The effect of feeding sulla (Hedysarum coronarium) or lucerne (Medicago sativa) on lamb parasite burdens and development of immunity to gastrointestinal nematodes
| Autor: | H.A Robertson, D Shelton, W.A.G. Charleston, J.H Niezen, G.C Waghorn, R.S. Green |
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| Rok vydání: | 2002 |
| Předmět: |
Male
Veterinary medicine Trichostrongylus Sheep Diseases Forage Pasture Feces Random Allocation Ostertagiasis Immunity parasitic diseases Grazing medicine Animals Anthelmintic Nematode Infections Parasite Egg Count Legume Larva geography Sheep geography.geographical_feature_category General Veterinary biology Ostertagia Trichostrongylosis Fabaceae General Medicine biology.organism_classification Nematode Female Parasitology Tannins Medicago sativa Phytotherapy medicine.drug |
| Zdroj: | Veterinary Parasitology. 105:229-245 |
| ISSN: | 0304-4017 |
| DOI: | 10.1016/s0304-4017(02)00014-6 |
| Popis: | Two experiments investigated the efficacy of the legume Hedysarum coronarium (sulla), which contains condensed tannins (CTs), for reducing gastrointestinal nematode infections relative to lucerne. Experiment 1 was aimed to show whether the lower faecal egg count (FEC) and larval establishment previously reported in lambs grazing sulla were due to direct effects of the forage on Ostertagia circumcincta and Trichostrongylus colubriformis or were mediated through an enhanced immune response. Experiment 2 evaluated the impact of feeding sulla relative to feeding lucerne (Medicago sativa), before, at, or after larval challenge on subsequent FECs and nematode burdens. In experiment 1, 64 Romney lambs were fed either freshly cut lucerne or sulla (32 lambs per herbage) for the duration of the trial. Within each herbage there were four treatment groups (n=8 per group). Initial levels of immunity were assessed in uninfected (UN) lambs which were maintained parasite-free until challenged with 15,000 O. circumcincta and 15,000 T. colubriformis larvae on day 63, and slaughtered on day 81. The other three treatment groups were trickle-infected with each of 5000 O. circumcincta and 5000 T. colubriformis larvae three times per week from day 1 to 35. Non-steroid infected (CONTROL) and steroid-treated (STER) groups were treated with anthelmintic on day 49 and challenged with 15,000 O. circumcincta and 15,000 T. colubriformis on day 63 and slaughtered on day 81. The STER lambs were given dexamethasone trimethylacetate from day 49 to 81 to determine effects of immunity on parasite infection. From day 35 an establishment group (EST) on each herbage was fed a common pelleted lucerne diet and slaughtered on day 56 to determine nematode establishment during trickle-infection. Diet did not affect FECs but feeding lucerne increased (P |
| Databáze: | OpenAIRE |
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