I don't eat beef, but if you do, I agree that you're much better off getting it from grass-fed cattle than from those that are raised on factory farms and fed grain (not to mention hormones and antibiotics). Cattle evolved to graze on grass; they are not adapted to digest grains, which wreak havoc with their digestive systems, even though they promote faster weight gain. In fact, the need for antibiotics in raising cattle on feedlots results from the alterations in the natural flora of their gastrointestinal tracts from eating grain-based diets.
Meat from grass-fed cattle is lower in saturated fat than meat from cattle fed on grain. It also has more omega-3 fatty acids, vitamin E and conjugated linoleic acid - all good for human health. Incidentally, organic beef isn't necessarily grass-fed. These cattle may be raised in pesticide-free pastures, but they are taken to feedlots and fed (organic) grain prior to slaughter.
Most connoisseurs prefer the stronger flavor of grass-fed beef, even though it varies from location to location and season to season. And it may be a bit less tender than the grain-fed variety. Restauranteurs and marketers tend to like the uniformity of feedlot beef.
People new to grass-fed beef may say it doesn't taste as good. In one taste test, panelists reported that grass-fed beef had off-flavors (like ammonia) or tasted gamey, bitter, liverish, old, rotten and sour. But Argentineans, who make beef consumption somewhat of a national religion, turn up their noses at our grain-fed steaks. Grass-fed beef is also somewhat more expensive than the meat you're accustomed to buying in the supermarket, even though it is becoming more widely available. You can find suppliers by searching for "grass fed cattle" on the internet. Grass-fed beef is also turning up more and more frequently in natural-food stores.
As far as wild game is concerned, that, too, is lower in fat and better nutritionally in other ways than most commercially available meat and poultry. But that doesn't mean that it is always safe. Some game animals, especially deer, can carry E. coli, and game birds can carry Salmonella. If you hunt and eat meat from the animals you kill, you need to know how to handle and prepare it safely.
Andrew Weil, M.D.