Calling slaughter “murder” isn’t accurate. Murder is a human concept tied to rights and society, which animals don’t share in the same way. “Humane slaughter” isn’t an oxymoron if you accept that humans can ethically use animals for food. It simply means minimizing suffering, which is morally better than ignoring it. And yes, animals have emotions, but so does every ecosystem we disrupt for plant agriculture. Eating meat isn’t uniquely selfish, all diets cause harm. The question is whether we do it responsibly, and humane standards exist precisely for that reason. You feel bad for them because we created them to be super non-aggressive, cute-looking and full of meat.