The Oxidation-Reduction Potential of Rumen Contents

Summary The relationship between the E h and pH of rumen fluid was found to be represented by the equation E h = E o – 0.06 pH. Investigation of the reductive capacity of rumen fluid removed from cows on various rations indicated: 1.A very small proportion of the reduced substances found in rumen fluid is associated with the bacterial cells. 2.The amount of reducing substances is significantly higher several hours after feeding than at other times during the day. 3.There is a definite relationship between the ration fed and the reducing capacity of rumen fluid removed at different times during a 24-hr. period. This relationship is in agreement with the fact that concentrates are digested more quickly than roughages. On the basis of the above observations, it is proposed that the reductive characteristics of rumen fluid can be used as an index of fermentation rate in much the same manner as pH is presently used.