Why Does My Horse Chew Wood?
Q: My mare has recently started chewing on any piece of wood that she can get her teeth on in her stall and surrounding area. I’ve read that wood chewing can be a result of lack of fiber in the diet, as well as boredom or change in activity. She normally gets turned out on a regular basis, but weather conditions have limited her turnout time some more recently (although we still make sure she gets exercise in the round pen when she’s not turned out in the pasture). Would adding more hay or fiber to her diet help curb the wood chewing? And if so, how can I increase the fiber/forage in her diet without her gaining weight? She’s a very easy keeper and currently gets grass hay both morning and night, along with a small portion of grain.

—JW, Kentucky

A: Wood chewing can be due to several factors, but I think you’re right that most likely, in this case, it’s because of having her forage intake reduced due to not being turned out on pasture or due to confinement. I actually experienced this myself a number of years ago. The horse I managed was typically turned out for four hours in the morning, but after heavy rain his pasture was under water and not suitable for turnout. As a mustang he was an easy keeper and the pasture was pretty sparse, so we didn’t make any dietary changes thinking he wasn’t getting much in turn-out anyway. He started to eat his shavings and manure. We increased his hay by half a flake (about 3 pounds) and he stopped eating the shavings.

This was a good reminder to me that horses are often consuming more in pasture, even a sparse pasture, than we realize. When you remove pasture access, you might need to make additional management changes.

Slow-feed hay net
If you’ve not already increased your mare’s hay intake to account for the missing pasture, you should be able to do that without worrying too much about weight gain. You’re essentially replacing calories that she was, up until recently, already consuming. However she’s moving less stalled versus walking around a pasture, so her energy requirement might have gone down a little, even with the additional round penning. Experiment to see what amount of hay you can give without causing weight gain.

Because she’s an easy keeper, you should already be feeding her hay with a lower nutritional quality. That should reduce the risk of undesired weight gain even if you increase her intake. You might also want to consider using a slow feeder for your hay so she takes longer to eat her ration. Depending on what space she is kept in, it might be possible to have a couple of these spread out to encourage her to walk around.

If you increase her hay intake and find that she does indeed gain weight, you might want to reconsider the grain/concentrate in her diet. I’m not sure what kind of grain you are feeding or exactly how much she’s getting, but this will be an added source of calories that could be replaced with forage. If your goal is for the grain to provide a source of vitamins and minerals not covered by the forage in the ration, you might look for a ration balancing supplement. These often have very small 3- to 4-ounce-per-day serving sizes and add fewer calories than the ration balancing feeds.