Anderson, who has bred the birds for 26 years, said the key technical advance was artificial insemination, which came into widespread use in the 1960s, right around the time that turkey size starts to skyrocket. The reason is that turkeys over 30 pounds are "inefficient" breeders: It's difficult for them to actually perform the natural mating act. With artificial insemination, the largest birds can still be used as sires, even if they have a hard time walking, let alone engaging in sexual reproduction.
"You can spread the one tom around better. It adds a whole new level of efficiency. You can spread him over more hens," Anderson said. "It takes the lid off how big the bird can be. If the size of the bird keeps them from mating, then you're stuck."
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