Effect of alfalfa fiber substrate on culture counts of rumen bacteria.

A medium has been developed using alfalfa fiber as the sole substrate. It gave high culture counts (3 X 10(9) to 8 X 10(9)/ml) of rumen bacteria. When this medium was combined with the medium 98-5 of Bryant and Robinson, modified to contain 33% rumen fluid instead of 40% clarified rumen fluid, a higher count was obtained than with either medium alone.