State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530004, China.
Guangxi Zhuang Autonomous Region Buffalo Milk Quality and Safety Control Technology Engineering Research Center, Guangxi Buffalo Research Institute, Chinese Academy of Agricultural Sciences, Nanning 530001, China.
Genes (Basel). 2024 Aug 15;15(8):1081. doi: 10.3390/genes15081081.
Milking methods have significant impacts on the microbiological composition, which could affect the quality of raw buffalo milk. Hence, the current study was conducted on the impact of milking methods on microorganisms in buffalo tank raw milk from 15 farms in Guangxi, China. The farms were divided into two groups based on the milking method: mechanical milking (MM, = 6) and hand milking (HM, = 9). Somatic cell counts, bacterial cell counts and nutrients of the raw buffalo milk samples were analyzed. The comparison of raw buffalo milk samples was analyzed using metagenomic sequencing to detect any differences between the two groups. There was no significant difference in the basic nutritional compositions and somatic cell count of raw buffalo milk between the two milking methods. However, the HM samples had significantly higher bacterial counts and diversity compared to the MM samples. The results showed that spp., spp., spp., and spp. were the major microbes present in canned raw buffalo milk. However, the differences between the two milking methods were the relative abundance of core microorganisms and their potential mastitis-causing genera, including the content of antibiotic-resistance genes and virulence genes. Our study revealed that spp. and spp. were significantly more abundant in the MM group, while spp. was more abundant in the HM group. Regardless of the milking method used, spp. was identified as the primary genus contributing to antibiotic resistance and virulence genes in canned raw buffalo milk. These findings affirm that there are differences in the microbial and genomic levels in canned raw milk. To prove the functional roles of the discovered genes and how these genes affect milk quality, further research and experimental validation are necessary.
挤奶方式对微生物组成有显著影响，这可能会影响生水牛乳的质量。因此，本研究对中国广西 15 个农场的生水牛乳中挤奶方式对微生物的影响进行了研究。根据挤奶方式将农场分为两组：机械挤奶（MM，n=6）和手工挤奶（HM，n=9）。分析了生水牛乳样品的体细胞计数、细菌细胞计数和营养成分。使用宏基因组测序分析生水牛乳样品的比较，以检测两组之间的差异。两种挤奶方式的生水牛乳基本营养成分和体细胞计数无显著差异。然而，HM 样品的细菌计数和多样性明显高于 MM 样品。结果表明， spp.、 spp.、 spp. 和 spp. 是罐装生水牛乳中的主要微生物。然而，两种挤奶方式的差异在于核心微生物及其潜在乳腺炎致病属的相对丰度，包括抗生素耐药基因和毒力基因的含量。我们的研究表明， spp. 和 spp. 在 MM 组中丰度显著更高，而 spp. 在 HM 组中丰度更高。无论使用哪种挤奶方式， spp. 被鉴定为生水牛乳罐中抗生素耐药和毒力基因的主要属。这些发现证实了罐装生乳在微生物和基因组水平上存在差异。为了证明所发现基因的功能作用以及这些基因如何影响牛奶质量，需要进一步的研究和实验验证。
