Pecking Order - Brakhot 40a

"Rav Yehuda said in the name of Rav: A person is forbidden to eat before he gives food to his beast, since it says, "and I will give grass in thy fields for thy cattle, and then, thou shalt eat and be satisfied." (Deut 11:15)"

The rabbinic commandment to always feed one's animals before oneself strikes me as an excellent example of the high value placed on animal life as well as human life. Aside from animals' uses as livestock and work-animals, they are also God's creation and our charge, and this small suggestion by Rav Yehuda illustrates that beautifully.