High-grain feedlot finishing diets improve feed conversion efficiency and produce high-quality, well-marbled beef. Corn has traditionally been the dominant feed grain in central and eastern Canada and the U.S., while barley is more common in western Canada. The structure of corn starch means that it will generally be digested more slowly than barley. Corn is usually steam-rolled to level the playing field in terms of digestibility and animal performance, while simpler and less costly dry rolling is adequate for barley. Corn has become more common in western Canadian finishing diets in recent years due to decreasing barley acres, increasing corn acres and corn imports. This has led some feedlots to install steam-rollers for corn. Research is underway to learn if steam-rolling improves digestibility and animal performance for barley-based diets.
High-grain diets must be managed carefully to avoid abnormal feeding behavior, rumen acidosis and liver abscesses that can negatively affect animal health and welfare. Forage (typically silage) is fed as a fiber source to help maintain normal rumen function, but this can come at the expense of feed intake and efficiency.
Finding the right forage-to-concentrate ratio is tricky, and a feedlot animal’s fiber requirements may go beyond just a minimum fiber level. Not all forages and fibers are the same. The important thing might be to provide the right level of the right kind of fiber. For example, fiber length is important. Fiber that is too short won’t be “physically effective” – it won’t provide the “scratch factor” that stimulates rumen activity. That’s why distiller’s grains can’t replace roughage in a finishing diet. Its particles are too fine to be physically effective.