In a hatchery pond with 70/30 BG/RES and limited duration the chances of crossing is small. Different hatchery's do things differently. Most I am aware of don't keep the parent fish in the pond for many generations. Some hatch there fish and move the babies to the growout pond. Others take a clean pond and add adult BG and RES in numbers to attempt to get the wanted %. I am sure there are other methods used as well.

Last edited by ewest; 06/20/19 10:01 AM.