本研究调查了藏绵羊和山羊在泌乳前56天的乳营养成分和微生物群落的动态变化。在分娩后的五个时间点(D0、D7、D14、D28、D56)系统地收集牛奶样品。在西藏羊,牛奶脂肪,蛋白质,酪蛋白含量在D0时最高,逐渐下降,并在D14后趋于稳定,而乳糖和半乳糖水平表现出相反的趋势。羊奶表现出相似的初始峰值,特别是在D0、D7、D14和D56之间有显著变化。16SrRNA基因测序显示,在哺乳期,这两个物种的微生物多样性都在增加。主坐标分析确定了对应于早期(D0-D7)的不同微生物簇,过渡(D14-D28),和成熟(D56)阶段。核心门,包括变形杆菌,Firmicutes,拟杆菌,和放线菌,主导着牛奶微生物群,具有显著的时间偏移。像乳酸菌这样的核心微生物,明串珠菌,链球菌在这两个物种中都很常见,观察到物种特异性分类群(例如,绵羊片球菌,山羊中的Shewanella)。此外,我们观察到绵羊和山羊奶中存在高度共有的核心微生物群,包括乳酸菌,明串珠菌,和链球菌。Spearman相关性分析强调了特定微生物属与牛奶营养素之间的显着关系。例如,乳酸菌与总固体呈正相关,非脂牛奶固体,蛋白质,和酪蛋白,而Mannheimia与蛋白质含量呈负相关。这项研究强调了藏绵羊和山羊的乳成分与微生物动力学之间复杂的相互作用,为牲畜管理和营养增强战略提供信息。关键点:•基于微生物群组成,牛奶可以分为三种类型•牛奶微生物群的变化与营养的变化密切相关•过滤掉牛奶中具有物种特异性和年龄特异性的微生物群。
This study investigates the dynamic changes in milk nutritional composition and microbial communities in Tibetan sheep and goats during the first 56 days of lactation. Milk samples were systematically collected at five time points (D0, D7, D14, D28, D56) post-delivery. In Tibetan sheep, milk fat, protein, and casein contents were highest on D0, gradually decreased, and stabilized after D14, while lactose and galactose levels showed the opposite trend. Goat milk exhibited similar initial peaks, with significant changes particularly between D0, D7, D14, and D56. 16S rRNA gene sequencing revealed increasing microbial diversity in both species over the lactation period. Principal coordinates analysis identified distinct microbial clusters corresponding to early (D0-D7), transitional (D14-D28), and mature (D56) stages. Core phyla, including Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria, dominated the milk microbiota, with significant temporal shifts. Core microbes like Lactobacillus, Leuconostoc, and Streptococcus were common in both species, with species-specific taxa observed (e.g., Pediococcus in sheep, Shewanella in goats). Furthermore, we observed a highly shared core microbiota in sheep and goat milk, including Lactobacillus, Leuconostoc, and Streptococcus. Spearman correlation analysis highlighted significant relationships between specific microbial genera and milk nutrients. For instance, Lactobacillus positively correlated with total solids, non-fat milk solids, protein, and casein, while Mannheimia negatively correlated with protein content. This study underscores the complex interplay between milk composition and microbial dynamics in Tibetan sheep and goats, informing strategies for livestock management and nutritional enhancement. KEY POINTS: • The milk can be classified into three types based on the microbiota composition • The changes of milk microbiota are closely related to the variations in nutrition • Filter out microbiota with species specificity and age specificity in the milk.