There is so much meat bred into them that they aren't even capable of normal poultry copulation. Their eggs have to be fertilized by artificial insemination.
Chances are better than 50-50 that a table bred turkey which survives Thanksgiving and Christmas will die of naturally causes by the next year. Heart attacks are one of the most frequent causes of death, probably second only to encounters with sharp edges.
. . . which is why turkey pardons are strictly for theatrical purposes.
I saw this on the Dirty Jobs show!