Here's our very limited tutorial, to give you a start. We're sure many of you know all of this, maybe more, so feel free to bring up more issues in the comments.
There is an environmental impact as well, since feedlots produce more waste than the ground can handle, polluting our water and air. Also, the impact of growing corn just to feed cows so that they can feed us is a little bit backwards when there's grass, a sustainable resource that those sweet cows would prefer to eat anyway.
So, what does grass-fed mean?
For starters, the animals have a better life. They roam, they chew grass, they take naps in the pasture. That sort of thing. They eat the diet they were born to eat, which means they are healthier. Having cows roam grasslands is good for the environment; as Niman writes, "Grazing animals keep invasive annual weeds under control by chomping on the seed heads. They keep perennial native grasses coming back by exposing the growth points to sunlight." Controlled grazing fertilizes the land and protects a natural resource. By not growing and shipping grain to feedlots, we're also saving energy.
Many grass-fed cows, including those from Niman Ranch, are grass-fed and grain-finished. What does that mean? Calves and young cows are allowed to graze as they would naturally, but because it takes much, much longer for solely grass-fed cows to reach a respectable weight, most are eventually moved to feedlots to fatten up towards the end of their lives. Companies who make a point to let their cattle graze, however, usually have very different feedlots than commercial producers. They feed the cows an all-natural, vegetarian diet.
How does that affect the taste of my steak?
Grass-fed beef tends to be leaner and less fatty than grain-fed beef. That's why ranchers usually switch the cows to grain; it gives the meat that all-important marbling. As LeFavour writes, "Cows are supposed to eat grass, with perhaps a little grain thrown in for dessert." A grass-fed steak, cooked properly, will be just as juicy, and it will have better flavor from the natural diet of the cow.
What do I look for in the grocery store?
If you are buying from a local butcher that you know, you can ask about your beef. If you are looking at labels in a grocery store, LeFavour says to look for things like "no added growth hormones" or "no antibiotics," since it's unlikely a cow was raised in a feedlot without them. More likely, that cow grazed in some fields and then had some grain for dessert.
(Images: Elizabeth Passarella*)
*A note on these photos: I took them on the side of the road in central California. While these cows may appear to be crowded against barbed wire, they were very spread out and happily grazing until a stranger pulled her car over and took out a camera.