Abstract
Female white-tailed deer fawns (16) (O. virginianus) were hand-reared in light-controlled chambers to evaluate the effects of photoperiod on the onset of puberty. Fawns raised on 16 h light and 8 h dark (16L-8D) were paired by weight at .apprx. 4 mo. of age (Oct. 16th) and randomly divided between 2 treatments. Treatment 1 was changed to 8L-16D on Oct. 16th and treatment II was changed to 8L-16D on Dec. 5th. Timing of pelage change, changes in growth rate and onset of puberty were affected (P < 0.05) by the initiation of the 8-h day. Similar time-related physiological responses were observed for both treatments immediately following the start of the short (8-h) day.