Quarter and cow-level risk factors for clinical mastitis and elevated somatic cell count in dairy cows: A review and preliminary findings from a recent UK research project

Individual quarter and cow-level risk factors for the development of clinical mastitis (CM) and elevated somatic cell count (SCC) are reviewed and a recent U.K. study attempting to quantify these factors is described. Observations including body condition score (BCS), udder and leg hygiene scores (UHS, LHS), hyperkeratosis of the teat-end (teat-end callosity or TEC), milking order and milking position were collected from eight commercial south-west dairy farms, totalling 1677 cows over a 12-month period. Cases of CM were recorded by the farmers and herdspersons using a pre-defined format and samples were requested from all cases using equipment and a Standard Operating Procedure (SOP) provided. A total of 53,364 teat-end scores, 29,282 hygiene scores and 14,074 body condition scores were available for analysis. Bacteriological analysis from 829 clinical mastitis cases where a sample was made available revealed Escherichia coli to be the most prevalent pathogen (219 isolates, 26.4%) and Streptococcus uberis to be the second-most prevalent pathogen (162 isolates, 19.5%). S. uberis was most commonly isolated from 240 sub-clinical mastitis samples (31 isolates, 12.9%).