SERUM IGE LEVELS IN DAIRY CALVES - EVALUATION OF PARASITE AND PASTUREEXPOSURE AS POSSIBLE DETERMINANTS OF IGE RESPONSE

Immunoglobulin E (IgE) has been regarded as an antibody isotype import ant in the host response to helminth infection and allergic conditions , Level of parasitic infection has been associated with serum total Ig E level and the highest levels have been observed during the spring wh en environmental allergen levels are also high, Two groups of five par asite-naive calves were maintained in a barn and one of the groups rec eived an experimental gastrointestinal nematode infection, One group o f five parasite-naive calves was placed on clean pasture and another g roup of five was placed on a nematode-contaminated pasture, The contam inated pasture group acquired an acute gastrointestinal nematode infec tion, compared with a relatively low infection in the experimentally i nfected group, The only difference between the groups was a significan t change (increase) in IgE level in calves on contaminated pasture, co mpared with the other three groups. This suggested that the infection acquired on pasture and not the experimental infection or environmenta l allergens encountered while grazing or in the barn stimulated an IgE response.