Abstract:
Calves raised worm-free were exposed to natural infection on unimproved pasture infected with Trichostrongylus axei, Haemonchus placei, Ostertagia ostertagia, Cooperia punctata and C. pectinata, and Oesophagostomum radiatum. Some calves received, in addition, experimental infections of O. radiatum and H. placei. All calves showed depressed body weight gains. Haematocrit, haemoglobin, and serum protein levels were reduced, returned to normal after 15