Research on subclinical mastitis and its etiology in different breeds of cows

Detection of subclinical mastitis in five different breeds of cows were done on the territory of a municipality Ključ, through all four year seasons by using the California mastitis test, at the level of the udder's quarter with a certificate of bacteriological findings in order to justify their application in the diagnosis of mastitis. In total, 2150 cows of different breed composition: Simmental 1090, red Holstein 322, Holstein-Friesian 340, montafon 108 and various crossbreeds of 290 in total. After 1978 tested cows, 56.02% of cases had positive reactions to the California mastitis test. The most common positive reaction we found in the milk was in one or two quarters with the intensity of the reaction of one and two plus. The most common causes of mastitis were staphylococci, streptococci and mixed infections. Continuing use of these methods it is possible to timely detect the presence of subclinical mastitis and get satisfactory results in the prevention and treatment of mastitis as well as increasing the quantity and improving the quality of milk

Clinic for obesterics and repression of infertility, Veterinary faculty – Sarajevo, Bosnia and

**Original scientific paper Abstract: With 268 heifers in farm breeding, udder examination has been performed for clinical mastitis during 14 days after calving. From each quarter we took secretion samples and performed bacteriological analysis. From total number of heifers, 56 of them had shown clinical signs of inflammation, and 12 were bacteriologicaly positive. By bacteriological analysis mastitis pathogens had been found, even in 14 heifers without inflammation signs, at least until the end of test period. From the total number of tested heifers in 3,35 % of cases Streptococcus agalactiae have been found, 4,85 % coagulase positive staphilococcae (CPS) and 1,49% Corynebacterium pyogenes. Because coagulasa positive staphilococci were the most present bacteries in the period of 14 days, we made opinion that the same are the most often mastitis pathogen. Heifers with intramammarian infections like these, represent source of infection fot other non-infected animals in herd