Sensible feeding and lots of turnout are keys to healthy bone development in young, growing horses. But management can play an important role in promoting and sustaining bone health in mature horses, as well.
Slow, long-distance exercise can change bone significantly. Long walks on firm footing are particularly good for building dense, strong bones. This is a key consideration when bringing a horse back into work after a long period of rest: Plan for weeks of walking over hard ground before introducing faster work. Remember that you need to condition his bones and sinews as well as his cardiovascular system.
If your horse is recovering from a bone injury, long, slow work will encourage his body to lay an area of new, strong remodeled bone without stressing the healing area. It’s a good idea to talk to your veterinarian about injury-specific considerations and timelines. Also, remember that turnout with an active, stable herd counts as slow exercise. The less time a horse stands still in a stall, the healthier his bones will be.
As far as feeding goes, a balanced diet will usually provide all the nutrients a mature horse needs for healthy bones. Commercially formulated feeds, combined with a good quality hay, will have the appropriate levels of vitamins and minerals. If you feel the need to add a supplement to promote bone health, consult with your veterinarian or an equine nutritionist to ensure that doing so won’t interfere with the overall balance of nutrients in your horse’s diet.