He said to him, “Bring me a heifer three years old, a female goat three years old, a ram three years old, a turtledove, and a young pigeon.” - Genesis 15:9
A young cow who has yet to give birth. (first page Google results)
When the Lord was establishing the Abrahamic covenant with Abram, Abram asked how he was to know that he is to possess the promised land. The Lord told him, “Bring me a heifer three years old, a female goat three years old, a ram three years old, a turtledove, and a young pigeon.” He brought them, cut all but the birds in half, and laid each half over against the other. When birds of prey came down on the carcasses, Abram drove them away. Abram fell into a deep sleep, and the Lord revealed the future of the nation that would descend from him. (Genesis 15)