The key appears to be maternal inheritance.

Fukushima's hybrid pigs aren't radioactive mutants but fast-breeding boar-pig crosses that reproduce year-round, creating ...

A Kenyan mayor ordered more than 500 pigs to be shot dead because they were mating with stray dogs, the East African Standard reported on Friday. Subscribe to read this story ad-free Get unlimited ...

Domestic pigs reproduce through a breeding process that is closely managed on farms around the world. During mating, a male pig, known as a boar, mounts the female, called a sow, in a behavior driven ...