Prior to about 1950, the vast majority of beef consumed in the U.S. was not grain fed. A certain amount of grain-finished beef was produced by farmer feeders for the “hotel trade” but this was not a significant portion of the total beef production. Most of the beef supply came from milk fat calves slaughtered at weaning and from fat young cows that had not calved. These two sources made up the majority of the kill because they were the only widely available classes of cattle with sufficient body fat to produce beef that was acceptable to the consumer. The calves were growing rapidly but received the extra energy needed to deposit fat from their mothers’ milk. The cows were able to lay on fat with only the energy supplied by good pasture since they were neither growing rapidly nor suckling a calf. Feeding concentrates to sheep is a very recent phenomena and largely unnecessary since sheep fatten well on the proper kind of pasture as do goats. Large scale grain feeding to ruminant animals is hard to justify from either an economic or an ecological viewpoint. It came to be standard agricultural practice mainly as a way to get rid of excess grain.