Intensive farms hold large numbers of animals, typically
cows,
pigs,
turkeys,
geese, or
chickens, often indoors, typically at high densities. Intensive production of livestock and poultry is widespread in
developed nations. For 2002–2003, the
United Nations'
Food and Agriculture Organization (FAO) estimates of industrial production as a percentage of global production were 7 percent for beef and veal, 0.8 percent for
sheep and
goat meat, 42 percent for pork, and 67 percent for poultry meat.
Chickens The major milestone in 20th-century poultry production was the discovery of
vitamin D, which made it possible to keep chickens in confinement year-round. Before this, chickens did not thrive during the winter (due to lack of sunlight), and egg production, incubation, and meat production in the off-season were all very difficult, making poultry a seasonal and expensive proposition. Year-round production lowered costs, especially for broilers. At the same time, egg production was increased by scientific breeding. After a few false starts, (such as the Maine Experiment Station's failure at improving egg production) success was shown by Professor Dryden at the Oregon Experiment Station. Improvements in production and quality were accompanied by lower labor requirements. In the 1930s through the early 1950s, 1,500 hens provided a full-time job for a farm family in America. In the late 1950s, egg prices had fallen so dramatically that farmers typically tripled the number of hens they kept, putting three hens into what had been a single-bird cage or converting their floor-confinement houses from a single deck of roosts to triple-decker roosts. Not long after this, prices fell still further and large numbers of egg farmers left the business. This fall in profitability was accompanied by a general fall in prices to the consumer, allowing poultry and eggs to lose their status as luxury foods. Robert Plamondon reports that the last family chicken farm in his part of Oregon, Rex Farms, had 30,000 layers and survived into the 1990s. However, the standard laying house of the current operators is around 125,000 hens. The
vertical integration of the egg and poultry industries was a late development, occurring after all the major technological changes had been in place for years (including the development of modern broiler rearing techniques, the adoption of the
Cornish Cross broiler, the use of laying cages, etc.). chickens, bred for meat production, regularly have health issues, as their genetics have been optimized for quick growth, sometimes causing
broiler ascites syndrome. By the late 1950s, poultry production had changed dramatically. Large farms and packing plants could grow birds by the tens of thousands. Chickens could be sent to
slaughterhouses for butchering and processing into prepackaged commercial products to be frozen or shipped fresh to markets or wholesalers. Meat-type chickens currently grow to market weight in six to seven weeks, whereas only fifty years ago it took three times as long. This is due to genetic selection and nutritional modifications (but not the use of growth hormones, which are illegal for use in poultry in the US and many other countries, and have no effect). Once a meat consumed only occasionally, the common availability and lower cost has made chicken a common meat product within developed nations. Growing concerns over the
cholesterol content of
red meat in the 1980s and 1990s further resulted in increased consumption of chicken. Today, eggs are produced on large egg ranches on which environmental parameters are well controlled. Chickens are exposed to artificial light cycles to stimulate egg production year-round. In addition,
forced molting is commonly practiced in the US, in which manipulation of light and food access triggers molting, in order to increase egg size and production. Forced molting is controversial, and is prohibited in the EU. On average, a chicken lays one egg a day, but not on every day of the year. This varies with the breed and time of year. In 1900, average egg production was 83 eggs per hen per year. In 2000, it was well over 300. In the United States, laying hens are butchered after their second egg laying season. In Europe, they are generally butchered after a single season. The laying period begins when the hen is about 18–20 weeks old (depending on breed and season). Males of the egg-type breeds have little commercial value at any age, and all those not used for breeding (roughly fifty percent of all egg-type chickens) are
killed soon after hatching. The old hens also have little commercial value. Thus, the main sources of poultry meat 100 years ago (spring chickens and stewing hens) have both been entirely supplanted by meat-type broiler chickens.
Pigs Intensive piggeries (or hog lots) are a type of
concentrated animal feeding operation (CAFO), specialized for the raising of
domestic pigs up to slaughter weight. In this system, grower pigs are housed indoors in group-housing or straw-lined sheds, whilst pregnant sows are confined in sow stalls (
gestation crates) and give birth in
farrowing crates. The use of sow stalls has resulted in lower production costs and concomitant
animal welfare concerns. Many of the world's largest producers of pigs (such as
U.S. and
Canada) use sow stalls, but some nations (such as the
UK) and
U.S. states (such as
Florida and
Arizona) have banned them. Intensive piggeries are generally large warehouse-like buildings. Indoor pig systems allow the pig's condition to be monitored, ensuring minimum fatalities and increased productivity. Buildings are ventilated and their temperature regulated. Most domestic pig varieties are susceptible to heat stress, and all pigs lack sweat glands and cannot cool themselves. Pigs have a limited tolerance to high temperatures and heat stress can lead to death. Maintaining a more specific temperature within the pig-tolerance range also maximizes growth and growth to feed ratio. In an intensive operation pigs will lack access to a wallow (mud), which is their natural cooling mechanism. Intensive piggeries control temperature through ventilation or drip water systems (dropping water to cool the system). Pigs are naturally
omnivorous and are generally fed a combination of grains and protein sources (soybeans, or
meat and bone meal). Larger intensive pig farms may be surrounded by farmland where feed-grain crops are grown. Alternatively, piggeries are reliant on the grains industry. Pig feed may be bought packaged or mixed on-site. The intensive piggery system, where pigs are confined in individual stalls, allows each pig to be allotted a portion of feed. The individual feeding system also facilitates individual medication of pigs through feed. This has more significance to
intensive farming methods, as the close proximity to other animals enables diseases to spread more rapidly. To prevent disease spreading and encourage growth, drug programs such as
antibiotics,
vitamins,
hormones and other supplements are pre-emptively administered. Indoor systems, especially stalls and pens (i.e. 'dry', not straw-lined systems) allow for the easy collection of waste. In an indoor intensive pig farm, manure can be managed through a lagoon system or other waste-management system. However, odor remains a problem which is difficult to manage. Piglets often receive range of treatments including
castration, tail docking to reduce tail biting, teeth clipped (to reduce injuring their mother's nipples, gum disease and prevent later tusk growth) and their ears notched to assist identification. Treatments are usually made without
painkillers. Weak
runts may be slain shortly after birth. Piglets also may be
weaned and removed from the sows at between two and five weeks old and placed in sheds. However, grower pigs – which comprise the bulk of the herd – are usually housed in alternative indoor housing, such as batch pens. During pregnancy, the use of a stall may be preferred as it facilitates feed-management and growth control. It also prevents pig aggression (e.g. tail biting, ear biting, vulva biting, food stealing). Group pens generally require higher stockmanship skills. Such pens will usually not contain straw or other material. Alternatively, a straw-lined shed may house a larger group (i.e. not batched) in age groups.
Cattle Cattle are
domesticated ungulates, a member of the
family Bovidae, in the
subfamily Bovinae, and descended from the
aurochs (
Bos primigenius). They are raised as livestock for their flesh (called beef and
veal),
dairy products (milk), leather and as
draught animals. As of 2009–2010 it is estimated that there are 1.3–1.4 billion head of cattle in the world. systems. As of 2010, in the U.S. 766,350 producers participate in raising beef. The beef industry is segmented with the bulk of the producers participating in raising beef calves. Beef calves are generally raised in small herds, with over 90% of the herds having less than 100 head of cattle. Fewer producers participate in the finishing phase which often occurs in a
feedlot, but nonetheless there are 82,170 feedlots in the United States. on a
feedlot in the
Texas Panhandle. Such confinement creates more work for the farmer but allows the animals to grow rapidly. Young cattle may begin by grazing with their mothers. Once cattle obtain an entry-level weight, about , they are transferred from the range to a
feedlot to be fed a specialized
animal feed which can include corn byproducts, barley, soy and other grains as well as alfalfa and
cottonseed meal. Typical industrial production mixes will include 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. There are many potential impacts on human health from intensive cattle farming.
Prophylactic antibiotics can be a source of antibiotic resistance. The intensive feeding systems lead to more
E. coli contamination, and increased saturated fat in the meat due to grain-based diets. The environmental impacts also pose indirect health risks.
Aquaculture cultivated in proximity to
Atlantic salmon in the
Bay of Fundy, Canada Integrated multi-trophic aquaculture (IMTA), also called integrated aquaculture, The system is multi-trophic as it makes use of
species from different
trophic or
nutritional level, unlike traditional aquaculture. Ideally, the biological and chemical processes in such a system should balance. This is achieved through the appropriate selection and proportions of different species providing different ecosystem functions. The co-cultured species should not just be
biofilters, but harvestable crops of commercial value. ==Regulation==