A survey of nutritive value, fermentability and digestibility of different genotypes of quinoa straw

Quinoa (Chenopodium quinoa willd.) is an annual plant considered as pseudocereals and belongs to the chenopodiaceae family. Quinoa has excellent properties as low water demand, resistant to drought, salinity and nutritional quality, which are the reason for the great interest in IRAN. The objective of this study was to determine nutritive value, fermentabiliy and digestibility of 10 genotypes of quinoa crop residues (Titicaca, Red Carina, Gizal, Q12, Q18, Q21, Q22, Q26, Q29 and Q31) in a completely randomized design. In the hardening stage of quinoa seeds, complete quinoa plants were harvested, were dried and then the seeds were separated. The quinoa straw samples were used for determine of chemical composition and fermentabiliy parameters via gas test production method. The concentration of chemical composition were different between different genotypes of quinoa straw. The range of variations were for dry matter between 92.44 to 94.29%, crude protein 3.53 to 11.0%, organic matter 84.25 to 89.65%, ether extract 1.20 to 2.30%, crude ash 9.90 to 15.59%, neutral detergent fiber 57.60 to 72.40%, acid detergent fiber 35.60 to 43.20% and nitrogen-free extract 9.41 to 18.09% and these difference between genotypes were significant (P<0.01), except of DM. The 24h gas production, potential of gas production (b), rate of gas production (c) were different between straw quinoa genotypes (P<0.01). The gas production in Red Carina, Q18, Q26 and Q29 genotypes were higher than other genotypes and (b) parameter in Gizal, Q18, Q26 and Q31 genotypes were higher than other genotypes (P<0.01). Furthermore, the digestibility of organic matter and metabolisable energy in different genotypes had range between 33.30 to 39.39% and 4.88 to 5.97 J/g, respectively (P<0.01). In general, the results have shown that the concentration of CP in Red Carina, Q12, Q18, Q21, Q22, Q26 and Q29 quinoa straw is higher than cereal straw and other agricultural residues and can be used as a new protein feedstuff for provide nutritive requirement of ruminants, especially ewes.