Feeding cows is different than feeding horses.Cows can eat less palatable hay,horses will colic or get heaves from moldy hay.Most round bales are wrapped now and see every little waste. As noted the water will run off them. There is a lot of sorghum type hay still laying out in windrows in eastern Colorado. It is cut later and takes longer to dry, but then it must be dry with a little moisture to bale. It isn't uncommon to see that hay out all winter. A lot of farms and ranches raising beef will grind that hay and feed it that way, instead of just setting round bales out or unrun rolling them.
Depends what area of the country it is.
