Abstract
Experiments were carried out to investigate the changes of feeding behaviour of laying hens with the rise of environmental temperature. Observations were made every two hours on the feeding behaviours, namely, the feed intake, the number of pecks and the time spent for pecking, of twelve hens reared on the pelleted feed under the constant temperature (25, 30, 32.5 or 35°C) conditions.
1) The rate of decrease in daily feed intake was 1.7% per centigrade rise of environmental temperature.
2) The number of pecks and the time spent for pecking per day did not change with different temperatures.
3) The feed intakes per peck and per minute decreased with the rise of temperature. This may be due to the fact that the "pecking for leisure", which occupied more than a half the total number of pecks at feed under the 25°C condition, increases as the environmental temperature is risen.
4) The diurnal patterns of feeding behaviour were not affected by different temperatures.
