What to do with Male Mulberries?

I have 9 mature (at least 10' tall) red mulberry trees on my property, the problem is all but 2 are males, even worse they are the smallest 2. Is there anything I can do to make the males more productive? I have read its possible to make them change sex, has anyone heard this before? I know I need males to pollinate but the trees are all inside of a maybe 2 acre spot so I really only need 2-3 males, not 7. If not im just going to cut some down and plant new trees.

I would think it might be possible to graft female twigs onto the male trunks, perhaps by means of a cleft graft. I tried this a few times when I lived in GA to get hybrid mulberry started on wild mulberry stock, but some kind of delayed incompatibility issue would kill the grafts after a couple of years. But assuming you are just grafting female onto male of the same variety I wouldn't think this would be a problem.

Do you have livestock? mulberry is a good forage food. Good food for rabbits, poultry, goats, etc. and they coppice/pollard well.

Not sure of other uses....worse come to worse, you can shred the wood for mulch in the garden or for making a hugelkultur bed.

They are all wild mulberries as far as I know, the oldest ones are probably 40-50 years old and I don't believe the owners at that time would have ever planted these, at any rate they are all the same kind. I might try and cut them and graft some branches off the female ones and see what I get. And yes I do have a dozen or so rabbits i've never tried feeding them any despite feeding them almost 100% foraged food. Ill see how they go for it.