析,共富集到28条功能通路,正离子模式下18条,负离子模式下10条。在奶绵羊血清中存在许多代谢物与抗微生物、抗病毒或抗癌有关,例如芬那酸、瑞德南特和水杨酸。研究结果为揭示乳畜产奶性状和乳成分差异调控机制提供了一定的理论依据,为改良乳畜泌乳性能提供了参考。

In order to investigate the differences in milk composition and potential regulatory mechanisms between the two species,the milk composition of sheep milk and cow milk and the serum metabolome of dairy sheep and cows during lactation were analyzed.Six milk samples from dairy sheep and cows were collected on the 90th day after parturition,along with blood samples.The milk routine composition of the two species was ana-lyzed by milk composition analyzer;and the serum metabolites were analyzed by non-targeted metabolomics for comparison.The results revealed that the fat,protein,casein,solids and non-dairy fat solids in sheep’s milk were significantly higher than those in cow’s milk(P<0.05),except for the lactose(P>0.05).Analysis of serum metabo-lites,a total of 1615 metabolites were detected,of which 486 were annotated and 412 differential metabolites were identified based on conditional screening.Pathway(Kyoto Encyclopedia of Genes and Genomes,KEGG)enrichment analysis of the differential metabolites matched to 28 functional pathways,18 in positive ion mode and 10 in negative ion mode.Many metabolites were presented in dairy sheep serum associated with antimicrobial,antiviral or anticancer,such as fenamic acid,preladenant and salicylic acid.The results of the study provide a the-oretical basis for revealing the mechanisms regulating milk production traits and milk composition differences in dairy animals,and also provide a reference for improving lactation performance of dairy animals.