In considering ethics, it is important to recognize that animals live and die in all kinds of conditions. Whether raised for eggs, milk, or meat, birds and mammals can be treated horribly or humanely. And whether on a ranch, at a slaughterhouse, or in the woods, they can be killed callously, with no concern for their suffering, or killed swiftly and carefully.
As any attentive observer of nature knows, life feeds on life. Every living thing, from mammals, birds, and fish to plants, fungi, and bacteria, eats other living things. Humans are part of the food web; but for the artifices of cremation and tightly sealed caskets, all of us would eventually be recycled into other life forms. It is natural for people, like other omnivores, to participate in this web by eating animals. And it is ethically defensible — provided we refrain from causing gratuitous suffering.
The article is very informative, but I believe that a vegan diet can be just as healthy as an omnivorous diet. However, I believe it is absolutely essential to remember that animals are living beings with spirits, too. And unfortunately, we DO cause unnecessary suffering to most animals produced for food.