The grain builds up the cow's fat reserves, creating the marbling that cooks love much faster than a purely grass-based diet. Because grass-fed cows never eat grain, they always have less fat.

Eat meat. That's the dietary advice given by a team of scientists ... healthier – ratio of omega-6 to omega-3 fatty acids in muscle meats, compared to grain-fed beef. "Both grass-fed steers and the ...

and she said there’s data that indicates calves can eat the same poorer quality rations and distillers grains as cows, but they tend to do better when they’re still getting milk.