Methods for diagnosing subclinical mastitis of cows during the lactation period in the conditions of the dairy complex

Under the modern conditions of dairy cattle breeding, mastitis is one of the most common diseases of cows. A regular inspection of the condition of cow’s udder will identify animals with risk of mastitis. The purpose of the work was to determine the extent of subclinical mastitis by lactating cows, factors contributing to the development of this disease. The research was carried out at Slavyanskoye CJSC of the Verkhovsky District, the Orel region in summer of 2019-2020. The object of the study was dairy cows in lactation period of the Holstein breed, the material was milk obtained from these animals. The cows were examined for mastitis during milking with Kerba Test and Kenotest diagnostics. The udder of the cows that had a positive result for mastitis was clinically examined with a preliminary study of the clinical background. To confirm the presence of mastitis, a sample of milk settling was carried out. Due to the fact that mastitis is a multifactorial disease and microorganisms play a leading role in it, a bacteriological study of milk from affected udder fraction was carried out, the sensitivity of isolated pathogens to antimicrobial drugs was determined. During the investigation, 800 cows were inspected, 400 heads per year. In 2019, 3.0% of cows in the lactating period with subclinical mastitis from the whole population with predominance of the involvement of one udder fraction were identified. In 2020, subclinical mastitis disease was noted by two cows or 0.5% of the studied animals, also with the damage of the front udder fraction. At the same time, all reacted animals had only one udder fraction affected. The affection of the front udder fraction was noted by cows with a rounded form of the udder. The main pathogenic organism of subclinical mastitis in the farm is S. aureus . Besides, Stragalactiae, E. coli, Proteus , fungi of the genus Candida were also detected.