Effects of Alcoholic Feeds on In vitro Ruminal pH, Ammonia, Alcohol and Volatile Fatty Acids Concentrations

摘要

In this study, changes of ammonia, alcohol and volatile fatty acid(VFA) concentrations or pH in in vitro ruminal fluid were studied to determine the effects of alcoholic feeds on in vitro ruminal fermentation characteristics. To formulate the alcoholic feeds, alcohol was added to commercial formulated feed at the levels of 1, 3, and 5 %. Experiments were done with four treatment groups, control(commercial feed), AF-1 (commercial feed + 1% alcohol), AF-3(commercial feed + 3% alcohol), and AF-5(commercial feed + 5% alcohol). Ammonia concentrations of AF-1 and AF-5 were significantly lower than that of control for the 12h incubation(p<0.05). Ruminal alcohol concentration was increased with the addition level of alcohol increased(p<0.05). TVFA concentrations of AF-1, AF-3 and AF-5 were significantly higher than those of control at 12h(p<0.05). Significant decrease of molar percentage of acetate was observed in control from 8 to 12h incubation, but molar percentage of acetate for AF-1, AF-3 and AF-5 wasconstant. Molar percentage of propionate was increased in control compared with AF-1, AF-3 and AF-5 from 8 to 12h incubation(p<0.05). Molar percentages of butyrate and valerate were higher in AF-1, AF-3 and AF-5 than in control(p<0.05). Molar percentageof caproate for AF-1, AF-3 and AF-5 was 0.05, 0.58 and 0.47M% at 8h, respectively, but that was not detected for control. Present results may indicate that the alcoholic feeds show positive effects on in vitro ruminal ammonia, alcohol and VFA concentrations or pH. Furthermore, the results of this study implies that the addition level of 5% could be more effective to ruminal fermentation than other addition levels.