Selenium status of horses in the Czech Republic

Abstract

The aim of this study was to determine the relation between selenium concentration and activity of glutathione peroxidase (GSH-Px, EC 1.11.19) in whole blood of horses, reference ranges for the activity of GSH-Px and to evaluate the selenium status of horses in the Czech Republic. Blood samples were collected from 159 horses from 35 different farms and processed using the AAS and photometric methods to determine concentrations of selenium and the GSH-Px activity, respectively. Data on both parameters were processed using correlation and regression analysis in order to obtain reference values of GSH-Px for the indirect evaluation of the selenium status of horses. The results were also used to evaluate the occurrence of selenium deficiency in the horses examined. A highly significant linear relation was found between both variables. It can be expressed using the Spearman's coefficient of rank correlation (rs = 0.873; p < 0.01) and the regression equation (y = 3.621x - 28.698; p < 0.01, r = 0.842). The value of 75 μg·l-1 of selenium in whole blood is considered as a threshold of selenium deficiency in horses. According to our results, the corresponding level of the activity of GSH-Px useful in the diagnostics is 200 μkat·l-1. Using these criteria, there was a high prevalence of selenium deficiency in the collection of horses examined amounting to 47% and 48% when evaluating the selenium status by the selenium concentration and the activity of GSH-Px, respectively. It can be concluded that there is a high correlation of the activity of GSH-Px and selenium concentration in whole blood of horses and that reference values of the activity of GSH-Px useful in the diagnostics of selenium deficiency in horses in the Czech Republic were determined. The occurrence of selenium deficiency in horses is a topical problem in the Czech Republic.