Passing down an ability in Pokémon Black 2
Solution 1:
According to this article about breeding, the male's ability cannot be passed down by breeding. If the male could pass down abilities, it could lead to a monstrosity of different pokémon with unknown abilities.
The article also says that there is a 50/50 chance to get either ability if the pokémon has two possible abilities. If the female has a rare ability from Pokémon Dream World, there is an 80% chance the ability will be passed down.