title: The relationship between the number and size of nematodes in the abomasum and the concentration of pepsinogen in ovine plasma.
abstract: Six-month-old lambs that had been naturally infected with predominantly Teladorsagia (Ostertagia) circumcincta were tested for plasma pepsinogen concentrations because pepsinogen concentrations may reflect the extent of damage to the abomasum. The distribution of pepsinogen concentrations among these lambs was positively skewed with most individuals having relatively low concentrations. Pepsinogen concentrations were more strongly associated with variation in the mean length of the adult female worms than with variation in the number of nematodes present. Previous trials have suggested that genetic variation in the growth of lambs is strongly influenced by genetic variation in worm length. Together these results imply that variation among lambs in the pathogenic effects of T. circumcincta depends upon the mean size of the worms as well as the number of worms present.
authors.affiliation: Glasgow University Veterinary School, Bearsden Road, Glasgow, G61 1QH, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Stear
authors.forename: K
authors.initials: K
authors.lastname: Bairden
authors.forename: Q A
authors.initials: QA
authors.lastname: McKeller
authors.forename: I
authors.initials: I
authors.lastname: Scott
authors.forename: S
authors.initials: S
authors.lastname: Strain
authors.forename: S C
authors.initials: SC
authors.lastname: Bishop
mesh_terms: D000018:Abomasum / Q000469:parasitology*; D000818:Animals; D005260:Female; D008297:Male; D009348:Nematoda; D009349:Nematode Infections / Q000097:blood / Q000469:parasitology* / Q000662:veterinary*; D020116:Pepsinogen A / Q000097:blood*; D012756:Sheep; D012757:Sheep Diseases / Q000097:blood / Q000469:parasitology*
chemical_list: D020116:Pepsinogen A