Final answer:
In the cycle of rumination, digestion is not included as one of the phases. The phases are regurgitation, re-chewing, cud chewing, and swallowing of the re-chewed cud.
Step-by-step explanation:
Rumination is a unique digestive process in certain herbivorous animals like cows and sheep, known as ruminants. The cycle of rumination consists of four distinct phases: regurgitation, re-chewing, cud chewing, and the swallowing of the re-chewed cud. Therefore, the option that is not included in the rumination process is digestion. Digestion continues after the food has been swallowed post-rumination and involves breaking down the food into absorbable components. This process indeed occurs in the digestive system but is not part of the rumination cycle itself.