Pathogens species composition and production losses assessment in sub-clinical cow mastitis in the Kostanay region farms (Kazakhstan)

The aim of the study is to assess production losses caused by subclinical mastitis. The study was carried out in two farms of the Kostanay Region (Republic of Kazakhstan), on two breeds - the Holstein breed (LLP "Bek +") and the black-and-white breed (JSC "Zarya"). In each of these farms, 200 animals were selected without signs of clinical mastitis. The study of the species composition of pathogens causing subclinical mastitis, the frequency of their isolation, as well as the nature of the distribution of pathogens, depending on the lactation period of cattle, was carried out. At the same time, the results of microbiological analysis were correlated with the results of analysis for the content of somatic cells in milk. Milk samples were taken from all animals selected for the study at least three times during the lactation period. Each sample was subjected to microbiological examination, quality analysis was carried out using the device "Laktan 1-4 M". The number of somatic cells was determined using the "Mastoprim" preparation on the "Somatos-Mini" analyzer. In groups of animals in which the number of somatic cells was more than 500 thousand per 1 cm3, significant production losses were observed, the volume of milk received decreased by 8.3 % in cows with a negative bacteriological status and by 12.47 % in cows with positive results of bacteriological analysis compared with the control group. In this regard, it is of great importance to increase the resistance of animals to the disease of mastitis through selection for resistance, as well as the development of measures for the prevention of this disease, taking into account both paratypical and genetic factors.