INFECTIOUS FACTOR IN THE ETIOLOGY OF MASTITIS IN HIGHLY PRODUCTIVE LACTATING COWS
In a bacteriological study of 412 samples of the udder secretion of sick cows with mastitis, 121 cultures of microorganisms of 15 species were isolated, which were represented in 54.9% of cases by gram-positive cocci, the remaining 45.1% by representatives of the Enterobacteriaceae and Ps. aeruginosa, staphylococci prevailed - 28.6%, streptococci - 22.6%, enterococci - 19.2%. When the incidence of cows with mastitis is more than 30%, the microflora was isolated from 81.8% of udder secretion samples, including pathogenic microflora (Staph. aureus, E. coli) - in 32.7% of cases, conditionally pathogenic (C. diversus, Ent. faecalis) - 23.6% and 20.0% - saprophytic microflora (Staph. saprophyticus, Staph. epidermidis, Ent. aerogenes, Ps. aeruginosa) and fungi (Сandida) - 5.5%. The results of the study showed that in clinically healthy lactating cows, the bactericidal activity of the udder skin varies depending on the functional state of the mammary gland and has a maximum value of 91.8 ± 2.0% in the first week after birth, decreasing to 87.8 ± 2 by the middle of lactation. .4% and becomes minimal during the launch period - 79.7±2.3%. The change in the bactericidal activity of the skin of the udder teats is associated with the state of other non-specific factors of local protection, in particular, the titer of lysozyme M and the level of somatic cells.