INCIDENCE AND PREVALENCE OF LAMENESS IN DAIRY-CATTLE

A survey was made of 37 dairy farms in Wirral, mid-Cheshire, mid-Somer set and Dyfed, Wales, to assess the incidence and prevalence of lamene ss in the cows between May 1989 and September 1991. The incidence was obtained from records made whenever a cow was examined for lameness or received preventive foot-trimming, The mean annual incidence was 54.6 new cases per 100 cows with a range from 10.7 to 170.1 and the mean v alues during summer and winter were 22.9 and 31.7, respectively. The p revalence of Lameness was measured by regular visits at which locomoti on was scored on a scale of 1 to 5, and the prevalence of lameness was calculated for each visit as the proportion of cows with scores of 3 or more, The mean annual prevalence over the whole period was 20.6 per cent with a range from 2.0 to 53.9 per cent for the 37 farms, The mea n prevalences during summer and winter were 18.6 and 25.0 per cent, re spectively. The prevalence measured at a single visit in midsummer or midwinter was significantly correlated with the mean prevalence over t he whole corresponding period and may be useful as an assessment of th e extent of lameness in a herd and the efficacy of control measures, T here was evidence that training farmers to recognise early cases of la meness and request veterinary treatment resulted in a marked reduction in the duration of cases of lameness.