Effect of intravenous hypertonic solution administration on the abomasal emptying in newborn calves

BACKGROUND: It has been shown that the rate at which a meal leaves the abomasum is influenced by the volume, constituents and pH of the chyme through duodenal receptors. A direct correlation between tonicity of oral solutions and abomasal emptying has been observed. It has been noted that if the osmolarity of an oral solution is increased, the rate of emptying from the abomasum decreases. Nowadays Hypertonic solutions are widely used to treat septic shock and diarrhea. OBJECTIVES: Determination of the effects of intravenous hypertonic Dextrose and Sodium Chloride solutions on the abomasal emptying in neonatal calves. METHODS: The present study was carried out on Six 5 to 8 day-old colostrum-fed Holstein-Friesian calves. Calves were administered each of 4 treatments in a crossover study. Each calf was weighed and then assigned to one of the following treatments at 1 ml/kg body weight (BW) IV in random order: 1) 0.9% NaCl, equivalent to 308 mOsm/L (volume control); 2) 7.2% NaCl, equivalent to 2500 mOsm/L (osmolality control); 3) 5% dextrose, equivalent to 0.05 g dextrose/kg BW at 250 mOsm/L; and 4) 50% dextrose, equivalent to 0.5 g dextrose/kg BW at 2500 mOsm/L. All 4 solutions were injected over 1 minute at a smooth rate, and time = 0 minutes was the start of injection. Immediately after administration of each treatment, the calves were allowed to suckle 2L of fresh cow's milk at room temperature (19؛ to 22؛C) that contained a dose of acetaminophen (50 mg/kg BW). Abomasal emptying rate was measured by use of the acetaminophen absorption technique as previously described. Venous blood samples for determination of plasma acetaminophen, glucose and insulin concentration were collected. Results: The results of the current study revealed that there was no difference in abomasal emptying rate between the 4 treatments. Conclusions: The results indicate that IV isotonic and hypertonic solutions, unlike the oral route have no effect on abomasal emptying.