Comparison of commercial isotonic fluids intravenously administered to rehydrate fasted bullocks.

Holstein bullocks were used in this study to compare the effectiveness of five commercial parenteral fluids (saline IS, Hartmann's IH, 5%-glucose 5G, Ringers IR, and 1/2 Ringer's and 2.5% glucose combination solutions RG) in correcting the disturbances associated with dehydration induced by fasting for 48 hr. These five commercial fluids (30 ml/kg) were given to bullocks with dehydration induced by fasting for 48 hr. Arterial and venous blood samples were taken before fasting, and at 0, 15, 30, 45, 60, 90, 120, 240, 360 min, and 24 hr after initiation of fluid administration. Fasting for 48 hr induced significant reductions in body weight and relative plasma volume (rPV), of approximately 7.72 and 21.93%, respectively. During the administration period, rPV showed a progressive increase from approximately 88.1% after fasting to 113.0% with no significantly differences between groups. A rapid decrease of rPV when fluid administration has been finished was observed in the 5G and RG groups. The results of the fluid administration trial showed that the 1/2 Ringer's and 2.5% glucose combination solution inhibited the acidification of the blood, produced no change in the electrolyte balance of serum, and induced a proper reabsorption rate of glucose in the renals, and was therefore considered the best choice for the rehydration of adult cattle which have had no appetite for over 2 days.