Trichostrongylosis and wool growth. 3. The wool growth response of resistant grazing sheep to larval challenge

Wool growth rates of grazing sheep that were resistant to infection with the intestinal nematode Trichostrongylus colubriformis were measured in the presence and absence of a larval challenge. In one experiment, resistant sheep exposed to a moderate level of larval challenge grew 11 per cent less wool than unchallenged resistant sheep grazing the same paddock. A second experiment confirmed the previous results but showed that the magnitude of this wool growth depression did not depend on the severity of the challenge