There is no excuse for those cows to be scared. The autistic biologist  Temple Grandin has made a career of figuring out  how to do it (she identifies with cows):

“I think we can eat meat ethically,” she says, “but we’ve got to give animals a good life.”

"Dr. Grandin has spent 30 years doing that by looking at the beef industry through the eyes of a cow. She lays down in muddy corrals, crawls through metal chutes, and even stands in the stun boxes where factory workers deliver their fatal blows.

She’s found a bunch of small ways that add up to a big difference in how humanely the beef industry treats cattle. Her discoveries include two inventions used in most slaughterhouses today: curved loading chutes and the center-track restrainer system."

http://theplate.nationalgeographic.com/2015/08/19/temple-grandin-killing-them-softly-at-slaughterhouses-for-30-years/