Identification of causative agents of cow mastitis in farms of Ternopil region

Mastitis in lactating cows is a problem that causes significant economic losses and is more common on large farms with machine milking. In addition, the microbial factor is considered dominant in the etiology of mastitis. The aim of the work was to determine the prevalence of mastitis among lactating cows and to identify pathogens that are released in clinical and subclinical forms of udder inflammation. The analysis of the prevalence of mastitis in cows was carried out on four dairy farms with untethered Holstein cows and milking in modern milking parlors in the Ternopil region (Ukraine). Identification of pathogens was carried out according to methods generally recognized in microbiological practice, while commercial test systems for identification of microorganisms API (bioMerieux, France) were used. It was established that on modern dairy farms, during the year, an average of 21% of lactating cows in the winter period, and an average of 17.6 % in the summer period, fell ill with a subclinical form of mastitis. At the same time, from 1.5 to 2.9 % of cows suffered from the clinical form of mastitis during the lactation period. Among the pathogens of subclinical mastitis of cows, Str. was most often identified in the monoculture. agalactiae, which was isolated from a third of the diseased quarters. A little less often in monoculture, the causative agent of mastitis was Staph. aureus, which was identified in 31.4 ± 2.7 % of quarters. The number of diseased udder quarters from which two pathogens Str. agalactiae and Staph. aureus was 27.8 ± 2.3 %. Association of three pathogens (Staph. aureus + E. coli + P. aeruginosa) caused subclinical mastitis in 7.3 ± 0.8 % of udder quarters. The main pathogen of the clinical form of mastitis in farms was Staph. aureus, which was identified in monoculture in 35.8 ± 3.1 % of sick cows. Only 2 % less E. coli was isolated from the inflamed mammary gland in monoculture (33.9 ± 2.8 %). Mixed microflora from three pathogens (Staph. aureus + E. coli + P. aeruginosa) was isolated for clinical mastitis in 22.6 ± 1.9 % of cases. Rarely (in 7.7 ± 0.6 %) an association of two pathogens (Staph. aureus + P. aeruginosa) was isolated from the udder quarters of patients with clinical mastitis. Therefore, the causative agents of the clinical form of mastitis are the same pathogens that cause subclinical mastitis, which must be taken into account in the prevention program of this disease.