Impacts of Milking and Housing Environment on Milk Microbiota

SIMPLE SUMMARY: Microbiota can enter and persist in raw milk at several stages of the farming chain. The development of culture-independent methods and high-throughput DNA sequencing techniques have improved the approach to study microbiota communities in milk and milk products. This work aimed to determine the effects of farming environments on milk microbiota using the high-throughput DNA sequencing technique, and to elucidate the relationship among the microbiota. The effects of the farming environment on the microbiota in milk can guide farm and management practices to ensure that the milk is not contaminated with bacteria during milking and processing, thereby improving the quality of the milk. ABSTRACT: The aim of the present study was to determine the effects of farming environments on microbiota in raw milk and to assess the relationship among microbes by 16S rRNA sequencing methods. Samples of raw milk, cow trough water, teat dip cup, teat, teat liner, dairy hall air, cowshed air, feces, feed, and bedding from two farms were collected. The two highest abundant bacterial groups of Moraxellaceae and Staphylococcaceae were found in milk and teat liner samples, respectively, at Zhengzhou farm, Henan Province. Moreover, the two highest abundant bacterial groups of Enterobacteriaceae and Moraxellaceae were found in milk and teat dip cup samples, respectively, at Qiqihar farm, Heilongjiang Province. Source Tracker analysis revealed that the teat liner and teat dip cup were the most important contributors of microbes in milk samples at Zhengzhou farm and Qiqihar farm, respectively, which could be attributed to the management level of the farm. Therefore, disinfection and cleaning procedures should be developed to improve the quality of raw milk.