Effect of immunization of sexually immature pullets against poly- -l-glutamic acid on long-term fertility

Abstract
Poly-.alpha.-L-glutamic acid (PGA) is a polypeptide synthesized within the upper oviduct and uterovaginal junction of the hen. Sexually immature pullets were immunized against PGA. These virgin pullets, and immunized and non-immunized controls, were inseminated at 25 weeks of age and then monthly throughout a 30-week egg production interval. While birds immunized against PGA were free of PGA as evidenced by an absence of immunoprecipitation when rabbit anti-PGA serum was overlayed with oviduct extract, immunization had no effect on long-term fertility and therefore is unlikely to have an immunosuppressive or antigen-masking biological role with respect to spermatozoa. We suggest instead that PGA could act as a calcium binding protein.