2014 Volume 67 Issue 11 Pages 844-849
To investigate changes in the ruminal fluid components in cattle after accessing a salt lick containing sodium bicarbonate, we measured the ruminal pH and volatile fatty acid (VFA) concentrations in two groups of cattle. Four rumen-cannulated Holstein steers (five months old) were divided into two groups. The licking group (LG) was freely fed a block-type agent containing 50% sodium bicarbonate and 40% salt, whereas the oral administration group (OG) had sodium bicarbonate powder administered orally after feeding. The ruminal pH was measured continuously every ten minutes using a wireless radio transmission pH sensor. Ruminal fluid and blood were collected prior to the experiment and on day 14. The 24-hour mean ruminal pH of the LG was significantly higher (P<0.05) than that of the OG on day 0 to day 3. Circadian changes in the ruminal pH in the LG tended to be stable, and the ruminal pH was slightly high after feeding in the morning and evening compared with the values in the OG. The ruminal VFA concentration and serum components did not differ significantly between the two groups. The results of the present study demonstrate that licking the block-type agent reduced the ruminal pH of SARA-affected steers more effectively than the oral administration of the same amount of sodium bicarbonate powder.