Wildflowers in my Coastal pasture

I have a 5 acre pasture of Coastal that's infested with Indian Paint Brush that I don't know how to restore.

Is that eatable for cows,Horses,Goats if I bale it?

I read where the flowers are eatable but the green part is toxic,but how toxic is it? 

How would you get rid of the flowers? Any help would be appreciated.

 

Wildflowers in my Coastal pasture