Abstract

Deslorelin acetate (Suprelorin®)^a is a GnRH agonist that is formulated as a subcutaneous, controlled release implant designed for use in dogs as a reversible contraceptive. Deslorelin reportedly suppresses reproductive hormones in dogs for 6–12 months,¹ and has been employed for reversible contraception in many species,^2-6 including anecdotal reports of reproductive suppression in several avian species.⁷ A randomized, masked, controlled study was performed with twenty, 8-week-old female Japanese quail (Coturnix coturnix japonica). Japanese quail were selected for this study because they are a high fecundity species that typically lay one egg every 24.5 hours.⁸ The birds were divided into control (n=10) and treatment (n=10) groups. Following a 7-day acclimation period of consistent egg laying, each bird received either a 4.7-mg deslorelin implant or identical placebo implant subcutaneously between the shoulder blades.

Egg production for all birds was monitored daily, and plasma sex hormone concentrations (17b-estradiol and androstenedione) were measured via commercially available radioimmunoassay (RIA) kits (ImmuChem Double Antibody 17b-Estradiol ¹²⁵I RIA and Double Antibody Androstenedione ¹²⁵I RIA, MP Biomedicals, Costa Mesa, CA, USA) at 0, 14, 30, 60, and 90 days post-implant placement. Six out of 10 birds of the treatment group stopped laying eggs one week following implant placement, and the mean egg production continued to be reduced throughout the study. In contrast, birds in the control group had no appreciable change in average egg production. The complete results, including the effect on egg production over 90 days and plasma hormone concentrations, will be presented after completion of the study.

Endnotes

a. Peptech Animal Health Pty Limited, Australia

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