Effects of Melatonin Implants in White-Tailed Deer
Melatonin implants were given to seven adult female white-tailed deer (Odocoileus virginianus) 15–17 September 1987. Progesterone pessaries administered 6–20 October 1987 and prostaglandin F2 alpha administered at pessary removal failed to induce preseason estrus. First estrus was observed about 2 weeks earlier than expected for one of the seven but was delayed 1 month or later than expected for the remaining does. Three of the seven does failed to have normal vernal molts in either 1988 or 1989 and molted from winter coat to winter coat in September 1988. Two of the three delayed vernal molts in late June and early August 1989. A fourth doe maintained her same winter coat from the time of implant through early August of 1989 when she underwent a delayed vernal molt. The remaining three does underwent normal molts in 1988. Six of the seven does gave birth in 1988, and no impediment of lactation was noted. Fawns nursed by one doe, like their dam, had a delayed (August) vernal molt in 1989. All other fawns had normal vernal molts in May. A melatonin implant was given an adult buck on 18 May 1989. His winter molt was completed by 4 July; velvet rub-out was completed on 10 July, and sperm presence was confirmed when electroejaculated on 24 July. All three events occurred at least 2 months earlier than normal.