While I didn't have animals in the classroom, having to care for animals has made me the person I am today. How can one learn absolute honesty or true loyalty from a person?
Very rarely, but those traits are abundant in animals.
Learning how to properly treat animals is a hands-on experience; books alone won't cut it. Logistically, I don't see it happening on a large scale.
If this was taught, I would not like to see teaching animal cruelty is bad; rather, I would prefer the focus to be the intimant value of properly caring for another living being.
And not how to farm an animal for profit. This is not the same as caring for another living being without being motivated by greed.