The influence of age on the variation among sheep in susceptibility to natural nematode infection

MJ Stear*, S Mitchell, S Strain, SC Bishop, QA McKellar

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


A longitudinal study of faecal nematode egg counts was made in naturally infected Scottish Blackface sheep over two grazing seasons to 75 weeks of age. Although egg counts were lower in the second grazing season the variation among animals was greater. Egg counts were repeatable from 3 months of age. The repeatability of faecal egg counts within and between grazing seasons was about 0.3. Animals with lower than average egg counts in the first grazing season tended to have lower than average egg counts in the second grazing season. Therefore lambs with relatively low faecal egg counts after 3 months of age are likely to retain their advantage in the following year. (C) 2000 Elsevier Science B.V. All rights reserved.

Original languageEnglish
Pages (from-to)31-36
Number of pages6
JournalVeterinary Parasitology
Issue number1-2
Publication statusPublished - 28 Mar 2000


  • sheep-nematoda
  • immunity
  • age influence
  • Teladorsagia circumcincta

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