Comparing nutritive values of modified and native barley varieties using gas production technique

In order to study the nutritive value of 8 cultivars of barley including four landrace cultivars (Khaton-Sarab, Gara-arpa, Goy-arpa and Ghavanjik) and four modified cultivars (Makui, CB-74-12, Valfajer, and M-82-12)], were cultivated in four experimental plots. After harvesting, samples of barley grains were ground to pass through a 1 mm sieve, and then were used for chemical analysis. An in vitro gas production technique was used to determine the nutritive value and partitioning factor (ratio of substrate truly degraded to gas volume produced at 24 h of incubation). The contents of the syringes were strained and the pH and NH3-N of the medium was determined immediately. Average crude protein, ash, acid detergent fiber (ADF), ether extract (EE) and natural detergent fiber (NDF) concentrations of the barley samples investigated was on average of 104.3, 28.5, 69.7, 34.3 and 254.5 g/kg, respectively; while the difference was significant (P<0.05) among the cultivars. Gara-arpa and Khaton-Sarab showed the highest ash and crude protein, respectively. Organic matter digestibility of landrace and improved cultivars ranged from 76.1 to 82.1 and 79.1 to 82.7 percent respectively. Their partitioning factor ranged from 2.18 to 2.6 and 2.32 to 2.63 respectively. The amount of NH3-N of landrace and improved cultivars were 6.55 to 7 and 6.15 to 7.07 mg/30ml. Among of landrace cultivars, Ghavanjik and Khaton-Sarab showed the highest organic matter digestibility and partitioning factor respectively, among of improved cultivars Valfajer and M-82-12 had the highest organic matter digestibility and partitioning factor respectively. In conclusion, although there were significant differences between native and modified cultivars with regard to organic matter digestibility and metabolisable energy, but some of native cultivars are comparable with the modified ones.