Enteral fluid therapy administered in continuous flow by naso-ruminal route using three maintenance electrolyte solutions: Effects on physiological biomarkers and the hemogram of bovines

Abstract

The aim of this study was to evaluate the effects of three enteral electrolyte solutions, each with different energy sources, administrated as continuous flow on the physiological parameters and blood count of healthy Holstein heifers. Six Holstein heifers were used in a crossover design. All animals received all three treatments: solution with calcium propionate, 4g of NaCl, 0.5g of KCl, 0.3g of MgCl2, and 10g of calcium propionate diluted in 1000mL of water (measured osmolarity: 299mOsm/L); solution with glycerol, 4g of NaCl, 0.5g of KCl, 0.3g of MgCl2, 1g of calcium acetate, and 10mL of glycerol in 1000mL of water (measured osmolarity: 287mOsm/L); solution with propylene glycol, 4g of NaCl, 0.5g of KCl, 0.3g of MgCl2, 1g of calcium acetate, and 15mL of propylene glycol in 1000mL of water (measured osmolarity: 378mOsm/L). Physical evaluations and blood samples were collected immediately before the initiation of fluid therapy, at 3-hour intervals over the 12-hour period of fluid therapy, and 12 hours after the end of fluid therapy. Animals presented no signs of stress or discomfort. All solutions resulted in a significant decrease in erythrocyte concentration, hemoglobin concentration, and hematocrit, without affecting the leukogram. Enteral fluid therapy administered as continuous flow via the naso-ruminal route was well-tolerated by animals with minimal effects on animal welfare, even when administered for 12 hours. This technique is indicated as an alternative route for parenteral maintenance fluid therapy. Electrolyte solutions proposed here were able to significantly expand blood volume.