EFFECTS OF DIETARY CATION-ANION BALANCE ON BLOOD-PH, ACID-BASE PARAMETERS, SERUM AND URINE MINERAL LEVELS, AND PARATHYROIDHORMONE (PTH) IN WEANLING HORSES

This study demonstrated that the feeding of treatment diets with calcu lated dietary cation-anion balances (DCAB) of +370.43 (H) and -25.69 ( L) did not have significant effects on blood pH, pCO(2), and HCO3-. Se rum Ca2+, P, Na+, and Cl- as well as plasma PTH did not differ (P > .0 5) between the two treatment groups. Serum K+ was higher (P < .05) in horses fed diet H rather than diet L. The DCAB of the diet significant ly affected urinary Ca2+, P, Na+, K+, and Cl- excretion in the young g rowing horse. Urine Ca2+ and Cl- levels were higher (P < .01) in horse s fed diet H versus diet L. Furthermore, levels of P, Na+, and K+ in t he urine were higher (P < .01) in horses on diet H as opposed to diet L. Results of this study indicate that horses were able to maintain ac id-base status regardless of diet. However, these data imply that grow ing horses consuming diets low in DCAB may be predisposed to abnormal bone mineralization due to the increase in calcium excretion which cou ld lead to a weakening of the skeletal system.