title: The effect of daily challenge with Trichostrongylus colubriformis larvae on the nutrition and performance of immunologically-resistant sheep.
abstract: Immunological resistance to Trichostrongylus colubriformis was developed in sheep by challenging them with 2500 larvae per day for 34 weeks. They were then rested for 24 weeks before being re-challenged with the same dose rate of the same larvae for 10 weeks. Nutritional, haematological and parasitological parameters were measured during the first 8 weeks of re-challenge infection. There were no faecal worm eggs excreted during the re-challenge infection. There was a small but significant increase in plasma-N leakage from Days 4 to 9 of dosing but this then declined to initial levels. There was no other detectable nutritional disturbance associated with re-infection. Re-challenge caused a rapid development of eosinophilia which peaked during Week 6 before declining to levels of the control animals by Week 8. Sheep resistant to T. colubriformis appear to be able to re-activate their immunological mechanisms when re-challenged with the parasite with little associated nutritional penalty.
authors.affiliation: Rowett Research Institute, Bucksburn, Aberdeen, Gt. Britain.
authors.forename: A E
authors.initials: AE
authors.lastname: Kimambo
authors.forename: J C
authors.initials: JC
authors.lastname: MacRae
authors.forename: P J
authors.initials: PJ
authors.lastname: Dewey
mesh_terms: D000818:Animals; D004802:Eosinophilia / Q000469:parasitology / Q000662:veterinary; D007113:Immunity, Innate; D007156:Immunologic Memory; D009584:Nitrogen / Q000378:metabolism; D009748:Nutrition Disorders / Q000469:parasitology / Q000662:veterinary*; D011506:Proteins / Q000378:metabolism; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology / Q000378:metabolism / Q000469:parasitology*; D013997:Time Factors; D014252:Trichostrongyloidiasis / Q000662:veterinary*; D014253:Trichostrongylosis / Q000276:immunology / Q000378:metabolism / Q000662:veterinary*; D014254:Trichostrongylus / Q000472:pathogenicity
chemical_list: D011506:Proteins; D009584:Nitrogen