Population dynamics of Trichostrongylus colubriformis in sheep: the effect of infection rate on loss of adult parasites.
Rejection of adult T. colubriformis was examined in lambs given 2000, 1124, 632 or 200 L3 day-1, 5 days per week for up to 20 weeks. Rejection of adults began at approximately the same time for the first three infection rates, and took about 9 weeks to complete. Approximately 20% of adults were rejected by week 10 of infection at the higher infection rates and it was estimated that rejection commenced at about week 7. This coincided with a decline in establishment of larvae to about 1%. For the low infection rate, there was a delay of about 5 weeks before adult worm rejection commenced and reached equivalent levels to those observed at the higher rates. This delay also coincided with an estimated 5-week delay in larval establishment declining to 1% at the low rate.
Dobson
R J
RJ
CSIRO Division of Animal Health, McMaster Laboratory, Private Bag, Glebe, New South Wales, Australia.
Waller
P J
PJ
Donald
A D
AD
D000818:Animals; D005260:Female; D012756:Sheep; D012757:Sheep Diseases / Q000469:parasitology*; D014252:Trichostrongyloidiasis / Q000662:veterinary*; D014253:Trichostrongylosis / Q000469:parasitology / Q000662:veterinary*; D014254:Trichostrongylus / Q000254:growth & development*