Cow

Cows are a species of quadruped mammals that roam Hyrule and its surrounding countries. They are generally docile, and often domesticated to be kept as livestock in farms such as Lon Lon Ranch. Although their most frequent vocalization is a sound similar to "moo", Link is able to understand and communicate in their language when in wolf form in Twilight Princess.

Cows are the source of milk, which contain nutritious healing properties. If Epona's Song is played within earshot of a cow, it would provide milk to the player provided an empty bottle was also present.

Ocarina of Time Master Quest
In the Master Quest of The Legend of Zelda: Ocarina of Time, cows made much more frequent appearances than in other Zelda games to date. Oddly, inside Lord Jabu-Jabu's belly, cows were seen protruding from the walls and ceiling, without explanation.