Which common livestock animal is often used for dairy production?

Cows are predominantly used for dairy production, making them the correct answer. Dairy cows are specifically bred and managed to produce milk, which can be processed into various dairy products such as cheese, yogurt, and butter. Their physiology allows for a higher milk yield compared to other livestock animals.

While goats are also used in dairy production, especially in the production of goat's milk and cheese, cows represent the largest portion of the dairy market globally. Pigs are primarily raised for meat, and chickens are mainly raised for their eggs or meat but not for milk production. This distinction underlines the reason why cows are recognized as the primary livestock for dairy operations.