Effects of feeding methods on eating frustration in stabled horses

Five feeding methods were tested in stabled horses: (i) cutting hay (hay was cut into 5 cm lengths), (ii) delaying feeding time (feeding was delayed until 1 h after the usual time), (iii) increasing the feeding frequency (hay was divided into two portions; one half was given at the normal time and the other 1 h later), (iv) increasing the feeding locations (hay was available at three locations), and (v) increasing the hay varieties (three species of hay were used). The behavioral durations in the 2 h after the experimental feedings were compared with those after usual feeding. In the cutting hay treatment, hay-eating time decreased (P < 0.05), whereas bedding-eating time and resting time tended to increase. In the delaying feeding time treatment, bedding investigation time increased (P < 0.01) and hay-eating time tended to increase. In the increasing the feeding frequency treatment, hay-eating time tended to increase. In the increasing the feeding locations treatment, bedding investigation time tended to decrease. In the increasing the hay varieties treatment, resting time tended to decrease and hay-eating time tended to increase. It was suggested that the former two feeding methods might stimulate and the latter three feeding methods might suppress eating frustration in terms of increasing consummatory behavior (eating) and decreasing appetitive (investigating) and displacement behavior (resting).