Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-26T00:36:04.850Z Has data issue: false hasContentIssue false

Annual variation in the growth of Haemonchus contortus in experimental infections of sheep and its relation to arrested development

Published online by Cambridge University Press:  06 April 2009

W. J. Coadwell
Affiliation:
Biochemistry Department, ARC, Institute of Animal Physiology, Babraham, CambridgeCB2 4AT
P. F. V. Ward
Affiliation:
Biochemistry Department, ARC, Institute of Animal Physiology, Babraham, CambridgeCB2 4AT

Extract

Fifty-six sheep, worm-free birth, were each given a sigle infection of 50 000 Haemonchus contortus larvae at varying at varying times over a 2 year period. They were killed from 13 to 89 days infection and the lengths of both male and female parasites measured. Using a computer, growth curves for each sex were constructed and the relative lengths of the worms in each infection were calculated by dividing their measured lengths by the lenghts predicted by the appropriate curve. Since there was no significant difference between the relation length of male and female worms in an infection, the mean value was used in further analyses. Differences in sex of host and duration of infection had no significant effect on the relative length of parasites. There was a close relation between relative length and the time of year of infection. The relation was cyclical and closely followed a sine curve with a maximum at day 90 and a minimum at day 275 of the year. Arrested development at the 4th larval stage occurred at the time of year risen again. It is suggested that this cyclic change in growth pattern and arrested development is controlled by the seasonal variation in concentration of a substances present in the host’s blood. Parasite relative length was also related to sheep age, but the relationship observed was largely an artifact of the close birth dates of many of the sheep.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1977

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anderson, N., Armour, J., Jennings, Fs. W., Ritchie, J. D. & Urquhaqrt, G. M. (1965). Inhibited development of Ostertagia ostertagi. Veterinary Record 77, 146–7.Google Scholar
Armour, J. (1970). Bovine ostertagiasis: a review. Veterinary Record 86, 184–90.Google Scholar
Blitz, N. M. & Gibbs, H. C. (1971). Morphological characterization of the stage of arrested development of Haemonchus contortus in sheep. Canadian Journal of Zoology 49, 991–5.Google Scholar
Blitz, N. M. & Gibbs, H. C. (1972a). Studies on the arrested development of Haemonchus contortus in sheep. I. The induction of arrested development. International Journal for Parasitology 2, 512.Google Scholar
Blitz, N. M. & Gibbs, H. C. (1972b). Studies on the arrested development of Haemonchus contortus in sheep. II. Termination of arrested development and the spring rise phenomenon. International Journal for Parasitology 2, 1322.Google Scholar
Coadwell, W. J. & Ward, P. F. V. (1975). Observations on the development of Haemonchus contortus in young sheep given a single infection. Parasitology 71, 505–15.Google Scholar
Golglazier, M. L., Kates, K. C. & Enzie, F. D. (1969). Anthelmintic activity of tetramisole, thiabendazole and purified fine paraticle phenothiazine against experimental infections of Haemonchus contortus and Trichostrongylus species in sheep. Proceedings of the Helminthological Society of Washington 36, 6874.Google Scholar
Connan, R. M. (1968). Studies on the worm population in the alimentary tract of breeding ewes. Journal of Helminthology 42, 928.Google Scholar
Connan, R. M. (1971). The seasonal incidence of inhibition of development of Haemonchus contortus. Research in Veterinary Science 12, 272–4.Google Scholar
Connan, R. M. (1975). Inhibited development in Haemonchus contortus. Parasitology 71, 239–46.Google Scholar
Cremers, H. J. W., M., & Eysker M. (1975). Experimental induction of inhibited development in a strain of Haemonchus contortus in the Netherlands. Tropical and Geographical Medicine 27, 229–30.Google Scholar
Dineen, J. K. & Wagland, B. M. (1966). The dynamics of the host parasite relationship IV. The response of sheep to graded and repeated infection with Haemonchus contortus. Parasitology 56, 639–50.Google Scholar
Harness, E., Sellwood, S. A. & Young, E. R. (1971). Experimental Haemonchus placei infections in calves. Influence of anaemia and numbers of larvae on worm development. Journal of Comparative Pathology 81, 129–36.Google Scholar
Knight, R. A., Vegors, H. H. & Glimp, H. A. (1973). Effect of breed and date of birth of lambs on gastrointestinal nematode infections. American Journal of Veterinary Research 34, 323–7.Google ScholarPubMed
Mckenna, P. B. (1973 a). The Significance of inhibition in the parasitic development of abomasal nematodes in the New Zealand sheep. New Zealand Veterinary Journal 21, 98102.Google Scholar
Mckenna, P. B. (1973 b). The effect of storage on the infectivity and parasitic development of thrid stage Haemonchus contortus larvae in sheep. Research in Vaterinary Science 14, 312–16.Google Scholar
Mckenna, P. B. (1974 a). The persistence and fate of inhibited Haemonchus contortus larvae in young sheep. New Zealand Veterinary Journal 22, 122–6.Google Scholar
Mckenna, P. B. (1974 b). The seasonal occurrence of inhibited abomasal nematodes in young sheep. New Zealand Veterinary Journal 22, 214–17.Google Scholar
Muller, G. L. (1968). The epizootiology of helminth infestations in sheep in the south western districts of the Cape. Onderspoort Journal of Veterinary Research 81, 129–36.Google Scholar
Radhakrishnan, C. V., Bradley, R. E. & Loggins, P. E. (1972). Host responses of wormfree Florida Native and Rambouillet lambs experimentally infected with Haemonchus contortus. American Journal of Veterinary Research 33, 817–23.Google ScholarPubMed
Southcott, W. H., Major, G. W. & Barger, I. A. (1976). Seasonal pasture contamination and availability of nematodes for grazing sheep. Australian Journal of Agricultural Research 27, 277–86.Google Scholar