Threshing
Separating grain from straw, traditionally done by driving cattle round over the harvested sheaves.
Also: treading out grain, threshing floor
Before machines, much of the world's grain was threshed by animals. Sheaves were spread on a hard, swept threshing floor and cattle were driven round and round over them, their hooves knocking the grain loose; in many places they pulled a threshing sledge studded with stones or a heavy roller. Oxen did this work across the Mediterranean, the Middle East and South Asia, and in India a line of bullocks tied to a central post can still be seen on some farms after the harvest. The Book of Deuteronomy says the ox treading out the grain should not be muzzled. Winnowing in the wind then separates the grain from the chaff.