Pasture has a pH of 7, which is neutral. However, starch digestion from low fibre grain results in acid build up, thus lowering rumen pH. To maintain healthy rumen the diet of a dairy cow requires adequate amounts of physically effective fibre. Physically effective fibre is obtained from feed such as hay, silage and other forages. Farmers must be cautious when adding silage to the diet as it has a naturally lower pH of due to the fermentation process. As a result many feed rations may be inadvertently lowering rumen pH.
