title: Reproductive seasonality and the effect of the GnRH agonist deslorelin as a contraceptive in captive male Black Flying-foxes (Pteropus alecto).
abstract: Effective contraception would enhance genetic management of captive Pteropus species, which typically breed well in captivity. Male reproductive seasonality was monitored (15-mo interval) in captive P. alecto (6 controls and 5 treated with 4.7 mg deslorelin). In untreated males, there were seasonal changes in testicular volume, body weight and testosterone secretion; testicular volume and body weight peaked in February and March, respectively, whereas testosterone concentration remained >5 ng/ml before rising (P < 0.001) to 24.9 ± 3.6 ng/ml (mean ± SEM) in April. However, there was no corresponding change in sperm quality, and seminal vesicle gland (SVG) secretions remained present in ejaculates. In treated males, testosterone concentration had an initial 'flare' response (mean ± SEM peak: 19.95 ± 3.27 ng/ml) before declining (P < 0.001) by 32 d to basal levels, where it remained. In these males, there was reduced sperm motility after 1 mo (P < 0.001) and the absence of SVG secretions after 4 mo. However, aspermic ejaculates were first recorded 5 mo post-treatment. At 10 mo after treatment, spermatogenesis was still disrupted, when membrane-intact, but non-motile sperm were present in two individuals. Motile sperm were first recovered from one of these males 13 mo after deslorelin treatment. We concluded that captive P. alecto males: (a) had seasonal reproductive changes in testicular volume, body weight and testosterone secretion; (b) produced motile, membrane-intact sperm and SVG secretions throughout the year; and (c) had a rapid decline in testosterone concentration and consequent suppression of testicular function for at least 5 mo following deslorelin administration.
authors: University of Queensland, School of Agriculture and Food Science, Gatton, Queensland, Australia. debra.melville@uqconnect.edu.au
authors: D F
authors: DF
authors: Melville
authors: G M
authors: GM
authors: O'Brien
authors: E G
authors: EG
authors: Crichton
authors: P
authors: P
authors: Theilemann
authors: A
authors: A
authors: McKinnon
authors: S D
authors: SD
authors: Johnston
mesh_terms: D000818:Animals; D002685:Chiroptera / Q000502:physiology*; D003272:Contraceptive Agents, Male / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists; D008297:Male; D012621:Seasons; D012726:Sexual Behavior, Animal / Q000502:physiology*; D017329:Triptorelin Pamoate / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D003272:Contraceptive Agents, Male; D004791:Enzyme Inhibitors; D017329:Triptorelin Pamoate; D007987:Gonadotropin-Releasing Hormone; C066438:deslorelin