Evaluation of acute ruminal lactic acidosis treatment by hypertonic saline solution (HSS) infusion in adult bovine

Abstract

With the increase of intensive cattle production in Brazil, a higher number of metabolic diseases occur, specially the rumen acute lactic acidosis (ALRA). The present study aims to evaluate the efficiency of treatment with hypertonic saline solution (SSH) in the correction of clinical sings (reversion of dehydration and systemic acidosis) and renal function. There will be used twelve rumen-cannulated steers, those who will be induced experimentally to ALRA through the administration of sucrose into the rumen, according to the corrected metabolic weight (ORTOLANI, 1995). The experiment consists in two groups randomly divided with 6 animals in each one. On treatment A, we remove 5 litters of rumen fluid through the ruminal cannula and replace the same volume with water. The animals will receive, in sequence, 5 mL/kg of body weight (B.W.) of isotonic saline solution (NaCl 0.9%) in ten minutes, sodium bicarbonate (1.3%) in thirty minutes and 20 mL/ kg of B.W. of isotonic saline solution in three hours. On the treatment B, will be execute the same procedures of treatment A, except the initial infusion, which will be with hypertonic saline solution (7.2% de NaCl 2.400 mOsm/L). Will be evaluated clinical; ruminal (pH, total lactic acid, L and D lactic acid and osmorality); and blood (pH, pCO2, bicarbonate, ABE, hematocrit, hemoglobin, osmolaridade, urea, creatinine, ammonia e phosphorous, total and L lactate) variables on zero hours, eight hours, fifteen hours and twenty hours after the induction and 30’, 60’, 90’, 120’, 180’ and 24 hours after the beginning of the treatments. The global urine will be collected during the experiment with punctual samples collected in the moments cited above, and analyzed for pH, osmorality, urea, creatinine, phosphorus and ammonium. There will be calculated the difference between ruminal and blood osmorality, the changes in the relative plasmatic volume, the glomerular filtration rate and the substance fractional excretion levels (EFx).