I've noticed that both my Paint and my Tennessee Walker gelding have had really thin manes, and both of them had beautiful long manes before. I looked out the window a couple of days ago and found out why. My donkey has been chewing their manes, which makes sense because the problem started a few weeks after I got him. He has not been castrated, which may be some of the problem because he does not respond to bad tasting sprays or anything I put on the manes. I'm planning on getting him castrated in two weeks when the vet comes for yearly shots. Hopefully the problem will go away, but how do I get the manes to regrow faster? I absolutely love full manes. Their nutrition and diet is great and they are both healthy, I'm just looking for a supplement or something to put on the manes to make it grow faster than it naturally would. Any suggestions would be great!