Gonadal Response to Testosterone Propionate during Breeding and Post-Breeding Phases in the Male Blossom-Headed Parakeet, Psittacula cyanocephala (Aves: Psittaciformes)

Abstract

Testosterone propionate (1 mg per 100 g body weight per day) was administered for 15 days, by injection into the pectoral muscles, to male blossomheaded parakeets during both the spermatogenetically active (February-March) and resting (August) phases of the annual cycle. It caused marked testicular atrophy when it was injected in the sexually active birds. In sexually regressed parakeets it resulted in spermatokinesis and differentiation of Leydig cells. It is evident that the same amount of exogenous testosterone may exert, possibly through pituitary gonadotrophic agent(s), either pro- or anti-gonadal influences depending upon the sexual status of the bird.