Feeder cattle, in some countries or regions called store cattle, are young cattle mature enough either to undergo backgrounding or to be fattened in preparation for slaughter. They may be steers (castrated males) or heifers (females who have not dropped a calf). The term often implicitly reflects an intent to sell to other owners for fattening (finishing). Backgrounding occurs at backgrounding operations, and fattening occurs at a feedlot. Feeder calves are less than 1 year old; feeder yearlings are between 1 and 2 years old. Both types are often produced in a cow-calf operation. After attaining a desirable weight, feeder cattle become finished cattle that are sold to a packer (finished cattle are also called fattened cattle, fat cattle, fed cattle, or, when contrasted with carcasses, live cattle). Packers slaughter the cattle and sell the meat in carcass boxed form.

Feedlots producing live cattle for slaughter will typically purchase 500–850 pounds (230–390 kg) feeder cattle calves and feed to grow the animals into 850–1,400 pounds (390–640 kg) cattle. Backgrounding operations will typically purchase 300–600 pounds (140–270 kg) feeder cattle calves and feed to grow the animals into 650–875 pounds (295–397 kg) backgrounded cattle. Backgrounding cattle that achieve weights of 650–700 pounds (290–320 kg) are suitable for sale to grass feeding operations, whereas those achieving weights of 800–825 pounds (363–374 kg) are suitable for sale to feedlot operators. Buyers of feeder cattle tend to look for high average gain (in weight) and low feed-to-gain ratio. Depending on circumstances, different feeder cattle buyers will look for different ranges of animal weight and grade.

Cattle producers and backgrounding operations balance feeder cattle prices, weights, time taken to fatten, death rates, and other feeder cattle factors against feed prices, live cattle prices, and other operating factors to profit from their operations.

The United States grades feeder cattle that have not reached an age of 36 months on three factors: frame size, thickness, and thriftiness.

The above three factors and their segmented categories combine to form individual grades. For examples, for thrifty cattle, the frame and thickness factors combine to form 12 different grades of thrifty cattle: No. 1; Large Frame, No. 2; Large Frame, No. 3; Large Frame, No. 4; Medium Frame, No. 1; Medium Frame, No. 2; Medium Frame, No. 3; Medium Frame, No. 4; Small Frame, No. 1; Small Frame, No. 2; Small Frame, No. 3; and finally Small Frame, No. 4.

Health status, and visual indicators of health, can give feeder cattle premiums or discounts when sold in auctions. Feeder cattle with dead hair and mud are often sold at a discount, and those that are classified as "stale" are sold at a discount. Feeder cattle with other obvious physical indicators that would imply sickness are heavily discounted.

The primary sickness encountered in feeder cattle is respiratory sickness. Discounts on sick feeder cattle compensate for their increased risk of death, and lower performance in weight gain even if they recover. Cattle that look visually "thin" or "fleshy" are generally given discounts or premiums distinct from sickness discounts, as these visual traits do not necessarily indicate sickness and could be advantageous in particular feeding scenarios.

Some feeder cattle are sold with some pre-existing health maintenance programs. These programs may include weaning 21 to 45 days before sale, vaccinating for respiratory and digestive diseases, de-horning, castrating, implanting growth implants, treating for external and internal parasites, and starting to switch the feeder cattle to grain-based feed.