Throughout history, people have been given gruesome accounts of slaughter in our art, music and literature. Just consider the recent movies: Schindler's List, Babe, Chicken Run, and those that attempted to promote tolerance and compassion to other species, including extraterrestrials: ET, Free Willy. It appears that they only served as entertainment, since the carnage of human atrocity keeps raging in every continent on one scale or another, on every terrestrial species, often in the name of religion, national interest, supremacy, or sports.
Humans are indeed master killers. I am not a so-called "animal lover," but I do practice moderation in eating meat. As a biochemist, I know--and I try to educate people on this--that meat is not as essential to human diet as some people might want us to believe. The need for protein can be largely, if not completely, met by non-animal sources. There is certainly no conceivable dietary reason why, in the very least, we would not treat the soon-to-be-slaughtered animals humanely.