Trichostrongylus colubriformis: relationship between ageing of infective larvae, infectivity and egg production by adult female worms.

Relationships between egg production and infectivity were studied with infective larvae of Trichostrongylus colubriformis which had been stored for up to 22 weeks at 24 degrees C. After different storage times, larvae were administered to lambs and the number of parasites which reached the adult stage was counted five weeks after infection. Egg production was estimated for the same batches of animals by performing a quantitative coproscopic examination from the third week of infection onwards. Infectivity was maximum and constant during the first six weeks of storage and then decreased regularly from the 9th week to the end of the experiment. However, the number of eggs produced per female worm was constant during the first 6 weeks then doubled and remained constant from the 9th to the 22nd week of storage.

[1]  S. Mallet,et al.  Relation entre l'activité enzymatique et le pouvoir infestant au cours du viellissement des larves infestantes de Heligmosomoides polygyrus (=nematospiroides dubius) , 1984 .

[2]  D. Kerboeuf.  Egg output of Heligmosomoides polygyrus (Nematospiroides dubius) in mice infected once only. , 1982, Annales de recherches veterinaires. Annals of veterinary research.

[3]  L. Gruner,et al.  A study of ovine gastro-intestinal strongylosis in a sheep flock on permanent pasture. II. Population dynamics of parasites on the pasture in 1977 and an epidemiological interpretation. , 1980, Annales de recherches veterinaires. Annals of veterinary research.

[4]  D. Kerboeuf.  The effects of time and temperature of storage on the infectivity of third-stage larvae of Heligmosomoides polygyrus (= Nematospiroides dubius). 1. Effects on the development to the adult stage in mice. , 1978, Annales de recherches veterinaires. Annals of veterinary research.

[5]  D. Kerboeuf.  The effects of time and temperature of storage on the infectivity of third-stage larvae of Heligmosomoides polygyrus (= Nematospiroides dubius). 2. Studies on the fecundity of female worms as a function of the infectivity of the third-stage larvae. , 1978, Annales de recherches veterinaires. Annals of veterinary research.

[6]  Smith Hj.  Investigation of maturation requirements for Ostertagia ostertagi and Cooperia oncophora larvae. , 1976 .

[7]  H. J. Smith.  Investigation of maturation requirements for Ostertagia ostertagi and Cooperia oncophora larvae. , 1976, Canadian journal of comparative medicine : Revue canadienne de medecine comparee.

[8]  T. Gibson,et al.  Egg output by Trichostrongylus axei in sheep given a single infection. , 1975, Journal of comparative pathology.

[9]  S. Stampa,et al.  A contribution towards the diagnosis of trichostrongylosis in flocks of sheep under field conditions. , 1972, Journal of the South African Veterinary Association.

[10]  G. E. Ford.  A maturation requirement for strongyle larvae , 1971, The Veterinary Record.

[11]  R. J. Thomas,et al.  The development and survival of free-living stages of Trichostrongylus colubriformis and Ostertagia circumcincta on pasture. , 1970, Research in veterinary science.

[12]  B. Ryan,et al.  Effects of cold storage on survival and infectivity of third-stage larvae of the stomach worm, Trichostrongylus axei (Cobbold, 1879). , 1970, The Journal of parasitology.

[13]  L. Chomicz,et al.  Coproscopical examination of Carpathian sheep and its relation to postmortem examinations. , 1970 .

[14]  Michel Jf.  The regulation of egg output by Ostertagia ostertagi in calves infected once only. , 1969 .

[15]  J. Michel.  The regulation of egg output by Ostertagia ostertagi in calves infected once only , 1969, Parasitology.

[16]  J. Michel.  Regulation of Egg Output of Populations of Ostertagia ostertagi , 1967, Nature.

[17]  T. Gibson,et al.  The ecology of the free-living stages of Trichostrongylus colubriformis , 1967, Parasitology.

[18]  D. A. Porter,et al.  The effect of culture temperature and age on the infectivity of the larvae of Trichostrongylus axei and T. colubriformis in rabbits and guinea pigs. , 1966, The Journal of parasitology.

[19]  H. Herlich.  Effects of eold storage on the infectivity of third-stage larvae of the intestinal worm, Trichostrongylus calubriformis (Giles, 1892) Ransom, 1911. , 1966 .

[20]  P. A. Kingsbury.  Relationship between egg counts and worm burdens of young sheep , 1965, Veterinary Record.

[21]  J. Rose.  Observations on the free-living stages of the stomach worm Haemonchus contortus , 1963, Parasitology.

[22]  J. Rose.  ECOLOGICAL OBSERVATIONS AND LABORATORY EXPERIMENTS ON THE FREE-LIVING STAGES OF COOPERIA ONCOPHORA. , 1963, Journal of comparative pathology.

[23]  J. Rose.  Some observations on the free-living stages of Ostertagia ostertagi, a stomach worm of cattle , 1961, Parasitology.