Incidence of Urinary Calculi in Sheep as Affected by Various Dietary Phosphates

Abstract
Wether lambs were used in nine treatment groups of 19 to 20 lambs and were fed a basal ration containing 0.25% phosphorus to which 0.35% additional phosphorus was added as monosodium phosphate, disodium phosphate, sodium tripolyphosphate or dicalicium phosphate to give 0.60% total phosphorus. Each ration was fed with two levels of calcium (0.31 and 0.58%), except dicalcium phosphate which was fed only at the higher calcium level. No urinary calculi occurred in lambs receiving 0.25% phosphorus in diets containing either 0.31 or 0.58% calcium or in lambs receiving dicalcium phosphate. The percent incidence of urinary calculi was 70, 65 and 60, respectively, for lambs receiving disodium phosphate, monosodium phosphate and sodium tripolyphosphate when these supplements were fed with 0.31% calcium. Increasing the calcium level to 0.58% significantly lowered, but did not prevent, the incidence of urinary calculi. Serum and urine phosphorus values were lowest in those groups where calculi were absent, with the controls (0.25% P and 0.31 or 0.58% Ca) having significantly(P<.05) lower values than groups in which calculi were present. Corresponding values for calcium and magnesium were more variable, and differences were generally not significant. Copyright © 1965. American Society of Animal Science . Copyright 1965 by American Society of Animal Science