Effect of Active Immunization Against Estradiol on Egg Shell Quality

Abstract

Seven 31-week-old White Leghorn hens were immunized with estradiol-17-6-(0-carboxymethyl) oxime-bovine serum albumin (.5 to 1 mg/hen; 1- to 7-week intervals for 44 weeks). Six control hens of similar egg shell quality received only bovine serum albumin. Within 35 weeks of immunization, four of the estradiol-17β(E2) antigen-treated birds developed significant titers of antibodies to E2 based on a four- to fivefold increased binding of tritiated labeled E2 to plasma; two hens had low titers (twofold increase), and one had none. Forty-eight weeks after the first injection, the specific gravity (1.0768) and percent shell (8.32) of the four high-titer birds were lower (P<.05) than those of the controls (1.0810 and 8.80, respectively).The six positively immunized hens laid a total of 29 soft-shell eggs out of a total of 1,626 eggs as compared with 7 out of a total of 1,658 eggs laid by the six control birds. No significant increase in plasma binding was observed for the nonphenolic steroid hormones such as progesterone, corticosterone, and testosterone.It was concluded that the effect of immunization on egg shell quality was due to neutralization of estrogen activity.