Effect of feeding frequency on fermentation pattern and microbial activity in the bovine rumen.

The influence of the feeding frequency on the fermentation in the bovine rumen was investigated by a single reversal trial with restricted supply of feed. The study comprised 6 rumen-fistulated dairy heifers fed a complete diet, low in crude fibre, at 2 frequencies. The effect of the treatment was assessed by the parameters: Concentration of microbial metabolites, total counts of microorganism, concentration of adenosine triphosphate (ATP), and fermentative activity in the rumen. Frequent feeding compared to feeding twice daily resulted in marked reduction of the diurnal variation in the concentration of ruminai metabolites without significant influence on the daily means of total VFA and pH, but the molar composition of the VFA mixture and the production rate of VFA were highly affected. The implications of these observations for improved feed utilization to milk production and fattening are discussed. Pronounced increment of the concentration of ATP was found by frequent feeding, but the total counts of microorganisms were found almost unaffected. Since the rate of fermentation was highly correlated with the concentration of ATP, the ATP pool may be an indicator of the fermentative activity of rumen microorganisms.