The spring-rise phenomenon: Seasonal changes in the worm burdens of breeding ewes and in the availability of pasture infection

Extract The “spring-rise” or post-parturient rise in the faecal egg count of breeding ewes in New Zealand was discussed by Brunsdon (1964 Brunsdon, R. V. 1966a. Importance of the ewe as a source of trichostrongyle infection for lambs: control of the spring-rise phenomenon by a single post-lambing anthelmintic treatment. N.Z. vet. J., 14: 118–125. [Taylor & Francis Online] , [Google Scholar]) who later demonstrated the importance of the phenomenon as a source of trichostrongyle infection for lambs (Brunsdon, 1966a Brunsdon, R. V. 1966a. Importance of the ewe as a source of trichostrongyle infection for lambs: control of the spring-rise phenomenon by a single post-lambing anthelmintic treatment. N.Z. vet. J., 14: 118–125. [Taylor & Francis Online] , [Google Scholar]).