THE EFFECTS OF FUMARIC ACID AND MALIC ACID ON THE IN VITRO TRUE DIGESTIBILITY AND OTHER FERMENTATION PARAMETERS OF ALFALFA HAY IN COWS' RUMEN FLUID

The aim of this study was to investigate the effects of different concentrations of fumaric acid (FA) and malic acid (MA) on the in vitro true digestibility and fermentation of alfalfa hay in cows' rumen fluid. The acids were added separately to individual fermenters at 0.1% FA, 0.2% FA and 0.3% FA; and 0.1% MA, 0.2% MA and 0.3% MA. Each treatment was replicated 16 times, and the incubation period was 48 hours. The mean in vitro true digestibility values in the 0.1% FA and 0.2% FA groups did not differ significantly from the control treatment (P > 0.05) but at the 0.3% level it was significantly lower (P < 0.05) for both. For MA, there was no significant difference (P > 0.05) between the control and the 0.1% MA group, whereas there was a significant difference (P < 0.05) between the control, and the 0.2% MA and 0.3% MA treatments. The lowest in vitro true organic digestibility levels were determined for the 0.3% FA and 0.2% and 0.3 MA groups which were significantly lower than the control (P< 0.05). The use of FA and MA at 0.1% did not positively or negatively affect the in vitro true digestibility (IVTD) and neutral detergent fiber digestibility (IVNDFD) of alfalfa hay. However, further studies are required to investigate the effects of FA and MA on in vivo ruminal fermentation with respect to feed consumption and performance in ruminants.