摘要：Effects of three alkaline treatments: NaOH, NaHCO3 and wood ash on the crude protein (CP), condensed tannin (CT), neutral detergent fiber (NDF), in vitro gas production kinetics and dry matter (DM) digestibility of sorghum grain were determined. The NaOH (2% w/v), NaHCO3 (2% w/v) and wood ash (5% w/v) treatments were completed by soaking of sorghum grain with treatment solutions in the proportion of 1 L of solution to 1 kg of grain for 12 h. Gas production was measured at 2, 4, 6, 8, 12, 16, 24, 36, 48, 72 and 96 h post incubation. Alkaline treatment decreased significantly the CT (P<0.001) and NDF content (P<0.05) of sorghum grain, where it had no effect on the CP content. Treated grain with wood ash extract showed the highest (P<0.05) maximum gas production (A), and NaOH treatment trended (P<0.06) to the fastest fractional fermentation rate. Fractional rate of gas production and cumulative gas production overall incubation times except of 48 h (P<0.05) were not changed by NaHCO3 and wood ash treatment. Maximum (P<0.01) in vitro DM digestibility of alkaline treatment of sorghum grain was observed by NaOH. Cumulative volatile fatty acids concentration was increased (P<0.01) at 4h for NaOH treated compared to untreated sorghum and then decreased (P<0.001) at 48 h post incubation. Alkaline treatment of sorghum grain may become attractive due to raise in nutritive values of sorghum and hide the negative effects of its tannin in the future if the costs of other processing continue to rise
关键词：in vitro dry matter digestibility; in vitro gas production; sorghum grain; sodium hydroxide; sodium bicarbonate; wood ash
