"wheat hay"  here is unheard of, oat hay yes, thou not as popular.  I do know the heads on wheat even in the soft dough has the 'seed spikes" which no cattle feeder is interested in. (here)

Cutting pre-heading out, would be pretty simple to send off a sample for testing for feed value.  Then price according to feed value.   All pretty dependent on what the feed value is, and if you can get it into some sort of bale in good condition.