Help Please! Heifer lost hair at tip of tail

Hello!

I am in need of some advice/help. My show heifer has lost most of the hair at the tip of her tail. Looks like “rat tail”. I doubt it is from a parasite because she is up to date with her ivomec. Does anyone have any tips on how to speed up hair regrowth in time for fall shows? Also any tips on how to deal with this for summer shows? Can you stick hair from another animal on her tail and if so, what is the best way to go about doing that?

Thank you very much

We have had this before, usually a result of very wet conditions.  Unfortunately, our barn seems to collect water and we've had lots of rain lately.  Way too much time spent scooping water out.  I have put Coppertox on the switch and that seems to help in time.  I have put Envirosep on them, too.  I'm sure there are other, better remedies, that I don't know about. 

Probably Fescue intolerant. Hair extensions if you need a quick fix.