Oats appear to have been domesticated as a secondary crop, as their seeds resembled those of other cereals closely enough for them to be included by early cultivators.

Oats grow thickly and vigorously, allowing them to outcompete many weeds, and compared to other cereals are relatively free from diseases.

Oats are a nutrient-rich food associated with lower blood cholesterol and reduced risk of human heart disease when consumed regularly.

One of the most common uses of oats is as livestock feed; the crop can also be grown as groundcover and ploughed in as a green manure.

Phylogenetic analysis using molecular DNA and morphological evidence places the oat genus Avena in the Pooideae subfamily.

That subfamily includes the cereals wheat, barley, and rye; they are in the Triticeae tribe, while Avena is in the Poeae, along with grasses such as Briza and Agrostis.

They survived as a Vavilovian mimic by having grains that Neolithic people found hard to distinguish from the primary crop.

A granary from the Pre-Pottery Neolithic, about 11,400 to 11,200 years ago in the Jordan Valley in the Middle East contained a large number of wild oat grains (120,000 seeds of A. sterilis).

[3][5][6] The oat is a tall stout grass, a member of the family Poaceae; it can grow to a height of 1.8 metres (5.9 ft).

[11] Traditionally, US farmers grew oats alongside red clover and alfalfa, which fixed nitrogen and provided animal forage.

Heating denatures enzymes in the seed that would make it go sour or rancid; the grain is then dried to minimise the risk of spoilage by bacteria and fungi.

[18] In 2022, global production of oats was 26 million tonnes, led by Canada with 20% of the total and Russia with 17% (table).

[25][26] Cultivated hexaploid oat has a unique mosaic chromosome architecture that is the result of numerous translocations between the three subgenomes.

[30] It is possible to hybridize oats with grasses in other genera, allowing plant breeders the ready introgression of traits.

To obtain Mendelian inheritance of these novel traits, radiation hybrid lines have been established, where maize chromosome segments have been introgressed into the oat genome.

[35][36] Uncooked oats are 66% carbohydrates, including 11% dietary fiber and 4% beta-glucans, 7% fat, 17% protein, and 8% water (table).

Regular consumption of oat products lowers blood levels of low-density lipoprotein and total cholesterol,[40] reducing the risk of cardiovascular disease.

[48][49] Oats are commonly used as feed for horses when extra carbohydrates and the subsequent boost in energy are required.

Oat forage is commonly used to feed all kinds of ruminants, as pasture, straw, hay or silage.

[51] Winter oats may be grown as an off-season groundcover and ploughed under in the spring as a green fertilizer, or harvested in early summer.

[57][66] In his 1755 Dictionary of the English Language, Samuel Johnson defined oats as "A grain, which in England is generally given to horses, but in Scotland supports the people.

"[67] "Oats and Beans and Barley Grow" is the first line of a traditional folksong (1380 in the Roud Folk Song Index), recorded in different forms from 1870.