I agree with Jay C. and R. Scott and I would just like to add a comment. By definition straw
should be thoroughly dry, since it is the left-over from threshing dry grain (wheat, rice, etc.). So unless the bales were left out in the weather, they should not need further drying. Hay on the other hand is fresh-cut grass that is allowed to air dry, then is baled, so it is very possible to have improperly dried hay in a bale, which can cause all kinds of problems.
I think too often there is confusion between straw and hay.
-Tom