ROLE OF TESTOSTERONE ON BODY MASS, BODY MOLTS, PRIMARY FLIGHT FEATHERS, PLUMAGE REGENERATION AND TESTES IN BRAHMINY MYNA (STURNUS PAGODARUM)

Abstract

Three groups (1-3) of birds were subjected to non stimulatory photoperiod (9L:15D), and received olive oil (0.1 ml), 10 and 50 ìg TP (Testosterone propionate) per bird on alternate day respectively. Next three groups (4-6) of birds were subjected to stimulatory photoperiod (15L:9D), and received olive oil (0.1 ml), 10 and 50 ìg TP (Testosterone propionate) per bird on alternate day respectively. In total, fifteen injection were made. Groups (1-3) were transferred to stimulatory photoperiod (15L:9D) after 60 days. Body mass, testis volume, plumage regenerations, primary flight feathers and body molts also studied in this experiment. Observations were made at the beginning, fortnightly and end of the 30 day experiment. The results of current study demonstrate the effect of TP on the testes, body weight, body molts, primary flight feathers and plumage regeneration in brahminy myna. Brahminy myna placed on 9L:15D did not induced testis growth till 60 days after that photoperiod of 9L:15D transferred to 15L:9D then the testis volume increased significantly and this clearly suggest that brahminy mynas were not sensitive to short photoperiod (non stimulatory photoperiod) and as expected, 15L:9D showed testicular response till 60 days then suddenly decreased and this can be taken to suggest that brahminy myna are a long day species and this study did not show an effect of prior treatment of testosterone hormone on photoperiodic induction of testicular growth