tailieunhanh - Báo cáo khoa học: "The Dynamics, Prevalence and Impact of Nematode Infections in Organically Raised Sheep in Sweden"

Tuyển tập các báo cáo nghiên cứu về bệnh thú y được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành thú y đề tài: The Dynamics, Prevalence and Impact of Nematode Infections in Organically Raised Sheep in Sweden. | Acta vet. scand. 2001 42 377-389. The Dynamics Prevalence and Impact of Nematode Infections in Organically Raised Sheep in Sweden By Ấ. Lindqvist1 B-L. Ljungstrom2 O. Nilsson2 and . Waller4 1Swedish Animal Health Service Sv DHV Kalmar 2Sv DI IV. National Veterinary Institute Uppsala 3Sv DHV Kristianstad and 4Department of Parasitology SWEPAR National Veterinary Institute Uppsala Sweden. Lindqvist Ả Ljungstrom B-L Nilsson O Waller PJ The dynamics prevalence and impact of nematode infections in organically raised sheep in Sweden Acta vet. Scand. 2001 42 377-389. - A three-year survey 1997-99 was carried out on organically reared sheep flocks throughout Sweden. The aim was to determine the prevalence and intensity of nematode infections and to establish relationships between sheep management practices and parasite infections. Faecal samples from ewes and lambs were collected from 152 organic flocks around lambing-time and during the grazing-period for analysis. Results were compared with the different management practices that farmers use to prevent parasitism in their flocks. A high proportion of the flocks was infected with nematodes. The most prevalent species were Haemonchus contortus Teladorsagia circumeincta Trichostrongylus axei T colubriformis and Chabertia ovina and infections progressively increased during summer in lambs grazing on permanent pastures. Severity of parasitic infection in lambs was highly dependent on egg output from the ewes. H. contortus was found in 37 of the flocks even at latitudes approximating the Polar Circle. Nematodirus battus was recorded for the first time in Sweden during the course of this study. Lambs turned out onto permanent pasture showed higher nematode faecal egg counts epg than lambs that had grazed on pastures which had not carried sheep the previous year. This beneficial effect of lambs grazing non-infected pastures persisted if the ewes were treated with an anthelmintic before turn-out and if the lambs were kept on .