Calcium and Phosphorus Percent Clearance Ratios of Nelore (Zebu) Cattle Related to Sex and Age

Abstract

Calcium, phosphorus and creatinine were measured in serum and urine samples taken from 120 healthy Zebu cattle (Nelore) in order to establish reference values for the percent clearance ratios of calcium and phosphorus. The animals were divided in 6 groups (n=20) according to sex and age(1 to 8; 8 to 24; and from 24 months and over) to evaluate differences considering these two factors. The results were analysed using descriptive statistics and through ANOVA. The serum levels of calcium, phosphorus and creatinine were all within normal values, and the variance of urine measurements was very large. The average calcium percent clearance ratios were as follows: 0,38 ± 0,34% (male calves), 0,48 ± 0,91% (female calves), 0,65 ± 0,69% (young males), 1,45 ± 0,92% (young females), 1,53 ± 1,34% (adult males), and, 2,36 ± 1,84% (cows). Phosphorus percent clearance ratios showed 0,83 ± 1,00%, 0,38 ± 0,56% e 1,53 ± 1,39% in male calves, young and adult males, respectively, and 2,90 ± 2,84% (female calves), 0,43 ± 0,39% (young females) and 0,97 ± 0,78% (cows). These two percent clearance ratios differed related to sex and age.