Testosterone Hormone Profile in One Antler Cycle of Timor Deer (Cervus timorensis) stag

Abstract

The growth and replacement of stags antler on temperate species is physiologically linked to the seasonal rhythms of reproductive hormones. The objective of this research was to determine the pattern of testosterone hormone secretion in timor stags during one annual antler cycle which could be used to determine the active reproductive period of the stag. This research was conducted for 18 months in four adult timor stags (4 – 6 years of age). Blood samples were collected at three weeks intervals for analysis of testosterone hormone using the radioimmunoassay (RIA) method during one antler cycle (i.e. velvet, hard antler and casting stage). Results of this research showed significant difference (P<0.05) in testosterone concentrations between the hard and velvet antler stage concentration of testosterone hormone (0.2 ng/ml) found at the casting period (basal level). These results supported the hypothesis that antler as a secondary sexual characteristic is closely linked to the sexual cycle and is controlled by the reproductive hormone. In conclusion, the pattern of testosterone hormone secretion and reproductive activities reflected the inter-relationship of the annual antler cycle with highest concentration during the hard antler stage and lowest in casting period.