Incidence of urinary calculi in goats fed a high phosphorus diet.

Abstract

Relationship between the incidence of phosphatic urinary calculi and mineral metabolism was observed in goats fed a high phosphorus diet. A basal diet and alfalfa hay cube were given to 6 goats (group B), and hay cube and a calculogenic diet (the basal diet supplemented with K2HPO4) to other 6 goats (group C) for 2 months. Urinary calculi were produced in 5 goats of group C (obstructive urolithiasis in one goat and nonobstructive calculi in 4 goats), but in no goats of group B. Group C presented a higher urinary P level and lower urinary Mg, Na and Cl levels than group B. There was little difference in urinary pH, Ca and K levels between the two groups. Serum mineral levels showed little difference between the two groups, except the inorganic P level which exhibited a transient increase in group C. The serum urea level showed a progressive increase in group C during the experimental period. In balance trials, the retention of Mg, P and K was higher and that of Na lower in group C than in group B. It was confirmed that the dietary supplement of K2HPO4 caused some alteration in Mg, Cl and Na metabolism and serum urea level in addition to changes in P and K metabolism. It seemed that especially changes in P, Cl and Mg metabolism might be related to the incidence of urinary calculi in goats.