TL;DR: If you care about farm animal welfare, work on minimizing actual animal suffering, not a human proxy for animal suffering.
Epistemic status: had a chat about this with a couple of local EA enthusiasts who attended the EA Global 2018 in San-Francisco, and apparently this was not high on the agenda. I have only done a cursory search online about this, and nothing of note came up.
When you read about farm animal welfare, what generally comes up is vegetarianism/veganism, humane treatment of farm animals, and sometimes vat-grown meat. This emphasis is quite understandable emotionally. Cows, pigs, chickens in industrial farms are in visible severe discomfort most of their lives, which are eventually cut short long before the end of their natural lifespan, often in painful and gruesome ways.
An animal welfare activist would ask themselves a question like "what is it like to be a chicken in a chicken farm?" and end up horrified. Their obvious solutions are those outlined above: have fewer farm animals and treat them "humanely." Less conventional approaches that reduce animal suffering get an immediate instinctive pushback, because we would not find them acceptable for ourselves. This is what I call the human proxy for animal suffering. Maybe there is a more standard name for this kind of anthropomorphizing? Anyway, let's list a few obvious approaches:
- breed chickens with smaller brains, so they have less capacity for suffering,
- inject a substance that would numb farm animals to physical pain,
- identify and surgically or chemically remove the part of the brain that is responsible for suffering,
- at birth, amputate the non-essential body parts that would give the animals discomfort later in life,
- breed animals who enjoy pain, not suffer from it,
- breed animals that want to be eaten, like the Ameglian Major Cow from the Hitchhiker's Guide to the Galaxy.
Many of these are probably way easier and more practical than shaming people into giving up tasty steak. But our morality immediately fights back, at least for most of us. "What do you mean, cut off baby chicken's legs so it does not have leg pain later? You, monster!"
Because most people do not truly care about reducing animal suffering, they care about a different metric altogether, a visible human proxy for animal suffering that they find immediately relatable. And so it appears that there is virtually no research or funding into the real suffering reduction, even though we know those will work. Because they work on humans already. Drug addicts are quite happy while under influence. Epidural works wonders for temporary pain removal, and so does spinal cord injury in many cases. The list of proven but not ethically acceptable ways to reduce suffering in humans is pretty long.
If you are an effective altruist who is concerned with farm animal welfare, what is stopping you from working on finding ways to apply what works but is not ethical for humans to what works and reduces actual suffering in animals?