Final answer:
A roundup refers to the herding of cattle for branding or sale, where cowboys gather the cattle and bring them together in one place.
Step-by-step explanation:
'Roundup' in this context refers to the herding of cattle for branding or sale. It is the process of collecting the cattle and bringing them together in one place. This usually involves cowboys on horseback working together to move the cattle to a specific location, such as a corral or feedlot. In the given passages, there are references to steers running and being led, which align with the process of rounding up the cattle.