Studies on Haemonchus contortus. X. The effect of Trichostrongylus axei in Merinos on artificial pastures.
A recently established Eragrostis curvula pasture 1,1 ha in size at Hennops River in the Transvaal Highveld was contaminated from 6 October 1976 until 20 May 1977 by 30 weaned Merinos, each infested with 7 000 infective larvae of H. contortus. On 2 November 1976 3 groups of weaned Merinos and again on 10 January 1977 a further group of Merinos were infested with 40 000 infective larvae of Trichostrongylus axei. From 19 November a single group of sheep, predosed with T. axei, and a control group grazed with the seeders for 8 weeks. After 6 weeks another group of sheep dosed with T. axei grazed with them, thus ensuring a 2-week overlap. This continued until autumn, when the last groups were removed. Efficacy against challenge reached Class C (greater than 50% effective against total worm burdens of H. contortus in greater than 50% of sheep) in early summer and autumn, but only reached significant levels of either P less than 0,01 or P less than 0,05 in summer. Peak worm burdens in controls were recorded in early autumn.
D000818:Animals; D005243:Feces / Q000469:parasitology; D006188:Haemonchiasis / Q000517:prevention & control / Q000662:veterinary*; D006189:Haemonchus / Q000502:physiology*; D006790:Host-Parasite Interactions; D008297:Male; D010270:Parasite Egg Count; D012756:Sheep / Q000469:parasitology*; D012757:Sheep Diseases / Q000517:prevention & control*; D014251:Trichostrongyloidea / Q000502:physiology*; D014252:Trichostrongyloidiasis / Q000662:veterinary*; D014253:Trichostrongylosis / Q000662:veterinary