Dr. Jacquie Jacob Ph.D., University of Kentucky
NOTE: Before using any feed ingredient, make sure that the ingredient is listed in your Organic System Plan and approved by your certifier.
Quinoa (pronounced ki-nwa) originated in South America where it is grown in the mountains. It is a pseudo-cereal grown for its edible seeds. As it is not a member of the grass family (therefore not a cereal), quinoa is more closely related to species such as beets and spinach.
Quinoa has an extensive root system, with many branches coming off a central tap root (Schlick and Bubenheim, 1993). As a result of this extensive root system, which may reach up to 30 cm from the main plant, quinoa has the potential to produce high yields under adverse conditions. It is drought- and frost-resistant, and is frequently grown on poor soils in South America.
While most quinoa is produced in South America, it is also grown in the United States (Colorado and California), China, Europe, Canada and India (James, 2009). Quinoa has been used in a crop rotation with potatoes. Such a rotation improves quinoa yield and preserves soil fertility. It also breaks the life cycle of several pathogenic microorganisms (Jancurová et al., 2009).
Quinoa has a number of antinutritional factors. Its seeds have a coating of bitter-tasting saponins. The bitterness is a benefit during production because it reduces the need for bird protection, but renders it unpalatable in poultry diets. Saponins are in the outer layers of the seed hull and can be removed by washing. Saponin content in quinoa varies considerably (0.14–0.73%). Quinoa also contains heat-labile trypsin inhibitors and tannins, but in low levels (Jancurová et al., 2009). The level of trypsin inhibitors in quinoa seed is variable but typically lower than in soybeans. The tannin levels are sufficiently low as to not be a factor in the use of quinoa in poultry diets.
As with cereals, the main component of quinoa seeds is starch, which is the main source of dietary energy for animals. The average starch content of quinoa seeds is 60%. The two main classes of cereal starches are amylose and amylopectin. The digestibility of starch in a grain depends on the type of starch present—amylopectin is easier to digest than amylose. Quinoa starch contains 3-20% amylose (James, 2009), which is similar to some rice varieties and higher than some barley varieties.
Compared to other cereals, quinoa is higher in protein (12–23%) (James, 2009). Quinoa protein has an excellent amino acid profile (Abugoch, 2008). Quinoa is high in both lysine (5.1–6.4%) and methionine (0.1–1%), making it complementary to other grains as well as to legumes. Quinoa protein is said to be comparable to that of casein, a protein in milk (Ranhotra et al., 1993). Quinoa also has higher levels of energy, calcium, phosphorus, iron, vitamin E and the B vitamins than corn, barley, wheat and oats (Vilche et al., 2003; James, 2009).
Quinoa seeds are higher in oil than corn, but not as high as soybeans. Lipid content can vary from 1.8% to 9.5%, depending on the variety and growing conditions (James, 2009). The fatty acid profile of quinoa seeds is similar to that of corn. Vitamin E can act as a natural antioxidant against lipid oxidation. Quinoa oil contains relatively high levels of vitamin E (0.59–2.6 mg/100 g) (James, 2009).
Including whole raw quinoa seeds in a broiler diet at 10–40% of the diet resulted in a linear depression in the growth of the chickens (Jacobsen et al., 1997). Removing the hull only improved body weight slightly, indicating that most of the growth depression observed was caused by something other than the saponins in the hull. The use of unprocessed quinoa seed should be limited to 15% of the diet (Jacobsen et al., 1997).
More research is needed on the most economical way of processing quinoa so that it can successfully be used in poultry diets.
This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.