The domesticated ones have been bred for oversize breasts for so long that allegedly they can no longer "do it" without mechanical help. "Mating saddles" are available from hatcheries, but I don't know if they REALLY need them or not. Turkey output stinks so badly I have no intention of ever raising them myself to find out.
Yikes! I can think of a lot of 'fat liberal chick jokes' to make here, but in honor of the season of sharing, I won't.
*SMIRK*