Submitted to: Avian Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/25/2002
Publication Date: 11/4/2002
Citation: Holt, P.S., Vaughn, L.E., Gast, R.K., Stone, H.D. 2002. Development Of A Lavage Procedure To Collect Crop Secretions From Live Chickens For Studying Crop Immunity. Avian Pathology. 31:589-592. 2002. Interpretive Summary: The crop (ingluvies) is an organ found in most avian species and is located on the esophagus just above the stomach. Because it was thought to function primarily as an organ for food storage when the stomach is full, little work has been conducted investigating immunity in the crop. We recently found that, in chickens infected with Salmonella enteritidis (SE), strong anti-SE immune responses could be found in samples taken from the crops of these birds. As this had not been shown previously, we decided to investigate further the development of immunity in this organ and how it compares with responses elsewhere in the bird. An important early aspect of this research was to develop a method for sampling the crops in living birds as this would allow us to take multiple samples from the same birds over time. Our method involved inserting a narrow tube down the throat of the test birds into the crop. A solution was then injected into the crop via a syringe attached to the tubing and then the crop flush was aspirated back into the syringe. The method was very simple to perform and caused minimal discomfort to the bird. Very good antibody levels could be detected in the samples taken from the birds in this manner.
Technical Abstract: The crop (ingluvies), an organ for food storage in most avian species, is located at the base of the esophagus. Previous work in our laboratory showed that following infection with Salmonella Enteritidis (SE), significant anti-SE antibody levels could be found in the crops of these birds. Samples in these previous studies were obtained by flushing the interiors of crops excised from sacrificed birds, which is both labor and animal intensive. A method was sought which allowed multiple sampling of the same birds over time. We found that lavage fluid could be administered directly into the crop down the esophagus using a narrow-diameter plastic tubing attached to a syringe and the fluid could then be aspirated back into the syringe. Antibody-containing crop secretions could be collected with minimal discomfort to the test animals. In a study where birds were challenged with SE, IgA anti-SE titers 3 weeks post challenge were similar in crop samples obtained by live lavage vs the flushing of crops removed from sacrificed birds. Such a sampling procedure may provide researchers with a simple method to follow mucosal immunity in chickens following infection or vaccination regimens.