Comparison of concentrations of copper in plasma and serum from farmed red deer (Cervus elaphus)

Abstract

AIM: To determine the relationship between the concentrations of Cu in plasma and serum in red deer, and to compare this relationship with those previously reported in cattle and sheep. METHODS: Paired serum and heparinised plasma samples from 114 red deer from 10 herds (n=6-20 per herd) were analysed for concentrations of Cu. Samples were collected either at slaughter (n=84; eight herds) or by jugular venepuncture (n=30; two herds). Thirty-nine of the samples taken at slaughter were from adult hinds from four herds, while other samples were taken from 10–14-month-old males, except for one herd (10 samples) where an equal number of 8–9-month-old males and females were sampled. The effect of age, gender and herd on the relationship between concentrations of Cu in plasma and serum was assessed using univariate ANOVA. The individual results for concentrations of Cu in serum were compared with those in plasma, using limits-of-agreement plotting. RESULTS: The mean concentration of Cu in plasma was not significantly different from that of serum (0.048; 95% CI=-0.14 to 0.24 µmol/L). There was no effect of age, sex or herd on this relationship. CONCLUSIONS: In deer, there was no significant difference between concentrations of Cu in plasma and serum regardless of age, sex or herd of origin. CLINICAL RELEVANCE: In contrast to the situation in cattle and sheep, the concentration of Cu in serum can be used interchangeably with that in plasma for the estimation of concentration of Cu in blood of red deer.