Typically ina grandfathered situation, it is the use that is grandfathered. So if a person had chickens at the time of the ordinance banning them went into effect you could keep chickens continually. You may not be able to expand your flock, but if the local government does not take an inventory of your chickens at the time of passing the ordinance, they cannot prove you have expanded the use. In most areas the non-conforming use may continue from owner to owner unless it is stopped for one-year. Check your local laws for how it applies to you.
