Characterisation of Clinical Mastitis Occurring in a Dairy Herd of Holstein Friesian Cows

The objective of the present study were to characterize clinical mastitis (CM) occurring in a dairy herd of Holstein Friesian cows located at Agricultural Research and Development Station (ARDS) Simnic-Craiova, Romania (182 m above sea level, 4°19'N and 23°48'E). The severity of CM was classified as grade 1 – when only the milk was abnormal, grade 2 – when abnormal milk was accompanied by swelling or redness of mammary gland and grade 3 – when the cow exhibited systemic signs of illness such as depression, anorexia, dehydration or fever. Only grade 1 and grade 2 of clinical mastitis were analysed in this study. Duplicate quarter milk samples from affected quarters when collected before treatment (Pre-treatment). After the collection, cows were treated using the form protocol. A second set of duplicate quarter milk sample were collected from enrolled quarters at 14 to 21 days after the end of treatment (Post-treatment). Cow level follow-up data was collected for 90 days after the enrolment. Microbiological diagnosis at enrolment included gram-negative, gram-positive and no growth. Data was collected between December 2016 and November 2020, of the 58 cases of CM only 52 cases of grade 1 (n=35) and grade 2 (n=17) were used in analysis. Six cases of CM were of grade 3 (not used in this study). Most causes of CM included in this study were caused by Gram-negative pathogens followed by gram positive pathogens. The common pathogens were E. coli, environmental streptococci Enterobacter spp. and coagulase-negative streptococci. Treatment cure was greater for Gram- negative pathogens. Identification of pathogens causing CM or severity is important in strategic treatment decisions.