Experimental infections with Trichostrongylus colubriformis (Giles, 1892) Loos, 1905 in lambs: worm burden, growth rate and host resistance resulting from prolonged escalating infections.

摘要: Lambs were infected at daily intervals from 3 weeks of age with increasing doses infective larvae Trichostrongylus colubriformis , according to an exponential infection schedule designed simulate the pattern experienced by grazing lambs during spring and early summer in Britain. The faecal egg counts worm burdens followed a similar trend for 12 after initial infection. T. these appeared be cumulative first weeks, which animals developed resistance further reinfection, was very strong 16 However, even refractory new continued harbour large numbers adult worms, caused clinical disease most lambs. There no evidence suggest that either turnover burden, inhibition larval development or sudden loss established parasites played any major role regulation young removal burden one lamb result partial challenge given 10 days later.