WORM CONTROL PRACTICES ON SHEEP FARMS IN DENMARK AND IMPLICATIONS FORTHE DEVELOPMENT OF ANTHELMINTIC RESISTANCE

A questionnaire survey was undertaken on sheep farms in Denmark to obt ain information on sheep management and worm control practices. The qu estionnaires were inserted in the June and July, 1993 issue of the Dan ish Sheep Breeders Journal, circulated monthly to approximately 1200 s heep breeders nationwide, A total of 183 (11%) questionnaires were ret urned, A second questionnaire was posted to 50 of the 183 responding f armers to examine the repeatability of responses to the first question naire. The majority (97%) of the 183 farmers used anthelmintics, The m ean number of doses per year for lambs (<12 months old) and adult shee p(>12 months old) were 1.9 and 2.3, respectively. Only 42% of the farm s followed predetermined drenching programmes, Live weights were deter mined by visual appraisal on 45% and 84% of the farms for lambs and ad ult sheep, respectively. In calculating anthelmintic doses for groups of lambs and adult sheep, the recommended weights of the heaviest anim als were only used on only 18% and 27% of the farms respectively, Benz imidazoles were the most commonly used anthelmintics from 1986 to 1993 . Eighty one percent of 94 responding farmers had been using the same class of anthelmintic for 3 or more consecutive years. Information fro m this study indicated lack of knowledge about worm control strategies , anthelmintic use and the problem of anthelmintic resistance among th e majority of Danish sheep farmers, The majority of responses to the q uestionnaire were repeatable st least to 3 fair degree except when far mers were asked to recall anthelmintics used in past years.