Blood Se Concentrations Research Articles

SELENIUM STATUS AND TOTAL BLOOD ANTIOXIDANT ACTIVITY IN RUSSIAN PARTURIENT WOMEN AND THEIR NEWBORNS

The aim: To study selenium (Se) status in Russian parturient women and their newborns as well as total serum blood antioxidant activity (AOA) as one of the integral indices of newborn and woman resistance to oxidative stress during labour. Methods: 81 mother-child pairs were enrolled in the opened, prospective medical observation. 51 pairs were from Moscow and 29 - from the other Russian town - Ryazan with lower socio-economic conditions of population life comparatively to Moscow. Selenium contents in serum blood of women and cord blood were measured by microfluorimetric method. Total serum blood AOA was determined by evaluation of malonic dialdehyde production decrease in egg yolk lipoproteins after adding to them of serum blood specimens. Results: Mean level of Se in serum blood was 75.7 ± 2.2 mkg/l (M ± m) in Moscow women, and 53.1 ± 2.2 mkg/l in Ryazanian women. Mean Se level in cord blood was 53.8 ± 1.4 mkg/l in Moscow and 44.3 ± 1.9 mkg/l - in Ryazan. The difference between cities was significant in both cases. Se status of Russian parturient women and their newborns was lower comparatively to normal levels according to the literature data (95-110 mkg/l for pregnant women and 81 mkg/l for newborns, respectively). Se content of cord blood correlated significantly with Se content in blood of women. Total serum cord blood AOA in Moscow as well as at Ryazan was higher then in parturient women blood. Total AOA depended on Se cord blood content but only at a range of Se level 50-95 mkg/l of cord blood. Summary: The Se status of Russian parturient women and their newborns is not optimal, especially at Ryazan, and needs in improvement. Total AOA is significantly higher in cord blood than in womens` blood. Total AOA correlated with Se blood level only in cord blood where Se level was in some cases very low. Conclusion: Se status of newborns depends on Se status of parturient women. The data received demonstrate the necessity to enrich the pregnant women diet with Se. Low Se status may be one of the factors limiting an increase of blood AOA necessary for prevention of oxidative stress in some physiological conditions that demand significant increase of blood AOA.

Status of selenium and vitamin E on Norwegian organic sheep and dairy cattle farms

Herbage selenium (Se) concentration is generally low in Norway. It is unknown whether feeding practices on Norwegian organic farms fulfil the dietary needs of Se and vitamin E for sheep and dairy cattle. Therefore we analysed Se in soil and herbage, and Se and vitamin E in animal blood in the indoor feeding season at 14 organic dairy and 14 organic sheep farms. The herbage Se concentration was low. Approximately 50 and 35% of all samples in the first and second cut, respectively, had Se concentrations below the detection limit of 0.01 mg/kg dry matter (DM). The median (10th, 90th percentile) Se concentrations were <0.01 (<0.01, 0.03) and 0.02 (<0.01, 0.06) mg/kg DM in the first and second cuts, respectively. Whole blood Se concentrations were 0.10 (0.04, 0.15) μg/g in dairy cattle and 0.14 (0.03, 0.26) μg/g in sheep. Vitamin E concentrations were 4.2 (2.7, 8.4) mg/l in dairy cattle and 1.3 (0.9, 2.4) mg/l in sheep. None of the soil or plant variables explained the variation in herbage Se concentration, although Se in soil and plant tended to be correlated. Herbage Se concentration was inadequate to meet the dietary Se requirements. Vitamin E requirement was only met in dairy herds. We recommend Se and vitamin E supplementation to ruminants on organic farms.

The relationship between whole blood selenium (Se) concentration and the activity of the seleno-enzyme, glutathione peroxidase (GSH-Px, E.C.I.11.1.9) in camel ( Camelus dromedarius)

The concentration of Se and the activity of the enzyme glutathione peroxidase (GSH-Px) were investigated in the whole blood of camels. Variable concentrations of whole blood Se (0.025–0.043 μg/ml) and GSH-Px activity (6.32–18.64 EU/ml) were demonstrated in both sexes, with females having significantly higher ( P < 0.001 ) blood Se concentration and GSH-Px activity than males. A highly significant correlation ( r = 0.88 , P < 0.001 ) has been demonstrated between whole blood Se concentration and the activity of the enzyme GSH-Px.

Effects of Feeding Supplemental Organic or Inorganic Selenium to Cow-Calf Pairs on Selenium Status and Immune Responses of Weaned Beef Calves

In current marketing channels, calves are purchased with little indication of nutritional status on which a fully functional immune system is dependant. Adequate immune function in recently weaned calves is required for development of disease resistance. At weaning, 18 spring-born steer calves (BW = 200 ± 5.2 kg) were randomly selected from six groups of 20 cows to test the effects ofSe supplementation and source of Se fed pre-weaning on Se status and immune function of calves after weaning. Mineral supplements supplying no Se, 26ppm of Se from sodium selenite, or 26ppm of Se from Se-yeast were fed in a free-choice mineral supplement. After weaning, calves were fed bermudagrass (Cynodon dactylon [L.] Pers.) hay and 1.40kg of supplement daily. Selenium status and immune characteristics of calves 22 d after weaning were tested by analysis of whole blood Se, glutathione peroxidase (GTH-Px) activity, lymphocyte proliferation, macrophage phagocytosis, and interferon-γ (IFN) production. In vivo cell-mediated immunity was tested by skin-swelling response to an intradermal phytohemagglutinin (PHA) injection. Whole blood Se concentrations and GTH-Px activities (54.7ppm and 40.2 Eu/gHb, respectively) suggested Se deficiency of control calves. Supplementation with Se increased (P<0.01) whole blood Se concentration and GTH-Px. Seleniumyeast increased (P<0.01) whole blood Se concentration and macrophage phagocytosis compared with sodium selenite. In vivo cell-mediated immune response tended (P=0.12) to increase with Se supplementation. Supplementation of cow herds with Se before weaning increases Se status of weaned calves in areas where Se deficiency may be a problem.

Effect of selenium-vitamin E injection in selenium-deficient dairy goats and kids on the Mexican plateau

Three experiments were carried out to determine the optimum selenium-vitamin E injection level to maintain acceptable blood selenium (Se) status of does and kids, as well as to determine the relation of that status to mortality rates in kids. In experiment 1, 238 goats were assigned to one of three groups during the mating period: A1-control, A2- 0.06mgSe+0.8IU vitE/kgBW and A3-0.125mgSe+1.7IU vitE/kgBW. No differences (P&gt;.05) for fertility and prolificacy were observed among the groups. Blood Se concentration did not differ among Se-vit E groups and control group before injection, and both groups showed Se deficient condition. There was a trend (P&lt;.05, 32%) to increase Se blood level 60 days post-treatment, but difference was not observed between A2 and control groups, while difference (P&lt;.05; 103%) was observed between A1 and A2 groups vs high Se injection (A3 group). In experiment 2, 48 goats were divided into four groups: B1- control, B2- 0.125mgSe+1.7IU vitE/kgBW, B3- 0.25mgSe+3.4IU vitE/kgBW and B4- 0.31mgSe+4.2IU vitE/kgBW. The B4 group reached the highest concentration at the third month after injection (0.11 ppm), then started to decline after 100 days, reaching a value slightly higher than B2 and B3 on the 135th day of pregnancy. Results of B2 and B3 groups were slightly higher that those of B1 (P&lt;0.05). In experiment 3, 194 kids (3 to 7 days postpartum) born from Se-deficient goats were used to compare the effectiveness of Se injection. They were divided into three groups: C1- control, C2- 0.3mgSe+4.2IU vit E/kg BW and C3- 0.6mgSe+8.4IU vit E/kg BW. C1 showed the highest percentage of mortality (60%) as compared to treated Se groups, that scored equal percentage of deaths (22% averaged). The concentration of Se in blood, on day 20th after the onset of the treatment rapidly increased, according with level of Se injection. The 0.3mgSe/kgBW Se injection increased the blood Se concentration in pregnant goats and it was effective to prevent white muscle disease lesions, besides enhancing the survival of kids until weaning.

Blood Selenium Associated with Health and Fertility in Norwegian Dairy Herds

A survey of blood selenium (Se) concentrations in Norwegian Red heifers and dry period cows was conducted to reveal possible association to management, feeding, health and fertility. Selenium contents were determined in 254 herd blood samples consisting of pooled samples from individual non-lactating animals from herds in 5 counties. The Se concentrations showed a normal distribution with mean 0.09 μg Se/g blood, with a standard deviation (SD) of 0.05, and ranged from 0.02 to 0.23 μg/g, with 50 % of the samples being between 0.06 and 0.11 μg/g. The herds with Se concentrations below 0.06 μg/g were smaller (21.4 ± 8.7 cow-years) than those with Se levels above 0.11 μg/g (27.5 ± 14.1 cow-years) (P < 0.01), but there were no differences in milk yield, incidence of replacement, proportion of animal culling, amount of concentrate or grass silage as percentage of energy consumption between the groups. Treatment registration records showed a tendency that more animals in the low Se herds were treated for all the diseases included in this investigation (64.8 animals per 100 cow-years) than those in the high Se herds (57.5 per 100 cow-years), while no such differences were revealed for individual disorders. There was, however, a significant difference in bulk milk somatic cell counts (BMSCC) between low and high Se herds, their values being 137 000 and 155 000 cells/ml, respectively. This difference was significantly influenced by herd size. Furthermore, a total of 4 916 lactations were analyzed from individual health and fertility recordings, including 2 934 first lactations and 1 982 later lactations. The present study revealed a reduced incidence of disease treatment with increased Se concentrations from 0.02 to 0.23 μg Se/g blood. In this regard, there seemed to be an optimum of 0.10 to 0.15 μg Se/g for all types of mastitis treatments summarized, and for treatment of retained placenta. Thus, herd Se concentrations below and above these values was connected with increased probability for sum mastitis and retained placenta, reflecting the effect of the quadratic term of Se. The cow (composite) milk somatic cell count (SCC) was lower in lactations from low Se herds than in high Se herds with a marked SCC increase in the Se concentration interval from 0.11–0.13 μg/g blood. In conclusion, heifers and dry period cows in Norway are low in blood Se content and there seems to be a positive association between increased blood Se concentration pre partum and decreased incidence of mastitis, ovarian cysts and anoestrus/silent oestrus post partum.

셀레늄급원으로 셀레늄강화버섯 폐배지의 급여가 거세한우의 도체특성, 혈중 GSH-Px활성 및 조직내 셀레늄축적에 미치는 영향

본 연구는 셀레늄급원으로 셀레늄강화버섯 폐배지(Se-SMC)를 거세한우에 급여하였을 때, 도체특성, 혈중 GSH-Px활성 및 조직내 셀레늄축적에 미치는 영향을 조사하기 위하여 실시하였다. 본 실험에 사용된 셀레늄급원은 유기셀레늄강화버섯을 생산한 후 폐기되는 버섯폐배지를 활용하였으며, 일반폐배지(SMC)를 조합하여 실험사료의 셀레늄 농도를 0.1, 0.3, 0.6, 0.9 ppm(건물기준)의 4처리구로 설정하였다. 실험동물은 비육후기 거세한우 20두(평균체중 613 kg, 20 <TEX>${\sim}$</TEX> 24개월령)를 공시하여, 처리구간 5두씩 배치하여 실험사료를 12주간 급여하였다. 실험기간 중 채혈하여 혈중 셀레늄농도와 혈장내 GSH-Px활성을 측정하였고, 근육(등심, 후지)과 간내 셀레늄함량과 도체특성을 측정하기위해 시험 후 도축하였다. Se-SMC의 보충으로 증가된 셀레늄수즌은 건물섭취량과 증체량에 영향을 미치지 않았고, 높은 농도의 처리군에서 중독증상은 발견되지 않았다. 도체특성 또한 처리구별 유의적인 차이를 나타내지 않았다. 혈중 셀레늄농도와 혈장내 GSH-Px활성은 Se-SMC 급여수준이 증가함에 따라 직선적으로 유의하게 증가하였다(P<0.01). 근육과 간내 셀레늄함량은 후지 및 간에서 사료중 셀레늄함량이 증가함에 따라 각각 건물 g당 0.27, 0.37, 0.40, 0.46<TEX>$\mu$</TEX>g 및 0.79, 1.40, 2.39, 3.10 <TEX>$\mu$</TEX>g를 나타내어 유의하게 증가하였다(P<0.05). 하지만, 등심내 셀레늄함량은 처리구간 유의적인 차이를 보이지 않았다. 이상과 같이 Se-SMC에 존재하는 셀레늄은 비육후기 거세한우에서 혈중 셀레늄농도와 GSH-Px활성을 유의하게 증가시킬 뿐만 아니라, 조직내 셀레늄함량을 증가시켜 저렴한 생산비로 셀레늄강화 쇠고기의 생산이 가능할 것으로 판단된다. This study was conducted to determine effects of spent composts of Se-enriched mushrooms (Se-SMC) as the dietary selenium source on carcass characteristics, plasma glutathione peroxidase(GSH-Px) activity and Se deposition in finishing Hanwoo steers. In combination with both Se-SMC and normal SMC, experimental treatment diets were formulated to contain 0.1, 0.3, 0.6 and 0.9 ppm of Se on a dry matter basis. A total of 20 finishing Hanwoo steers (average BW = 613 kg, average age = 20 to 24 mo) were allotted to treatments in four groups of five steers per pen for 12 wk preceding slaughter. While the experiment is employed, blood samples were taken to analyze Se concentration and GSH-Px activity, and muscle and liver samples were collected for analyses of Se contents in their tissues after slaughter. DMl and BW gain were not affected by dietary Se level and any toxic symptoms in treatments with a higher level of Se were not observed. No differences were noted for carcass characteristics. Se concentration in whole blood and plasma GSH-Px activity were linearly increased with the increasing level of dietary Se (P < 0.01). Se content in the hind leg for Se-SMC supplemented groups significantly increased (P < 0.05) upon dietary Se level, with 0.27, 0.37, 0.40 and 0.46 !1g1g dry, respectively. However, Se content in the loin was not affected by dietary Se levels. Se content in the liver was significantly increased(P < 0.05) as dietary Se increased, with 0.79, 1.40, 2.39 and 3.10 !1g1g dry, respectively. These results suggested that Se in the Se-SMC was highly bioavailable, and Se-SMC might be used not only as an inexpensive way of providing Se for ruminants but also as another way of producing Se-fortified beef.

Is Leucaena leaf useful as a selenium supplement for growing Philippine goats?

ABSTRACTThe effects of Leucaena leucocephala leaf (LL) supplementation on selenium (Se) status of growing Philippine goats were determined in the present study. A total of 12 3–4 month old male goats with mean bodyweight of 8.8 kg was used. All animals received a basal diet comprised of different forages. Six of the animals were supplemented with LL (22.9% CP) while the remaining six animals were not supplemented (control). The rate of LL to the total forage diet offered to the LL‐supplemented animals was 25%. Bodyweight measurement, blood and forage sampling were carried out every 2 weeks during the 4 months of experiment. Selenium, sulfur, calcium, phosphorus, magnesium, copper and zinc concentrations were analyzed after wet digestion. Leucaena leaf seemed to have higher Se and calcium, but lower copper and zinc concentrations than was observed in grasses fed to the animals. Bodyweight of growing goats in LL‐supplemented group tended to be higher than that of control animals. Supplementation of LL resulted in high whole blood Se concentration of growing goats. In the last month of this experiment, whole blood in all supplemented animals contained higher Se concentration than the deficient level of 20 ng/mL, while Se concentration in the control group was slightly above the deficient level.

Tolerance of inorganic selenium in wether sheep

This experiment evaluated the maximum tolerable level of inorganic Se fed to growing wether lambs for 1 year. Sodium selenite was added to provide 0.2, 2, 4, 6, 8, and 10 ppm Se to a basal diet. Thirty-nine crossbred wether lambs initially weighing 22.8 ± 3.3 kg were randomly allotted to one of six treatments. Blood samples were collected and liveweight gain determined at 28-day intervals and tissue samples were collected at experiment termination. Serum, whole blood, wool, hooves, bile and five tissues were analyzed for Se concentrations. Five tissues at experiment termination were microscopically evaluated for tissue breakdown due to Se toxicosis. Also, five enzyme activities and albumin were determined. Lamb BW were not influenced by dietary Se concentrations ( P > 0.15). Both serum and whole blood Se concentrations increased at each collection period as dietary Se level increased ( P < 0.01) and the serum had a dietary Se level × time interaction ( P < 0.01). The whole blood Se concentration was two to three times greater than serum Se concentration. There was a strong positive correlation ( r = 0.92) between serum and whole blood Se concentration. At termination of the study, all tissues and wool, hoof, and bile Se concentrations increased as dietary Se level increased ( P < 0.01). Liver had the highest Se concentration followed by the kidney in all but the lowest treatment of 0.2 ppm. Both gross and microscopic evaluation of tissues revealed no significant lesions for any treatment groups. There was no apparent pathological suggestion of selenosis based on tissue evaluation. Albumin and serum enzyme levels suggestive of tissue breakdown as a result of selenosis did not vary ( P > 0.15) among treatments, and enzymes were within their respective normal ranges. These results suggest that ≤10 ppm dietary Se as selenite is not toxic to wether lambs when fed for 1 year. It seems plausible, therefore, to consider the maximum tolerable level of Se as selenite for sheep to be considerably higher than 2 ppm as previously suggested.

Maternal-fetal status of copper, iron, molybdenum, selenium and zinc in insulin-dependent diabetic pregnancies.

The objective was to assess the status of essential trace elements such as copper, iron, molybdenum, selenium and zinc in insulin-dependent diabetic pregnancies at term and to compare the data with a control group. Fetal-maternal ratios of the elements and copper:zinc ratio were also computed in the control and study populations. Samples from maternal vein, umbilical artery and umbilical vein of diabetic and control women were collected at the time of spontaneous delivery or cesarean section and activities of trace elements evaluated by atomic absorption spectrophotometry. Cu, Fe, Mo, Se and Zn concentrations in maternal venous blood averaged 2,156, 2,020, 13, 102 and 656 microg/l in control women (n=17) while in the diabetic group (n=14), the corresponding values for the trace elements averaged 3,135, 3,675, 15, 85 and 628 microg/l respectively. Values for copper and molybdenum were significantly higher (p<0.05) in the study group compared to control while those of zinc, iron and selenium were not significantly different (p>0.05). Iron and molybdenum values were significantly higher (p<0.05) and that of zinc significantly lower (p<0.05) in umbilical arterial samples of diabetic group compared to controls. In the case of molybdenum, copper the values were significantly higher (p<0.05) in umbilical venous samples of diabetic group compared to that of control. Significant differences in Cu:Zn ratio of maternal venous and umbilical samples and fetal-maternal ratios of some elements were noted between control and study group as well. We speculate that altered status of some essential trace elements and altered antioxidant mineral ratio observed in insulin dependent diabetic patients could have deleterious influences on the health of the mother as well as the fetus and newborn.

Selenium status in Greenland Inuit

In Greenland, the human intake of selenium has always been relatively high and is closely connected to intake of the traditional food of marine origin. Analyses of historic and present day human and animal hair samples have indicated that the selenium level in the marine environment has been constant over time, while the levels in humans have declined corresponding to a decrease in intake of traditional food. The Inuit population in Greenland is in dietary transition where western-style food will increasingly dominate. As a consequence, the ample supply of selenium may not be sustained in the future. We report here the selenium status in three Greenlandic population groups, Ittoqqortoormiit and Tasiilaq on the east coast and Uummannaq on the west coast. Mean whole blood concentrations ranged from 178 μg/l in Tasiilaq men to 488 μg/l in Uummannaq men. Plasma concentrations ranged from 79 μg/l in Tasiilaq women to 113 μg/l in Uummannaq men. With increasing Se concentrations in whole blood, the plasma concentrations increased but tended to stabilise a level approximately 140 μg/l. Selenium blood levels were highly significantly correlated with long chain marine fatty acids. Dietary survey and food composition data from the west coast showed that whale skin, muktuk, is the main source of Se followed by birds, seal meat and organs, and fish. Terrestrial animals contributed only insignificantly to the selenium intake. In West Greenland, daily Se intake (235 μg/day) was estimated by dietary survey; it corresponded well with a calculated intake (220 μg/day) based on the mean blood concentration.

Selenium and glutathione peroxidases in blood of patients with different stages of chronic renal failure

In patients with chronic renal failure (CRF) Se concentration in blood components is usually lower as compared with healthy controls. One of the five known forms of Se-dependent glutathione peroxidases (GSH-Px), the plasma GSH-Px, is synthesized primarily in the kidney. In CRF patients, plasma GSH-Px activity is reduced and the reduction increases with the progress of the disease. The Se concentration in blood components was measured spectrofluorometrically with 2,3-diaminonaphthalene as complexing reagent. Activities of GSH-Px in red cells and in plasma were assayed by the coupled method with t-butyl hydroperoxide as substrate. The study group consisted of 150 patients in different stages of CRF. The results were compared with the values for 30 healthy subjects. Se concentrations in whole blood and plasma of the entire group of patients were significantly lower (p < 0.01) as compared with the healthy subjects. In the incipient stage, however, the Se levels in all blood components were non-significantly lower. In whole blood and plasma the Se levels gradually decreased, reaching in the end stage values that were lower by 29 to 32% (p < 0.0001) as compared with the control group. Total protein and albumin levels in plasma of patients were significantly lower (p < 0.0001) as compared with healthy subjects and they decreased linearly with the progress of the disease. Positive and highly significant correlations were noted between total plasma protein and plasma Se concentrations (p < 0.0001) as well as between plasma albumin and plasma Se concentrations (p < 0.0001). Red cell GSH-Px activity in the entire group of patients was lower (p < 0.05) than in the control group and did not change significantly with the progress of the disease. In plasma, however, GSH-Px activity of the entire group was lower by 33% (p < 0.0001) as compared with healthy subjects and decreased gradually with increasing renal failure. Highly significant, inverse correlations were seen between creatinine levels and plasma GSH-Px activities (p < 0.0001) as well as between urea nitrogen levels and plasma GSH-Px activities (p < 0.0001) when all stages of the disease were included. In conclusion, patients with CRF exhibit lower Se levels in blood components as compared with healthy subjects. In whole blood and plasma these levels decrease with the progress of the disease. Plasma GSH-Px activity in patients was extremely reduced and it dramatically decreased with the progress of the illness.

Gestational changes in concentrations of selenium and zinc in the porcine fetus and the effects of maternal intake of selenium.

The effect of maternal dietary selenium (Se) and gestation on the concentrations of Se and zinc (Zn) in the porcine fetus were determined. Mature gilts were randomly assigned to treatments of either adequate (0.39 ppm Se) or low (0.05 ppm Se) dietary Se. Gilts were bred and fetuses were collected throughout gestation. Concentrations of Se in maternal whole blood and liver decreased during gestation in sows fed the low-Se diet compared to sows fed the Se-supplemented diet. Maternal intake of Se did not affect the concentration of Se in the whole fetus; however, the concentration of Se in fetal liver was decreased in fetuses of sows fed the low-Se diet. Although fetal liver Se decreased in both treatments as gestation progressed, the decrease was greater in liver of fetuses from sows fed the low- Se diet. Dietary Se did not affect concentrations of Zn in maternal whole blood or liver or in the whole fetus and fetal liver. The concentration of Se in fetal liver was lower but the concentration of Zn was greater than in maternal liver when sows were fed the adequate Se diet. These results indicate that maternal intake of Se affects fetal liver Se and newborn piglets have lower liver Se concentrations compared to their dams, regardless of the Se intake of sows during gestation. Thus, the piglet is more susceptible Se deficiency than the sow.

Microelements in Colostrum and Blood of Cows and their Calves during Colostral Nutrition

Pavlata L., A. Pechova, R. Dvofiak: Microelements in Colostrum and Blood of Cows and their Calves during Colostral Nutrition. Acta Vet. Brno 2004, 73: 421-429. The goal of the study was to use evaluation of blood and colostrum selenium (Se), copper (Cu) and zinc (Zn) concentrations of cows and the same blood concentrations of calves during the period of colostral nutrition to study differences in the metabolism of the different microelements in the mother and its young. Blood was collected from 12 cows and their calves before first intake of colostrum on the calving day and then at the end of the period of colostral nutrition to determine Se, Cu and Zn concentrations. First colostrum was collected from all cows. Se concentration was determined from whole blood and colostrum samples using hydride technique AAS. Cu and Zn concentrations were determined from colostrum and blood serum using flame AAS. The cows under examination were shown to have average concentrations of Se of 0.87 ± 0.30 and 0.47 ± 0.15 µmol·l -1 in whole blood and colostrum respectively, of Cu 8.95 ± 1.95 and 5.37 ± 1.80 µmol·l-1 in blood serum and colostrum respectively, and of Zn 11.62 ± 2.35 and 416.76 ± 120.07 µmol·l -1 in blood serum and colostrum respectively. Blood of calves before the first intake of colostrum was characterized by a significantly higher ( p < 0.001) mean concentration of Zn (25.88 ± 8.79 µmol·l -1 ) and a significantly lower ( p < 0.001) concentration of Cu (3.23 ± 1.08 µmol·l-1) compared with the mothers. Blood Se concentration of the calves (0.91 ± 0.26 µmol·l-1) was not significantly different from blood Se concentration of the cows. A significant increase ( p < 0.001) in blood Cu concentration of the calves to 7.53 ± 1.98 µmol·l-1 and an insignificant increase in the mean Zn and Se concentrations to 26.40 ± 6.58 µmol·l -1 and 0.93 ± 0.32 µmol·l -1 respectively occurred during colostral nutrition. Correlation analysis showed a significant correlation ( p < 0.01) between blood Se concentrations of the mothers and their newborn calves (r = 0.72). No significant correlation was found between Cu and Zn concentrations of cows and their calves. No significant relation between blood and colostrum concentrations of the different microelements of cows was found either. We have shown major differences as to the parameters of the micromineral metabolism under examination at the level of the mother/young relationship. While the calf organism can accumulate Zn throughout the intrauterine development and Zn is cumulated in cow colostrum, too, serum Cu concentrations of newborn calves are significantly lower compared with the mothers and colostrum Cu concentrations reach just about 60% of serum Cu concentrations of the cows. Although blood Cu concentration of calves increases throughout the period of colostral nutrition, it does not reach the level of serum Cu concentration of the mother by the end of the period. The Se status of newborn calves is similar to that of the mother cows and just like with Cu, Se is not cumulated in colostrum to any significant extent. Selenium, zinc, copper, placental transfer, cattle, metabolism, mother-young relation Selenium (Se), copper (Cu), and zinc (Zn) are microelements ranking among substances with biological activity in intermediate metabolism. They get into the organism mainly as components of animal diet and their transplacental transfer is an important factor in the young. The level of absorption and retention of microelements is modulated by their actual levels in the organism and their concentrations in the diet and is generally higher for intake of their organic forms ( Knowles et al. 1999; C a o et al. 2000; Pavlata et al. 2001;

Urinary selenium excretion in selenite-loaded sheep and subsequent Se dynamics in blood constituents

Renal selenium excretion in sheep was measured during intravenous infusion of sodium selenite, and the post-infusion dynamics of Se levels in whole blood, plasma and red blood cells (RBC) were investigated for the next 5 days. The plasma Se level increased almost twenty fold with the infusion of Na2SeO3 (from 0.39 +/- 0.02 to 7.83 +/- 0.33 micromol x L(-1), P < 0.001) compared with the baseline value. The selenium concentration in urine (0.07 +/- 0.02 vs. 18.53 +/- 2.56 micromol x L(-1), P < 0.001), the amount of Se excreted (0.14 +/- 0.07 vs. 21.40 +/- 2.31 nmol x min(-1), P < 0.001) and the renal clearance of Se (0.1 9 +/- 0.03 vs. 3.01 +/- 0.34 mL x min(-1), P < 0.001) were found to be highly significantly elevated during selenite loading. The clearance measurements showed no changes in the urinary flow rate or in the glomerular filtration rate. During and at the end of infusion the highest Se level was attained in plasma, followed by whole blood and RBC. The plasma Se level fell rapidly within 10 min after the end of infusion, but the concentration of Se in RBC was stable up to the fourth hour, when it started to decrease too. On day 5 the Se concentrations in plasma, RBC and whole blood were found to be only slightly but still significantly higher than before the selenite infusion. The large disproportion between the infusion rate of Se (8.76 microg x min(-1)) and its renal excretion rate (1.69 microg x min(-1)) found in clearance measurements suggests low glomerular filtration of infused selenium, which might primarily be caused by the binding of selenite metabolites to blood constituents. The presented results confirm the low bioavailability to ruminants of Se from sodium selenite.

Effects of supplementary selenium source on the performance and blood measurements in beef cows and their calves.

On December 2, 1999, 120 pregnant cows were weighed, their body condition scored, and then sorted into six groups of 20 stratified by BCS, BW, breed, and age. Groups were assigned randomly to six, 5.1-ha dormant common bermudagrass (Cynodon dactylon [L.] Pers.) pastures for 2 yr to determine the effects of supplemental Se and its source on performance and blood measurements. During the winter, each group of cows had ad libitum access to bermudagrass/dallisgrass (Paspalum dilatatum Poir.) hay plus they were allowed limited access (1 to 4 d/wk) to a 2.4-ha winter-annual paddock planted in half the pasture. Treatments were assigned randomly to pastures (two pastures per treatment), and cows had ad libitum access to one of three free-choice minerals: 1) no supplemental Se, 2) 26 mg of supplemental Se from sodium selenite/kg, and 3) 26 mg of supplemental Se from seleno-yeast/kg (designed intake = 113 g/cow daily). Data were analyzed using a mixed model; year was the random effect and treatment was the fixed effect. Selenium supplementation or its source had no effect (P > or = 0.19) on cow BW, BCS, conception rate, postpartum interval, or hay DMI. Birth date, birth weight, BW, total BW gain, mortality, and ADG of calves were not affected (P > 0.20) by Se or its source. Whole blood Se concentrations and glutathione peroxidase (GSH-Px) activity at the beginning of the trial did not differ (P > or = 0.17) between cows receiving no Se and cows supplemented with Se or between Se sources. At the beginning of the calving and breeding seasons, cows supplemented with Se had greater (P < 0.01) whole blood Se concentrations and GSH-Px activities than cows receiving no supplemental Se; cows fed selenoyeast had greater (P < or = 0.05) whole blood Se concentrations than cows fed sodium selenite, but GSH-Px did not differ (P > or = 0.60) between the two sources. At birth and on May 24 (near peak lactation), calves from cows supplemented with Se had greater (P < or = 0.06) whole blood Se concentrations than calves from cows fed no Se. At birth, calves from cows fed seleno-yeast had greater (P < or = 0.05) whole blood Se concentrations and GSH-Px activities than calves from cows fed sodium selenite. Although no differences were noted in cow and calf performance, significant increases were noted in whole blood Se concentrations and GSH-Px activities in calves at birth as a result of feeding of seleno-yeast compared to no Se or sodium selenite.

Influence of short-term supplementation of various quantities of organically bound selenium upon serum and urine selenium concentration

To assess satisfactory supplemental load of selenium for persons with very low Se status, serum Se by neutron activation analysis and urine Se by fluorimetry have been followed in 3 groups of participants of the supplemental test. Supplementation was performed with 100 or 50 μg Se/day or with placebo after determination of basic Se status, which was very low (48 μg Se/1 serum, 10 μg Se/1 urine, urine excretion 11.7 μg Se/day, 16.9 μg Se/g creatinine). Basic Se intake calculated on the grounds of analyses of the whole day-whole week diet of the boarding home was about 30 μg Se/day. Serum Se of both supplemented groups increased continuously and significantly to 115 μg Se/1(100 pg Se/day) or 86 μg Se/1(50 μg Se/day). The placebo group was without significant changes. As for urine, the group supplemented by 100 μg Se/day presented continuous significant increase in urine excretion to 26 μg Se/day while the group supplemented by 50 μg Se/day reached maximum of 20 pg Se/day in 12 days with subsequent decrease to 18 pg Se/day in 41st day of the test. In conclusion, supplement of 50 pg Se/day (in the opposite to supplement 100 pg Se/day) seems insufficient to cover both increase in blood Se content and repletion of tissue Se, and additionally to increase urine Se excretion in very Se-depleted organism in the first stages of the supplementation.

Effects of Intraruminal Soluble Glass Bolus on Blood Selenium and Plasma Mineral Level of Grazing Does under Backyard Conditions in Selected Areas in Nueva Ecija, Philippines

Soluble glass bolus with selenium (Se), copper (Cu) and cobalt (Co) was administered intraruminally to Philippine grazing does fed under backyard farming conditions to determine its effect on blood mineral status. Forty-five does were dosed with SGB intraruminally every 6 months, whereas 15 were without SGB during this experimental period of 10 months. Blood of does in both treatment groups were collected every other month and blood Se, plasma Cu, Ca, P and Mg were determined in this study. All does did not show clinical Se, Cu, Ca, P or Mg deficiency during this experimental period. Selenium concentration of treated does increased (p<0.01) after beginning of this experiment, whereas the level of control does decreased slowly (p<0.01). Two months after SGB administration, all treated does had higher blood Se than the lower limit of 20 µg/l suggested by NRC (1981), whereas some control does had lower blood Se concentration than the lower limit of 20 µg/l. On the other hand, plasma Cu concentration of treated does started to increase more remarkably than control does 4 months after this experiment had started although the difference was insignificant. There were no significant differences between plasma Ca, P or Mg concentration of does in both treatment groups. Soluble glass bolus had no harmful effects on plasma macro mineral concentrations of grazing does. This study showed that SGB was available as mineral supplement to improve imbalances of selected mineral of grazing goats in the traditional backyard conditions in Luzon Island, Philippines. (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 2 : 189-197)

Concentrations of trace elements in eggs and blood of spectacled and common eiders on the Yukon-Kuskokwim Delta, Alaska, USA

We examined the relations among nesting success, egg viability, and blood and egg concentrations of As, Cd, Pb, Hg, and Se in a threatened population of spectacled eiders (Somateria fischeri) and a sympatric population of common eiders (S. mollissima) on the Yukon-Kuskokwim Delta, Alaska, USA, during 1995 and 1996. During the early breeding season, males and females had mean Se concentrations in their blood of 19.2 microg/g and 12.8 microg/g wet weight, respectively. Blood Se concentrations of females were correlated with egg concentrations. During brood rearing, blood Se levels were higher in adult females than in ducklings. Blood concentrations of Pb in spectacled eider females were higher than in common eider females captured at hatching, but blood concentrations of Se were similar. Trace element concentrations were not related to nest success or egg viability. We submit that nest success and egg viability of spectacled eiders are not related to concentrations of the trace elements we measured. Because blood Se concentrations declined rapidly through the breeding season and were not related to nest success or egg viability, we suggest that spectacled eiders are exposed to high concentrations of Se during winter that pose little threat to this population.

A reference curve using blood selenium concentration to diagnose selenium deficiency and predict growth responses in lambs

AIMS: To quantify the relationship between blood selenium (Se) concentration and growth response to Se supplementation in lambs, in order to assess the reliability of current reference ranges and to predict the magnitude of likely responses to supplementation. METHODS: Data from 24 Se-supplementation growth-response trials which used the following general protocol were collated and analysed: in each trial, weaned lambs (n=20–30) were allocated randomly to untreated or to Se-supplemented groups. Supplemented groups received 5 mg Se/month as Na2SeO3 in 20 trials, and 1 mg Se/kg liveweight as BaSeO4 in 4 trials. The duration of the trials was 150–196 days, during which time all lambs were weighed every 4–6 weeks and blood samples were taken at various intervals from 10 lambs/group. RESULTS: Among the 24 trials, flock mean blood Se concentrations of the untreated lambs ranged from 32–569 nmol/l, and growth rate of supplemented lambs was -3 to 63g/day higher than that of untreated lambs. The relationship between blood Se concentration (X) and growth response (Y) was described by the following hyperbolic-decay equation: Y = -2.6 (SE 3.6) + 1850 (SE 230) / X (R2=0.74). CONCLUSIONS: For Se-deficient lambs, the potential for a growth response to Se supplementation was strongly related to blood Se concentration. Economically significant liveweight gains of >10 g/day were observed when initial blood Se concentrations were <130 nmol/1. CLINICIAL RELEVANCE: Blood Se concentrations can be used to diagnose Se deficiency in lambs and to predict the magnitude of likely growth responses to Se supplementation.