SELECTED PHYSIOLOGICAL EFFECTS RESULTING FROM ADDITION OF SODIUM BICARBONATE TO DIETS FOR YEARLING HORSES

Abstract

Sodium bicarbonate or a commercial vitamin-mineral mixture was included at the 1% level (air-dry weight) in the diets of 16 yearling horses over a 140-day period in a 2 × 2 factorial design. Feed additives resulted in a pH range from 5.78 to 7.87 in the concentrate portion of the diets. Feces, urine and venous blood were collected 24 h after feeding the concentrate. Average daily gain, respiration rate, venous pCO2 and pO2, as well as serum K, Cl, Ca, P, urea N and protein levels were unaffected by treatment. Horses receiving the vitamin-mineral supplement had higher serum Na and lower serum glucose concentrations than horses not receiving the supplement. Horses receiving sodium bicarbonate had a higher urine pH, lower fecal pH, higher packed cell volume, lower blood pH and lower serum glucose concentrations at 24 h after a meal than horses not receiving the buffer. Key words: Horse, sodium bicarbonate, dietary supplements, hematology