Seasonal Variations in Somatic Cell Count and Their Impact on the Physicochemical Composition of Raw Cow Milk

Understanding milk quality is essential for ensuring dairy products meet required standards. Somatic cell count (SCC) serves as a commonly used measure of milk quality within the dairy sector. While it offers valuable insights into the udder health of dairy cows, its reliability is influenced by various non-infectious factors, notably seasonal variations. This study aimed to investigate the impact of seasonal variations on SCC in raw cow milk, and subsequently, how these variations may lead to changes in its physicochemical composition. Over a year, 4,287 samples were collected from three dairies in Bitola, Macedonia. Standard accredited methodologies were employed, adhering to ISO 21187:2011 for total bacteria count (TBC), ISO 13366-2:2010 for SCC determination, ISO 9622:201 for analyzing fat, protein, and lactose content, and ISO 5764:2010 for determining freezing point. Statistical analysis using SPSS 15.0 was conducted on the acquired data. Significant differences were observed in the lactose content (p0.05), while for the other parameters (proteins, freezing point, and solids-non-fat) seasonal variations were observed with the increase in SCC in summer and autumn. TBC in summer is the highest (1,992 x 103 CFU/ml) while in winter is the lowest (1,168 x 103 CFU/ml), which is not the case for SCC where the highest values are also in summer (537 x 103 SCC/ml), but the lowest values were determined in spring (449 x 103 SCC/ml). These findings underscore the importance of considering seasonal variations when evaluating milk quality and suggest potential implications for dairy industry practices and regulations.