Induction of ovarian growth and ovulation by administration of a chicken gonadotrophin preparation to Japanese quail kept under a short‐day regimen

Abstract

1. Chronic administration of a glycoprotein fraction from chicken pituitary using an ALZET osmotic pump at 12–5 μg/h for 2 weeks induced growth of ovarian follicles to a mature size in the ovary and deposition of yolk in sexually immature 6‐week‐old Japanese quail females which were kept under 8L:16D short‐day conditions. However, no ovulation was induced in these birds.

2. Injection of 500 μg of the glycoprotein into other immature short‐day females was performed following the above chronic administration, 12 or 14 and 15 d after implantation of the osmotic pump. About 24 h after injection, 3 of 14 females laid one or two eggs. Ovulation was confirmed in 4 females by autopsy. A total of 5 of 14 females ovulated 6 eggs, and significant development of the oviduct and the cloacal opening were observed in all of the treated females.

3. Thus, complete ovarian function could be induced in sexually immature female Japanese quail by administration of avian gonadotrophin using a combination of an osmotic pump and an injection.