Influence of feed type and its effect on repressing wool-biting behavior in housed sheep

Sheep sometimes develop an abnormal behavior termed as wool-biting when kept in an indoor system; however, little is known about this behavior. As the provided feed type may affect the foraging behavior and repress abnormal behavior in animals, we tested the effect of feed type on repressing wool-biting behavior in this study. We used hay prepared in three forms, that is hay bales, rolls and cubes. The wool-biting frequency associated with hay bales was significantly higher than that associated with rolls (P < 0.05) and cubes (P < 0.05); however, there was no significant difference between rolls and cubes. For hay rolls, wool-biting significantly decreased after feeding (P < 0.05), suggesting that rolls may provide sheep with appropriate oral stimulation; thus, decreasing the post-feeding oral abnormal behavior. An individual difference of wool-biting behavior between sheep was also detected, and an unexpected bed-eating behavior was found in the hay cube treatment. We suggest that sheep performing movements that are similar to their natural foraging behavior while grazing would repress wool-biting behavior, which happened in hay roll and hay cube treatments. Considering sanitation and animal welfare, providing sheep with hay rolls may provide an easier method to control wool-biting behavior in housed sheep.