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<.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<.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.
