1708
Could lactic acid treatment decrease in-vitro gas production of barley grain
The aim of present study was evaluation the effects of treatment barley grain with lactic acid on gas production characteristics. Rolled barley steeped in an equal quantity (wt/vol) of tap water containing 2.5, 5 and 7.5 mL lactic acid (LA) per liter for 24 h. Treated barley were dried and was ground through a 1-mm screen. Then 300 mg of ground barley pre-loaded into 125-ml serum vials. Ruminal fluid was collected from three fistulated Holstein cows. Cow’s ruminal fluid mixed in equal quantity and mixed Menke and sreingass, 1988 buffer solution. Inoculums was dispensed anaerobically (40 ml/vial) under a steam of 02-free with co2, followed immediately by sealing and affixing to incubator at 39 0c. Triplicate vials containing no substrate were also prepared as blank controls. Gas produced was measured at 2, 4, 6, 8, 10, 12, 24 and 48 h of incubation. Cumulative gas production data were fitted to a model of Y=b (1-e-ct); Y= potential of gas production at time t; b= the asymptotic gas volume (ml); c= gas production constant rate (ml/h); t= incubation time (h). Data analyzed by GLM procedure of SAS (2003). According to the result of this study steeping barley in water containing 7.5 gr LA for 24 h decreased gas volume in the early time of incubation and gas production constant rate in comparison to dry rolled barely. On the other hands, it showed that treated barley grain with 7.5 gr LA decreased barely grain digestibility until 6 h of incubation and may be decrease acidosis in ruminant.
Keywords: rolled barley, lactic acid and steeping