I don’t want my horses chewing wood! They can get splinters in their mouths, and worse, in their guts. That would be expensive, very expensive. The Quitt has pine in it, so that satisfies any need for pine trees.
If you feed free choice hay, the horses won’t need to chew. But when they do chew even when they have hay, it is because they need minerals or supps or something to entertain them. My 2 horses have each other when they are stall bound. So they can reach over and interact. They also have hay and they have supps and they have a brick of ration balancer. Keeps them out of trouble while they are stalled.