Are Pain-Free Animals the Solution?

A friend of mine posted a link to this article from New Scientist yesterday and I still haven't really decided how I feel about it. The gist of it is, scientists are working on ways to essentially engineer animals that feel no physical pain. From the article:

"In a provocative paper published this month, Shriver contends that genetically engineered pain-free animals are the most acceptable alternative ... 'I'm offering a solution where you could still eat meat but avoid animal suffering.'"

I have several responses to this. First of all, this assumes that physical pain is the only kind of suffering endured by animals on factory farms. (Because, to be clear this is proposed for animals going into factory farms, not as an alternative.) What about mental anguish? I know people start rolling their eyes when you suggest that cows have feelings. But go watch cows in line for slaughter and tell me they're not aware of what's about to happen. Listen to their moaning and tell me they're not suffering. Furthermore, pain or no pain, is it ethical to enslave any sentient creature? Is it ethical to engineer an animal in this way? Would we engineer humans to not feel pain?

And of course, this says nothing of the dreadful environmental impact of factory farming. If you think about it, environmental concern is ultimately an ethical issue, albeit a separate one. So how exactly is this the most acceptable alternative? It seems what he means is that it's the laziest alternative.

It's the alternative that doesn't force to consumer to examine or change his or her purchasing habits. It's like people who don't want to eat better diets or exercise and just want to take drugs to lower their cholesterol. You're not actually creating healthier circumstances.

But then what about the welfarist side of this issue? Should we support any efforts being made to decrease suffering? The way I see it in this case I have little control over the results. I don't get to vote on how the money going into this research is spent. I could protest but that would do very little. So I suppose I am passively supporting it and if factory farming is going to continue then it is better that animals will suffer to a lesser degree. But I will continue to remind people that at best this is a weak-ass band-aid on a pretty gaping wound.

What do you think?