Look at the bright side ... at least you're not callous about having to kill something. Says a lot about a person when they can do what's necessary without enjoying it.
one does not need to take joy and jump up and down about it but you could go in and thank them and be at ease and rest knowing they had a good life and a dignified end to there life and that might give one some pride and in reverence that you helped them live a good life. I am sure there are those whom look forward to butchering because they feel it a sort of honor to be involved with the circle of life and the life cycle of an animal raised for meat, not that they enjoy "the kill" not as I said but somehow being involved in all stages in the life and helping a quick and in a sense a meaning through the animals death it will nurish and continue life a person who gives thanks for that animal and it's sacrafice.