A stocker operation takes newly weaned calves from a cow-calf operation and prepares them to enter the feedlot. Calves spend several weeks grazing pasture or eating forage during this period. This allows the animals to gain weight before entering the feedlot while consuming relatively cheap feedstuffs. If calves were not preconditioned, they may receive vaccinations and be dehorned or castrated during the stocker phase.

Additional Resources:

Beef Stocker Informational Site