wood chewing

[Missmac]

My mare is a wood chewer. She does it out of habit but it is made worse if she is stressed or bored. She has a balanced diet so isnt deficient and im certain its not ulcers or teeth although the dentist is coming out on wednesday.

I want to spray/paint the fencing in the field so does anyone have any suggestions for products or recipies of some yukky tasting concoctions i could treat rhe wood with. The cheaper the better please as the whole of her 2 acre paddock is post and rail!!

Thanks