Acquired Immunity to Trichostrongylus axei in Lambs: Investigations of the Development of Immune Competence

Abstract

Investigations are described in which lambs were given either 1,000 or 5,000 3rd stage infected larvae of T. axei at 2, G, or 10 weeks age and were subsequently challenged with 200,000 3rd stage larvae at either 5 or 7 months of age. The immunity acquired following primary infection was manifest by a reduction in the numbers and size of the worms developing after challenge infection.