Responses of fowls to an operant feeding procedure and its potential use for reducing randomness in meal occurrence

Abstract

Adult laying hens were tested with increasing and decreasing procurement costs (pecks at a disc) which allowed access to food for unlimited periods. This was done to observe changess in feeding behaviour, to see whether apparent randomness in meal occurrence can be reduced, and, if so, to identify an appropriate fixed ratio (FR) for incorporating in investigations of physiological correlates of hunger and satiety. Daily food intake stayed the same at all but the highest (160 pecks) FR. FR sizes were related negatively to total time feeding and meal frequency, and positively to intermeal interval length, meal size and rate of eating within meals. They were also related positively to meal length, but only weakly so. Frequency distributions of meal and interval lengths, and postprandial correlation coefficients, indicated that randomness in feeding did decline at higher FRs, and FR20 seems the most appropriate schedule for potential use in physiological experiments.