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Studies on Ostertagia spp. from Greenlandic Sheep: Arrested Development and Worm Length
Undersøgelser over Ostertagia spp. i får i Grønland: “arrested development” og ormestørrelse
Acta Veterinaria Scandinavica volume 31, pages 333–337 (1990)
Abstract
Studies were conducted to investigate earlier observations that lambs slaughtered in Greenland in late September/early October have relatively few arrested larvae in the abomasal mucosa and that the adult Ostertagia from such lambs are abnormally large. Post mortem examination of naturally infected ewes in mid-winter demonstrated that a significant proportion of their Ostertagia population was hypobiotic at this time of year, while an experimental study showed that considerable numbers of larvae of Greenlandic origin became arrested following cold conditioning for 10 weeks. A comparison of adult Ostertagia of Greenlandic and Britain origins from lambs experimentally infected with larvae cultured under identical conditions demonstrated that the “giant” size of the arctic worms was attributed mainly to environmental rather than genetic influences.
Sammendrag
I en tidligere undersøgelse på Grønland fandtes påfaldende få Ostertagia-larver hos lam slagtet om efteråret, og de kønsmodne orm var usædvanlig store. Med denne baggrund gennemførtes to nye undersøgelser, én over naturligt inficerede lam, som aflivedes midt på vinteren, og én over lam, som blev eksperimentelt podet med infektive larver, som forud var blevet kulde-konditioneret. I begge tilfælde fandtes et betydeligt antal hypobiotiske larver, hvilket måske tyder på, at grønlandske løbeorm kan overvintre i fårenes slimhinde, som hypobiotiske larver. En sammenlignende undersøgelse over størrelsen af voksne orm, hidrørende fra henholdsvis et grønlandsk og et engelsk podemateriale, viste ingen signifikant forskel, hvorfor den tidligere antagelse af, at grønlandske orm skulle være særlig store, måtte tilbagevises. Det tidligere fund af “store” orm kan eventuelt have en miljømæssig baggrund, men næppe en genetisk.
References
Hong C, Timms BJ: Variation in size of Ostertagia circumcincta, a nematode parasite of sheep, induced experimentally and during preparation and preservation. Systematic Parasitology 1986, 9, 39–42.
Michel JF: Arrested development of nematodes and some related phenomena. Advanc. Parasitol. 1974, 13, 279–366.
Rose CH, Jacobs DE, Jørgensen RJ, Nansen P: Studies on the helminth parasites of sheep in southern Greenland. Nord. Vet.-med. 1984, 36, 77–87.
Rose CH, Jacobs DE: Epidemiology of sheep nematodes in sub-arctic Greenland: sources of infection on rangeland grazing. Acta vet. scand. 1990, 31, 339–345.
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Jacobs, D.E., Rose, C.H. Studies on Ostertagia spp. from Greenlandic Sheep: Arrested Development and Worm Length. Acta Vet Scand 31, 333–337 (1990). https://doi.org/10.1186/BF03547545
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DOI: https://doi.org/10.1186/BF03547545