I personally find feeder cows disturbing.
And eggs! What's with people eating eggs!
And OMG! FISH!!!! I saw a guy eating tuna today! I almost lost it!
--over-reaction phase completed--
Really, as long as the animals don't suffer, and are being used to feed other animals, it is neither sick nor unethical.
Legalities on the other hand, you might want to look into, because now someone is going to report you as a murderer and abuser of kittens. Talk to a vet as opposed to a shelter. If you get a volunteer on the phone at a shelter, you may find they will only raise the bar on how high the excitability of people can go.