Editing Agriculture (section)

=== Livestock production systems ===
{{Main|Livestock|Animal husbandry}}
{{See also|List of domesticated animals}}
[[File:Hog confinement barn interior.jpg|thumb|[[Intensive animal farming|Intensively farmed]] pigs]]

Animal husbandry is the breeding and raising of animals for meat, milk, [[egg (food)|eggs]], or [[wool]], and for work and transport.<ref name=Clutton-Brock>{{cite book |author=Clutton-Brock, Juliet |title=A Natural History of Domesticated Mammals |url=https://books.google.com/books?id=cgL-EbbB8a0C&pg=PA1 |year=1999 |publisher=Cambridge University Press |isbn=978-0-521-63495-3 |pages=1–2 |access-date=10 February 2019}}</ref> [[Working animal]]s, including horses, [[mule]]s, [[ox]]en, [[water buffalo]], camels, llamas, alpacas, donkeys, and dogs, have for centuries been used to help cultivate fields, [[harvest]] crops, wrangle other animals, and transport farm products to buyers.<ref>{{cite book |last=Falvey |first=John Lindsay |author-link=Lindsay Falvey |year=1985 |title=Introduction to Working Animals |isbn=978-1-86252-992-2 |location=Melbourne, Australia |publisher=MPW Australia}}</ref>

Livestock production systems can be defined based on feed source, as grassland-based, mixed, and landless.<ref name="FAO lps">{{cite web |author1=Sere, C. |author2=Steinfeld, H. |author3=Groeneweld, J. |year=1995 |url=http://www.fao.org/WAIRDOCS/LEAD/X6101E/x6101e00.htm#Contents |title=Description of Systems in World Livestock Systems – Current status issues and trends |publisher=U.N. Food and Agriculture Organization |access-date=8 September 2013 |url-status=live |archive-url=https://web.archive.org/web/20121026004040/http://www.fao.org/WAIRDOCS/LEAD/X6101E/X6101E00.HTM#Contents |archive-date=26 October 2012}}</ref> {{as of|2010}}, 30% of Earth's ice- and water-free area was used for producing livestock, with the sector employing approximately 1.3&nbsp;billion people. Between the 1960s and the 2000s, there was a significant increase in livestock production, both by numbers and by carcass weight, especially among beef, pigs and chickens, the latter of which had production increased by almost a factor of 10. Non-meat animals, such as milk cows and egg-producing chickens, also showed significant production increases. Global cattle, sheep and goat populations are expected to continue to increase sharply through 2050.<ref name=LP>{{cite journal |title=Livestock production: recent trends, future prospects |author=Thornton, Philip K. |doi=10.1098/rstb.2010.0134 |pmid=20713389 |journal=Philosophical Transactions of the Royal Society B |date=27 September 2010 |volume=365 |issue=1554 |pages=2853–2867 |doi-access=free |pmc=2935116}}</ref> [[Aquaculture]] or fish farming, the production of fish for human consumption in confined operations, is one of the fastest growing sectors of food production, growing at an average of 9% a year between 1975 and 2007.<ref>{{cite magazine |url=http://content.time.com/time/health/article/0,8599,1663604,00.html |title=Fish Farming's Growing Dangers |magazine=Time |author=Stier, Ken |date=19 September 2007 |url-status=live |archive-url=https://web.archive.org/web/20130907071708/http://content.time.com/time/health/article/0,8599,1663604,00.html |archive-date=7 September 2013}}</ref>

During the second half of the 20th century, producers using selective breeding focused on creating livestock [[breed]]s and [[crossbreed]]s that increased production, while mostly disregarding the need to preserve [[genetic diversity]]. This trend has led to a significant decrease in genetic diversity and resources among livestock breeds, leading to a corresponding decrease in disease resistance and local adaptations previously found among traditional breeds.<ref>{{cite journal |title=A global view of livestock biodiversity and conservation – Globaldiv |author=Ajmone-Marsan, P. |journal=Animal Genetics |date=May 2010 |doi=10.1111/j.1365-2052.2010.02036.x |pmid=20500752 |volume=41 |issue=supplement S1 |pages=1–5 |url=http://infoscience.epfl.ch/record/148417 |url-status=live |archive-url=https://web.archive.org/web/20170803140941/https://infoscience.epfl.ch/record/148417 |archive-date=3 August 2017}}</ref>

[[File:Broiler Chicks.jpg|thumb|Raising chickens intensively for meat in a broiler house]]

Grassland based livestock production relies upon plant material such as [[shrubland]], [[rangeland]], and [[managed intensive rotational grazing|pastures]] for feeding [[ruminant]] animals. Outside nutrient inputs may be used, however manure is returned directly to the grassland as a major nutrient source. This system is particularly important in areas where crop production is not feasible because of climate or soil, representing 30–40&nbsp;million pastoralists.<ref name="CS" /> Mixed production systems use grassland, [[fodder]] crops and grain feed crops as feed for ruminant and monogastric (one stomach; mainly chickens and pigs) livestock. Manure is typically recycled in mixed systems as a fertilizer for crops.<ref name="FAO lps" />

Landless systems rely upon feed from outside the farm, representing the de-linking of crop and livestock production found more prevalently in [[Organisation for Economic Co-operation and Development|Organization for Economic Co-operation and Development]] member countries. Synthetic fertilizers are more heavily relied upon for crop production and manure use becomes a challenge as well as a source for pollution.<ref name="FAO lps" /> Industrialized countries use these operations to produce much of the global supplies of poultry and pork. Scientists estimate that 75% of the growth in livestock production between 2003 and 2030 will be in [[confined animal feeding operations]], sometimes called [[factory farming]]. Much of this growth is happening in developing countries in Asia, with much smaller amounts of growth in Africa.<ref name=LP /> Some of the practices used in commercial livestock production, including the usage of [[growth hormone]]s, are controversial.<ref>{{cite web |url=http://europa.eu/rapid/press-release_IP-02-604_en.pdf |title=Growth Promoting Hormones Pose Health Risk to Consumers, Confirms EU Scientific Committee |date=23 April 2002 |access-date=6 April 2013 |publisher=European Union |url-status=live |archive-url=https://web.archive.org/web/20130502123053/http://europa.eu/rapid/press-release_IP-02-604_en.pdf |archive-date=2 May 2013}}</ref>