A lavage procedure was used to study the kinetics of alimentary fluid IgA concentration in 15 specific-pathogen-free white leghorn chickens for 8 weeks post-hatch. Lavage solution was administered orally and collected from the distal alimentary tract following an intraperitoneal injection of pilocarpine. Concentrations of IgA, quantitated by enzyme-linked immunosorbent assay, were more than 0.04 mg/ml by 3 weeks and were negligible before this age. This level gradually increased over the next 5 weeks, peaking at nearly 0.4 mg/ml at 8 weeks of age. Alimentary lavage was easy to perform, required no necropsy or surgical manipulation, and facilitated repeated collection of alimentary fluid from live birds. Repeated lavage did not alter concentrations of IgA and IgG in alimentary fluid, and concentrations of IgA and IgG in alimentary fluid were stable during incubation at 37 C for 24-48 hr.