Article Text

Investigation of risk factors for clinical mastitis in British dairy herds with bulk milk somatic cell counts less than 150,000 cells/ml
  1. K. M. O’Reilly, BSc1,
  2. M. J. Green, BVMS, MSc, PhD, MRCVS1,
  3. E. J. Peeler, MA, VetMB, MSc, PhD, MRCVS3,
  4. J. L. Fitzpatrick, BVSc, PhD, MRCVS4 and
  5. L. E. Green, BVSc, DCHP, PhD, MRCVS2
  1. 1Ecology and Epidemiology Group, Department of Biological Sciences, University of Warwick, Coventry CV4 7AL
  2. 2Orchard Veterinary Group, Wirral Park Road, Glastonbury, Somerset BA6 9XE
  3. 3Department of Clinical Veterinary Science, University of Bristol, Langford, North Somerset BS40 5DU
  4. 4University of Glasgow Veterinary School, Bearsden Road, Bearsden, Glasgow G61 1QH


A sample of dairy farms in Great Britain with a monthly bulk milk somatic cell count of less than 150,000 cells/ml was enrolled into a 12-month prospective study. At the end of the study, a questionnaire on milking practice and other farm management practices was sent to the 482 farmers who had collected data on the occurrence of mastitis throughout the 12 months. The response rate was 93 per cent. The reported mean incidence of clinical mastitis was 36·9 cases per 100 cow-years. Factors associated with an increase in the incidence of clinical mastitis were cleaning out the straw yard less frequently than every six weeks, more than 5 per cent of cows leaking milk outside the parlour, checking the foremilk, wearing gloves during milking, an average annual milk yield of more than 7000 litres per cow, dipping or spraying teats before milking and keeping milk with a high somatic cell count out of the bulk tank. Factors associated with a decrease in the incidence of clinical mastitis were using a cloth to dry the teats after washing them as part of premilking preparation, using calving boxes for less than 40 per cent of calvings, and using both cubicles and straw yards to house dry cows, as opposed to other housing.

Statistics from


  • Dr Peeler’s present address is Centre for Environment, Fisheries and Aquaculture Science, Weymouth Laboratory, Weymouth, Dorset DT4 8UB

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.