grandparent stock

Grandparent stock used in livestock breeding is imported from abroad to breed parent stock which are then raised on the company's farms.

To be classified as heritage poultry, birds must be recognized by the American Poultry Association as having parent and grandparent stock prior to the mid-20th century.

While true control can only be achieved by elimination of the infection from elite and grandparent stock, and hence parent stock, biosecurity must play a vital part in protecting the flock".