Importance of the ewe as a source of trichostrongyle infection for lambs: Control of the spring-rise phenomenon by a single postlambing anthelmintic treatment

Abstract

Extract There are two principal sources of initial infection for the young lamb, the ewe grazing with it and the residual pasture infection resulting from any previous grazing. Several workers (Hawkins et al., 1944 Hawkins, P. A. , Cole, C. L. , Kline, E. E. and Drudge, J. H. 1944. Studies of sheep parasites. I. The course of untreated nematode infections. Vet. Med., 39: 154–161. [Google Scholar] ; Leiper, 1951 Leiper, J. W. G. 1951. Anew approach to phenothiazine therapy in sheep. Vet. Rec., 63: 885–889. [Google Scholar] ; Spedding and Brown, 1956 Spedding, C. R. W. and Brown, T. H. 1956. The “spring rise” in the nematode egg-count of sheep. J. Helminth., 29: 171–178. [Crossref] [Google Scholar] ; Spedding, 1962 Spedding, C. R. W. 1962. Modern trends in animal health and husbandry. The agricultural ecology of sheep grazing. Brit. vet. J., 118: 461–481. [Google Scholar] ; Crofton, 1958 Crofton, H. D. 1958. Nematode parasite populations in sheep on lowland farms. V. Further observations on the post-parturient rise and a discussion of its significance. Parasitology, 48: 243–250. [Google Scholar] ; Soulsby, 1962 Soulsby, E. J. L. 1962. “Immunity to helminths and its effect on helminth infections”. In Animal Health and Production, 165–183. London: Butterworths. [Google Scholar] ) believe that the former is generally the more important.