Here's a breakdown:
1. Regurgitation: The cow brings partially digested food from the rumen (first stomach chamber) back up to its mouth.
2. Chewing: The cow chews the food thoroughly, breaking it down into smaller particles and mixing it with saliva.
3. Re-swallowing: The chewed food is then swallowed again and passes back into the rumen.
This process of rumination can continue for hours, helping the cow extract maximum nutrients from its diet.