Abstract

Despite continuous advancements in the farm management of primary milk production, inflammation of the mammary gland - mastitis remains a critical challenge in dairy herds, adversely affecting milk quality and food safety. The primary objective was to evaluate the impact of environmental and physiological factors on mammary gland health by identifying intramammary infections (IMI) and the associated pathogen spectrum in dairy cows during the first 100 days of lactation. A study conducted in 10 herds in eastern Slovakia on a sample of 1,000 dairy cows (100 cows from each farm) during early lactation confirmed that mammary gland health is fundamentally threatened by intramammary infections (IMI) and a specific spectrum of pathogens. The findings revealed a 20.7% overall incidence of mastitis within the monitored herds. Subclinical mastitis was the most common, affecting 14.2% of the examined cows, while clinical mastitis (CM) accounted for 6.5% of the positive cases. Microbiological analysis identified staphylococci as the dominant etiological agents, responsible for 55.8% of IMI cases. Other significant pathogens included Gram-negative bacteria (18.6%) and streptococci (17.8%). Beyond causal pathogens such as Staphylococcus aureus, Streptococcus uberis, and Streptococcus agalactiae, coagulasenegative staphylococci are increasingly prominent. Due to their high pathogenicity and virulence factors including biofilm formation, hemolysin production, and DNA hydrolysis play a pivotal role in the pathogenesis of IMI. Targeted management of these emerging pathogens is essential to minimize economic losses for producers and ensure public health protection against milk-borne diseases.

Keywords

early lactation, subclinical mastitis, pathogens, coagulase-negative staphylococci