Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-27T03:53:52.387Z Has data issue: false hasContentIssue false
  • English
  • Français

Observations on the development of Haemonchus contortus in young sheep given a single infection

Published online by Cambridge University Press:  06 April 2009

W. J. Coadwell  and
P. F. V. Ward
W. J. Coadwell
Affiliation:
Biochemistry Department, A.R.C. Institute of Animal Physiology, Babraham, Cambridge, GB2 é4AT
P. F. V. Ward
Affiliation:
Biochemistry Department, A.R.C. Institute of Animal Physiology, Babraham, Cambridge, GB2 é4AT
Get access Rights & Permissions [Opens in a new window]

Extract

Worm free lambs 2–4 months old were given a single infection of 50 000 Haemonchus contortus larvae. The changes in packed red cell volume were compared with those of uninfected sheep and the infected sheep were divided into two groups according to the rate of change of packed cell volume. In group 1, packed cell volume fell sharply from the 10th day of infection and the sheep eventually died. In group 2, the fall was less marked and the packed cell volume returned to normal after about 40 days. The rates of increase of parasite body length and dry weight were compared for the two groups. Parasites in group 1 sheep grew more slowly than their group 2 contemporaries. Accurate planning of metabolic studies on H. contortus was made possible by using this information to predict the course of an infection and the size of the worms. Parasite development was also measured in sheep for which the packed cell volume was not recorded. Computer analysis showed that adult worm length increase did not follow a simple growth pattern starting from the last ecdysis, but consisted of a rapid elongation followed by a simple negative exponential increase. Dry weight increase also followed a negative exponential during the second phase. Measurements of dry weight as a percentage of wet weight indicated that the rapid elongation was possibly linked with cell enlargement by the uptake of water.

Type
Research Article
Information
Parasitology , Volume 71 , Issue 3 , December 1975 , pp. 505 - 515
Copyright
Copyright © Cambridge University Press 1975

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

Baermann, G. (1917). Eine einfache Methode zur auffindung von Anchylostomum (Nematoden) Larven in Erdproben. Geneeskundig Tijdschrift voor Nederlandsch-Indië 57, 131–7.Google Scholar
Christie, M. G., Brambell, M. R. & Charleston, W. A. G. (1964). Worm populations in young sheep dosed daily with 10,000 larvae of Haemonchus contortus. Journal of Comparative Pathology 74, 435–46.CrossRefGoogle Scholar
Gordon, H. M. & Whitlock, H. V. (1939). A new technique for counting nematode eggs in sheep faeces. Journal of the Council for Scientific and Industrial Research, Australia 12, 50–2.Google Scholar
Schultz, H. P. von (1967). Versuche zur Kultivierung der Parasitichen Larvenstadient von Haemonchus contortus in vitro. Berliner und Münchener Tierärztliche Wochenschrift 80, 89–96.Google Scholar
Veglia, F. (1915). The anatomy and life history of the Haemonchus contortus (Rud.). Report on Veterinary Research, Department of Agriculture, Union of South Africa 3, 4, 349–500.Google Scholar
Ward, P. F. V. (1974). The metabolism of glucose by Haemonchus contortus in vitro. Parasitology 69, 175–90.CrossRefGoogle Scholar