Why would a loving God make animals sentient…?

If they only exist to serve and feed humans? Doesn’t it make more sense to create robots who can’t feel pain when we kill them and force labour onto them?
Why he created them SENTIENT (able to feel pain)

What are the pros & cons of being alive, and of being a sentient robot?

What are the philosophical differences between robots and life?
What do animals have exactly, that robots don’t have, that gives them sentient?
“gives them sentient.”
I meant “gives them sentience.”

What are the pros & cons of being alive vs. being a sentient robot?

Also, what exactly do animals have that makes them sentient, that logical robots don’t have?
Also, what are some other philosophical differences between living beings and robots?