Nguyen Thuong Thi, Wu Haoming, Nishino Naoki
Department of Animal Science, Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan.
Asian-Australas J Anim Sci. 2020 Nov;33(11):1858-1865. doi: 10.5713/ajas.19.0506. Epub 2019 Dec 24.
The microbiota of dairy cow milk varies with the season, and this accounts in part for the seasonal variation in mastitis-causing bacteria and milk spoilage. The microbiota of the cowshed may be the most important factor because the teats of a dairy cow contact bedding material when the cow is resting. The objectives of the present study were to determine whether the microbiota of the milk and the cowshed vary between seasons, and to elucidate the relationship between the microbiota.
We used 16S rRNA gene amplicon sequencing to investigate the microbiota of milk, feces, bedding, and airborne dust collected at a dairy farm during summer and winter.
The seasonal differences in the milk yield and milk composition were marginal. The fecal microbiota was stable across the two seasons. Many bacterial taxa of the bedding and airborne dust microbiota exhibited distinctive seasonal variation. In the milk microbiota, the abundances of Staphylococcaceae, Bacillaceae, Streptococcaceae, Microbacteriaceae, and Micrococcaceae were affected by the seasons; however, only Micrococcaceae had the same seasonal variation pattern as the bedding and airborne dust microbiota. Nevertheless, canonical analysis of principle coordinates revealed a distinctive group comprising the milk, bedding, and airborne dust microbiota.
Although the milk microbiota is related to the bedding and airborne dust microbiota, the relationship may not account for the seasonal variation in the milk microbiota. Some major bacterial families stably found in the bedding and airborne dust microbiota, e.g., Staphylococcaceae, Moraxellaceae, Ruminococcaceae, and Bacteroidaceae, may have greater influences than those that varied between seasons.
奶牛乳中的微生物群随季节变化，这在一定程度上解释了引起乳腺炎的细菌和牛奶变质的季节性变化。牛舍的微生物群可能是最重要的因素，因为奶牛休息时乳头会接触垫料。本研究的目的是确定牛奶和牛舍的微生物群在不同季节之间是否存在差异，并阐明微生物群之间的关系。
我们使用16S rRNA基因扩增子测序来研究夏季和冬季在一个奶牛场采集的牛奶、粪便、垫料和空气尘埃中的微生物群。
牛奶产量和牛奶成分的季节性差异很小。粪便微生物群在两个季节中保持稳定。垫料和空气尘埃微生物群的许多细菌分类群表现出明显的季节性变化。在牛奶微生物群中，葡萄球菌科、芽孢杆菌科、链球菌科、微杆菌科和微球菌科的丰度受季节影响；然而，只有微球菌科与垫料和空气尘埃微生物群具有相同的季节性变化模式。尽管如此，主坐标的典型分析揭示了一个由牛奶、垫料和空气尘埃微生物群组成的独特群体。
虽然牛奶微生物群与垫料和空气尘埃微生物群有关，但这种关系可能无法解释牛奶微生物群的季节性变化。在垫料和空气尘埃微生物群中稳定发现的一些主要细菌科，如葡萄球菌科、莫拉克斯氏菌科、瘤胃球菌科和拟杆菌科，可能比那些随季节变化的细菌科有更大的影响。
