I think referring to conventional feedlot cattle as "grain fed" is unfortunate. I think it's an insult on small local family farmers who raise their cows mainly on pasture, but supplement a little grain here and there. Sometimes I buy this kind of beef. It's not terribly different nutrient-wise from completely 100% grass-fed beef. And many people prefer the taste. Furthermore, it's often very affordable, as low as $2-$4 a lb if you buy in bulk.