The phrase "chew the cud" refers to the process of a ruminant animal regurgitating and re-chewing their food to aid in digestion. The spelling of the word "cud" follows the IPA symbol for "ʌ" which produces the short "u" sound. The "ch" sound can be spelled in various ways in English, but in this case, it follows the IPA symbol for "tʃ" which produces a "ch" sound. Together, these sounds create the unique pronunciation of "chew the cud."
To "chew the cud" is a phrase commonly used in reference to animals, especially ruminants, that engage in a specific form of digestion known as rumination. "Chewing the cud" refers to the process in which an animal regurgitates semi-digested food from its first stomach compartment (called the rumen) back into its mouth to be chewed again. This regurgitated food, called the cud, is thoroughly chewed and mixed with saliva to increase its digestibility before being swallowed again in order to undergo further digestion.
During rumination, animals such as cows, sheep, and goats gather food quickly by grazing, swallowing it without fully chewing it, and storing it in the rumen. They then find a sheltered area to relax and bring the cud back up into their mouths for re-chewing. The action of chewing the cud provides several benefits, including breaking down the food further, making it easier to digest, and increasing the extraction of nutrients. Additionally, it aids in microbial fermentation within the rumen, which plays a crucial role in extracting energy from plant material.
Metaphorically, "chewing the cud" can also be used to describe the act of deep contemplation or thinking. It implies engaging in reflective or introspective thought, similar to the deliberate chewing of food during rumination. In this context, "chewing the cud" suggests pondering or mulling over an idea or situation, carefully considering its different aspects, and deriving deeper understanding or insight from the mental process.