Abstract
A relatively large part of the Slovak territory consists of the “marginal regions”, which in terms of the economy of ruminants keeping can efficiently produce animal commodities only occasionally. The geographic, social and economic stability of these regions is strongly influenced by the rearing of ruminants and the associated market milk production. The aim of this study was to evaluate the prevalence and aetiological agents of mastitis in two herds of dairy cows situated in the marginal parts of Slovakia. In total, 530 of the Slovak spotted breed and Holstein cows were involved in the study. The diagnosis of mastitis was performed on the basis of the clinical examination of the udder, macroscopic evaluation of the milk, determination of somatic cell count (SCC), and the bacteriological examination of the milk. The prevalence of mastitis in the two herds of dairy cows ranged from 34.7 % to 18.8 %, respectively. From the total of 2120 quarter milk samples, 36.3 % were positive to the California mastitis test (CMT). Also, pathogenic microorganisms causing intramammary infection (IMI) were isolated from 25.6 % of the samples, which accounted for most subclinical mastitis forms (23.3 %), with the SCC under 400 000, mainly caused by coagulase-negative staphylococci (CoNS) and coliform bacteria E. coli and Enterobacter aerogenes. The clinical forms of mastitis accounted for 13.0 % of all infected cows and were caused mainly by the bacteria: Streptococcus uberis, Streptococcus agalactiae, Staphylococcus aureus and coagulasenegative staphylococci.