Abstract Pen-housed sheep are restricted from grazing and expressing other natural behaviors. This restriction can result in stress and reduced welfare. Therefore, determining enrichment methods to promote natural behaviors like rumination and locomotion are needed. Research has found supplementing hay to penned sheep can reduce undesired behaviors like wool-biting. However, the singular and combined effects of nutritional supplementation (e.g., hay) and occupational enrichment on other sheep behavior have not been thoroughly studied. The objective of this study was to assess the potential positive welfare impacts of providing pen-housed sheep with large inflatable balls, loose hay, and hay-filled balls. Using a return-to-baseline within-subjects design we assessed the behavior of forty-eight ewes housed in dirt pens in groups of 4 animals of similar weight and breed (i.e., Rambouillet, Southdown, Suffolk, Royal White). Once assigned to their pens, all animals received a 7-day baseline acclimation period during which no nutritional or occupational enrichment was provided. Following these 7 days, pens were randomly assigned to receive one of the three enrichments for 5-7 days. After the last day with the enrichment all animals received no enrichment for 5-7 days as a washout period to prevent any carryover treatment effects. This was repeated until all animals received all three enrichment treatments. Pen behavior was video recorded on the last day of all washout weeks (i.e., no treatment) and on days 1, 3, and 5 of enrichment weeks. Video recording began each day when the enrichment was provided (∼0700) and lasted for four hours. Two-minute scan sampling was used to evaluate the frequency of behavior. Results indicate inflated balls increased standing and locomotion more than the other enrichment, while also reducing lying behavior. Relative to baseline, hay supplementation increased locomotion, rumination, and feeding behaviors and reduced lying. Sheep interacted with hay balls more than the inflated balls and hay ball enrichment resulted in the least lying and standing behavior, but in the greatest amount of rumination and locomotion. Overall, these results indicate that occupational and nutritional enrichment can be used to promote natural behaviors in pen-housed sheep, thus promoting their welfare.
Webberson et al. (Wed,) studied this question.