So the Lord said to him, “Bring me a heifer, a goat and a ram, each three years old, along with a dove and a young pigeon.”
Abram brought all these to him, cut them in two and arranged the halves opposite each other; the birds, however, he did not cut in half.
Genesis 15:9-10 (NIV)
It seems very sad to me that Abram cut up the animals. If you look closely, God did not ask him to do this.