Are you sure this is correct? I'm fairly sure cruelty to animals is punished purely because of ethical considerations for the animal's well being.
The well being of an animal is no better after a slow cruel death than a quick painless one. When well being comes into play we tend to prohibit killing specifically and instrumental uses in general, as is the case with humans.
The free range chicken on your plate is no less dead than one raised under factory conditions which make us feel better about ourselves. Neither has any more being to which degrees of wellness may be applied.
I don't think that's fair. It's more that we recognise the futility in punishing a house cat, which is incapable of changing its ways nor of comprehending the pain it inflicts.
> the house cat who plays with the bird before killing it without eating it
Small birds have sharp beaks and claws. Mice have sharp teeth and claws.
Cats have a hunting instinct. Wild cats survive by hunting. To hunt and eat prey a cat needs working jaws.
The sharp teeth / beak / claws of prey only needs to puncture the skin of a cat's jaw once to cause infection which would leave that cat at serious risk of death, if not from infection then from lack of food because of reduced hunting.
"Playing" with the prey is a good way to weaken the prey before the killing bite is inflicted.
No it isn't, it extends the amount of time the prey is alive and capable of causing harm, and the amount of contact between predator and prey. Domestic animals play with prey because they still have deeply ingrained hunting instinct, but have no actual need to hunt. This is why they will hunt a laser pointer just as intently as a mouse. They aren't after food, just reacting to instinct.
There's nothing wrong with wanting to be humane to animals, even ones that are ultimately killed for their meat (such as pigs). It's possible for an animal to live a perfectly content life and then be killed quickly and with as little pain as possible. And that's what a lot of people are campaigning for.
Reducing animal cruelty is not at odds with breeding livestock for food. We can have both. And to not support one because you want the other is disingenuous.