MALDI-TOF mass spectrometry analysis of seasonal variations in culturable milk microbiota and physico-chemical properties in Poland: Implications for dairy management and quality control

The primary objective of this study was to systematically examine the seasonal fluctuations within the milk microbiome with the use of MALDI-TOF-MS technique. Moreover, the quality of milk was evaluated based on the basic milk parameters such as total protein and fat content, titratable acidity (SH), pH, density, total bacteria count, and somatic cell count (SCC). The results revealed significant seasonal variations in both the microbial composition and the physico-chemical properties of milk. Spring exhibited the highest microbial diversity, while autumn showed the lowest. Dominant bacterial genera included Staphylococcus, Corynebacterium, Aerococcus, and Bacillus , with specific genera such as Brevundimonas appearing exclusively in spring and Jeotgalicoccus in summer. Physico-chemical analysis indicated that milk fat and protein content were highest in winter and lowest in summer, correlating with changes in photoperiod and heat stress effects on cows. The highest bacterial counts and somatic cell numbers were observed in summer and autumn, corresponding with increased incidences of mastitis. These findings underscore the importance of monitoring seasonal changes to ensure milk quality and safety, suggesting that targeted management practices could mitigate the seasonal impact on milk production. The research sheds light on the influence of seasonal dynamics on the milk microbiome and its quality indicators, offering crucial information to advance dairy management strategies and ensure superior product quality control. • MALDI-TOF-MS is a valuable tool for dairy quality control systems. • MALDI-TOF-MS proved useful for monitoring seasonal milk microbiota. • Distinct bacterial genera appeared seasonally, affecting milk quality. • Tie-stall housing may contribute to high mastitis incidences in dairy cows. • Mastitis-related bacteria are more prevalent in summer and autumn, less in spring.