Study of gastro-intestinal strongylosis in a sheep flock on permanent pasture 2. Sheep parasitism in 1978-1979.
The epidemiological study carried out in 1977 in the Limousin region of France was continued for the next two years. Eighty-five lambs were slaughtered at the rate of five animals every weeks: sixty were slaughtered from May 1978 to March 1979 and twenty-five from May to September 1979. Total parasite counts and coprological examinations were carried out. In spring the infestation of the lambs was early and heavy, and revealed that certain free-living stages can survive in low temperatures. The pattern of development of the parasites differed according to the year. It was concluded that control programmes based on theoretical patterns of evolution of the parasite will need profound study of climatic variations. Three species were found most frequently: Ostertagia circumcincta, Nematodirus spp. and Trichostrongylus colubriformis. Haemonchus contortus, exceptionally numerous in 1977, did not return to its normal level until 1979. A significant correlation was demonstrated between the number of eggs per gram of faeces and the number of female adult parasites. Thus the usefulness of coprological examinations in the diagnosis of ovine digestive strongylosis was proven. In spite of relatively high parasitism, no significant difference was found over the two years between the weight gains of regularly treated and untreated lambs.
D000818:Animals; D002980:Climate; D005243:Feces / Q000469:parasitology; D005602:France; D006188:Haemonchiasis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D007411:Intestinal Diseases, Parasitic / Q000469:parasitology / Q000662:veterinary*; D009348:Nematoda / Q000302:isolation & purification; D010270:Parasite Egg Count / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology*; D014252:Trichostrongyloidiasis / Q000662:veterinary*