The influence of dietary selenium levels on blood levels of selenium and glutathione peroxidase activity in the horse

Twenty mature geldings, averaging 535 kg, were used to determine the influence of dietary selenium (Se) on the blood levels of Se and Se-dependent glutathione peroxidase (SeGSH-Px) activity in the horse. Horses were randomly assigned within breed to four treatments consisting of five horses each and fed a basal diet containing .06 ppm of naturally occurring Se. Diets were supplemented with .05, .10 and .20 ppm Se, as sodium selenite. Blood was drawn for 2 wk before, and for 12 wk following, the inclusion of supplement Se in the diets. Whole blood and plasma Se concentrations and plasma SeGSH-Px activities were determined from all blood samples. Selenium concentrations in plasma and whole blood increased linearly from wk 1 to wk 5 and 6, respectively, in Se-supplemented horses. After these times, no significant changes in Se concentration were observed in Se-supplemented or in unsupplemented horses throughout the remainder of the 12-wk trial. Plasma Se reached plateaus of .10 to .11, .12 to .14, and .13 to .14 micrograms/ml in horses supplemented with .05, .10 and .20 ppm Se, respectively. Whole blood Se reached plateaus of .16 to .18, .19 to .21, and .17 to .18 micrograms/ml in horses supplemented with .05, .10 and .20 ppm Se, respectively. Plasma SeGSH-Px activity was not significantly affected by dietary treatment. Therefore, this enzyme was not a good indicator of dietary Se in these mature horses.     

为什么要测定硒酵母中硒代蛋氨酸的水平

Wrouw国际营养公司和Selko饲料添加刺公司的质量评价部门对来自于英国和美国的硒酵母产品样本进行了一项实验室分析、结果表明：在产品样拳中硒代蛋氨酸水平差异很大，而它是硒酵母中最有效和活性最高的混合物.     

饲粮中添加不同硒源对仔猪血浆硒含量和血清抗氧化能力的影响

试验旨在研究饲粮中添加不同硒源及不同硒水平对仔猪血浆硒含量和血清抗氧化能力的影响。选用体重相近[(12.38±0.43)kg]、健康良好的杜长大三元杂交仔猪168头,随机分成7组,每组3个重复,每个重复8头仔猪。第7组为对照组,饲喂基础饲粮;其余6组均为试验组,即分别以0.30、0.50、0.80 mg/kg 3个硒水平添加到基础饲粮中,并配成6种试验饲粮,试验期40 d。试验结果显示:不同硒源及添加水平间,仔猪血浆硒含量均高于对照组,但纳米硒在0.30、0.50 mg/kg水平时,血浆硒含量均显著高于对照组和亚硒酸钠组(P<0.05);纳米硒在0.50 mg/kg水平时,血清GSH-Px活性、T-AOC显著高于对照组(P<0.05)。同一硒源组添加不同硒水平对仔猪血清中SOD活性、MDA含量差异均不显著(P>0.05),但纳米硒组不同硒水平,仔猪血清SOD活性显著高于对照组(P<0.05),血清MDA含量低于对照组和亚硒酸钠组(P<0.05)。试验说明饲粮中添加纳米硒能显著提高仔猪血清抗氧化能力,并有提高血浆硒含量的趋势。     

Effect of organic and inorganic selenium sources and levels on sow colostrum and milk selenium content

A study was conducted to evaluate the short-term effects of feeding two dietary Se sources at various Se levels on the transfer of Se to the dam's milk and nursing pig. Six dietary treatments were arranged in a 2 x 2 factorial arrangement with two additional treatments in a randomized complete block designed experiment. Inorganic (sodium selenite) or organic (Se-enriched yeast) Se sources were added to the diet at .15 or .30 ppm Se. A non-Se-fortified corn-soybean meal basal diet served as a negative control, and a sixth group was fed .15 ppm Se from both inorganic and organic Se sources. A total of 43 sows were fed their treatment diets at 2.2 kg/d from 6 d prepartum to parturition and at full feed through a 14-d lactation period. Ten sows were initially bled at 6 d prepartum, and three sows and three pigs from their litters were bled at 7 and 14 d postpartum. Serum was analyzed for its Se concentration and glutathione peroxidase (GSH-Px) activity. Colostrum was collected within 12 h postpartum and milk at 7 and 14 d of lactation. When the basal diet was fed, sow serum GSH-Px activity declined from 6 d prepartum and remained low throughout lactation. When dietary Se levels increased, sow serum Se concentration and serum GSH-Px activity increased (P < .05) at both 7 and 14 d postpartum. The short-term feeding of either Se source at .15 or .30 ppm Se did not affect colostrum Se content when inorganic Se was fed, but it was increased when organic Se was provided. This resulted in a significant Se source x Se level interaction (P < .01). Milk Se at 7 and 14 d postpartum was 2.5 to 3 times higher when the organic Se source was provided and resulted in a significant Se source x Se level interaction (P < .05). When the combination of inorganic and organic Se was fed at .15 ppm Se, colostrum and milk Se contents were similar to those of sows fed .15 ppm Se from the organic Se source. Pig serum GSH-Px activity was not affected at 7 and 14 d of age by dietary Se level or Se source fed to the sow, but serum Se increased (P < .05) as dietary Se level increased, particularly when sows had been fed organic Se. The results demonstrated that organic Se increased milk Se content more than did inorganic Se and increased the nursing pig's serum Se. These results indicate that inorganic Se was more biologically available for sow serum GSH-Px activity, but organic Se was more effectively incorporated into milk.     

Comparative effects of high dietary levels of organic and inorganic selenium on selenium toxicity of growing-finishing pigs

This experiment evaluated the effect of high dietary Se levels using organic or inorganic Se on the selenosis responses in growing-finishing swine. A 2 x 4 factorial arrangement of treatments in a randomized complete block design was conducted in two replicates. Sodium selenite or Se-enriched yeast was added at 5, 10, 15, or 20 ppm Se to corn-soybean meal diets. A basal diet without added Se was a ninth treatment group. Ninety crossbred barrows initially averaging 24.7 kg BW were allotted at five pigs per pen. Pigs were bled at 3-wk intervals and plasma Se, glutathione peroxidase (GSH-Px) activity, glutamic oxalacetic transaminase (PGOT), hemoglobin, packed cell volume, and blood cell Se concentration were measured. After 12 wk, pigs were killed and various tissues and bile were collected for Se analyses. Pig body weights, daily gains, and feed intakes were similar for both Se sources when provided at < or = 5 ppm Se, but each measurement declined in a different manner for each Se source as the dietary Se level increased. The decline was more rapid when the inorganic rather than organic Se source was fed, resulting in interaction responses (P < 0.01). Hair loss (alopecia) and separation of the hoof at the coronary band site occurred at > or = 10 ppm inorganic Se but at > or = 15 ppm organic Se level. Plasma GSH-Px activity increased (P < 0.01) when high dietary Se levels of either Se source was fed. Plasma and blood cell Se increased at each period as dietary Se level increased (P < 0.01) and was greater when organic Se was provided (P < 0.05). Blood cell Se concentration reached a plateau when inorganic Se, but not when organic Se, was fed and increased as the experiment progressed. This resulted in a three-way interaction (P < 0.01). Plasma GOT activity at the 12-wk period was elevated when inorganic Se was provided at > or = 15 ppm Se but not when organic Se was fed, resulting in an interaction (P < 0.05). Tissue Se concentrations increased as dietary Se level increased and when organic Se was provided, resulting in interaction responses (P < 0.05). Bile was a yellow color when the basal diet was fed but was dark brown at > 10 ppm inorganic Se and at 20 ppm when organic Se was provided. Bile Se increased as dietary Se level increased (P < 0.01). These results suggest that dietary Se from inorganic or organic sources was toxic at > or = 5 ppm Se, but subsequent selenosis effects were more severe and occurred sooner when sodium selenite was the Se source.     

Cadmium and selenium levels in kidneys from Danish horses

The content of cadmium and selenium in horse kidneys from Jutland , Denmark, in relation to age, local geographical variation and possible relationship between the two elements has been investigated. During the winter of 1982-1983 kidneys from 50 horses were sampled and analysed for cadmium and selenium. The cadmium content of the horse kidneys was recorded in connection with the age of the horses. The cadmium level increases until the animal has reached approximately 7 years of age. At this age the cadmium concentration levels off. A significant regional difference was shown. The cadmium content is higher in horse kidneys from South and Central Jutland than in kidneys from North Jutland (Fig. 2). This geographic pattern is consistent with the one for atmospheric deposition of cadmium and cadmium content in Danish cattle kidneys from Jutland . The cadmium level in kidneys from Danish horses is considerably lower than the level in Norwegian and Swedish horse kidneys. Differences in water hardness and atmospheric deposition may explain some of this difference within Scandinavian countries. The selenium concentration shows no relationship with neither age, cadmium content nor place of rearing. So, the study did not reveal any relationship between the cadmium and selenium concentrations in horse kidneys. The high level of cadmium found in Danish horse kidneys emphasizes the importance of a prohibition against the use of the kidneys in animal and human nutrition, as proposed by others.     

The effect of different levels of selenium in mineral mixtures and salt licks on selenium status in sheep

This paper describes 3 experiments comparing the effect of 10, 25 and 40 mg Se/kg, as sodium selenite, in mineral mixtures and salt licks fed to sheep. The supplement was given during the indoor season from October to May to 7 different flocks, each consisting of 50 to 100 sheep, in areas with selenium deficiency problems. The average selenium level in the basic diets did not exceed 0.05 mg/kg. Selenium status was monitored in the blood of ewes and lambs, and in milk. Blood selenium in lambs correlated well with blood selenium in their dams (r = 0.85). Selenium levels in milk on day 1 (colostrum) correlated well with selenium levels in dams (r = 0.92) and in offspring (r = 0.87). Statistically significant differences were found between the different flocks. In areas with extreme selenium deficiency, 10 mg Se/kg in mineral mixtures and salt licks proved insufficient. A content of 25 mg Se/kg, providing a daily intake of about 0.4 mg selenium, resulted in selenium levels in ewes’ blood, ewes’ milk and in the offspring that should prevent selenium deficiency disease without causing any toxic effects.     

不同硒水平对生长育肥猪生产性能的影响

试验研究了宁夏常用饲粮中不同硒水平(添加硒0，0．15，0．30，0．45，0．60mg／kg)对生长育肥猪生产性能的影响。结果表明：(1)在饲粮中添加不同水平的硒，对各个饲养阶段生长育肥猪的日增重、日采食量和饲料报酬没有明显影响。但从全期来看。饲粮中添加硒0．30mg／kg时日增重最高。料重比最低。(2)综合肉质品质各项指标的测定结果。饲粮中添加硒0．30，0．45，0．60mg／kg时，肌肉保水性、嫩度较好。以饲粮中添加硒0．30mg／kg时为最好。补硒组肉色评分、肌肉新鲜度和抗应激能力均较缺硒组高，肉色评分以饲粮中添加硒0．30mg／kg时最为理想。(3)在宁夏缺硒地区的玉米-豆粕、胡麻饼型饲粮中。从满足正常生长发育的代谢需要、改善肉的品质及降低发病率等方面综合考虑。在15～90kg体重的生长育肥猪基础饲粮中建议添加0．30mg／kg硒为宜，饲粮硒水平为0．33mg／kg，特别是在15～30kg体重的仔猪阶段。从降低发病率的角度考虑。硒的添加量可适当提高。     

不同硒水平对生长育肥猪血液生化指标的影响

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     

Milk and blood levels of silicon and selenium status in bovine mastitis

Milk and blood levels of silicon, selenium and the selenoenzyme glutathione peroxidase (GSH-Px) were measured in 20 healthy and 21 mastitic cows. In milk samples from healthy quarters the mean silicon concentration was 0.81 and in affected ones 0.39 ppm. In serum the mean silicon values were 1.63 and 1.02 ppm respectively. The selenium status was not altered but the level of erythrocyte GSH-Px was lowered in mastitic animals. Silicon is known to have marked effects on free radical formation, lipid peroxidation and macrophage activity. Its possible role in infection and inflammation is evaluated. Some of the functions of silicon may resemble those of selenium. The possibility of lowered levels of silicon and of the selenoenzyme in mastitis calls for experimentation with dietary or pharmaceutical supplementation of these trace elements.     

Serum selenium levels in sheep from birth to 90 days of age]

The results of the study of the dynamics of selenium in the blood serum were compared in 31 piglets from birth to the age of 90 days. The analyzed selenium values in the blood serum immediately after birth (0.14--0.20 ppm) provide evidence of the intra-uterine placental passage of selenium. In the period of colostral and milk nutrition, the serum concentrations of selenium showed a statistically insignificant variation, followed by an abrupt drop of the level of the microelement in the weaning period (60th day). The individual values in this period ranged from 0.08 to 0.12 ppm. Towards the end of the study, the level of selenium in the blood serum of the piglets returned to its initial value; this indicates that although the critical period connected with weaning has a transient nature, it should be averted for preventing the occurrence of a selenium-deficit disease; this can be done by adding a supplement of 0.2% solution of sodium selenate or a combined preparation of selenium and vitamin E-Selevit.     

补饲硒 维生素E对奶牛激素水平的影响

为进一步研究硒、维生素E对奶牛繁殖性能的影响,在某奶牛场选择临床健康、年龄、体重相近的荷斯坦奶牛50头。随机分为对照组、试验A组和试验B组,对试验A组补饲维生素E,试验B组补饲亚硒酸钠维生素E,每5 d采血1次,用高效液相色谱法测定血清中的雌三醇、4-壬基酚、17α-乙烃基雌二醇、17α-雌二醇、17β-雌二醇、双酚A的含量。结果显示,补饲维生素E、亚硒酸钠维生素E后血液中雌三醇、4-壬基酚、17α-雌二醇、17β-雌二醇、双酚A的含量均有所增加,补亚硒酸钠维生素E后各激素含量的变化明显优于补饲维生素E的变化。     

Comparison of selenium levels and glutathione peroxidase activity in bovine whole blood.

Blood glutathione peroxidase activity and selenium levels were found to correlate well, indicating that glutathione peroxidase activity can be used to assess blood selenium levels in beef cattle. The glutathione peroxidase activity of blood is less stable than is the selenium concentration but when blood was stored at 4 degrees C, the glutathione peroxidase activity remained constant for seven days.     

Vitamins a, e and selenium blood levels in the fat cow syndrome

Blood plasma analyses for vitamins A, E and selenium were performed from calving to five weeks of lactation in 29 cows. Twelve of the 29 cows had fat cow syndrome. The healthy cows had significantly higher (P<0.01) plasma vitamin A (40 μg/dL) and vitamin E (5 μg/mL) levels than the cows with fat cow syndrome (29 μg vitamin A/dL and 3 μg vitamin E/mL). At parturition, vitamin A level in plasma was low (25 μg/dL) but increased progressively thereafter (up to 51 μg/dL) in healthy cows, whereas cows with fat cow syndrome had lower levels of vitamin A, bordering on deficiency. The possible role of vitamin E in the alleviation of fat cow syndrome by affecting oxidation-reduction reactions in the liver is discussed. Significant (P<0.01) difference was not observed in selenium blood plasma level (35 ng/mL) between the two groups of cows or in another random group of 12 cows clinically affected by fat cow syndrome.     

An investigation of bulk tank milk selenium levels in the San Joaquin Valley of California

We evaluated selenium determination of bulk milk tank samples as an alternative to testing blood selenium for evaluating herd selenium status in DHIA dairy herds in the San Joaquin Valley of California. A method of determining milk selenium levels using inductively coupled plasma spectrometry is described. Mean bulk tank milk selenium levels were 0.0224 mg/L (Range 0.0126-0.0418 mg/L). No statistically significant relationships were found between bulk tank milk selenium levels of a herd and calving interval, days open or log somatic cell counts. Mean herd blood and milk levels were directly proportional to bulk tank milk selenium levels. Within a herd milk selenium levels of a cow were directly proportional to the cow's blood selenium level. Herd selenium levels were not significantly related to soil selenium levels. Determination of bulk tank milk selenium levels has the potential to be a low cost, non-invasive means of evaluating herd selenium levels in order to determine selenium deficiency. Further studies with this technique in areas which are deficient in selenium may provide estimates of the sensitivity, specificity and predictive value of bulk milk tank selenium for determining selenium deficiency in dairy herds.     

Vitamin E levels in the ovine serum after administration of vitamin E and selenium]

The effects of drugs containing vitamin E for peroral administration (Combinal E), intramuscular injection (Erevit) and parenteral administration of a combined drug containing vitamin E and selenium (Selevit) on vitamin E levels in the ovine blood serum were studied. A uniform dose of 15 mg tocopherol acetate per 1 kg live weight was administered to the experimental animals. The level of vitamin E after the peroral administration of Combinal E was affected to a lesser extent than in swine and calves. The serum was examined before and after saponification to determine the effect of the intramuscular injection of Erevit; it was found out that tocopherol acetate prevailed in the blood serum in the first hours after such a route of administration. The best results were obtained after both subcutaneous and intramuscular administration of Selevit, the levels of free tocopherol showing high values even at the end of the experiments. These results may be made use of in determining effective preventive and therapeutic measures to do away with the white muscle disease in practice.     

日粮中添加高水平纳米硒对蛋鸡肝脏硒含量及抗氧化能力的影响

选取288只42周龄健康农大三号商品蛋鸡,随机分为6个组,每组设4个重复,在基础日粮中以亚硒酸钠的形式添加硒0.3 mg/kg;其余各组以纳米硒的形式分别添加硒0.3、0.5、2.5、5.0、10.0 mg/kg.试验期为60 d.结果显示:试验至30 d,添加0.5～10.0 mg/kg纳米硒能显著提高肝脏硒的含量,添加纳米硒能显著提高T-AOC活性(P<0.05),极显著提高T-SOD活性(P<0.01).试验至60 d,添加2.5～10.0 mg/kg纳米硒能极显著提高GSH-Px活性,添加0.5～10 mg/kg极显著降低NO含量(P<0.01).结果表明,日粮中添加高水平的纳米硒能提高蛋鸡肝脏的抗氧化能力.     

Different levels of selenomethionine on the meat quality and selenium deposition in tissue of finishing pigs

The aim of the study was to verify the influence of selenomethionine (SM) supplementation on performance, carcass yield, characteristics of meat quality and Se tissue deposition of finishing pigs. A total of 128 hybrid pigs with an average weight of 76 kg were distributed in randomized blocks according to body weight in eight treatments and eight replicates. The experimental treatments were two Se levels from sodium selenite‐SS (0.3 and 0.6 ppm), four Se levels from SM (0.3, 0.4, 0.5 and 0.6 ppm) and two combinations of SS with SM (SS 0.15 + SM 0.15 ppm and SS 0.3 + SM 0.3 ppm) providing 0.3 and 0.6 ppm Se in the diet respectively. The feeds were based on corn and soya bean meal. After 30 days on test, were analysed the performance indices and the pigs were slaughtered at commercial slaughterhouse. The cold carcass yield, the physicochemical characteristics of the loin meat and the Se content in muscle and liver were evaluated. There was no significant difference in performance indices (p > .05); however, there was a linear effect on the increase in pig carcass yield by increasing SM (p < .05). The use of SM solely or combined with SS provided higher Se deposition in muscle compared to SS (p < .05). The highest Se deposition in muscle occurred for SM at 0.4 ppm (p < .05). The SS provided higher Se deposition in liver (p < .05). The SM presented best results for meat quality compared to other sources (p < .05). The level of 0.4 ppm Se promoted the best results for the indices of yellow, luminosity, cooking loss and pH (p < .05). The use of SM at any level promotes higher oxidation stability of pig meat (p < .05). The supplementation of SM at a level of 0.4 ppm promotes better physicochemical characteristics and higher Se deposition on swine meat.