A few weeks ago, there was a ton of discussion in the blogosphere about a recent study that suggested that grass-fed beef produced 50% more carbon emissions than grain-finished beef. With all the discussion regarding the environmental damage of the feed-lot system, this news really surprised a lot of people. The reason of course, was simple. Grass-fed cows live longer, and therefore fart more. It doesn't help that Cows are particularly awful at the task of converting feed into meat.
Of course, in my opinion to look at the CO2 and methane emissions of a single cow over it's lifetime woefully oversimplifies the environmental picture of the food system. The vast lagoons of animal waste so toxic that no one would dream of spreading them on food crops. The relatively high-acid rumens of grain-fed cattle which encourages the growth of acid-tolerant strains of bacteria (E.coli in particular), the high levels of antibiotics present in feedlot beef. At least with grass-finished cattle, they tend to be raised in smaller herds and can therefore provide a closer-to-real-nature ecosystem.
However, when compared to other animals, perhaps the real problem is simply stated: There are simply too many cows. Go to your local supermarket, and you'll generally see three main kinds of land-based meat prominently displayed: beef, pork, and chicken. And it's not uncommon for the beef section to be larger than the pork and chicken sections combined. Now, I love beef. And we eat a fair amount of it. Compared to chicken and pork (and the wide variety of other animals we could choose to eat), we eat more beef than any other meat. However, we are looking at converting our beef to locally raised heritage cattle (Belted Galloway's), which will support a healthier poly-culture in the beef world, as well as hopefully having less environmental impact than the meat-factory breeds favored by most cattlemen today.
Still we need to be looking at other sources of meat as well. I've yet to find a local source of Pork, but the same person who sells the Belted Galloway's also sells chickens at reasonable prices. When we have our own house, my wife and I certainly plan to raise chickens (mostly for eggs), and have also discussed raising rabbits for meat as well. The rabbits thing is particularly interesting, not because I've been told I would be the one responsible for the actual slaughter, but rather because it wasn't terribly long ago that rabbit was a reasonably common meat. My father remembers raising rabbits for food when he was young, but my only experience with rabbit was in the form of a cassoulet I had at a Pullman restaurant over a year ago. Luckily for me (I think), my University offers a helpful document on raising rabbits in Washington State, which actually mentions raising Rabbits to supplement your family's meat supply. Not surprisingly, the document is originally dated 1914.
Like I said, most people these days have never really thought about these animals as food, I guess.
I understand a lot of people would have a mental block with eating rabbit meat. I would have some trouble being comfortable with eating dog or cat. For me, the greater point, is that we need to diversify our meat production. Personally, I think it's worth doing some of this raising on our own, but then I think that most people are simply too far removed from their food.
Above all, just look at different alternatives. Rabbit, Lamb, Pork, Game, so much more. There are so many tastes our there that we're potentially missing out on, and frankly, the more diverse our food system is, the healthier both ourselves, and quite possibly our planet, is likely to be.