The effect of sodium bicarbonate level on rumen metabolism in steers with induced subacute acidosis

Sodium bicarbonate at 1 or 2% of dry matter intake was evaluated as a means of alleviating subacute acidosis, using six fistulated Holstein steers in a controlled acidosis challenge model. Steers were feed challenged by withholding an evening feeding and then feeding 2.5% of BW for two consecutive mornings. Postchallenge rumen pH for control steers (no sodium bicarbonate) was lower (P\u3c.05) than for steers fed either 1% or 2% sodium bicarbonate, which were similar to each other. Hours below pH 5.6 were less (P\u3c.01) postchallenge for steers fed sodium bicarbonate and w ere similar between the 1 and 2% levels. Although sodium bicarbonate reduced ruminal pH hours below 5.6, it did not appear to alter concentrations of volatile fatty acids or lactate in acidotic steers. Sodium bicarbonate appears to be beneficial in managing subacute acidosis in situations where wide intake fluctuations are common or expected