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1.
Three flocks of sheep in typical selenium-deficient areas were injected with 2 ml Deposel® (100 mg selenium as barium selenate) in the autumn of 1982 and/or 1983. The selenium status in 10 ewes from each flock, and their offspring, was monitored by selenium analyses of blood samples. The injection induced an adequate increase in blood selenium within 8 weeks. Adequate selenium levels were maintained throughout the lambing season and the following summer. The selenium status in lambs from treated ewes was adequate until they were put out to pasture. Elevated selenium levels were maintained even throughout the next lambing season, and the second injection gave significantly higher blood selenium as compared to the first. The present preparation seems to be suitable and safe for protecting sheep against selenium deficiency. The dosage used seems sufficient to maintain an adequate selenium status for as long as 2 consecutive lambing seasons.  相似文献   

2.
Blood serum glutathione peroxidase activity and blood selenium concentration were measured in blood samples from pigs subjected to experimentally induced selenium deficiency and dietary selenium supplementation on graded levels. A highly significant correlation between blood selenium and serum GSH-Px activity in pigs, especially in selenium deficient pigs, was demonstrated. There was also a strong relationship between blood selenium concentration and serum GSH-Px activity in pigs receiving dietary selenium at graded levels. Serum GSH-Px activity exhibited an excellent close-response relationship to dietary selenium. Linear regression analysis showed that the increased serum GSH-Px activity was a function of the dietary selenium concentration. The fitness of serum in monitoring slight changes of the selenium status of pigs with help of the estimation of GSH-Px activity was discussed. The measurement of serum GSH-Px activity seems to provide a useful and rapid means for defining selenium requirements and for identifying selenium deficiency in growing pigs.  相似文献   

3.
The selenium status of three different classes of goats ((i) female lactating, (ii) female non-lactating, and (iii) male goats) grazing semi-arid pasture in the southern part of the Punjab province, Pakistan and that of selenium concentration of soil and dietary sources, ingested by those animals were investigated during two different seasons of the year (winter and summer). Soil, forage, feed, water from the pasture and blood plasma, urine, faeces, and (if applicable) milk from these goats were collected fortnightly. The samples were analyzed for selenium concentrations. Soil selenium showed both seasonal and sampling periods effect on its concentration while forage selenium was affected only by the seasonal changes. No significant effect of seasons or fortnights on feed selenium level was observed. In fecal samples selenium concentration in lactating and non-lactating and plasma of male goats were affected by sampling periods. While fecal selenium in male goats showed significant effect on its concentration both seasonal and within fortnights. Severe deficient level of soil selenium during both seasons and marginal deficient level of forage selenium during summer were observed. Selenium concentrations in feed slightly exceeded the requirements of ruminants in feed during both seasons of the year. Plasma selenium concentrations in all goat classes were higher in winter than that in summer showing no seasonal or fortnight variation and its concentration was slightly lower in lactating goats as compared to other classes. On the bases of these results, it is concluded that overall selenium status of the goats based on plasma selenium concentration may be considered adequate mainly due to the mineral supplement provided all over the year, since soil and forage selenium concentrations were low to deficient.  相似文献   

4.
旨在通过大田试验,探讨广西“台农一号”芒果在不同生长时期叶面喷施硒肥后芒果品质的变化及果实硒的迁移转化规律,探索硒肥溶液的最佳叶面喷施时期,为广西富硒芒果生产提供参考。根据试验地芒果生长状况,划分3个硒肥溶液喷施时期,分别为花期（FL）、幼果期（YF）和膨果期（FE）。设低浓度（F0.1：0.1%硒肥溶液）、中浓度（F0.2：0.2%硒肥溶液）和高浓度（F0.4：0.4%硒肥溶液）3个硒肥喷施浓度水平,以不喷施硒肥作为对照（CK）,共10个处理,每个处理设3次重复,共30株芒果树。分阶段采集叶片及果实样本,测定硒含量,并待芒果成熟后测定芒果可溶性固形物、Vc、可溶性糖和总酸度。结果显示：（1）叶面喷施硒肥溶液后,有机硒为芒果果实中硒主要存在形态,约占芒果果实总硒的95%。（2）叶面喷施硒肥溶液后芒果果实与叶片中硒含量显著上升,喷施浓度越高,含量越高,芒果不同部位在喷施硒肥溶液后硒含量表现为叶片>果皮>果肉。（3）随喷施后时间推移,在芒果花期和幼果期喷施硒肥溶液的处理果实硒含量下降,在膨果期喷施的处理果实硒含量则无显著变化。收获期时不同时期处理果实硒含量表现为膨果期>花期=幼果期。（4）不同时期下叶面喷施硒肥均有改善芒果果实品质、提升风味口感的效果。结果证明,在芒果膨果期喷施叶面硒肥更有利于芒果果实中硒积累,基于不同处理芒果硒含量和品质指标综合评价结果得到,在芒果膨果期叶面喷施0.4%硒肥溶液是生产富硒芒果的较优硒肥施用方式。  相似文献   

5.

Background

Selenium is part of the antioxidant defence system in animals and humans. The available selenium concentration in soil is low in many regions of the world. The purpose of this study was to evaluate the effect of organic versus inorganic selenium supplementation on selenium status of ewes, their lambs, and slaughter lambs.

Methods

Ewes on four organic farms were allocated five or six to 18 pens. The ewes were given either 20 mg/kg inorganic selenium as sodium selenite or organic selenium as selenized nonviable yeast supplementation for the two last months of pregnancy. Stipulated selenium concentrations in the rations were below 0.40 mg/kg dry matter. In addition 20 male lambs were given supplements from November until they were slaughtered in March. Silage, hay, concentrates, and individual ewe blood samples were taken before and after the mineral supplementation period, and blood samples were taken from the newborn lambs. Blood samples from ewes and lambs in the same pens were pooled. Muscle samples were taken from slaughter lambs in March. Selenium concentrations were determined by atomic absorption spectrometry with a hydride generator system. In the ANOVA model, selenium concentration was the continuous response variable, and selenium source and farm were the nominal effect variables. Two-sample t-test was used to compare selenium concentrations in muscle samples from the slaughtered lambs that received either organic or inorganic selenium supplements.

Results

In all ewe pens the whole blood selenium concentrations increased during the experimental period. In addition, ewe pens that received organic selenium had significantly higher whole blood selenium concentrations (mean 0.28 μg/g) than ewe pens that received inorganic selenium (mean 0.24 μg/g). Most prominent, however, was the difference in their lambs; whole blood mean selenium concentration in lambs from mothers that received organic selenium (mean 0.27 μg/g) was 30% higher than in lambs from mothers that received inorganic selenium (mean 0.21 μg/g). Slaughter lambs that received organic selenium had 50% higher meat selenium concentrations (mean 0.12 mg/kg wet weight) than lambs that received inorganic selenium (mean 0.08 mg/kg wet weight).

Conclusion

Organic selenium supplementation gave higher selenium concentration in ewe and newborn lamb blood and slaughter lamb meat than inorganic selenium supplementation.  相似文献   

6.
Two trials were undertaken with lambs grazing selenium deficient pasture to determine if copper would enhance liveweight and fleece-weight responses to selenium supplementation. In the first trial, lambs given selenium or selenium plus copper gained significantly more weight and had higher fleece-weights after 260 days than did control lambs or lambs given copper alone. Copper given alone or together with selenium had no significant effect on liveweight or fleece-weight when compared with control lambs and lambs that were given selenium alone respectively. This finding was confirmed in a second trial when growth and fleece-weights of selenium and selenium plus copper treated lambs were compared and no significant differences found. In both trials copper significantly raised liver copper levels. In selenium supplemented but not in selenium deficient sheep, copper significantly increased blood selenium levels.  相似文献   

7.
A survey of the selenium status of beef cows in Alberta.   总被引：1，自引：1，他引：0  
An epidemiological survey was conducted in Alberta to measure the selenium status in blood of beef cows during the fall and to determine the risk of selenium deficiency among specific geographic regions of Alberta. Three census divisions of Alberta based on the Statistics Canada Census of Agriculture were chosen as the study areas for the project. Soils and plants in area A (Edmonton area) and area B (Calgary area) were known to be deficient in selenium, while soils and plants in area C (southeast corner of Alberta) were known to have adequate levels of selenium. Blood samples were collected from 335 cows on 29 farms from the 3 study areas. These samples were collected from cows that had recently been removed from pasture in October and November 1992. Answers to a short questionnaire pertaining to various herd characteristics and management practices were also obtained for each herd. The average value of selenium for all cows sampled was 2.20 mumol/L. The average value of selenium of cows in areas A and B was 1.93 mumol/L. The average value of selenium of cows in area C was significantly (P < 0.05) higher at 2.70 mumol/L. Nine percent of the cows in the study were considered marginal or deficient in selenium (< 1.27 mumol/L selenium). Herds located in area C, herds that were provided with supplemental feed on pasture, and herds that were pregnancy checked had higher average herd selenium values than did other herds. Cow-calf producers located in areas with selenium-deficient soils should pay particular attention to selenium supplementation for their cows. Some of the negative "geographic" effects on selenium values can be overcome by more progressive management practices.  相似文献   

8.
本试验旨在研究饲粮中硒添加水平对产蛋高峰期临武鸭产蛋性能、蛋品质、血清抗氧化指标和蛋硒含量动态变化的影响。试验选用29周龄体况良好、产蛋率接近的正处于产蛋高峰期的临武鸭200只,随机分为5组,每组5个重复,每个重复8只。对照组饲喂基础饲粮(不额外补充硒源,实测硒含量为0.15 mg/kg)45 d,Ⅰ组、Ⅱ组、Ⅲ组、Ⅳ组分别在基础饲粮中以酵母硒形式添加0.10、0.20、0.40、0.80 mg/kg的硒,饲喂35 d添加硒饲粮后改喂基础饲粮10 d。结果显示:1)饲粮中硒添加水平对蛋鸭产蛋性能和蛋品质各指标均无显著影响(P0.05)。2)与对照组和Ⅰ组相比,饲粮中添加0.40和0.80 mg/kg的硒可以显著提高蛋鸭血清中硒和谷胱甘肽(GSH)含量以及超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性(P0.05),显著降低血清中丙二醛(MDA)含量(P0.05)。3)随试验天数的增加,对照组和Ⅰ组蛋硒含量无显著变化(P0.05),而Ⅱ组、Ⅲ组、Ⅳ组蛋硒含量均呈现先升高后降低的趋势,且均在试验第9天达到峰值。试验第7、9、13、17、21、28和35天,Ⅱ组、Ⅲ组、Ⅳ组蛋硒含量显著高于对照组和Ⅰ组(P0.05);停喂添加硒饲粮的第1~4天,Ⅱ组、Ⅲ组、Ⅳ组蛋硒含量仍显著高于对照组(P0.05);停喂添加硒饲粮的第5~8天,Ⅲ组和Ⅳ组蛋硒含量显著高于对照组(P0.05);停喂添加硒饲粮的第9天,各试验组蛋硒含量均衰减至与对照组相同水平(P0.05)。由此可见,饲粮中添加不同水平的酵母硒形式的硒对产蛋高峰期临武鸭的产蛋性能和蛋品质均无不良影响。饲粮中添加0.40和0.80 mg/kg酵母硒形式的硒可以提高产蛋高峰期临武鸭的蛋硒含量、血清硒含量和抗氧化能力,延长蛋硒的存留时效。综合考虑各因素,产蛋高峰期临武鸭饲粮中硒(以酵母硒形式添加)的适宜添加水平为0.40 mg/kg。  相似文献   

9.
不同硒水平对生长育肥猪血液生化指标的影响   总被引：5，自引：1，他引：4  
试验研究了宁夏常用饲料中不同硒水平对生长育肥猪血液生化指标的影响。结果表明 :(1 )谷胱甘肽过氧化物酶 (GSH PX)活性随饲粮硒水平的增加 ,呈现下降 上升 下降的动态变化趋势。谷胱甘肽硫转移酶可反映缺硒的程度。 (2 )缺硒组仔猪血硒含量和全血中GSH PX均处于缺硒边缘状态 ,在临界值以下 ,不能满足仔猪的代谢需要。 (3)随饲粮硒水平的逐渐增加 ,猪瘟的抗体水平和淋巴细胞转化率明显升高 ,以饲粮中添加硒 0 45mg/kg时达到最高 ,仔猪发病率最低  相似文献   

10.
The response of cats to dietary sodium selenite (Na(2) SeO(3)) and organically bound selenium was studied in two separate studies with four cats per treatment and three levels of selenium supplementation (targets 1.0, 1.5 and 2.0 μg/g DM) for each Se source. Whole blood and plasma selenium concentrations and glutathione peroxidase (GPx) activity were determined at 7-time points across the 32-day study. Faeces were quantitatively collected during the last 8 days and urine was collected daily during both studies. The basal diet used had a low apparent faecal selenium absorption of 25.3 ± 3.0%. Daily faecal and urinary selenium excretion increased linearly with increasing selenium intake for both Se sources. Urinary selenium concentration of the cats fed the supplemented diets increased rapidly (～2 days) and remained constant throughout the remainder of the study. Apparent faecal selenium absorption was high for both selenium sources (73.2% and 80.0%). Plasma, and to a lesser extent, whole blood selenium concentrations increased in a dose-dependent manner with supplementation. Whole blood and plasma GPx activity were highly variable and showed a variable response to dietary selenium intake. Cats closely regulate selenium homeostasis through increasing urinary excretion whilst faecal absorption remains unaffected.  相似文献   

11.
LOW RELEASE OF SELENIUM FROM RECOVERED RUMINAL PELLETS   总被引：1，自引：0，他引：1  
The effectiveness of selenium pellets in grazing Merino sheep was examined by comparing the selenium status of treated and untreated animals over a 13 month period. The selenium status of treated sheep, as measured by blood glutathione peroxidase levels, had reached a maximum 3 months after treatment and there was a marked decline between 5 and 13 months. All pellets were recovered from treated sheep at slaughter this confirmed that the observed decline was not due to a loss of pellets.
In a separate study sheep were slaughtered 14 months after treatment and some of the recovered pellets were readministered to sheep maintained on a low selenium diet. The selenium status of the sheep receiving recovered pellets remained low. This bioassay technique indicated that there was little available selenium released from these pellets. The selenium status of sheep given previously unused pellets was declining after 18 weeks.  相似文献   

12.
In a feeding trial, rabbits allotted in 3 experimental groups were fed rations containing 2.09, 9.83 and 19.5 mg selenium/kg feed in the form of selenium-enriched alfalfa green meal pellets. The selenium enrichment was done by foliar application (spraying) of the 20--25 cm high plant stand with 2.5 kg SeO2 per hectare in watery solution. The control animals were given normal alfalfa green meal pellets of 0.16 ppm selenium content. Toxicity and lethality, tolerance limit and nutritive effect of the pellets were studied. Plant-assimilated selenium was found to be converted more efficiently by the animal organism than was selenium from inorganic compounds (higher retention rate, better gain in body weight and lower feed expenditure). Therefore, the selenium supply to farm animals should be improved by feeding crops that were given selenium dressings.  相似文献   

13.
本试验旨在研究酵母硒和亚硒酸钠作为硒源对产蛋高峰期蛋鸡生产性能、蛋硒含量、蛋品质以及储存期内蛋品质的影响。选用27周龄600只产蛋高峰期海兰褐蛋鸡,随机分为2个处理,每个处理3个重复,每个重复100只鸡。在日粮中分别添加0.2 mg/kg的亚硒酸钠和酵母硒(试验日粮实测硒含量分别为0.227、0.233 mg/kg),预试期1周,正试期8周,对鸡蛋28 d内的鸡蛋蛋品质进行跟踪检测。结果表明:酵母硒和亚硒酸钠对海兰褐蛋鸡生产性能的影响不显著;与亚硒酸钠组相比,酵母硒组对28 d鸡蛋蛋品质无显著影响,但可显著提高56d鸡蛋的蛋白高度和哈氏单位(P<0.05);与添加亚硒酸钠相比,添加酵母硒减缓了储存期鸡蛋哈氏单位的降低,有利于延长鸡蛋货架期;酵母硒组蛋黄、蛋清中硒含量显著高于亚硒酸钠组(P<0.05)。由此可见,相较于亚硒酸钠,饲喂含酵母硒的日粮在延长鸡蛋货架期、提高蛋黄和蛋清中的硒沉积方面效果更好。  相似文献   

14.
Blood selenium levels were found to fluctuate throughout the year, being highest during the indoor season when the greatest amounts of compound concentrates were fed. From October to January the average blood selenium levels increased from 0.10 μg/ml to 0.18 μg/ml (15 cows). Subcutaneous injections of barium selenate (500 mg selenium) increased the blood selenium levels significantly. The treated group (15 cows) reached average levels of about 0.21 μg/ml blood during the indoor season.The effect of oral supplementation of sodium selenite (for 2 months) on the levels of plasma selenium, blood selenium and glutathione peroxidase activity was investigated. Plasma selenium was found to give an immediate reflection of the daily selenium intake. Maximum activity of glutathione peroxidase was reached 1 month after the end of the supplementation period.It is concluded that if selenium enriched concentrates are used in a normal feeding regimen, further supplementation with selenium does not seem to be necessary.  相似文献   

15.
The majority of beef cattle assayed for whole blood glutathione peroxidase (GSH-Px) activity in Idaho and Washington were deficient in selenium. Cattle in the more arid sections of these states tended to have higher selenium levels than those in areas with moderate and high rainfall. Animals pastured on irrigated forages had lower selenium concentrations than those grazed on dry land pasture. Cattle were supplemented by the addition of sodium selenite to a salt-mineral mixture. Ninety mg selenium per kg (ppm) salt-mineral mix fed to cattle significantly (P less than 0.001) elevated selenium (GSH-Px) levels well into normal ranges by 3 months when fed to extremely selenium deficient animals. Thirty ppm selenium was insufficient to raise GSH-Px levels into normal ranges. In addition, 20 ppm selenium was insufficient to sustain blood selenium concentrations of selenium adequate animals. Selenium given in the salt-mineral mix provided an effective, economical, and easily regulated source of dietary selenium. This supplement can be provided the entire year even under range conditions. Calves of cows placed on the 90 ppm selenium supplement had significantly (P less than 0.005) improved weaning weights (10 months) and an indication of a decreased incidence of infectious diseases.  相似文献   

16.
The question addressed was whether the influence of dietary copper concentration on selenium metabolism depends on the amount of selenium in the diet. Weanling, male rats were fed purified diets containing either 1 (low), 4 (normal) or 42 (high) mg Cu/kg diet and either 0.03 (low), 0.05 (normal) or 1.0 (high) mg Se/kg diet in a 32 factorial design. Extra copper was added to the diets in the form of CuSO4 · 5H2O and selenium as Na2SeO3 · 5H2O. In rats fed either the low or normal amounts of selenium, higher intakes of copper decreased the apparent intestinal selenium absorption and increased urinary selenium excretion. The effects of copper on selenium absorption, excretion and retention were not seen in rats fed the high-selenium diets. An increase in dietary copper concentrations elevated selenium concentrations in the liver and kidneys, but slightly lowered those in the spleen of rats that were fed the diets with the normal level of selenium. In rats that were fed the diets with either low or high selenium concentration, copper intake had no effect on organ selenium concentrations. Glutathione peroxidase activity in erythrocytes was raised by feeding the diets which contained either normal or high copper content instead of those that were low in copper. It is concluded that the amount of selenium in the diet determines whether or not an increase in dietary copper concentration affects selenium metabolism.  相似文献   

17.
OBJECTIVE: To evaluate the respiratory excretion and elimination kinetics of organic and inorganic selenium after oral administration in sheep. ANIMALS: 38 crossbred sheep. PROCEDURES: Selenium was administered PO to sheep as a single dose of 0, 1, 2, 3, or 4 mg/kg as sodium selenite or selenomethionine. Expired air was collected and analyzed from all sheep at 4, 8, and 16 hours after administration. RESULTS: Clinical signs consistent with selenium intoxication were seen in treatment groups given sodium selenite but not in treatment groups given the equivalent amount of selenium as selenomethionine. However, a distinct garlic-like odor was evident in the breath of all sheep receiving 2 to 4 mg of selenium/kg. The intensity of odor in the breath did not correlate with clinical signs in affected animals receiving sodium selenite treatment. CONCLUSIONS AND CLINICAL RELEVANCE: The concentration of selenium in expired air was greater in sheep receiving selenium as selenomethionine than sodium selenite. The concentration of selenium in expired air from sheep receiving high doses of selenium (3 and 4 mg of selenium/kg) was larger and selenium was expired for a longer duration than the concentration of selenium in expired air from sheep receiving low doses of selenium (1 and 2 mg of selenium/kg).  相似文献   

18.
Selenium is essential for normal mammalian development. Being a component of antioxidant enzyme, glutathione peroxidase, it plays a major role in protecting the cells from free radical damage. The level of glutathione peroxidase was directly related to the amount of selenium present in various tissues and organs. A decrease in selenium leads to various pathological changes in humans as well as in various laboratory animals. The aim of the present study was to understand whether there is an increase in the level of selenium in different brain regions of rat pups whose mothers were supplemented with selenium, either 2 or 4 mg/l of their drinking water throughout the period of their pregnancy. There was a significant increase in the level of selenium in the cerebellum, cortex and hypothalamic and hippocampal tissues of selenium supplemented mothers as compared with those of non-supplemented mothers. The brain stem of these animals did not show any significant difference in the level of selenium. Furthermore, the differences in the level of selenium between the rat pups of 2 mg/l selenium supplemented mothers and 4 mg/l selenium supplemented mothers were not statistically significant. These studies suggest that supplementation of selenium to mothers during the period of their pregnancy can selectively increase the level of this trace element in different brain regions. Further studies are necessary to understand the significance of selective accumulation of selenium in specific brain regions on brain development and function.  相似文献   

19.
The aim of the study was to define possible differences between selenite, selenate and selenium yeast on various aspects of selenium status in growing cattle. Twenty-four Swedish Red and White dairy heifers were fed no supplementary selenium for 6 months. The basic diet contained 0.026 mg selenium/kg feed dry matter (DM). After the depletion period the animals were divided into 4 groups; group I-III received 2 mg additional selenium daily as sodium selenite, sodium selenate, and a selenium yeast product, respectively. Group IV, the control group, received no additional selenium. The total dietary selenium content for groups I-III during the supplementation period was 0.25 mg/kg DM. After the depletion period the mean concentration of selenium in blood (640 nmol/l) and plasma (299 nmol/l) and the activity of GSH-Px in erythrocytes (610 mukat/l) were marginal, but after 3 months of supplementation they were adequate in all 3 groups. The concentration of selenium in blood and plasma was significantly higher in group III than in groups I and II, but there was no significant difference between groups I and II. The activity of GSH-Px in erythrocytes did not differ between any of the supplemented groups. The animals in the control group had significantly lower concentrations of selenium in blood and plasma and lower activities of GSH-Px in erythrocytes than those in the supplemented groups. The activity of GSH-Px in platelets was also increased by the increased selenium intake. There was no difference in the concentration of triiodothyronine (T3) between any of the groups, but the concentration of thyroxine (T4) was significantly higher in the unsupplemented control group.  相似文献   

20.
Twenty Norwegian Landrace pigs were divided into 5 groups and fed a basal diet consisting of a mixture of dried skim milk and whey powder together with ground barley. The diet was supplemented with 0, 0.2, 0.8, 1.2 and 2.2 μg selenium as sodium selenite and was fed for 12 weeks. The muscle selenium level was increased by a factor of about 4 and the liver selenium by a factor of about 12 when the dietary selenium supplement was increased from zero to 2.2 μg/g. There was a significant linear correlation between dietary selenium and selenium concentrations in tissues. Possible benefit for humans consuming meat from animals having received the selenium doses used in this experiment are discussed.dietary selenium; tissue levels; pigs.  相似文献   

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