Oxbow Harvest Stacks are the latest in hay innovation.ÿ Using special compression technology, we transform 100% all-natural, hand-sorted Oxbow Western Timothy hay into compact, convenient-to-feed portions which produce 80% less airborne dust than loose hay when fed according to instructions. ÿFeed Harvest Stacks as a primary hay source or supplement with loose hay to encourage enrichment. ÿHarvest Stacks make a great feeding option when traveling or anytime storage space is limited.