My grandfather was a slaughterman for a while and a really good butcher. When he talked about the animals going to be killed he said he could tell many of them at the end probably knew what was going to happen to them. It clearly did bother him a bit and he did feel sorry for the animals but said it was quick and humane overall. In everyday life he hated to see animals mistreated or suffering. There’s no hypocrisy in showing some emotion, especially when it’s something you’ve not experienced before.