Pain-free cows? what?

There, of all things, are now cows engineered to not feel pain. Although all the cows that have this are eventually slaughtered, and it does make it slightly more humane, does that mean that they don't suffer? I remember learning in another class that for animals, pain is one thing, but fear is much more of an almost excruciating feeling for these animals. I cannot imagine how the slaughterhouses will change because of the fact that the animals can no longer feel pain. The moral responsibility to reduce pain will be extinguished an the slaughterhouses will increase the unhabitable conditions of these animals.