Abstract
This study aimed to evaluate seasonal variations in the main components of raw cow’s milk and to assess the relationships between milk composition and selected physiological indicators, including milk urea nitrogen (MUN), lactoferrin (LF), and somatic cell count (SCC). A total of 3000 milk samples from 250 clinically healthy dairy cows were collected across four seasons on a commercial farm in eastern Slovakia. Milk fat and protein exhibited significant seasonal differences (p < 0.001), with the lowest values in summer and the highest in autumn. Lactose concentrations remained relatively stable throughout the year, showing no significant seasonal variation. MUN showed notable seasonal variation, with significantly lower levels in winter compared with other seasons, reflecting changes in feeding regime and nitrogen metabolism. Lactoferrin levels were lowest in summer and highest in autumn, likely reflecting physiological changes associated with the lactation stage. Seasonal changes in SCC were not statistically significant, although a trend toward higher values in summer was observed. These findings highlight the influence of nutrition, physiological state, and environmental conditions on milk composition and udder health. Understanding seasonal dynamics is essential for optimizing dairy herd management, mastitis monitoring, and technological quality of raw milk.