Quantification of the immunoglobulin classes IgG and IgA in the young and adult pigeon (Columba livia).

Pigeon immunoglobulin classes IgG and IgA were purified and specific isotype antisera were produced in rabbits. The antisera were used to develop a quantitative assay for both immunoglobulins. Serum IgG concentrations in relation to age showed a similar pattern in pigeons to that in chickens. The same applies to the transfer of maternal immunoglobulins via egg. Besides this transfer mechanism, an additional transfer of immunoglobulins exists in the pigeon via feeding of crop milk. Crop milk contains considerable amounts of IgA (1.45 mg/ml) and significantly less IgG (0.34 mg/ml). During day 1 intestinal absorption of IgA is possible to a very low extent. Most of the IgA, as well as IgG, remains in the intestine to provide local immunity.