Effects of different selenium sources on tissue selenium concentrations, blood GSH-Px activities and plasma interleukin levels in finishing lambs

Abstract

Thirty-two wether lambs of Tan sheep were randomly assigned into four dietary treatment groups (eight per group) for an 8-wk study and then fed a basal diet deficient in Se (0.06 mg/kg) or diets supplemented to provide 0.10 mg/kg Se from sodium selenite, selenized yeast, and seleniumenriched probiotics, respectively. Blood samples were collected at d 0, 28, and 56 of the experiment and tissue samples were collected at experiment termination. Tissue and blood Se concentrations, blood glutathione peroxidase (GSH-Px) activities, and plasma interleukin levels were analyzed. The results showed that the concentrations of Se in the kidney, liver, and muscle increased in all of the supplemented groups (p < 0.01) compared with the control group. However, the Se concentrations in the kidney, liver, and muscle in the groups supplemented with Se yeast and Se-enriched probiotics were higher than those in the group supplemented with sodium selenite (p < 0.01). The activities of GSH-Px and the concentrations of Se in blood also increased in all of the supplemented groups during the period of supplementation (p < 0.01) compared with the control group. The activities of GSH-Px and the concentrations of Se in the whole blood of the lambs fed with selenized yeast and Se-enriched probiotics were higher than those of lambs fed with sodium selenite (p<0.01 or p<0.05). The concentrations of interleukin-1 and interleukin-2 in plasma significantly increased in all of the supplemented groups during the entire period of experiment (p<0.01) compared with the control group, but had no significant differences among all of the supplemented groups. In conclusion, a diet supplemented with Se for finishing lambs was able to increase the concentrations of Se in tissue and blood, activities of GSH-Px in blood, and levels of interleukins in plasma. Organic Se sources (selenized yeast and Se-enriched probiotics) were more effective than the inorganic Se source (sodium selenite) in increasing tissue and blood Se concentrations and blood GSH-Px activities of lambs. However, there were no significant differences in plasma interleukin levels of lambs between organic and inorganic Se sources.

Effect of dietary supplementation with selenium-enriched yeast or sodium selenite on ruminal enzyme activities and blood chemistry in sheep

“…Similar results were reported by Qin et al (2007). However, Van Ryssen et al (1989) and Gunter et al (2003) found no differences in the GPx activity in whole blood of animals given organic or inorganic selenium.…”

“…Qin et al (2007) also showed a significantly higher whole blood selenium concentration and GPx activities in lambs fed Se-yeast enriched diet (0.10 mg/kg of diet) compared to lambs fed similar concentrations of sodium selenite. The differences in results obtained by the researchers might be explained by the fact that although whole blood Se concentration is closely correlated with the GPx activity (Brigelius-Flohe et al 1994), there is evidence that the percentage of Se in erythrocytes associated with GPx may vary depending on the Se source (Belstein and Whanger 1986;Van Ryssen et al 1989).…”

“…It is established that selenocompounds from dietary inorganic and organic Se sources follow different metabolic pathways (Qin et al 2007;Wang et al 2009). Intestinal absorption of Se is much lower in ruminants than in nonruminants.…”

Selenium persistency and speciation in the tissues of lambs following the withdrawal of dietary high-dose selenium-enriched yeast

“…Studies with both dairy cows and beef cattle have shown that SY is more efficiently absorbed and assimilated than -E-mail: d.t.juniper@rdg.ac.uk inorganic Se, as SeMet can be taken up via methionine transporter mechanisms within the gastro-intestinal tract and non-specifically incorporated into body proteins in place of methionine (Weiss, 2003), resulting in elevated concentrations of Se in both milk (Juniper et al, 2006) and body tissues (Qin et al, 2007). Surai (2006) reported that SeMet is retained in tissue proteins to a greater extent than selenocysteine (SeCys) or Se derived from inorganic forms.…”

Effect Of Organic Selenium And Iodine Supplementation On Selenium And Thyroid Hormones Status Of Lactating Ewes And Lambs

“…It is generally accepted that the inorganic form is not utilized as effi ciently as the organic form [6]. Moreover, organic forms of Se are absorbed and retained more readily by ruminants than inorganic forms [11]. Therefore, recent studies have focused on comparing both these forms [12,13].…”