EXPERIMENTAL CONCURRENT INFECTIONS WITH OSTERTAGIA-OSTERTAGI AND COOPERIA-ONCOPHORA IN THE CALF

An experiment was conducted to investigate the effects of experimental concurrent infection with Ostertagia ostertagi and Cooperia oncophora compared with the effects of monospecific infections with O ostertagi under conditions designed to mimic natural conditions on pasture duri ng a grazing season. The present experiment was not able to demonstrat e any significant effect of C oncophora on the course of an O ostertag i infection. Neither did C oncophora influence the build up of immunit y to O ostertagi as demonstrated by post mortem worm count results fro m challenge infections with hypobiosis-prone larvae.