Effect Of Organic Selenium Supplementation Research Articles

Hepatic Expression of Genes Related to Fatty Acid Biosynthesis during Tropical Summer in Broilers: Effect of Organic Selenium Supplementation

Background: The physiological responses during adaptation to summer in poultry could be related to modulation of energy metabolism. Enhanced deposition of fat in spite of reduced feed intake seems to have an advantage under hot conditions. Thus, the present study was conducted to investigate the seasonal status of de novo synthesis of fatty acids in broiler chicken (Gallus gallus) and its response to organic selenium supplementation. Methods: The study was conducted in two phases, one during autumn and the other during summer, with a total of 300 birds as autumn control, summer control, group-I (0.3 ppm SeMet), group-II (0.6 ppm SeMet) and group-III (0.9 ppm SeMet) groups. Blood samples and hepatic tissues were collected at 21 and 42 d for further analysis. Result: An elevation in serum lipid profile, glucose, cortisol and T4 levels was observed during the summer while the T3 concentration decreased compared to the autumn. The hepatic expression of Acetyl Co. A carboxylase α (ACCα) and Fatty acid synthase (FASN) was increased at 21 d, while it was decreased at 42 d during summer in broilers. Serum total cholesterol levels and LDL levels decreased with SeMet at 0.6 and 0.9 ppm levels. The expression of hepatic ACCá and FASN genes was decreased with selenium supplementation at higher levels. Increased serum total cholesterol levels were associated with lower de novo fatty acid synthesis at 42d during summer in broilers.

Exploring effects of organic selenium supplementation on pork loin: Se content, meat quality, antioxidant capacity, and metabolomic profiling during storage.

This research was conducted to study the effects of organic selenium (Se) supplements at different levels on pork loin quality during storage. Fifteen pork loins were procured randomly from three groups, Con (fed basal diet), Se15 (fed 0.15 ppm organic Se along with 0.10 ppm inorganic Se), and Se45 (fed 0.45 ppm organic Se along with 0.10 ppm inorganic Se). Each sample was analyzed for Se contents, antioxidant properties (glutathione peroxidase [GPx] activity, 2,2'-azinobis-[3-ethylbenzothiazoline-6-sulfonic acid] [ABTS] and 2,2-diphenyl-1-picrylhydrazyl [DPPH] radical scavenging activities, 2-thiobarbituric acid reactive substances), physicochemical properties (water holding capacity, pH, color), and metabolomic analysis during 14-day storage period. Se45-supplemented group showed significantly higher Se contents and GPx activity than the other groups throughout the storage period. However, other antioxidant properties were not significantly affected by Se supplementation. Selenium supplementation did not have an adverse impact on physicochemical properties. Nuclear Magnetic Resonance-based metabolomic analysis indicated that the selenium supply conditions were insufficient to induce metabolic change. These results suggest that organic Se (0.15 and 0.45 ppm) can accumulate high Se content in pork loins without compromising quality.

Effect of Organic Selenium Supplementation on the Antioxidant Status, Immune Response, and the Relative Expression of IL-2 and IFN-γ Genes in Ewes During the Hot Season.

This study was conducted to evaluate the effects of different doses of selenium (Se) from Sel-Plex© (selenium-enriched Saccharomyces cerevisiae yeast) supplement on the antioxidant status, the antibody titers against the foot-and-mouth disease virus, and the expression of interleukin-2 (IL-2) and interferon-γ (IFN-γ) genes in ewes during the hot season. Six ewes were kept at 25 °C and received basal diet (the negative control group), and 24 ewes were kept at 38 °C for 5 h per day and received no supplement (the positive control), 0.15, 0.30, and 0.45 mg Se/kg. Ewes in the positive control had higher (P<0.001) liver enzyme activity, malondialdehyde (MDA), and cortisol levels, and lower antibody titer than the negative control. The liver enzymes' lowest (P<0.001) activities were observed in ewes receiving 0.30 and 0.45 mg Se/kg. Ewes receiving 0.30 and 0.45 mg Se/kg had lower MDA levels than other treatments. Ewes receiving 0.30 and 0.45 mg Se/kg had higher (P<0.001) total antioxidant capacity levels than those receiving 0.15 mg Se/kg and the positive control. Se-supplemented groups had lower (P<0.001) relative expression of IL-2 and higher (P<0.04) expression of IFN-γ than the positive control. The antibody titer was the same in the positive control and the group receiving 0.15 mg Se/kg. Ewes fed a diet with 0.30 and 0.45 mg Se/kg had higher (P<0.011) antibody titer than the positive control. The Se supplementation can reverse the decrease of antioxidant capacity and immune function caused by heat stress, and 0.3 mg Se/kg from Sel-Plex©is the best dose.

Efecto de la suplementación con selenio orgánico sobre la calidad de la canal y la vida útil de la carne de vaquillonas terminadas en feedlot

The objective of this work was to evaluate the effect of organic selenium supplementation (Selplex®) on heifer’s carcass quality and meat shelf life in a feedlot system. Thirty Hereford heifers were used: 14 of 20 months of age, with an initial weight of 323 ± 26.27 kg, and 16 of 36 months and 405 ± 30.52 kg. Animals were housed in individual pens and drawn within each age category to 2 treatments: Control and Supplementation with organic selenium at a rate of 0.9 mg Se/kgDM/day. All animals were fed a fully mixed ration (RTM) including 15% moha bale (Setaria italica) and 85% commercial ration for fattening cattle. Animals were slaughtered after 62 days of feeding. Color evolution, lipid and protein oxidation were measure on sample packed using an oxygen permeable film and stored during 12 days in a refrigerated display case. Selenium supplementation resulted in an increase level of glutathione peroxidase (GSH-Px) (195.9 vs 259.7 U/gr Hg, p<0.0001), a decrease lipid oxidation (0.65 vs. 0.57 mg MDA/kg) (p<0.05) and shear force after 7 days of ageing (3.22 vs. 2.68 kg) (p<0.05). Twenty months heifers supplemented with selenium achieved higher levels of GSH-Px (242 vs. 213 U/gr Hg) (p<0.05) and was detected a lower rancid flavor in relation to those of 36 months (2.9 vs. 3.6) (p<0.05). Organic selenium supplementation may be an alternative to decrease meat lipid oxidation, however it had no effect on color evolution and in reducing protein oxidation (0.31 vs.0.35 nmoles/mg) (p ≥ 0.05).

Effect of Organic Selenium Supplementation in Diet on Gastrointestinal Tract Performance and Meat Quality of Goat

Effect of Organic Selenium Supplementation in Diet on Gastrointestinal Tract Performance and Meat Quality of Goat

Effect of Organic Selenium Supplementation on Selenium Status, Oxidative Stress, and Antioxidant Status in Selenium-Adequate Dairy Cows During the Periparturient Period.

The periparturient period represents a stressful time for dairy cows as they transition from late gestation to early lactation. Oxidation stress occurs during this period owing to the increased metabolic activity. Antioxidants supplementation slightly above the suggested requirements may be beneficial in relieving this kind of stress. The objective of this study was to determine whether supplementing selenium (Se) yeast to diets with adequate Se concentrations affects Se status, oxidative stress, and antioxidant status in dairy cows during the periparturient period. Twenty multiparous Holstein cows were randomly divided into two groups with ten replicates in each group. During the last 4weeks before calving, cows were fed Se-yeast at 0 (control) or 0.3mg Se/kg dry matter (Se-yeast supplementation), in addition to Na selenite at 0.3mg Se/kg dry matter in their rations. The concentrations of Se, reactive oxygen species (ROS), hydrogen peroxide (H2O2), hydroxyl radical, malonaldehyde (MDA), α-tocopherol and glutathione (GSH), the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT), and the total antioxidant capacity (T-AOC) in plasma or erythrocyte of dairy cows were measured at 21 and 7days prepartum, and at 7 and 21days postpartum. Cows fed Se-yeast supplement during the last 4weeks of gestation had higher plasma Se and lower MDA concentrations at 7days prepartum, and at 7 and 21days postpartum, and had higher whole blood Se and lower plasma ROS and H2O2 concentrations at 7 and 21days postpartum compared with control cows. Se-yeast supplementation increased plasma and erythrocyte GSH-Px activities and erythrocyte GSH concentration at 7days postpartum as compared to Se-adequate control cows. Compared with control cows, the enhanced SOD and CAT activities, increased α-tocopherol and GSH concentrations, and improved T-AOC in plasma at 7 and 21days postpartum in Se-yeast-supplemented cows were also observed in this study. The results indicate that feeding Se-adequate cows a Se-yeast supplement during late gestation increases plasma Se status, improves antioxidant function, and relieves effectively oxidative stress occurred in early lactation.

Effects of Organic Selenium Supplementation on Growth, Accumulation, Haematology and Histopathology of Juvenile Barramundi (Lates calcarifer) Fed High Soybean Meal Diets

Soybean meal (SBM) has been commonly utilised as a substitute for fishmeal (FM) in the diets of several fish species. However, little is known regarding their effects on trace element availability and thus their importance to fish. The present study employed two feeding trials to evaluate the implications of dietary selenium (Se) on the growth, accumulation, antioxidant, and histopathological responses of juvenile barramundi (Lates calcarifer). In the first trial, each of three basal diets containing 0, 15 and 43% SBM as replacements for 0, 25 and 75% of FM protein on an isoproteic and isocalorific basis were either supplemented or not supplemented with 2mgkg-1 organic Se (OS). In the second trial, the potential effect of OS supplementation in a high SBM diet was investigated in a feeding trial with five experimental diets: 75% SBM protein as replacement of FM was supplemented with 2, 3, 4, 5 or 7mg OSkg-1. Growth was independently influenced by the SBM level and the OS supplementation level but not by their interaction. Glutathione peroxidase (GPx) activity, haematocrit, Se accumulation and muscle tissue integrity were significantly enhanced in fish fed on OS-supplemented diets. Furthermore, when high SBM was included in diets, elevated Se tended to lower the barramundi's performance. These findings suggest that dietary supplementation of OS at 2-3gkg-1 diet is necessary when high plant protein ingredients are incorporated in the diet, in order to maintain better growth and to afford protection against oxidative stress.

Effects of organic selenium supplementation on growth, glutathione peroxidase activity and histopathology in juvenile barramundi (Lates calcarifer Bloch 1970) fed high lupin meal-based diets

Very limited information is available on the relationship between dietary selenium (Se) and plant protein (PP) sources in carnivorous marine aquaculture species. Therefore, this study employed a 2×3 experimental layout to investigate the effects of lupin meal (LM) protein inclusion levels (0, 25 and 75%) and organic selenium (OS) levels (0 or 2gkg−1) on the growth, physiology and histopathology of juvenile barramundi (Lates calcarifer). The experimental diets (LM0, LM0+OS, LM25, LM25+OS, LM75 and LM75+OS) were formulated on an isonitrogenous (48.8% crude protein) and isocalorific (20.6MJkg−1 gross energy) basis. In the 60-day feeding experiment, final weight (FW), specific growth rate (SGR) and weight gain (WG) were improved by the supplementation of Se in LM-based diets. Fish fed diets containing Se had higher FW, SGR and WG compared with those fed diets lacking Se supplementation (P<0.05). Both LM inclusion levels and Se supplementation levels affected the apparent digestibility coefficient of protein (ADC-P). Meanwhile, survival and the thermal growth coefficient (TGC) were not significantly different among all dietary treatments. The inclusion of a high LM level resulted in decreased glutathione peroxidase (GPx) activities, but this effect was not observed when Se was supplemented in the diets. Furthermore, there was a linear relationship between muscle Se level and Se concentration of the experimental diets. Se-induced myopathy was observed in skeletal muscles of fish fed LM diets without Se supplementation. In addition, structural alteration was found in the liver; however, the kidney, spleen and intestine were histologically normal. Overall, these results suggest that high LM diets supplemented with organic selenium can enhance growth, physiological and histological performances of juvenile barramundi. Statement of relevanceWhile plant-based feed sources such as lupin meal have the potential to reduce the reliance on unsustainable wild fishmeal in aquaculture, such products may reduce the feed availability of selenium, an essential element for aquatic animals. We believe that the findings of this study are relevant to the general field of commercial aquaculture.

Use of Organic Selenium Supplements in Soybean Meal- Based Diets for Juvenile Yellowtail Kingfish (Seriolalalandi)

Sustainable aquaculture, from both ecological and economic perspectives, demands a substantial reduction of the amount of fishmeal used in aqua feed. Instead, plant-derived protein feed stuff, which provide a nutritious diet offer a promising alternative for inclusion in aqua feed. In this study, the effects of organic selenium supplementation in low and high soybean meal-based practical diets for yellowtail kingfish (Seriola lalandi) were evaluated over a 60-day feeding experiment. The juvenile yellowtail kingfish (initial weight 5.02 ± 0.04 g fish −1 ) were fed five iso-nitrogenous and iso-caloric diets containing 49% crude protein and 22 MJ kg −1 gross energy. The control diet(C) includes 46% fishmeal, whereas the other diets used soybean meal to replace 25% and 75% of the fishmeal protein, both without and with organic selenium supplementation (SBM 25 , SBM 25+Se , SBM 75 , and SBM 75+Se ). Fish were fed ad libitum two times a day at 09:00 and 15:00 hours. No differences were observed in feed intake among dietary treatment groups (P > 0.05). Organic selenium-supplemented diets improved final weight; however, final weight was significantly reduced when fish were fed high soybean meal diets (P < 0.05). Organic selenium supplementation had a significant effect on specific growth rate at low soybean meal diets, but did not affect specific growth rate when fish were fed high soybean meal diets. Selenium accumulation in fish fillet was strongly correlated with selenium concentration in the diets. While fish fed the SBM 25+Se diets had significantly higher glutathione peroxidase activity than those fed other diets, the lowest glutathione peroxidase activity was found in fish fed SBM 75 diets. Histologically, selenium-deficient diets induced myopathy and alterations in tissue structure were most prevalent in fish fed the SBM 75 diet. The findings of this study indicate that, with Se supplementation, soybean meal could supply 25% of the protein in yellowtail kingfish diets.

Effect of organic selenium supplementation in the diets of finishing sheep on meat color and pH during shelf life

Supplementation of Selenium (Se) can improve the oxidative stability of meat products and retard metmyoglobin formation; so prolonging color. Effect of organic Se addition in the diets of sheep on meat stability; color and pH are limited and need to be studied. A study was conducted with eighteen Pelibuey female sheep at the finishing stage, and supplemented with organic Se-enriched Saccharomyces cerevisiae for sixty days to evaluate its effect on color and pH of Longissimus dorsi muscle. The research was conducted in a block randomized design considering three treatments; control (Se0) without the addition of yeast, or with 0.35 ppm of yeast (Se34) or with 0.60 ppm (Se59). Sheep were slaughtered at an average weight of 39.5 ± 4.41 kg. Meat color and pH were recorder in the cold carcass, 24 h after slaughtering, and during shelf life at 0, 4, 6 and 8 days after slaughtering under refrigeration at 4 °C. No significant differences were observed (P&gt;0.05) for meat color and pH characteristics due to treatment. Decreased redness (a*) and Chroma (C*) values due to storage time were observed; however, the yellowness (b*) and angle Hue were increased. It could be concluded that supplementation of Se-enriched yeast in finishing sheep with 0.35 ppm and 0.60 ppm has no effect on meat color and pH characteristics.

Effect of selenium on the reproductive performance of ewes and white muscle disease in lambs

A study using 60 Awassi ewes fed either a control (unsupplemented) diet or one containing selenium-enriched yeast (Selplex™, Alltech Incorporated, USA) at a dose rate of 0.2 mg/kg diet was conducted to investigate the effects on white muscle disease occurrence in progeny. The effects of organic selenium on oestrus, fertility, lamb birth weights, weaning weights and rates of white muscle disease were recorded. There was no effect of organic selenium supplementation on pregnancy rates as recorded by ultrasound at 40 and 80 days after mating (P>0.05). Likewise, there were no significant differences in lambing, single or twinning rates between the control ewes and those receiving organic selenium. Birth and weaning weights were not significantly different in either single or twin lambs from either control or Se-supplemented ewes. However, the Se-supplemented ewes gave birth to lambs which had significantly less incidence of white muscle disease (37.5% versus 3.3%; P

Effects of organic selenium supplementation on growth performance, nutrient utilisation, oxidative stress and selenium tissue concentrations in broiler chickens

The effects of organic selenium (Se) supplementation of diets for broiler chickens were evaluated in the present study. Broiler diets had average background Se concentrations of 0.36 mg/kg Se (control diet) and were supplemented with two organic Se sources, namely BiOnyc® Tor-Sel (selenohomolanthionine = SH) and Alltech’s Sel PlexTM (selenomethionine = SM); their addition increased dietary selenium concentrations by an average of 0.57 mg/kg Se. Their effects on growth performance, nutrient utilisation and oxidative status of broiler chickens were determined. Growth performance was very similar across all dietary treatments; in contrast, significant differences in nutrient utilisation were observed. The N-corrected apparent metabolisable energy value for the control group (14.14 MJ/kg) and SH (14.15 MJ/kg) diet was significantly (P &lt; 0.01) higher than that for the SM (13.64 MJ/kg) diet. Alternatively, N retention with the SM (68.4%) diet was significantly (P &lt; 0.005) higher than that for the control (65.2%) and SH (64.5%) diets. Neither of the Se sources influenced plasma concentrations of reactive oxygen metabolites, biological antioxidant potential and advanced oxidation protein products. The activity of glutathione peroxidase, superoxide dismutase in both plasma and tissues samples and the concentration of plasma glutathione were increased by SH and SM compared with the control group. Our findings suggest that SH and SM improved the antioxidant status of broilers by elevating activities of antioxidant enzymes and concentrations of antioxidant. Both Se supplements significantly (P &lt; 0.001) increased Se concentrations in liver and muscle, and in liver tissue there was no statistical difference between the two supplements. However, SH generated significantly higher Se concentrations in muscle tissue (0.283 versus 0.257; P &lt; 0.005) than did SM. In summary, SH was at least the equivalent to SM as a source of organic Se for broiler chickens under the conditions of the present feeding study. This is reflected in the outcome that SH generated significantly higher Se concentrations in muscle tissue than did the alternative Se supplement.

Effects of organic selenium supplementation on growth performance, carcass measurements, tissue selenium concentrations, characteristics of reproductive organs, and testis gene expression profiles in boars1

The objective was to compare growth and physiological responses in boars fed diets supplemented with organic or inorganic sources of Se. At weaning, crossbred boars (n = 117; 8.3 kg of BW) were placed in nursery pens (3 boars/pen) and assigned within BW blocks to receive on an ad libitum basis 1 of 3 dietary treatments: I) basal diets with no supplemental Se (controls), II) basal diets supplemented with 0.3 mg/kg of organic Se, and, III) basal diets supplemented with 0.3 mg/kg of sodium selenite (13 pens/dietary treatment). Average daily gain (470 g/d), ADFI (896 g/d), and G:F (0.54) were similar among groups. Blood Se concentrations were greater (P < 0.01) for boars consuming organic Se (107.5 ± 4.8 µg/L) or sodium selenite (114.7 ± 4.8 µg/L) compared with controls (28.4 ± 4.8 µg/L). Intact pens of boars (11 pens/dietary treatment) were moved to a grow-finish barn and continued to receive appropriate diets on an ad libitum basis. Average daily gain (1,045 g/d) and ADFI (2,716 g/d) were similar among groups. Gain:feed was affected by treatment (P = 0.02) and was greater (P < 0.06) for boars fed organic Se (0.378 ± 0.004) compared with boars fed sodium selenite (0.368 ± 0.004) or controls (0.363 ± 0.004). Blood Se concentrations were greater (P < 0.01) in grow-finish boars consuming organic Se (198.9 ± 5.5 µg/L) than boars consuming sodium selenite (171.4 ± 5.4 µg/L) or controls (26.7 ± 5.4 µg/L). Treatment did not affect (P > 0.15) HCW, dressing percent, carcass length, LM area, standardized fat-free lean, lean percentage, backfat thickness, visual color, firmness, marbling, or Minolta loin color scores. Selenium supplementation did not affect (P > 0.17) testis or accessory sex gland sizes. Concentrations of Se in loin, liver, kidney, testis, cauda epididymis, and accessory sex glands were greatest (P < 0.01) in boars receiving organic Se, intermediate in boars receiving sodum selenite, and least in control boars. Microarray analysis of testis gene expression did not detect differences (P > 0.05) due to dietary treatment. Testis gene expression of glutathione peroxidase 4, as determined using quantitative PCR, was increased (P < 0.01) in boars fed organic Se compared with those fed sodium selenite. In summary, dietary supplementation of boars with organic Se failed to alter ADG or ADFI but enhanced G:F during grow-finish. More research is needed to discern the mechanism by which organic Se improves feed efficiency in boars.

Selênio orgânico na alimentação de matrizes de tilápia-do-Nilo (Oreochromis niloticus)

Organic selenium in the diet of Nile tilapia (Oreochromis niloticus) broodstock. The aim of this study to test the effect of organic selenium supplementation in the diets of Nile tilapia broodstock. Growth, reproductive performance and performance of fingerlings were evaluated. Eighty adult fish were used, with average weight of 121.7 g and divided into groups of four animals (3 female and 1 male) stocked in 20 tanks with 1.5 cubic meters. The fish were fed five diets containing different levels of organic selenium (0.0, 0.25, 0.50, 0.75, and 1.0 mg kg -1 ration). In the experimental period, females from all tanks were captured and the eggs collected. The experimental design was entirely randomized, with five treatments and four replicates. To evaluate progeny performance, the fingerlings were shared in four aquariums and fed during 30 days with commercial diet (45% CP). The supplementation with organic selenium did not affect the productive performance as with the reproductive parameters of the broodstock (p > 0.05). On the other hand, the broodstock fed with 0.50 mg of organic selenium produced fingerlings that presented improved weight gain (p < 0.05) compared to fish fed the control diet.

Effect of Organic Selenium Supplementation on Growth, Se Uptake, and Nutrient Utilization in Guinea Pigs

Forty weaned male guinea pigs (Cavia porcellus) of 152.6 +/- 7.96 g mean body weight were divided into four equal groups and fed a common basal diet comprised of 25% ground cowpea (Vigna unguiculata) hay, 30% ground maize (Zea mays) grain, 22% ground gram (Cicer arietinum) grain, 9.5% deoiled rice (Oryza sativa) bran, 6% soybean (Glycine max) meal, 6% fish meal, 1.5% mineral mixture (without Se), and ascorbic acid at 200 mg/kg to meet their nutrient requirements along with 0, 0.1, 0.2, and 0.3 ppm of organic selenium (Se) in groups I, II, III, and IV, respectively. Experimental feeding lasted for a period of 10 weeks, during which, daily feed intake and weekly body weights were recorded. Intake and digestibility of dry matter, organic matter, ether extract, crude fiber, and nitrogen-free extract as well as uptake of calcium and phosphorus were similar (P > 0.05) among the four groups. Feed:gain ratio was also similar (P > 0.05) in the four groups. However, digestibility of crude protein was significantly (P < 0.001) higher in group II supplemented with 0.1 ppm organic Se as compared to other three group. Intake and absorption of Se was significantly (P < 0.001) higher in all the Se supplemented groups as compared to control group. Average daily gain (ADG) was significantly (P < 0.05) higher in group II (3.16 g/day) and III (3.38 g/day) as compared to group I (2.88 g/day). However, ADG in group IV (supplemented 0.3 ppm organic Se) was significantly (P < 0.05) lower (2.83 g/day) than group II and III, but comparable (P > 0.05) to group I. Findings of the present experiment suggests that Se requirements of guinea pigs are > or =0.2 ppm, as supplementation of 0.1 ppm organic Se in the diet (having 0.1 ppm Se) not only enhanced their growth rate but also improved the protein utilization.

The effects of organic selenium supplementation on the rumen ciliate population in sheep

The effect of selenium supplementation on the rumen protozoan population of sheep was demonstrated. Both the total and generic counts of rumen ciliates in sheep fed a diet with basal Se content (70 microg/kg dry matter) were compared to those of animals given feed supplemented with inorganic (disodium selenite) or organic Se (selenized yeast) (310 microg/kg dry matter). The genera of Entodinium, Isotricha, Dasytricha, Ophryoscolex, Diploplastron and Polyplastron occurred in all sheep except for the control, in which Ophryoscolex was not observed. The population of Ophryoscolex caudatus f. tricoronatus was significantly higher in sheep supplemented with organic Se than in animals given inorganic Se (by 160 %). Supplementation of feed with selenized yeast induced significant growth in the Diploplastron population (by 63 %) while no change occurred in sheep given selenite. The populations of Dasytricha ruminantium and Polyplastron multivesiculatum were higher than control in both Se-supplemented groups. The ciliate population of Entodinium spp. was not influenced by Se supplements. Our results suggest a protective effect of Se feed supplementation on the development of some rumen ciliate species in young ruminants.

Selenium status and the effect of organic and inorganic selenium supplementation in a group of elderly people in Denmark.

The selenium status of 57 elderly people (> or = 65 years) has been investigated on the basis of selenium concentration in serum, whole blood and erythrocytes and on the basis of the activity of the selenium-dependent enzyme glutathione peroxidase (GSH-px) in erythrocytes and plasma. Thirty-six elderly subjects participated in a 4-month trial of supplementation: 12 subjects were supplemented with 125 micrograms organic selenium, 12 subjects were supplemented with 125 micrograms inorganic selenium and 12 subjects participated as controls. The results showed that the selenium status of the elderly people was not significantly lower than that of younger people (p > 0.05). The effect of organic and inorganic selenium on the activity of GSH-px in plasma and erythrocytes showed a nearly identical increase (25-35%) during the period of supplementation. The effect of inorganic selenium supplementation caused a 30% increase in selenium concentration in plasma and erythrocytes which stabilized after 4 weeks. The effect of organic selenium supplementation on selenium concentration in plasma and erythrocytes showed an increase of up to 100% and 120% during the period of supplementation.