Sischo William M, Short Diana M, Geissler Mareen, Bunyatratchata Apichaya, Barile Daniela
Department of Veterinary Clinical Sciences, Food and Waterborne Disease Research, Washington State University, Pullman 99164.
Department of Veterinary Clinical Sciences, Food and Waterborne Disease Research, Washington State University, Pullman 99164.
J Dairy Sci. 2017 May;100(5):3883-3892. doi: 10.3168/jds.2016-12388. Epub 2017 Mar 17.
Prebiotics are nondigestible dietary ingredients, usually oligosaccharides (OS), that provide a health benefit to the host by directly modulating the gut microbiota. Although there is some information describing OS content in dairy-source milk, no information is available to describe the OS content of beef-source milk. Given the different trait emphasis between dairy and beef for milk production and calf survivability, it is plausible that OS composition, diversity, and abundance differ between production types. The goal of this study was to compare OS in milk from commercial dairy and beef cows in early lactation. Early-lactation multiparous cows (5-12 d in milk) from 5 commercial Holstein dairy herds and 5 Angus or Angus hybrid beef herds were sampled once. Milk was obtained from each enrolled cow and frozen on the farm. Subsequently, each milk sample was assessed for total solids, pH, and OS content and relative abundance. Oligosaccharide diversity and abundance within and between samples was transformed through principal component analysis to reduce data complexity. Factors from principal component analysis were used to create similarity clusters, which were subsequently used in a multivariate logistic regression. In total, 30 OS were identified in early-lactation cow milk, including 21 distinct OS and 9 isomers with unique retention times. The majority of OS detected in the milk samples were present in all individual samples regardless of production type. Two clusters described distribution patterns of OS for the study sample; when median OS abundance was compared between the 2 clusters, we found that overall OS relative abundance was consistently greater in the cluster dominated by beef cows. For several of the structures, including those with known prebiotic effect, the difference in abundance was 2- to 4-fold greater in the beef-dominated cluster. Assuming that beef OS content in milk is the gold standard for cattle, it is likely that preweaning dairy calves are deprived of dietary-source OS. Although supplementing rations with OS is an approach to rectify this deficiency, understanding the health and productivity effects of improving OS abundance being fed to preweaning calves is a necessary next step before recommending supplementation. These studies should account for the observation that OS products are variable for both OS diversity and structural complexity, and some products may not be suitable as prebiotics.
益生元是不可消化的膳食成分，通常为寡糖（OS），通过直接调节肠道微生物群为宿主带来健康益处。尽管有一些信息描述了乳制品源牛奶中的OS含量，但尚无信息描述牛肉源牛奶中的OS含量。鉴于奶牛和肉牛在产奶量和犊牛存活率方面的性状重点不同，不同生产类型之间的OS组成、多样性和丰度可能存在差异。本研究的目的是比较商业奶牛和肉牛在泌乳早期牛奶中的OS。对来自5个商业荷斯坦奶牛群和5个安格斯或安格斯杂交肉牛群的泌乳早期经产奶牛（产奶5 - 12天）进行了一次采样。从每头入选奶牛采集牛奶并在农场冷冻。随后，对每个牛奶样本进行总固体、pH值以及OS含量和相对丰度的评估。通过主成分分析对样本内和样本间的寡糖多样性和丰度进行转换，以降低数据复杂性。主成分分析的因子用于创建相似性聚类，随后用于多变量逻辑回归。在泌乳早期奶牛牛奶中总共鉴定出30种OS，包括21种不同的OS和9种具有独特保留时间的异构体。无论生产类型如何，在所有单个样本中均检测到大多数牛奶样本中的OS。两个聚类描述了研究样本中OS的分布模式；当比较两个聚类之间的OS丰度中位数时，我们发现以肉牛为主的聚类中总体OS相对丰度始终更高。对于几种结构，包括那些具有已知益生元效应的结构，以牛肉为主的聚类中丰度差异大2至4倍。假设牛奶中的牛肉OS含量是牛的黄金标准，那么断奶前的奶牛犊可能会缺乏膳食来源的OS。尽管用OS补充日粮是纠正这种不足的一种方法，但在推荐补充之前，了解提高断奶前犊牛所摄入OS丰度对健康和生产力的影响是必要的下一步。这些研究应考虑到OS产品在OS多样性和结构复杂性方面存在差异，并且一些产品可能不适合作为益生元这一观察结果。
