A feedlot or feed yard is a type of animal feeding operation (AFO) which is used in intensive animal farming, notably beef cattle, but also swine, horses, sheep, turkeys, chickens or ducks, prior to slaughter. Large beef feedlots are called concentrated animal feeding operations (CAFO) in the United States  and intensive livestock operations (ILOs)  or confined feeding operations (CFO)  in Canada. They may contain thousands of animals in an array of pens.
The basic principle of the feedlot is to increase the amount of muscle gained by each animal as quickly as possible; if animals are kept in confined quarters rather than being allowed to range freely over grassland, they will gain weight more quickly and efficiently with the added benefit of economies of scale.
Most feedlots require some type of governmental approval to operate, which generally consists of an agricultural site permit. Feedlots also would have an environmental plan in place to deal with the large amount of waste that is generated from the numerous livestock housed. The environmental farm plan is set in place to raise awareness about the environment and covers 23 different aspects around the farm that may affect the environment.  The Environmental Protection Agency has authority under the Clean Water Act to regulate all animal feeding operations in the United States. This authority is delegated to individual states in some cases.  In Canada, regulation of feedlots is shared between all levels of government. Certain provinces are required by law to have a nutrient management plan, which looks at everything the farm is going to feed to their animals, down to the minerals.  New farms are required to complete and obtain a license under the livestock operations act, which looks at proper manure storage as well as proper distance away from other farms or dwellings.  A mandatory RFID tag is required in every animal that passes through a Canadian feedlot, these are called CCIA tags (Canadian Cattle Identification Agency)  which is controlled by the Canadian Food Inspection Agency CFIA.  In Australia this role is handled by the National Feedlot Accreditation Scheme (NFAS). 
The cattle industry works in sequence with one another, prior to entering a feedlot, young calves are born typically in the spring where they spend the summer with their mothers in a pasture or on rangeland. These producers are called cow-calf operations, and are essential for feedlot operations to run.  Once the young calves reach a weight between 500 to 700 pounds (230 to 320 kg) they are rounded up and either sold directly to feedlots, or sent to cattle auctions for feedlots to bid on them. Once transferred to a feedlot, they are housed and looked after for the next six to eight months where they are fed a total mixed ration (TMR)  to start the journey of their further growth away from their mothers. Typically these TMR's consist of forage, grains, minerals, and supplements to benefit the animals health and to maximize feed efficiency. These rations are also known to contain various other forms of feed such as 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 various grains. Some rations may also contain roughage such as corn stalks, straw, sorghum, or other hay, cottonseed meal, premixes which may contain but not limited to antibiotics, fermentation products, micro & macro minerals and other essential ingredients that are purchased from mineral companies, usually in sacked form, for blending into commercial rations. Many feed companies are able to be prescribed a drug to be added into a farms feed if required by a vet. Farmers generally work with nutritionists who aid in the formulation of these rations to ensure their animals are getting the recommended levels of minerals and vitamins, but also to make sure the animals are not wasting feed in their manure.  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. 
Feedlot diets are high in protein, to encourage growth of muscle mass and the distribution of some fat (known as marbling in butchered meat). The marbling is desirable to consumers, as it contributes to flavour and tenderness. These animals may gain an additional 400-600 pounds (180 kg) during its approximate 200 days in the feedlot,  depending on its entrance weight into the lot, and also how well the animal gains muscle.  Once cattle are fattened up to their finished weight, the fed cattle are transported to a slaughterhouse.
A feedlot is highly dependent on the health of its livestock, as disease can have a great impact on the animals, and controlling sickness can be difficult with numerous animals living together. Many feedlots will have an entrance protocol in which new animals entering the lot are given vaccines to protect them against potential sickness that may arise in the first few weeks in the feedlot. These entrance protocols are usually discussed and created with the farm's veterinarian, as there are numerous factors that can impact the health of feedlot cattle.  One challenging but crucial role on a feedlot is to identify any sick cattle, and treat them in order to rebound them back to health. Knowing when an animal is sick is sometimes difficult as cattle are prey animals and will try and hide their weakness from potential threats. A sick animal will generally look gaunt, may have a snotty nose and/or dry nose, and will have droopy ears, catching these symptoms early may be the key to successfully treating an animal. The best indicator of health is the body temperature of a cow, but this is not always possible when looking over many animals per day. 
There are a few common methods of waste recycling within feedlots, with the most common being spreading it back on the cropping fields used to feed the livestock. Generally, feedlots provide bedding for their animals such as straw, sawdust, wood shavings, or other byproducts from crops (soybean chaff, corn chaff), which are then mixed in with the manure as the livestock use the bedding. Once the bedding has outlasted its use, the manure is either spread directly on the fields or stock piled to breakdown and begin composting. A less common type of recycling in the feedlot industry is liquid manure which is where minimal bedding is found in the manure, so it stays a liquid and is then spread on the fields in a liquid form. Increasing numbers of cattle feedlots are utilizing out-wintering pads made of timber residue bedding in their operations.  Nutrients are retained in the waste timber and livestock effluent and can be recycled within the farm system after use. Biogas plants are also able to use livestock manure to create biofuels, but most farmers cannot afford to lose their valuable nutrients found in the manure which they use to spread on their fields. 
Cattle feeding on a large scale was first introduced in the early 60's, when a demand for higher quality beef in large quantities emerged.  Farmers started becoming familiar with the finishing of beef, but also showed interest in various other aspects associated with the feedlot such as soil health, crop management, and how to manage labour costs. From the early 60's to the 90's feeding beef cattle in the feedlot style showed immense growth, and even today the feedlot industry is constantly being upgraded with new knowledge and science as well as technology. In the early 20th century, feeder operations were separate from all other related operations and feedlots were non-existent.  They appeared in the 1950s and 1960s as a result of hybrid grains and irrigation techniques; the ensuing larger grain crops led to abundant grain harvests. It was suddenly possible to feed large numbers of cattle in one location and so, to cut transportation costs, grain farms and feedlot locations merged. Cattle were no longer sent from all across the southern states to places like California, where large slaughter houses were located. In the 1980s, meat packers followed the path of feedlots and are now located close by to them as well.
There are many methods used to sell cattle to meat packers. Spot, or cash, marketing is the traditional and most commonly used method. Prices are influenced by current supply & demand and are determined by live weight or per head. Similar to this is forward contracting, in which prices are determined the same way but are not directly influenced by market demand fluctuations. Forward contracts determine the selling price between the two parties negotiating for a set amount of time. However, this method is the least used because it requires some knowledge of production costs and the willingness of both sides to take a risk in the futures market. Another method, formula pricing, is becoming the most popular process, as it more accurately represents the value of meat received by the packer. This requires trust between the packers and feedlots though, and is under criticism from the feedlots because the amount paid to the feedlots is determined by the packers’ assessment of the meat received. Finally, live- or carcass-weight based formula pricing is most common. Other types include grid pricing and boxed beef pricing. The most controversial marketing method stems from the vertical integration of packer-owned feedlots, which still represents less than 10% of all methods, but has been growing over the years.  Canadian beef is well known worldwide for its high quality, and continues to thrive with this reputation. Canadian beef has market access to many foreign countries all across the world, which is what maintains a relatively healthy industry for Canadian beef farmers. 
This is a major controversy towards farms today as consumers have shown their concern for the welfare of these animals. For farmers, the prioritization of the well-being and care of their animals comes before many other things on the farm.  Another controversial topic within the feedlot industry is the diet of these animals, and the different ingredients within the ration. Often grain or corn will be added into the mix of feed which is designed to provide energy and protein to the growing animals, and is often seen as a negative aspect, but close monitoring of the animals by the farmer ensures that the perfect amount of grain is being introduced into the feed of the animals in order to maintain a healthy and efficient growing period.  Too much grain in the diet can cause cattle to have issues such as bloating, diarrhea and digestive discomfort, which is why close monitoring of the animals, as well as working with ruminant nutritionists is very important for farmers. 
The alternative to feedlots is to allow cattle to graze on grass throughout their lives, but this is not efficient and can be very challenging. For Canada and the Northern USA, year round grazing is not possible due to the severe winter weather conditions. Though controlled grazing methods of this sort necessitate higher beef prices and the cattle take longer to reach market weight. 
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