Impact of Farm Hygiene Practices and Seasonal Variations on the Microbial Population of Raw Milk in Small-Scale Dairy Farms in the Istog Region of Kosovo

This study evaluated the microbial quality of raw cow milk in relation to seasonal variation and on-farm hygiene practices across 102 small-scale dairy farms in the Istog region of Kosovo. In total, 1,574 bulk tank milk samples were collected over one year and analyzed using 3M™ Petrifilm™ Aerobic Count Plates to determine total aerobic colony counts (CFU/mL). Monthly mean counts ranged from 1.26 × 10⁵ CFU/mL in December to 2.84 × 10⁵ CFU/mL in January, with an overall annual mean of 1.99 × 10⁵ ± 0.86 × 10⁵ CFU/mL. The Kruskal–Wallis test showed significant differences among months (p < 0.001), while seasonal effects were not significant (p = 0.586), despite higher values in summer and autumn. Across farms, CFU/mL ranged from 2.0 × 10³ to 1.0 × 10⁶ (p < 0.001), indicating large inter-farm differences associated with udder hygiene, equipment sanitation, and milk cooling practices. Regular udder disinfection, thorough milking machine cleaning, and immediate milk cooling to ≤ 4℃ are cost-effective priorities to improve milk safety and the economic sustainability of smallholder dairy farms.