The effect of inorganic and organically bound forms of selenium on glutathione peroxidase activity in the blood of goats

The goal of the experiment was to compare the effect of supplementation of inorganic and the new organically bound (lactate-protein selenium complex) form of selenium (Se) in feed for goats. The 31 goats were split into three groups: control (C) without Se supplementation, AN group administered sodium selenite, ORG group administered lactate-protein selenium complex (Selene Chelate, Agrobac, Czech Republic) produced by cultivation of Lactobacillus acidophilus on a substrate containing natrium selenite. The total Se intake in goats was 0.15 mg in group C, and 0.43 mg in the groups AN and ORG. The effect of Se supplementation was assessed based on the determination of Se concentration and the activity of glutathione peroxidase (GSH-Px) in whole blood. Samples were taken before the beginning of Se supplementation, 14 and 30 days after the start of supplementation, and then two and three months after the beginning of supplementation. Average Se concentrations in the blood of goats in individual groups (C, AN, ORG) before the start of supplementation were 109.6 ± 34.3, 117.5 ± 34.7, and 105.4 ± 43.6 μg/l respectively, and the activity of GSH-Px in whole blood was 745.3 ± 289.2, 810.7 ± 280.4, and 791.0 ± 398.1 μkat/l respectively. While in group C goats neither the Se concentration nor the GSH-Px activity changed substantially during the experiment, in the goats in the experimental groups there was a statistically significant increase (P < 0.01) in both Se concentrations and the GSH-Px activities. At the end of the experiment Se concentrations in the blood of AN and ORG groups amounted to 168.5 ± 12.2 and 168.8 ± 26.8 μg/l. The GSH-Px activities in goats supplemented with Se also increased significantly over the course of the experiment (at the end of the experiment it was 1178.0 ± 127.3 in the AN group and 1030.1 ± 152.3 μkat/l in the ORG group), and the difference between the groups was significant (P = 0.038). Regarding the dynamics of GSH-Px activity changes during the monitored period, a markedly quicker increase in GSH-Px activity was recorded in the AN group – one month after the beginning of Se supplementation, compared to three months after the beginning of Se supplementation in the ORG group. The results thus show that the effects of supplementation with selenite and the lactate-protein selenium complex are similar with regard to Se status, but that the increase in GSH-Px activity occurred much faster with selenite, which therefore appears to be a more biologically available form of selenium for creation of biologically active selenoproteins.