Cud stretched, forming a vacuum in the gullet that sucks the semi-liquid stomach content into the esophagus. From the esophagus it is taken back to the mouth with retro peristaltic movements. When the stomach content, or the cud, arrives in the mouth of the ruminant, it is pushed against the palate with the tongue to remove excess liquid, the latter is swallowed and the solid material is chewed thoroughly so the cattle can extract the minerals present in the cud brought to the surface during rumination. The function of rumination is that food is physically refined to expose more surface area
Chewing sensory perception of the food being eaten, controlling when the food is swallowed. Avoiding chewing, by choice or due to medical reasons as tooth loss, is known as a soft diet. Such a diet may lead to inadequate nutrition due to a reduction in fruit and vegetable intake. Chewing also stimulates the hippocampus and is necessary to maintain its normal function. Chewing is largely an adaptation for mammalian herbivory. Carnivores generally chew very little or swallow their food whole or in chunks. This act of gulping food (or medicine pills) without chewing has inspired the English idiom "wolfing it down".