Prior to entering a feedlot, cattle spend most of their life grazing on rangelandor on immature fields of grain such as green wheat pasture. Once cattle obtain an entry-level weight, about 650 to 700 pounds (300 kg), they are transferred to a feedlot to be fed a specialized animal feed which consists of corn, corn byproducts (some of which is derived from ethanol and high fructose corn syrup production), milo, barley, and other grains as well as roughage which may consist of alfalfa, corn stalks, sorghum, or other hay, cottonseed meal, and premixes composed of microingredients such as vitamins, minerals, chemical preservatives,antibiotics, fermentation products, and other essential ingredients that are purchased from premix companies, usually in sacked form, for blending into commercial rations. Because of the availability of these products, a farmer who uses his own grain can formulate his own rations and be assured his animals are getting the recommended levels of minerals and vitamins.[6] In the American northwest and Canada, barley, low grade durum wheat, chick peas (garbanzo beans), oats and occasionally potatoes are used as feed.[citation needed]
In a typical feedlot, a cow's diet is roughly 62% roughage, 31% grain, 5% supplements (minerals and vitamins), and 2% premix. High-grain diets lower the pH in the animals' rumen. Due to the stressors of these conditions, and due to some illnesses, it may be necessary to give the animals antibiotics on occasion. [7]
Feedlot diets are high in protein, to encourage growth of muscle mass and the deposition of some fat (known asmarbling in butchered meat). The marbling is desirable to consumers, as it contributes to flavor and tenderness. The animal may gain an additional 400 pounds (180 kg) during its approximate 200 days in the feedlot.[citation needed]Once cattle are fattened up to their finished weight, the fed cattle are transported to a slaughterhouse.
