Effects of Different Dietary Selenium Sources on Antioxidant Status and Blood Phagocytic Activity in Sheep

Abstract

The objective of this experiment was to investigate the effects of feed supplementation with equivalent doses of selenium from sodium selenite (SS) or selenized yeast (SY) on Se deposition, selenoenzyme activity and lipid peroxidation in tissues as well as in bacterial and protozoal fractions of rumen contents in sheep. The phagocytic activity of monocytes and neutrophils in whole blood was also assessed after 3 months of dietary treatment. While animals in the control group were fed with unsupplemented basal diet (BD) containing only background Se (0.16 mg/kg DM), the diet of the other two groups (n = 6) consisted of identical BD enriched with 0.4 mg Se/kg DM either from SS or SY. Concentrations of Se in blood and tissues were found to be significantly increased in both supplemented groups. No response in Se deposition was recorded in the musculus longissimus dorsi of sheep given dietary SS. The intake of SY resulted in a significantly higher Se level in the blood, kidney medulla, skeletal muscles, heart, intestinal and ruminal mucosa than in the case of SS supplementation. No differences appeared between tissue Se contents in the liver and kidney cortex due to the source of added Se. Regardless of source, Se supplementation to feeds significantly increased the glutathione peroxidase (GPx) activity in blood and tissues except the kidney medulla and jejunal mucosa. Supplementation with SY resulted in significantly higher activity of thioredoxin reductase in the liver and ileal mucosa, and also reduced malondialdehyde content in the liver and duodenal mucosa. Dietary Se intake increased Se concentrations in the total rumen contents and bacterial and protozoal fractions. The accumulation of Se in rumen microbiota was associated with increased GPx activity. Phagocytic cell activity was enhanced by Se supplementation. Our results indicate that Se from both sources has beneficial effects on antioxidant status in sheep and can be utilized by rumen microflora.

Effects of rumen‐protected folic acid and rumen‐protected sodium selenite supplementation on lactation performance, nutrient digestion, ruminal fermentation and blood metabolites in dairy cows

“…The literature demonstrated that ruminal microbes incorporate Se from the diet to form their protein and cell wall components . Dietary Se addition enhanced the ability of microbes against oxidative damage by improving the antioxidant status of the rumen environment and microbial cell . The contradiction of the unchanged total methanogens and higher cellulolytic bacteria and protozoa populations was due to the higher production of propionate, which would consume hydrogen of the rumen .…”

“…found that milk yield, ruminal total VFA concentration, propionate molar proportion and nutrient digestibility increased with selenized yeast (Se yeast) addition. The data indicated that microbial growth and enzyme activity were stimulated due to an improved antioxidant status of microbial cells and ruminal environment with Se supplementation . However, the influence of dietary Se addition on ruminal microflora and enzyme activity in dairy cows was limited.…”

“…The data indicated that microbial growth and enzyme activity were stimulated due to an improved antioxidant status of microbial cells and ruminal environment with Se supplementation. 12 However, the influence of dietary Se addition on ruminal microflora and enzyme activity in dairy cows was limited. Furthermore, some studies in rats found that FA and Se interacted to influence one-carbon unit metabolism, 13 and effectively prevented peroxidation of protein products.…”

Effects of sodium selenite addition on ruminal fermentation, microflora and urinary excretion of purine derivatives in Holstein dairy bulls

“…Literature demonstrated that ruminal microbes incorporate dietary Se to form their protein and cell wall component in the form of selenomethionine (Hidiroglou et al, ), and Se could protect cell membrane against oxidative damage by scavenging free radicals (Surai, ). Cobanova et al () reported that Se content and glutathione peroxidase activity of ruminal bacteria and protozoa increased when 0.4 mg/kg DM of Se was supplemented in diet of sheep. Similarly, Hidiroglou et al () observed an increased ruminal microbial concentration with Se addition in sheep fed a purified diet low in Se.…”

“…Recent studies found that daily weight gain and feed efficiency in bulls (Netto et al, ), milk production (Wang et al, ) and activity of blood glutathione peroxidase and superoxide dismutase (Sun et al, ) in dairy cows increased with dietary Se addition. Literature demonstrated that ruminal microbes incorporate Se from the diet to form their protein and cell wall component (Hidiroglou, Heaney, & Jenkins, ), and the resistance of cell membrane against oxidative damage was improved with Se addition (Cobanova et al, ; Mihalikova et al, ). Some studies found that concentrations of short‐chain fatty acids and acetate tended to be increased with selenomethionine addition in vitro (Kim, Soest, & Combs, ).…”