Veggie oil, WD-40 and baby oil, all will do the trick.
MRJ, you can get bale feeders for horses that they won't rub their manes out on. They work real well.
On the Appy horses or any horses that don't grow a mane, it is because the mane and tail hairs are brittle and they tend to break real easily. I have heard that if you soak the mane and tail in oil, you can get them to grow out.
Oops, forgot what kind of oil :???:
Feeding horse mineral will also do the trick. :wink: