ena-STUDY-IBERS-22-05-2014-18:37:11:145-304
The rumen microbial network is key to understanding how the mode of action of yeast and bicarbonate differs.
The rumen microbiota plays an essential role in maintaining an optimal fermentation pattern to satisfy the energy and protein requirement of the host. In this study, the effect of 2 additives (live yeast: YD and sodium bicarbonate: SBD) on the rumen microbial network structure was investigated in dairy cattle fed highly fermentable diets. Both YD and SBD were able to restore rumen fermentation, probably mediated through a stabilisation of the pH, however there seemed to be differences in the way this was actually achieved. Lactate concentration decreased and higher NDF digestibility was recorded with YD compared to either SBD or control. These changes were associated with different shifts in the bacterial population: higher bacterial richness in the solid fraction, decrease in Ruminobacter and increase in Megasphaera with YD, increase in Fibrobacter and Ruminococcus and decrease in Prevotella with both YD and SBD. Bacterial network and canonical correspondence analysis revealed the presence of 2 major bacterial consortiums (mutualistic groups composed of 6 and 4 genera respectively) negatively correlated with each other and having an opposite effects on VFA and acetate production. The use of network and interaction plots has shed new light on the mode of action, of apparently similar additives, on the rumen microbiota.
The rumen microbiota plays an essential role in maintaining an optimal fermentation pattern to satisfy the energy and protein requirement of the host. In this study, the effect of 2 additives (live yeast: YD and sodium bicarbonate: SBD) on the rumen microbial network structure was investigated in dairy cattle fed highly fermentable diets. Both YD and SBD were able to restore rumen fermentation, probably mediated through a stabilisation of the pH, however there seemed to be differences in the way this was actually achieved. Lactate concentration decreased and higher NDF digestibility was recorded with YD compared to either SBD or control. These changes were associated with different shifts in the bacterial population: higher bacterial richness in the solid fraction, decrease in Ruminobacter and increase in Megasphaera with YD, increase in Fibrobacter and Ruminococcus and decrease in Prevotella with both YD and SBD. Bacterial network and canonical correspondence analysis revealed the presence of 2 major bacterial consortiums (mutualistic groups composed of 6 and 4 genera respectively) negatively correlated with each other and having an opposite effects on VFA and acetate production. The use of network and interaction plots has shed new light on the mode of action, of apparently similar additives, on the rumen microbiota.