THE EFFECT OF SLAFRAMINE ON SALIVARY OUTPUT AND SUBACUTE AND ACUTE ACIDOSIS IN GROWING BEEF STEERS

Experiments were conducted to determine 1) the effect of injecting sla framine (SF) on salivary output in growing beef steers and 2) whether increased salivary output after SF injection would inhibit the decreas e in ruminal pH that occurs after experimentally induced subacute and acute ruminal acidosis. In Exp. 1 and 2, we measured ruminal pH and sa livary output in ruminally and esophageally cannulated beef steers fed an 88% concentrate diet. Injections of 66 or 100 mu g of SF/kg BW inc reased salivary flow approximately 50% compared with controls. Those d oses were tested in subacute and acute acidosis models using ruminally cannulated beef steers in Exp. 3 and 4, respectively. In these experi ments, salivation was assessed indirectly using a visual scoring syste m. In the subacute acidosis model, SF reduced (P < .10) the decrease i n ruminal pH (1.1, .7, and .6 pH units for control, 66, and 100 mu g o f SF/kg BW doses, respectively), and excessive salivation was observed in all SE-injected steers. In the acute acidosis model, there were no differences (P > .10) in ruminal pH at 12 h after injection between c ontrol and SE-treated steers. Mean ruminal lactate concentrations for all treatment groups were between 87 and 112 mM. Although treatment wi th 66 mu g of SF/kg BW reduced (P < .10) ruminal lactate concentration s, all ruminal lactate concentrations were indicative of acute acidosi s. These results indicate that SF will reduce the decrease in ruminal pH associated with subacute acidosis in growing beef steers, but SF do es not attenuate acute ruminal acidosis.