View source for Biology:Oat

{{short description|Cool weather staple grain, animal feed}}
{{speciesbox
| name = Oat
| image = Avena sativa L.jpg
| image_caption = [[Biology:Inflorescence|Inflorescence]]s
| image_alt = Oat plants with [[Biology:Inflorescence|inflorescence]]s
| genus = Avena
| species = sativa
| authority = [[Biography:Carl Linnaeus|L.]] (1753)
}}

The '''oat''' (''Avena sativa''), sometimes called the '''common oat''', is a [[Biology:Species|species]] of [[Biology:Cereal|cereal grain]] grown for its seed, which is known by the same name (usually in the plural, unlike other cereals and pseudocereals). Oats are used for human consumption as [[Biology:Oatmeal|oatmeal]] and [[Biology:Rolled oats|rolled oats]]. Oats are a [[Earth:Nutrient|nutrient]]-rich food associated with lower blood [[Chemistry:Cholesterol|cholesterol]] and reduced risk of human heart disease when consumed regularly.<ref name=ajcn/> One of the most common uses of oats is as livestock feed.

Avenins are oat gluten proteins, similar to gliadin in [[Biology:Wheat|wheat]]. They can trigger [[Medicine:Coeliac disease|celiac disease]] in a small proportion of people.<ref name=Biesiekierski2017>{{cite journal| author=Biesiekierski JR| title=What is gluten? | journal=Journal of Gastroenterology and Hepatology | year= 2017 | volume= 32 | issue=Suppl 1 | pages= 78–81 | pmid=28244676 | doi=10.1111/jgh.13703 | s2cid=6493455 | type=Review | quote= Similar proteins to the gliadin found in wheat exist as secalin in rye, hordein in barley, and avenins in oats and are collectively referred to as "gluten." Derivatives of these grains such as triticale and malt and other ancient wheat varieties such as spelt and kamut also contain gluten. The gluten found in all of these grains has been identified as the component capable of triggering the immune-mediated disorder, coeliac disease.| doi-access=free }}{{open access}}</ref><ref name=cjgh/> Also, oat products are frequently contaminated by other gluten-containing grains, mainly wheat and [[Biology:Barley|barley]].<ref name="cjgh">{{cite journal|pmc=4904695|year=2016|last1=La Vieille|first1=S|title=Celiac Disease and Gluten-Free Oats: A Canadian Position Based on a Literature Review|journal=Canadian Journal of Gastroenterology and Hepatology|volume=2016|pages=1–10|last2=Pulido|first2=O. M.|last3=Abbott|first3=M|last4=Koerner|first4=T. B.|last5=Godefroy|first5=S|doi=10.1155/2016/1870305|pmid=27446825|doi-access=free }}</ref><ref name=CominoMoreno2015 /><ref name=FricGabrovska2011>{{cite journal|vauthors=Fric P, Gabrovska D, Nevoral J|title=Celiac disease, gluten-free diet, and oats|journal=Nutrition Review|volume=69|issue=2|pages=107–15|date=Feb 2011|pmid=21294744|doi=10.1111/j.1753-4887.2010.00368.x|type=Review}}</ref>

==Origin==
[[File:Avena-sativa.jpg|thumb|right|Florets (small flowers)|alt=Closeup of florets (small flowers)]]
The wild ancestor of ''Avena sativa'' and the closely related minor crop {{endash}} ''[[Biology:Avena byzantina|A. byzantina]]'' {{endash}} is ''[[Biology:Avena sterilis|A. sterilis]]''. ''A. sterilis'' is a wild oat that is naturally hexaploid. [[Biology:Genetic analysis|Genetic evidence]] shows the ancestral forms of ''A. sterilis'' grew in the [[Place:Fertile Crescent|Fertile Crescent]] of the Near East.<ref name="zhou">{{Cite journal|issue=2|year=2008|pages=113–122|last1=Burger|first1=Jutta C.|last2=Chapman|first2=Mark A.|last3=Burke|first3=John M.|volume=95|s2cid=8521495|pmid=21632337|doi=10.3732/ajb.95.2.113|title=Molecular insights into the evolution of crop plants|journal=American Journal of Botany |doi-access=free}}</ref><ref>{{Cite journal|last1=Zhou|first1=X.|last2=Jellen|first2=E.N.|last3=Murphy|first3=J.P.|year=1999|title=Progenitor germplasm of domesticated hexaploid oat|url=|journal=Crop Science|volume=39|issue=4| pages=1208–1214|s2cid=8521495|pmid=21632337|doi=10.2135/cropsci1999.0011183x003900040042x}}
</ref> Oats are usually thought to have emerged as a secondary crop, i.e., derived from a weed of the primary [[Biology:Cereal|cereal]] domesticates, then spreading westward into cooler, wetter areas favorable for oats, eventually leading to their domestication in regions of the Middle East and Europe.<ref name=zhou/>

==Cultivation==
{| class="wikitable" style="float:right; clear:right; width:14em; text-align:center; margin-right:1em;"
|+ Oats production – 2021<ref name="faostat">{{cite web|url=http://www.fao.org/faostat/en/#data/QC|title= Oats production in 2021, Crops/Regions/World list/Production Quantity/Year (pick lists)|date=2023|publisher=UN Food and Agriculture Organization, Corporate Statistical Database (FAOSTAT)|access-date=14 June 2023}}</ref>
|-
!  style="background:#ddf; | Country
!  style="background:#ddf; | Millions of [[Tonne|tonne]]s
|-
| {{RUS}} || 3.8
|-
| {{CAN}} || 2.8
|-
| {{AUS}} || 1.9
|-
| {{POL}} || 1.6
|-
| {{ESP}} || 1.2
|-
| {{GBR}} || 1.1
|-
| '''World''' || '''22.6'''
|}

Oats are best grown in temperate regions. They have a lower summer heat requirement and greater tolerance of rain than other cereals, such as wheat, [[Biology:Rye|rye]] or barley, so they are particularly important in areas with cool, wet summers, such as Northwest Europe and even Iceland. Oats are an [[Biology:Annual plant|annual plant]], and can be planted either in autumn/fall (for late summer harvest) or in the spring (for early autumn harvest).

==Production==
In 2021, global production of oats was {{convert|22.6|e6t|abbr=off}}, led by Russia with 17% of the total and Canada with 12% (table).

==Uses==
Oats have numerous uses in foods; most commonly, they are [[Biology:Rolled oats|rolled]] or crushed into [[Biology:Oatmeal|oatmeal]], or ground into fine oat [[Biology:Flour|flour]]. Oatmeal is chiefly eaten as [[Biology:Porridge|porridge]], but may also be used in a variety of baked goods, such as [[Biology:Oatcake|oatcake]]s, oatmeal cookies and oat bread. Oats are also an ingredient in many cold cereals, in particular [[Biology:Muesli|muesli]] and [[Biology:Granola|granola]]. Oats are also used for production of milk substitutes ("[[Biology:Oat milk|oat milk]]").<ref name="Hitchens">{{cite magazine |author=Hitchens, A |date=6 August 2018 |title=Hey, Where's my oat milk? |magazine=The New Yorker |access-date=10 December 2018 |url=https://www.newyorker.com/magazine/2018/08/06/hey-wheres-my-oat-milk}}</ref> As of late 2020, the oat milk market became the second-largest among plant milks in the United States, following the leader, [[Biology:Almond milk|almond milk]], but exceeding the sales of soy milk.<ref name="watson9-20">{{cite web |author1=Elaine Watson |title=Oatmilk edges past soymilk for #2 slot in US plant-based milk retail market |url=https://www.foodnavigator-usa.com/Article/2020/09/25/Oatmilk-edges-past-soymilk-for-2-slot-in-US-plant-based-milk-retail-market-as-almondmilk-continues-to-drive-category-sales#|
publisher=FoodNavigator-USA.com, William Reed Business Media, Ltd |access-date=20 December 2020 |date=25 September 2020}}</ref>
[[File:MapOats-1907.jpg|alt=World map of oat cultivation, 1907|thumb|World map of oat cultivation, 1907]]
Historical attitudes towards oats have varied. [[Biology:Oat bread|Oat bread]] was first manufactured in Britain, where the first oat bread factory was established in 1899. In Scotland, they were, and still are, held in high esteem, as a mainstay of the national diet.

In Scotland, a dish was made by soaking the husks from oats for a week, so the fine, floury part of the meal remained as sediment to be strained off, boiled and eaten.<ref name="Gauldie1981">{{cite book|last=Gauldie|first=Enid|title=The Scottish country miller, 1700–1900: a history of water-powered meal milling in Scotland|year=1981|publisher=J. Donald|location= [[Place:Edinburgh|Edinburgh]] |isbn=978-0-85976-067-6}}</ref> Oats are also widely used there as a thickener in soups, as barley or rice might be used in other countries.

Oats are also commonly used as feed for horses when extra carbohydrates and the subsequent boost in energy are required. The oat hull may be crushed ("rolled" or "crimped") for the horse to more easily digest the grain,<ref>{{Cite web |date=2003-12-29 |title=Oats: The Perfect Horse Feed? |url=https://ker.com/equinews/oats-perfect-horse-feed/ |access-date=2023-06-20 |website=Kentucky Equine Research |language=en-US}}</ref> or may be fed whole. They may be given alone or as part of a blended food pellet. Cattle are also fed oats, either whole or ground into a coarse flour using a roller mill, [[Engineering:Burr mill|burr mill]], or hammermill. Oat forage is commonly used to feed all kinds of ruminants, as pasture, straw, hay or silage.<ref>{{Cite web
| publisher=[[Organization:Institut national de la recherche agronomique|Institut national de la recherche agronomique]] (INRA), CIRAD, Association Française de Zootechnie and FAO
|title=Oat forage |url=https://www.feedipedia.org/node/500|access-date=2023-03-27|website= Feedipedia |year=2016
| author1= Valérie Heuzé
| author2 = Gilles Tran
| author3 = Anne Boudon
| author4 = François Lebas
}}</ref>

Winter oats may be grown as an off-season [[Biology:Groundcover|groundcover]] and ploughed under in the spring as a green fertilizer, or harvested in early summer. They also can be used for pasture; they can be grazed a while, then allowed to head out for grain production, or grazed continuously until other pastures are ready.<ref name="Manage oat growth">{{cite web|access-date=2013-03-27|date=2008-02-11|archive-date=2017-11-23|archive-url=https://web.archive.org/web/20171123003745/http://articles.extension.org/pages/13262/grazing-of-oat-pastures|url=http://www.extension.org/pages/13262/grazing-of-oat-pastures|title=Grazing of Oat Pastures|publisher=eXtension}}</ref>

Oat [[Biology:Straw|straw]] is prized by cattle and horse producers as bedding, due to its soft, relatively dust-free, and absorbent nature. The straw can also be used for making [[Biology:Corn dolly|corn dollies]]. Tied in a muslin bag, oat straw was used to soften bath water.

Oats are also occasionally used in several different drinks. In Britain, they are sometimes used for brewing beer. Oatmeal stout is one variety brewed using a percentage of oats for the wort. The more rarely used oat malt is produced by the Thomas Fawcett & Sons Maltings and was used in the Maclay Oat Malt Stout before Maclays Brewery ceased independent brewing operations. A cold, sweet drink called [[Biology:Avena (drink)|''avena'']] made of ground oats and milk is a popular refreshment throughout Latin America. Oatmeal caudle, made of ale and oatmeal with spices, was a traditional British drink and a favourite of Oliver Cromwell.<ref>''The Compleat Housewife'', p. 169, Eliza Smith, 1739</ref><ref>''Food in Early Modern Europe'', Ken Albala, Greenwood Publishing Group, 2003, {{ISBN|0-313-31962-6}}</ref>

==Health==
===Nutrient profile===
{{Infobox nutritional value
| name=Oats
| kJ=1628
| protein=16.9 g
| fat=6.9 g
| satfat          = 1.21 g
| transfat        = 
| monofat         = 2.18 g
| polyfat         = 2.54 g
| omega3fat       = 
| omega6fat       = 
| carbs=66.3 g
| fiber=11.6 g
| calcium_mg=54
| iron_mg=5
| magnesium_mg=177
| phosphorus_mg=523
| potassium_mg=429
| sodium_mg=2
| zinc_mg=4
| manganese_mg=4.9
| thiamin_mg=0.763
| riboflavin_mg=0.139
| niacin_mg=0.961
| pantothenic_mg=1.349
| vitB6_mg=0.12
| folate_ug=56
| opt1n=[[Biology:Oat beta-glucan|β-glucans (soluble fiber)&nbsp;]]<ref>{{cite web |title=Oat and barley ß-glucans |url=http://www5.agr.gc.ca/resources/prod/doc/misb/fb-ba/nutra/pdf/B-Glucans_Eng.pdf |archive-url=https://web.archive.org/web/20180513202232/http://www5.agr.gc.ca/resources/prod/doc/misb/fb-ba/nutra/pdf/B-Glucans_Eng.pdf |archive-date=2018-05-13 |url-status=live |publisher=[[Organization:Agriculture and Agri-Food Canada|Agriculture and Agri-Food Canada]], Government of Canada |access-date=27 July 2019 |date=1 August 2008}}</ref>
| opt1v=4 g
| note=[https://fdc.nal.usda.gov/fdc-app.html#/food-details/169705/nutrients FoodData Central  entry]}}

Oats contain diverse essential nutrients. In a 100 gram serving, oats provide {{convert|389|kcal|kJ|lk=on}} and are a rich source (20% or more of the Daily Value, DV) of [[Biology:Protein (nutrient)|protein]] (34% DV), dietary fiber (44% DV), several [[Chemistry:B vitamins|B vitamins]] and numerous dietary minerals, especially [[Chemistry:Manganese|manganese]] (233% DV) (table). Oats are 66% [[Chemistry:Carbohydrate|carbohydrate]]s, including 11% dietary fiber and 4% [[Chemistry:Beta-glucan|beta-glucan]]s, 7% [[Chemistry:Fat|fat]] and 17% protein (table).

The established property of their cholesterol-lowering effects<ref name="ajcn">{{cite journal|journal=American Journal of Clinical Nutrition|year=2014|volume=100|issue=6|pages=1413–21|doi=10.3945/ajcn.114.086108|title=Cholesterol-lowering effects of oat β-glucan: a meta-analysis of randomized controlled trials|last1=Whitehead|first1=Anne|last2=Beck|first2=Eleanor J|last3=Tosh|first3=Susan|last4=Wolever|first4=Thomas MS|pmid=25411276|pmc=5394769}}</ref> has led to acceptance of oats as a [[Unsolved:Health food|health food]].<ref name="cdc">{{cite web|url=https://www.cdc.gov/nutrition/everyone/basics/carbs.html|title=Nutrition for everyone: carbohydrates|publisher=Centers for Disease Control and Prevention, US Department of Health and Human Services|date=2014|access-date=8 December 2014}}</ref>
[[File:Haverkorrels Avena sativa.jpg|right|thumb|With husk|alt=Grains in their husks]]

===Soluble fiber===
Oat bran is the outer casing of the oat. Its daily consumption over weeks lowers [[Medicine:Low-density lipoprotein|LDL]] and total cholesterol, possibly reducing the risk of heart disease.<ref name="ajcn"/><ref name="WebMD">{{cite web|url=http://www.webmd.com/cholesterol-management/features/the-new-cholesterol-diet-oatmeal-oat-bran|title=LDL Cholesterol and Oatmeal|website=[[Company:WebMD|WebMD]]|date=2 February 2009}}</ref>

One type of soluble fiber, [[Biology:Oat beta-glucan|beta-glucans]], has been proven to lower cholesterol.<ref name="ajcn"/>

After reports of research finding that dietary oats can help lower cholesterol, the United States [[Organization:Food and Drug Administration|Food and Drug Administration]] (FDA) issued a final rule<ref name="fda">{{cite web|url=http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=101.81|title=Title 21--Chapter 1, Subchapter B, Part 101 - Food labeling - Specific Requirements for Health Claims, Section 101.81: Health claims: Soluble fiber from certain foods and risk of coronary heart disease (CHD) (revision 2015)|publisher=US Department of Health and Human Services, [[Organization:Food and Drug Administration|Food and Drug Administration]] (FDA) |date=1 April 2015|access-date=10 November 2015}}</ref> that allows food companies to make health claims on food labels of foods that contain soluble fiber from whole oats (oat bran, oat flour and rolled oats), noting that 3.0&nbsp;grams of soluble fiber daily from these foods may reduce the risk of heart disease. To qualify for the health claim, the food that contains the oats must provide at least 0.75&nbsp;grams of soluble fiber per serving.<ref name=fda/>

Beta-D-glucans, usually referred to as beta-glucans, comprise a class of indigestible [[Chemistry:Polysaccharide|polysaccharide]]s widely found in nature in sources such as grains, [[Biology:Barley|barley]], [[Biology:Yeast|yeast]], [[Biology:Bacteria|bacteria]], [[Biology:Algae|algae]] and [[Biology:Mushroom|mushroom]]s. In oats, barley and other cereal grains, they are located primarily in the [[Biology:Endosperm|endosperm]]{{'}}s [[Biology:Cell wall|cell wall]]. The oat beta-glucan health claim applies to oat bran, [[Biology:Rolled oats|rolled oats]], whole oat [[Biology:Flour|flour]] and oatrim, a soluble fraction of [[Biology:Alpha-amylase|alpha-amylase]] from hydrolyzed oat bran or whole oat flour.<ref name=fda/>

Oat [[Chemistry:Beta-glucan|beta-glucan]] is a [[Chemistry:Polysaccharide|polysaccharide]] of high [[Physics:Viscosity|viscosity]] made up of units of the monosaccharide D-glucose. Oat beta-glucan is composed of mixed-linkage polysaccharides. This means the [[Chemistry:Chemical bond|bonds]] between the D-glucose or D-glucopyranosyl units are either beta-1,3 linkages or beta-1,4 linkages. This type of beta-glucan is also referred to as a mixed-linkage (1→3), (1→4)-beta-D-glucan. The (1→3)-linkages break up the uniform structure of the beta-D-glucan molecule and make it soluble and flexible. In comparison, the indigestible polysaccharide [[Chemistry:Cellulose|cellulose]] is also a beta-glucan, but is not soluble because of its (1→4)-beta-D-linkages.{{citation needed|date=December 2014}} The following are percentages of beta-glucan in the various whole oat products: oat bran, from 5.5 to 23.0%; rolled oats, about 4%; and whole oat flour about 4%.

===Protein===
Oats are the only cereal containing a [[Biology:Globulin|globulin]] or [[Biology:Legume|legume]]-like protein, avenalin, as the major (80%) storage protein.<ref>{{cite web|url=http://www.plantcell.org/cgi/reprint/7/7/945.pdf |archive-url=https://web.archive.org/web/20150924074020/http://www.plantcell.org/cgi/reprint/7/7/945.pdf |archive-date=2015-09-24 |url-status=live |title=Seed Storage Proteins: Structures 'and Biosynthesis |publisher= Plant Cell |access-date=2013-03-27}}</ref> Globulins are characterised by solubility in dilute saline as opposed to the more typical cereal proteins, such as gluten and [[Biology:Zein|zein]], the prolamines (prolamins). The minor protein of oat is a prolamine, avenin.

Oat protein is nearly equivalent in quality to [[Biology:Soy protein|soy protein]], which [[Organization:World Health Organization|World Health Organization]] research has shown to be equal to meat, milk and egg protein.<ref>{{cite book|last=Lasztity|first=Radomir|year=1999|title=The Chemistry of Cereal Proteins|publisher= Akademiai Kiado |isbn=978-0-8493-2763-6}}</ref> The protein content of the hull-less oat kernel (groat) ranges from 12 to 24%, the highest among cereals.

===Celiac disease===

[[Medicine:Coeliac disease|Celiac disease (coeliac disease)]] is a permanent [[Medicine:Autoimmune disease|autoimmune disease]] triggered by certain gluten proteins. It almost always occurs in genetically predisposed people, having a prevalence of about 1% in the [[Finance:Developed country|developed world]].<ref name=TovoliMasi/> The provocative gluten types are present in wheat, [[Biology:Barley|barley]], [[Biology:Rye|rye]], oat, and all their species and hybrids<ref name=Biesiekierski2017 /><ref name=TovoliMasi>{{cite journal | vauthors = Tovoli F, Masi C, Guidetti E, Negrini G, Paterini P, Bolondi L| title = Clinical and diagnostic aspects of gluten related disorders| journal = World Journal of Clinical Cases| volume = 3| issue = 3| pages = 275–84| date = Mar 16, 2015| pmid = 25789300|pmc= 4360499| doi = 10.12998/wjcc.v3.i3.275| doi-access = free}}</ref> and contains hundreds of proteins, with high contents of prolamins.<ref name=LamacchiaCamarca2014>{{cite journal|vauthors=Lamacchia C, Camarca A, Picascia S, Di Luccia A, Gianfrani C| title=Cereal-based gluten-free food: how to reconcile nutritional and technological properties of wheat proteins with safety for celiac disease patients|journal= Nutrients |volume=6| issue=2| pages=575–90| date=Jan 29, 2014| pmid=24481131|pmc= 3942718| doi=10.3390/nu6020575| doi-access=free}}</ref>

Oat prolamins, named avenins, are similar to gliadins found in wheat, hordeins in barley, and [[Biology:Secalin|secalin]]s in rye. These are all types of glutens which are commonly called "gluten" in lay speech.<ref name=Biesiekierski2017 /> Avenins' toxicity in celiac people depends on the oat [[Biology:Cultivar|cultivar]] consumed because of prolamin genes, protein amino acid sequences, and the immunoreactivities of toxic prolamins which vary among oat varieties.<ref name=cjgh/><ref name=CominoMoreno2015>{{cite journal | vauthors = Comino I, Moreno Mde L, Sousa C | title = Role of oats in celiac disease | journal = World Journal of Gastroenterology | volume = 21 | issue = 41 | pages = 11825–31 | date = Nov 7, 2015 | pmid = 26557006 |pmc= 4631980 | doi = 10.3748/wjg.v21.i41.11825 |quote= It is necessary to consider that oats include many varieties, containing various amino acid sequences and showing different immunoreactivities associated with toxic prolamins. As a result, several studies have shown that the immunogenicity of oats varies depending on the cultivar consumed. Thus, it is essential to thoroughly study the variety of oats used in a food ingredient before including it in a gluten-free diet. | doi-access = free }}</ref><ref name=PenaginiDilillo>{{cite journal | vauthors = Penagini F, Dilillo D, Meneghin F, Mameli C, Fabiano V, Zuccotti GV| title = Gluten-free diet in children: an approach to a nutritionally adequate and balanced diet | journal = Nutrients | volume = 5| issue = 11| pages = 4553–65| date = Nov 18, 2013| pmid = 24253052|pmc= 3847748| doi = 10.3390/nu5114553| doi-access = free }}</ref> Also, oat products are frequently cross-contaminated with other gluten-containing cereals during grain harvesting, transport, storage or processing.<ref name=CominoMoreno2015 /><ref name=PenaginiDilillo /><ref name=DeSouzaDeschenes2016>{{cite journal| vauthors=de Souza MC, Deschênes ME, Laurencelle S, Godet P, Roy CC, Djilali-Saiah I| title=Pure Oats as Part of the Canadian Gluten-Free Diet in Celiac Disease: The Need to Revisit the Issue | journal= Canadian Journal of Gastroenterology and Hepatology | year= 2016 | volume= 2016 | issue=  | pages= 1–8 | pmid=27446824 | doi=10.1155/2016/1576360 | pmc=4904650 | type= Review | doi-access=free }}</ref> Pure oats contain less than 20 [[Parts per million|parts per million]] of gluten from wheat, barley, rye, or any of their hybrids.<ref name=cjgh/><ref name=CominoMoreno2015 />

Use of pure oats in a gluten-free diet offers improved nutritional value from the rich content of oat protein, vitamins, minerals, fiber, and lipids,<ref name=CominoMoreno2015 /><ref name=PintoSanchezCausadaCalo2017>{{cite journal|pmid=28431885|year=2017|last1=Pinto-Sánchez|first1=M. I.|title=Safety of Adding Oats to a Gluten-free Diet for Patients with Celiac Disease: Systematic Review and Meta-analysis of Clinical and Observational Studies|journal=Gastroenterology|volume=153|issue=2|pages=395–409.e3|last2=Causada-Calo|first2=N|last3=Bercik|first3=P|last4=Ford|first4=A. C.|last5=Murray|first5=J. A.|last6=Armstrong|first6=D|last7=Semrad|first7=C|last8=Kupfer|first8=S. S.|last9=Alaedini|first9=A|last10=Moayyedi|first10=P|last11=Leffler|first11=D. A.|last12=Verdú|first12=E. F.|last13=Green|first13=P|doi=10.1053/j.gastro.2017.04.009|type= Systematic Review and Meta-analysis |url=http://eprints.whiterose.ac.uk/115341/1/FordSafety%20of%20Adding%20Oats.pdf |archive-url=https://web.archive.org/web/20171007031039/http://eprints.whiterose.ac.uk/115341/1/FordSafety%20of%20Adding%20Oats.pdf |archive-date=2017-10-07 |url-status=live}}</ref> but remains controversial because a small proportion of people with celiac disease react to pure oats.<ref name=cjgh/><ref name=CiacciCiclitira2015>{{cite journal|vauthors=Ciacci C, Ciclitira P, Hadjivassiliou M, Kaukinen K, Ludvigsson JF, McGough N, etal| title=The gluten-free diet and its current application in coeliac disease and dermatitis herpetiformis | journal=United European Gastroenterological Journal | year= 2015 | volume= 3 | issue= 2 | pages= 121–35 | pmid=25922672 | doi=10.1177/2050640614559263 | pmc=4406897 | type=Review}}</ref> Some cultivars of pure oat could be a safe part of a gluten-free diet, requiring knowledge of the oat variety used in food products for a gluten-free diet.<ref name=cjgh/><ref name=CominoMoreno2015 /> Determining whether oat consumption is safe is critical because people with poorly controlled celiac disease may develop multiple severe health complications, including [[Medicine:Cancer|cancer]]s.<ref name=HaboubiTaylor2006 />

Use of pure oat products is an option, with the assessment of a health professional,<ref name="cjgh" /> when the celiac person has been on a gluten-free diet for at least 6 months and all celiac symptoms have disappeared clinically.<ref name="cjgh" /><ref name=PulidoGillespie2009 /> Celiac disease may relapse in few cases with the consumption of pure oats.<ref name=RashidButzner2007>{{cite journal|vauthors=Rashid M, Butzner D, Burrows V, Zarkadas M, Case S, Molloy M, etal| title=Consumption of pure oats by individuals with celiac disease: a position statement by the Canadian Celiac Association | journal=Canadian Journal of Gastroenterology | year= 2007 | volume= 21 | issue= 10 | pages= 649–51 | pmid=17948135 | pmc=2658132 | type=Guideline | doi=10.1155/2007/340591 | doi-access=free }}</ref> Screening with [[Medicine:Coeliac disease#Blood tests|serum antibodies for celiac disease]] is not sensitive enough to detect people who react to pure oats and the absence of digestive symptoms is not an accurate indicator of intestinal recovery because up to 50% of people with active celiac disease have no digestive symptoms.<ref name=RashidButzner2007 /><ref name="MorenoRodríguezHerrera2017"> {{cite journal | vauthors=Moreno ML, Rodríguez-Herrera A, Sousa C, Comino I | title=Biomarkers to Monitor Gluten-Free Diet Compliance in Celiac Patients | journal=Nutrients | year= 2017 | volume= 9 | issue= 1 | pages=46 | pmid=28067823 | doi=10.3390/nu9010046 | pmc=5295090 | type= Review | doi-access=free }}</ref><ref name=Newnham2017>{{cite journal| author=Newnham ED| title=Coeliac disease in the 21st century: paradigm shifts in the modern age | journal=Journal of Gastroenterology Hepatology | year= 2017 | volume= 32 | issue=Suppl 1 | pages= 82–85 | pmid=28244672 | doi=10.1111/jgh.13704 | s2cid=46285202 | type= Review | quote= Intuitively, resolution of symptoms, normalization of histology, and normalization of coeliac antibodies should define response to treatment. But asymptomatic CD may occur in up to 50% of affected individuals,<sup>5</sup> symptoms correlate poorly with mucosal pathology,<sup>6</sup> and even with excellent dietary adherence, histology and coeliac antibodies can take several years to normalize.<sup>7</sup>| doi-access=free }}{{free access}}</ref> The lifelong follow-up of celiac people who choose to consume oats may require periodic performance of [[Medicine:Coeliac disease#Endoscopy|intestinal biopsies]].<ref name=HaboubiTaylor2006>{{cite journal|vauthors=Haboubi NY, Taylor S, Jones S|title=Coeliac disease and oats: a systematic review|journal=Postgraduate Medical Journal|volume=82|issue=972|pages=672–8|date=Oct 2006|pmid=17068278|pmc=2653911|doi=10.1136/pgmj.2006.045443|type=Review}}</ref> The long-term effects of pure oats consumption are still unclear<ref name=HaboubiTaylor2006 /><ref name=PulidoGillespie2009>{{Cite book|vauthors=Pulido OM, Gillespie Z, Zarkadas M, Dubois S, Vavasour E, Rashid M, etal| title=Introduction of oats in the diet of individuals with celiac disease: a systematic review | year= 2009 | volume= 57 | pages= 235–85 | pmid=19595389 | doi=10.1016/S1043-4526(09)57006-4 | type= Systematic Review| series=Advances in Food and Nutrition Research | isbn=978-0-12-374440-1 }}</ref> and further well-designed studies identifying the cultivars used are needed before making final recommendations for a gluten-free diet.<ref name=DeSouzaDeschenes2016 /><ref name=PintoSanchezCausadaCalo2017 />

==Agronomy==
[[File:2013 07 13 Avoine noire d'Epinal.JPG|thumb|left|''Noire d'Epinal'', an ancient variety]]
[[File:SK-OatAvena-sativa.JPG|thumb|upright=0.9|Oats in Saskatchewan near harvest time]]
Oats are sown in the spring or early summer in colder areas, as soon as the soil can be worked. An early start is crucial to good fields, as oats go dormant in summer heat. In warmer areas, oats are sown in late summer or early fall. Oats are cold-tolerant and are unaffected by late frosts or snow.

===Seeding rates===
Typically, about {{convert|125 to 175|kg/ha|abbr=off}} (between {{convert|2.75 and 3.25|USbsh|abbr=off}}) are sown, either [[Engineering:Broadcast spreader|broadcast]] or [[Biology:Seed drill|drilled]]. Lower rates are used when interseeding with a legume. Somewhat higher rates can be used on the best soils, or where there are problems with weeds. Excessive sowing rates lead to problems with lodging, and may reduce yields.

===Fertilizer requirements===
Oats remove substantial amounts of [[Chemistry:Nitrogen|nitrogen]] from the soil, at a rate of about 1 pound per bushel. They also remove phosphorus in the form of P<sub>2</sub>O<sub>5</sub>([[Chemistry:Phosphorus pentoxide|Phosphorus pentoxide]]) at the rate of {{convert|0.25|lb/USbsh}} pound per bushel ({{convert|1|USbsh}} = {{convert|38|lb}} at 12% moisture).{{Citation needed|date=December 2007}} Phosphate is thus applied at a rate of {{convert|30|to|40|kg/ha}}. Oats remove [[Chemistry:Potash|potash]] (K<sub>2</sub>O) at a rate of {{convert|0.19|lb/USbsh}}, which causes it to use {{convert|15|-|30|kg/ha}}. A sufficient amount of nitrogen, usually {{convert|50|-|100|kg/ha}} of nitrogen in the form of [[Chemistry:Urea|urea]] or [[Chemistry:Ammonia|anhydrous ammonia]], is particularly important for plant height, straw quality and yield. When the prior-year crop was a legume, or where ample manure is applied, nitrogen rates can be reduced somewhat.

===Weed control===
The vigorous growth of oats tends to choke out most weeds. A few tall broadleaf weeds, such as [[Biology:Ragweed|ragweed]], goosegrass, wild mustard, and buttonweed (velvetleaf), occasionally create a problem, as they complicate harvest and reduce yields. These can be controlled with a modest application of a broadleaf herbicide, such as 2,4-D, while the weeds are still small.

===Pests and diseases===
{{main|Biology:List of oat diseases}}
Oats are relatively free from diseases and pests. Nonetheless, it does suffer from some leaf diseases, such as Leaf Rust, Stem Rust (''Puccinia graminis'' f. sp. ''avenae''), and Crown Rust (''P. coronata'' var. ''avenae'').<ref name = "Alien-Transfer" >
 {{ Cite book
    | language    = en
    | year        = 2014
    | location    = New York, NY, US
    | publisher   = Springer Science+Business Media, LLC
    | pages       = xvii + 424
    | first2      = Jitendra
    | first1      = Aditya
    | last2       = Kumar
    | last1       = Pratap
    | volume      = 2 : Achievements and impacts
    | title       = Alien Gene Transfer in Crop Plants
    | id          = {{ISBN|978-1-4614-9572-7}}
    | doi         = 10.1007/978-1-4614-9572-7
    | isbn        = 978-1-4614-9571-0
    | s2cid = 26278759
 | lccn        = 2013957869
    | oclc        = 870451823
 }}
</ref>{{ RP|page=51}}. Crown rust infection can greatly reduce photosynthesis and overall physiological activities of oat leaves, thereby reducing growth and crop yield.<ref>{{Cite journal |last1=Nazareno |first1=Eric S. |last2=Li |first2=Feng |last3=Smith |first3=Madeleine |last4=Park |first4=Robert F. |last5=Kianian |first5=Shahryar F. |last6=Figueroa |first6=Melania |date=May 2018 |title=Puccinia coronata f. sp. avenae : a threat to global oat production|journal=Molecular Plant Pathology |language=en |volume=19 |issue=5 |pages=1047–1060 |doi=10.1111/mpp.12608 |pmc=6638059 |pmid=28846186}}</ref><ref>{{Cite web|url = http://www.ars.usda.gov/Main/docs.htm?docid=9919|title = Oat crown rust|date = 18 April 2008|access-date = 15 November 2015|website = Cereal Disease Laboratory|publisher = United States Department of Agriculture{{!}} Agricultural Research Service}}</ref> A few [[Biology:Caterpillar|caterpillar]]s of [[Biology:Lepidoptera|lepidoptera]] feed on the plants—e.g. rustic shoulder-knot and [[Biology:Setaceous Hebrew character|setaceous Hebrew character]] moths, but these rarely become a major pest.

===Harvesting===
[[File:Havreskjering Fossheim Lindahl.jpeg|thumb|Harvest in Jølster, Norway, ''ca.'' 1890 <br />''(Axel Lindahl/Norwegian Museum of Cultural History)'']]
Harvest techniques are a matter of available equipment, local tradition, and priorities. Farmers seeking the highest yield from their crops time their harvest so the kernels have reached 35% moisture, or when the greenest kernels are just turning cream-colour. They then harvest by [[Engineering:Swather|swathing]], cutting the plants at about {{convert|10|cm|in|abbr=on}} above ground, and putting the swathed plants into windrows with the grain all oriented the same way. They leave the windrows to dry in the sun for several days before combining them using a [[Engineering:Combine harvester#Combine header|pickup header]]. Finally, they bale the straw.

Oats can also be left standing until completely ripe and then [[Engineering:Combine harvester|combined]] with a grain head. This causes greater field losses as the grain falls from the heads, and to harvesting losses, as the grain is threshed out by the reel. Without a draper head, there is also more damage to the straw, since it is not properly oriented as it enters the combine's throat. Overall yield loss is 10–15% compared to proper swathing.

Historical harvest methods involved cutting with a scythe or sickle, and threshing under the feet of cattle. Late 19th- and early 20th-century harvesting was performed using a [[Engineering:Reaper-binder|binder]]. Oats were gathered into shocks, and then collected and run through a stationary [[Engineering:Threshing machine|threshing machine]].

===Storage===
After combining, the oats are transported to the farmyard using a grain truck, semi, or [[Engineering:Road train|road train]], where they are [[Engineering:Screw conveyor|auger]]ed or conveyed into a [[Engineering:Grain bin|bin]] for storage. Sometimes, when there is not enough bin space, they are augered into portable grain rings, or piled on the ground. Oats can be safely stored at 12-14% moisture; at higher moisture levels, they must be aerated or dried.

===Yield and quality===

[[File:Avena sativa 004.JPG|frameless|right|alt=Seeds]]

In the United States, No.1 oats weigh {{convert|36|lb/USbu|0}}; No.2 oats must weigh {{convert|33|lb/USbu}}. No.3 oats must weigh at least {{convert|30|lb/USbu|0|abbr=on}}. If {{convert|27|lb/USbu|0|abbr=on}}, they are graded as No.4, and oats under {{convert|27|lb/USbu|0|abbr=on}} are graded as "light weight".

In Canada, No.1 oats weigh {{convert|42.64|lb/USbu|0|abbr=on}}; No.2 oats must weigh {{convert|40.18|lb/USbu|0|abbr=on}}; No.3 oats must weigh at least {{convert|38.54|lb/USbu|0|abbr=on}} and if oats are lighter than {{convert|36.08|lb/USbu|0|abbr=on}} they do not make No.4 oats and have no grade.<ref>{{cite web|url=http://www.grainscanada.gc.ca/oggg-gocg/07/oggg-gocg-7e-eng.htm|title=Oats – Chapter 7 – Official Grain Grading Guide – 5 / 7 |publisher=Grainscanada.gc.ca |date=2012-07-27 |access-date=2013-03-27}}</ref>

Oats are bought and sold and yields on the basis of a bushel equal to {{convert|32|lb|1|disp=x| (}} or {{convert|32|lb/USbu|abbr=on|0|disp=output only}}) in the United States, and a bushel equal to {{convert|34|lb|1|disp=x| (}} or {{convert|34|lb/USbu|abbr=on|0|disp=output only}}) in Canada. "Bright oats" were sold on the basis of a bushel equal to {{convert|48|lb|1|disp=x| (}} or {{convert|48|lb/USbu|abbr=on|0|disp=output only}}) in the United States.

[[Earth:Crop yield|Yields]] range from {{convert|60|to(-)|80|USbu/acre}} on marginal land, to {{convert|100|to(-)|150|USbu/acre}} on high-producing land. The average production is {{convert|100|USbu/acre}}, or {{convert|3.5|MT/ha}}. Straw yields are variable, ranging from {{convert|1-3|MT/ha}}, mainly due to available nutrients and the variety used (some are short-strawed, meant specifically for straight combining).

=== Genome ===
''Avena sativa'' is an allohexaploid species with three ancestral genomes (2''n'' = 6''x'' = 42; AACCDD).<ref name="Mosaic"/><ref name="Use linkage map to compare Avena genomes">{{Cite journal|year=2022|issue=11|last1=Park|first1=R. F.|last2=Boshoff|first2=W. H. P.|last3=Cabral|first3=A. L.|last4=Chong|first4=J.|last5=Martinelli|first5=J. A.|last6=McMullen|first6=M. S.|last7=Fetch|first7=J. W. Mitchell|last8=Paczos-Grzęda|first8=E.|last9=Prats|first9=E.|last10=Roake|first10=J.|last11=Sowa|first11=S.|last12=Ziems|first12=L.|last13=Singh|first13=D.|pages=3709–3734|s2cid=249381794|doi=10.1007/s00122-022-04121-z|id=RFP {{ORCID|0000-0002-9145-5371}}|title=Breeding oat for resistance to the crown rust pathogen ''Puccinia coronata'' f. sp. ''avenae'': achievements and prospects|journal=Theoretical and Applied Genetics |volume=135 |pmid=35665827 |pmc=9729147 }}</ref><ref>{{cite journal|last1=Latta|first1=Robert G.|last2=Bekele|first2=Wubishet A.|last3=Wight|first3=Charlene P.|last4=Tinker|first4=Nicholas A.|title=Comparative linkage mapping of diploid, tetraploid, and hexaploid ''Avena'' species suggests extensive chromosome rearrangement in ancestral diploids|journal=Scientific Reports|date=23 August 2019|volume=9|issue=1|pages=12298|s2cid=201283146|id=CPW {{ORCID|0000-0003-1410-5631}}|doi=10.1038/s41598-019-48639-7|pmid=31444367|pmc=6707241|bibcode=2019NatSR...912298L}}</ref> As a result, the genome is large (12.6 Gb, 1C-value = 12.85) and complex.<ref name="Estimate Avena genome sizes">{{Cite book|year=2020|pages=133–169|title=Genomic Designing of Climate-Smart Cereal Crops|s2cid=211554462|doi=10.1007/978-3-319-93381-8 |isbn=978-3-319-93380-1 |editor-last1=Kole |editor-first1=Chittaranjan }}</ref><ref>{{Cite journal |last1=Yan |first1=Honghai |last2=Martin |first2=Sara L. |last3=Bekele |first3=Wubishet A. |last4=Latta |first4=Robert G. |last5=Diederichsen |first5=Axel |last6=Peng |first6=Yuanying |last7=Tinker |first7=Nicholas A. |date=2016-01-17 |title=Genome size variation in the genus ''Avena''|journal=Genome |volume=59 |issue=3 |pages=209–220 |language=en|s2cid=22267641|doi=10.1139/gen-2015-0132|pmid=26881940 |hdl=1807/71262 |hdl-access=free }}</ref> Cultivated hexaploid oat has a unique mosaic chromosome architecture that is the result of numerous translocations between the three subgenomes.<ref name="Mosaic">{{Cite journal |language=en|year=2022|publisher=BioMed Central|volume=18|issue=128|    first2=Harmeet|first1=Marina|first3=Curtis|last3=Pozniak|last2=Singh|last1=Marone|journal=Plant Methods|issn=1746-4811|s2cid=254152395|title=A technical guide to TRITEX, a computational pipeline for chromosome-scale sequence assembly of plant genomes|page=128|doi=10.1186/s13007-022-00964-1|pmid=36461065|pmc=9719158|doi-access=free}}</ref><ref>{{Cite journal|display-authors=3 |last1=Kamal |first1=Nadia |last2=Tsardakas Renhuldt |first2=Nikos |last3=Bentzer |first3=Johan |last4=Gundlach |first4=Heidrun |last5=Haberer |first5=Georg |last6=Juhász |first6=Angéla |last7=Lux |first7=Thomas |last8=Bose |first8=Utpal |last9=Tye-Din |first9=Jason A. |last10=Lang |first10=Daniel |last11=van Gessel |first11=Nico |last12=Reski |first12=Ralf |last13=Fu |first13=Yong-Bi |last14=Spégel |first14=Peter |last15=Ceplitis |first15=Alf |date=2022-06-01 |title=The mosaic oat genome gives insights into a uniquely healthy cereal crop |journal=Nature |language=en |volume=606 |issue=7912 |pages=113–119 |doi=10.1038/s41586-022-04732-y|s2cid=248890897|issn=1476-4687 |pmc=9159951 |pmid=35585233|bibcode=2022Natur.606..113K}}
</ref> These translocations may cause breeding barriers and incompatibilities when crossing varieties with different chromosomal architecture. Hence, oat breeding and the crossing of desired traits has been hampered by the lack of a reference genome assembly. In May 2022, a fully annotated reference genome sequence of ''Avena sativa'' was reported.<ref name="Mosaic" /> The AA subgenome is presumed to be derived from ''Avena longiglumis'' and the CCDD from the tetraploid ''Avena insularis''.<ref name="Mosaic"/>

=== Genetics and breeding ===
Species within Avena can hybridize and genes [[Biology:Introgression|introgressed]] from other "A" genome species has contributed with many valuable traits, like oat crown rust ([[Biology:Puccinia coronata f. sp. avenae|''Puccinia coronata'' f. sp. ''avenae'']]) resistance.<ref name="Identify putative genes for crown rust resistance">{{Cite journal|issue=1|year=2021|volume=14|pages=27–39|last1=Ye|first1=Chu-Yu|last2=Fan|first2=Longjiang|s2cid=229342158|doi=10.1016/j.molp.2020.12.013|title=Orphan Crops and their Wild Relatives in the Genomic Era|journal=Molecular Plant |pmid=33346062 |doi-access=free}}</ref><ref>{{Cite journal |last1=Maughan |first1=Peter J. |last2=Lee |first2=Rebekah |last3=Walstead |first3=Rachel |last4=Vickerstaff |first4=Robert J. |last5=Fogarty |first5=Melissa C. |last6=Brouwer |first6=Cory R. |last7=Reid |first7=Robert R. |last8=Jay |first8=Jeremy J. |last9=Bekele |first9=Wubishet A. |last10=Jackson |first10=Eric W. |last11=Tinker |first11=Nicholas A. |last12=Langdon |first12=Tim |last13=Schlueter |first13=Jessica A. |last14=Jellen |first14=Eric N.|display-authors=3 |title=Genomic insights from the first chromosome-scale assemblies of oat (''Avena'' spp.) diploid species |journal=BMC Biology |date=22 November 2019 |volume=17 |issue=1 |pages=92|s2cid=208225185|doi=10.1186/s12915-019-0712-y |pmid=31757219 |pmc=6874827 |doi-access=free }}</ref> {{ Visible anchor | Pc98 }} is one such trait, introgressed from ''A. sterilis'' CAV 1979, conferring all stage resistance (ASR) against ''Pca''.<ref name="Pca">{{cite journal | year = 2022 | publisher = Springer Science and Business Media LLC|display-authors=3 | first13 = D. | first12 = L. | first11 = S. | first10 = J. | first9 = E. | first8 = E. | first7 = J. | first6 = M. | first5 = J. | first4 = J. | first3 = A. | first2 = W. | first1 = R. | last13 = Singh | last7 = Fetch | last6 = McMullen | last5 = Martinelli | last4 = Chong | last3 = Cabral | last2 = Boshoff | last12 = Ziems | last11 = Sowa | last10 = Roake | last9 = Prats | last8 = Paczos | last1 = Park | journal = Theoretical and Applied Genetics | issn = 0040-5752 | doi = 10.1007/s00122-022-04121-z  | title = Breeding oat for resistance to the crown rust pathogen ''Puccinia coronata'' f. sp. ''avenae'': achievements and prospects| series = Breeding towards Agricultural Sustainability| volume = 135 | issue = 11 | pages = 3709–3734 | pmid = 35665827 | pmc = 9729147 | s2cid = 249381794 | doi-access = free }}</ref>

It is also possible to do introgression of traits in oats from very wide [[Biology:Hybrid#Taxonomy|intergeneric hybridization]]. In contrast to [[Biology:Wheat|wheat]], oats sometimes retain chromosomes from [[Biology:Maize|maize]] or [[Biology:Pearl millet|pearl millet]].<ref name="Create maize oat addition lines">{{Cite journal|year=2021|issue=13|volume=72|last1=Thondehaalmath|first1=Tejas|last2=Kulaar|first2=Dilsher Singh|last3=Bondada|first3=Ramesh|last4=Maruthachalam|first4=Ravi|s2cid=242417200|doi=10.1093/jxb/erab161|pages=4646–4662|title=Understanding and exploiting uniparental genome elimination in plants: insights from ''Arabidopsis thaliana''|journal=Journal of Experimental Botany |pmid=33851980 |id=RB {{ORCID|0000-0002-8869-1947}}. RM {{ORCID|0000-0003-0036-3330}}}}</ref><ref>{{Cite journal| issn = 0032-0889| volume = 125| issue = 3| pages = 1216–1227| last1 = Kynast| first1 = Ralf G| last2 = Riera-Lizarazu| first2 = Oscar| last3 = Vales| first3 = M Isabel| last4 = Okagaki| first4 = Ron J| last5 = Maquieira| first5 = Silvia B| last6 = Chen| first6 = Gang| last7 = Ananiev| first7 = Evgueni V| last8 = Odland| first8 = Wade E| last9 = Russell| first9 = Charles D| last10 = Stec| first10 = Adrian O| title = A complete set of maize individual chromosome additions to the oat genome| journal = Plant Physiology| date = 2001| doi = 10.1104/pp.125.3.1216|s2cid=22852580|pmid = 11244103| pmc = 65602}}</ref><ref>{{cite book | year=2017 | last1=Ishii | first1=Takayoshi | title=Oat | publisher=Springer New York | publication-place=New York | isbn=978-1-4939-6680-6 | issn=1064-3745 | pages=31–42 | s2cid=23707249 | doi=10.1007/978-1-4939-6682-0_3 | chapter=Wide Hybridization Between Oat and Pearl Millet| series=Methods in Molecular Biology | volume=1536 | pmid=28132141 }}</ref> These wide crosses are typically made in order to generate doubled haploid breeding material where the rapid loss of the alien chromosomes from the unrelated pollen donor results in a plant with only a single set of chromosomes (a [[Biology:Haploid|haploid]]).

The addition lines with alien chromosomes can be used as a source for novel traits in oats, for example, research on oat-maize-addition lines has been used to map genes involved in C4 photosynthesis. In order to obtain Mendelian inheritance of these novel traits, [[Biology:Radiation hybrid mapping|radiation hybrid]] lines have also been established, where maize chromosome segments have been introgressed into the oat genome. This technique {{endash}} which potentially transfer thousands of genes from a species that is distantly related {{endash}} is not considered a GMO technique, according to the European Union definition, since sexual hybridization and radiation-induced introgression are explicitly excluded from the definition.<ref>{{Cite journal| doi = 10.1002/jsfa.9227| issn = 0022-5142| volume = 99| issue = 1| pages = 8–12| last = Halford| first = Nigel G| title = Legislation governing genetically modified and genome‐edited crops in Europe: the need for change| journal = Journal of the Science of Food and Agriculture| date = 2019-01-15| pmid = 29952140| pmc = 6492171| bibcode = 2019JSFA...99....8H}}</ref>

A 2013 study applied simple sequence repeat and found five major groupings, commercial [[Biology:Cultivar|cultivar]]s and four [[Biology:Landrace|landrace]] groups.<ref name = "Diversity" >{{ Cite journal | issue = 3 | year = 2016 | publisher = Springer Science and Business Media LLC | volume = 64 | last1 = Riaz | first1 = Adnan | last2 = Hathorn | first2 = Adrian | last3 = Dinglasan | first3 = Eric | last4 = Ziems | first4 = Laura | last5 = Richard | first5 = Cecile | last6 = Singh | first6 = Dharmendra | last7 = Mitrofanova | first7 = Olga | last8 = Afanasenko | first8 = Olga | last9 = Aitken | first9 = Elizabeth | last10 = Godwin | first10 = Ian | last11 = Hickey | first11 = Lee|display-authors=3 | pages = 531–544 | doi = 10.1007/s10722-016-0380-5 | title = Into the vault of the Vavilov wheats: old diversity for new alleles | journal = Genetic Resources and Crop Evolution | s2cid = 254499298 | issn = 0925-9864 }}</ref><ref>{{ cite journal | issue = 6 | year = 2013 | publisher = Springer Science and Business Media LLC|display-authors=3 | last1 = Montilla-Bascón | first1 = G. | last2 = Sánchez-Martín | first2 = J. | last3 = Rispail | first3 = N. | last4 = Rubiales | first4 = D. | last5 = Mur | first5 = L. | last6 = Langdon | first6 = T. | last7 = Griffiths | first7 = I. | last8 = Howarth | first8 = C. | last9 = Prats | first9 = E. | title = Genetic Diversity and Population Structure Among Oat Cultivars and Landraces | journal = Plant Molecular Biology Reporter| volume = 31 | issn = 0735-9640 | eissn = 1572-9818 | doi = 10.1007/s11105-013-0598-8 | pages = 1305–1314 | hdl = 10261/95010 |s2cid=18581328| hdl-access = free }}
</ref>

==Processing==
[[File:Porridge oats.JPG|thumb|right|Porridge oats before cooking]]

===Cleaning and sizing===
Upon delivery to the milling plant, chaff, rocks, metal, oversized materials and foreign grains are removed from the oats. As different sized oats de-hull at differing velocities, once the raw oats have been removed of impurities, they are then separated by width and length into different classifications before de-hulling.

===Dehulling===
Centrifugal acceleration is used to separate the outer hull from the inner oat [[Biology:Groat (grain)|groat]]. Oats are fed by gravity onto the centre of a horizontally spinning impeller, which accelerates them towards an outer mill ring. Groats and hulls are separated on impact. The lighter oat hulls are then aspirated away, while the denser oat groats are taken to the next step of processing. Oat hulls can be used as feed or as a biomass fuel and are often used within the oat processing line to power solid fuel boilers for steam and power generation. Excess oat hulls are generally pelletised before being provided as feed.

===Kilning===
The unsized oat groats pass through a heat and moisture treatment to balance moisture for optimal storage conditions and to deactivate self catalysing enzyme activity. Oat groats are high in fat (lipids) and once removed from their protective hulls and exposed to air, enzymatic ([[Biology:Lipase|lipase]]) activity begins to break down the fat into free fatty acids, ultimately causing an off-flavour or rancidity. Depending on temperature, humidity and moisture content, de-hulled oats can begin to show signs of enzymatic rancidity rapidly if not stabilized. This process is primarily done in food-grade plants, not in feed-grade plants. Groats are not considered raw if they have gone through this process; the heat disrupts the germ and they cannot sprout.

===Sizing of groats===
Some whole oat groats break during the de-hulling process so additional processing of the groats is required. Groats are sized again and separated by length and width using shaker screens and indent cylinders until uniform product streams are generated. Modern oat milling technologies also sort impurities by colour with colour sorting machines or more traditionally, on specific gravity with paddy tables or gravity table separators. A final grade of whole oat groats should have minimal oat hulls, other seeds or broken groats.

When the whole oat groats are to be flaked for use in porridge, the whole groats are passed through a groat cutter machine to create uniform pieces of cut groats for quick or instant style porridge whereas traditional style porridge is flaked from whole groats.

The small percentage of broken groats generated throughout the de-hulling process are also utilised in various other products or even in flaking for porridge.

===Final processing===
Three methods are used to make the finished product:

====Flaking====
This process uses two smooth cylinders rotating at a controlled distance, before which the cut groats are conditioned and then passed through the cylinders for flaking. Conditioning of the groats for flaking ensures production of stable and consistent flakes with minimal crumbling and is done by adding moisture and heat to the groats with sufficient retention time prior to flaking.
Oat flake thickness is a key control point dependant of the type of oat flakes to be produced which typically range from around half a millimetre for quick or instant style porridge and up to around 1mm for traditional style porridge.
After flaking, the oats are then dried to a sufficient moisture for storage and transport.

====Oat bran milling====
This process takes the oat groats through several roll stands to flatten and separate the bran from the flour (endosperm). The two separate products (flour and bran) get sifted through a gyrating sifter screen to further separate them. The final products are oat bran and debranned oat flour.

====Whole flour milling====
This process takes oat groats straight to a grinding unit (stone or hammer mill) and then over sifter screens to separate the coarse flour and final whole oat flour. The coarser flour is sent back to the grinding unit until it is ground fine enough to be whole oat flour.{{cn|date=September 2023}}

====Preparation at home====
Oat flour can be ground for small scale use by pulsing [[Biology:Rolled oats|rolled oats]] or old-fashioned (not quick) oats in a [[Engineering:Food processor|food processor]] or spice mill.<ref>The Sparkpeople cookbook: love your food, lose the weight, Galvin, M., Romnie, S., May House Inc, 2011, {{ISBN|978-1-4019-3132-2}}, page 98.</ref>

==Oats futures==
[[File:Oats Futures Prices.webp|frameless|right|300px|alt=[[Finance:Futures exchange|Futures prices]]]]
Oats [[Finance:Futures exchange|futures]] are traded on the [[Organization:Chicago Board of Trade|Chicago Board of Trade]] and have delivery dates in March (H), May (K), July (N), September (U) and December (Z).{{CN|date=September 2023}}

==See also==

===Oat products and derivatives===
{{div col|colwidth=10em}}
* Export hay
* [[Biology:Muesli|Muesli]]
* [[Biology:Oat bread|Oat bread]]
* [[Biology:Oat milk|Oat milk]]
* [[Biology:Oatcake|Oatcake]]
* [[Biology:Oatmeal|Oatmeal]]
* Parkin (cake)
* [[Biology:Porridge|Porridge]]
* [[Biology:Rolled oats|Rolled oats]]
* [[Biology:Steel-cut oats|Steel-cut oats]]
{{div col end}}

==References==
{{Reflist}}

{{Taxonbar|from=Q12104}}

{{Bioenergy}}

[[Category:Oats| ]]
[[Category:Avena]]
[[Category:Cereals]]
[[Category:Demulcents]]
[[Category:Medicinal plants]]

{{Sourceattribution|Oat}}