Effect of changing daylength on the diurnal pattern of intake and feeding behaviour in penned red deer (Cervus elaphus).

Voluntary food intakes by 12 housed red deer hinds were recorded during six 2-week periods between April and November. Diurnal patterns of intake and feeding activity were measured by weighing food at either 5-min (April, May and June) or 1-min intervals (July, September and November). At each time of the year, mean rates of food intake, amount of feeding activity and frequency of feeding bouts were significantly greater during periods of daylight than during darkness. Food intake rate and feeding activity during daylight did not vary significantly with length of day. In darkness, however, mean food intakes per hour were less and feeding activity per hour was greater in the months when day-length was short.