First, I doubt we would be able to agree on a viable definition of "humane" commercial farming. But even if we did, I would not take the farmer's word for how the animals are treated. What I have heard from a former farmhand, who worked on several small farms, is that abuse of animals is simply the norm.

It sounds reasonable to me that this is the situation, except perhaps in very small farms. History has taught me this: whenever humans have physical control over other humans, they tend to abuse their subjects in terrible ways. Slavery. The Holocaust. Gulags. North Korean concentration camps. It seems to me that the way we are treating animals is simply a manifestation of this tendency toward sadism. It is not difficult to find recorded evidence of pure sadism playing out both in small and large farms. Since I have no way to verify a given farmer's claims, I will not take the risk.

Second, a well-balanced, strictly vegetarian diet is far more healthy than a diet that is based on animal products [1,2]. I know that many people do not believe this, and they base their views on the vast amount of disinformation that is out there. To get to the truth you have to listen to the experts. The book [1] I am citing was written by Dr. Walter Willett, one of the leading researchers on the relation between nutrition and disease. His recommendation is basically to eat as I suggested above. More precisely, he recommends (based on decades of research) to reduce animal-based foods as much as possible, and to reduce processed foods in favor of whole foods. There are of course additional recommendations that I will not go into.

[1] http://www.amazon.com/Eat-Drink-Be-Healthy-Harvard/dp/074326...

[2] http://www.youtube.com/watch?v=30gEiweaAVQ

Others have already answered, but to address the health issue allow me to mention a credible source [1], written by one of the leading experts on the relation between nutrition and health. The word 'vegan' appears only a couple of times in this book, but what it advises approaches veganism, based on purely decades-long research.

The research shows that more than a little meat is not healthy (unless you have no better alternative), and there is no harm in not eating meat at all.

[1] http://www.amazon.com/Eat-Drink-Be-Healthy-Harvard/dp/074326...

I'll throw my support behind this: http://www.amazon.com/Eat-Drink-Be-Healthy-Harvard/dp/074326...

I recommend Eat Drink and Be Healthy for credible advice grounded in scientific research http://www.amazon.com/Eat-Drink-Be-Healthy-Harvard/dp/068486...