Studies on serum selenium and tocopherol in white muscle disease of foal

In order to clarify the cause of white muscle disease (W.M.D.) in foals, tocopherol and selenium concentrations in serum and glutathione peroxidase activities in blood were measured. Examination was made on the samples from horses affected with W.M.D., the foal kept with them in the same stable, the foals kept in the stables without affected foals, and respective mares. The heavy-breed horses in Fukuoka prefecture and Tokachi district were also examined for comparison. Serum tocopherol levels of these foals were normal because after intake of colostrum. Mares of affected foals showed lower tocopherol levels than other examined mares (p less than 0.01). Serum selenium levels of all foals were below 65 ppb, showing deficient levels. The mares of affected foals had lower selenium levels than other mares (p less than 0.01). There was a good correlation between serum selenium concentration and blood glutathione peroxidase activity (r = 0.81). Selenium levels in the liver of affected foals were lower than the foals which succumbed with other diseases. Diet supplied in the stables with affected foals showed low alpha-tocopherol and selenium contents. These findings suggest that W.M.D. in foals is attributed to nutritional muscular dystrophy caused by tocopherol and selenium deficiency of their mares in late gestation period.     

AN EXAMINATION OF THE SELENIUM NUTRITION OF SHEEP IN VICTORIA

The selenium nutrition of sheep throughout Victoria was assessed by a survey of the blood glutathione peroxidase activity in 708 flocks. It was shown that the blood glutathione peroxidase activity in sheep had a seasonal variation with lowest levels in the spring. The enzyme activity was correlated with the blood selenium concentration. Areas where blood selenium was less than 0.03 μg/ml in spring were defined. Sheep with low selenium nutrition were grazing pastures in the high rainfall areas on acid soils, particularly those derived from granite.
Selenium concentrations in pasture samples examined were greater than 0.02 mg/kg, and it was found that superphosphate application had no significant effect on the selenium content of pasture. However, management practices such as high stocking rates and rates of application of superphosphate to pasture were associated with low blood glutathione peroxidase activities in sheep.
It was concluded that the selenium nutrition of most of the sheep flocks in Victoria is adequate, and that the deficient areas are localised. There seems little requirement for supplementation of adult sheep. As the delayed type of white muscle disease in spring lambs appears to be the main selenium-responsive disorder, direct supplementation of lambs in the low selenium areas would be the most effective method of ensuring adequate selenium nutrition.     

Dietary incorporation of feedstuffs naturally high in organic selenium for racing pigeons (Columba livia): effects on plasma antioxidant markers after a standardised simulation of a flying effort

Selenium is a trace element of importance for animal health. It is essential for adequate functioning of many enzymes such as, the antioxidant enzyme, glutathione peroxidase, which protects the cell against free radicals. A muscular effort induces a rise in reactive oxygen species production which, in turn, can generate an oxidative stress. Two groups of eight racing pigeons were fed respectively with a diet containing 30.3 (control group) and 195.3 (selenium group) μg selenium/kg diet. The pigeons were submitted to a standardised simulation of a flying effort during 2 h. Blood was taken before and after the effort to measure antioxidant markers and blood parameters related to muscle metabolism. Plasma selenium concentration and glutathione peroxidase activity were significantly higher in the selenium group. There were no significant differences for the other measured parameters. As a consequence of the effort, the pigeons of the selenium group showed a higher increase of glutathione peroxidase activity and a smaller increase of plasma lactate concentration. Variations because of the effort in the other markers were not significantly different between the two groups. It is concluded that the selenium status was improved with the feeding of feedstuffs high in Selenium.     

Studies on serum tocopherol, selenium levels and blood glutathione peroxidase activities in calves with white muscle disease

For the purpose of clarifying the cause of white muscle disease (WMD) in calves, tocopherol and selenium levels and blood glutathione peroxidase (GSH-Px) activity were measured on 10 calves with WMD and nine of their dams. The main clinical symptoms of the 10 calves with WMD were motor disturbances including recumbency and stiffness. Serum enzyme activities (GOT, GPT, CPK, LDH) in calves with WMD increased markedly, and this increase was also observed in some of their dams. Serum tocopherol levels of calves with WMD were low, 70% of which showing deficient levels of less than 70 micrograms/100 ml. Serum selenium levels of all the calves were lower than 35 ppb, indicating a deficiency, and were accompanied by low blood GSH-Px activity. alpha-Tocopherol and selenium concentrations in organs were very low. Dams of calves with WMD showed low serum tocopherol levels, 22% of which indicating deficient levels below 150 micrograms/100 ml. Serum selenium levels in dams showed a marked decrease to under 20 ppb, and also low blood GSH-Px activity. Feedstuffs supplied in the farms to affected calves indicated very low alpha-tocopherol contents (below 3 mg/100g DM) and low selenium concentrations below 50 ppb in DM. It was concluded that WMD in calves was attributable to nutritional muscular dystrophy caused by deficiencies in tocopherol and selenium in feedstuffs supplied to their dams.     

LOW ALPHA-TOCOPHEROL LEVELS IN LIVERS OF WEANER SHEEP WITH NUTRITIONAL MYOPATHY

SUMMARY Outbreaks of ovine weaner nutritional myopathy occurring in the southwest of Western Australia outside the recognised selenium-responsive areas have been investigated. One hundred and five sheep died in 3 outbreaks following 5 months grazing cereal stubble paddocks. Liver selenium and glutathione peroxidase activities, measured as an index of biological availability of dietary selenium, indicated that the selenium status of the animals was probably adequate. A comparison of liver selenium and α-tocopherol concentrations and glutathione peroxidase activity was made with both selenium supplemented sheep and sheep affected with selenium-responsive nutritional myopathy. In all cases investigated in this study liver α-tocopherol levels in affected animals were low and this may be important in the aetiology of this myopathy.     

Nutritional muscular dystrophy in a four-day-old Connemara foal

This report describes a four-day-old, full-term Connemara colt, presented for the evaluation of a progressive inability to rise unassisted. A diagnosis of nutritional muscular dystrophy was made based on muscular weakness, elevated muscle enzymes and low vitamin E, selenium and glutathione peroxidase activity. The foal was treated with intramuscular vitamin E-selenium and made a full recovery.     

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.     

Observations on the selenium status of cattle in the north-east of Scotland.

Cattle on 18 of 21 farms in north-east Scotland were found to have low whole blood activities of the selenium-containing enzyme, glutathione peroxidase (less than 5 units per ml whole blood), and a low blood concentration of selenium (less than 0.05 mg per litre). These cattle had all been fed on locally produced feedstuffs without any mineral supplementation. The low selenium status in cattle occurred on farms with soils derived from a range of parent material, no one particular type predominating.     

The biological selenium status of livestock in Britain as indicated by sheep erythrocyte glutathione peroxidase activity.

The reliability of erythrocyte glutathione peroxidase activity as an indicator of selenium status in livestock is discussed. Based on this measurement, a survey is described of the biological selenium status of sheep on each of 329 farms in Britain. Results showed that 47 per cent of these farms were probably unable to provide grazing livestock with sufficient selenium to maintain blood levels greater than 0.075 microgram per ml. Increased selenium deficiency from the increasing use of home grown feeds as a major constituent of livestock rations may be causally related to the increase of white muscle disease and other selenium responsive diseases in Britain.     

Distribution of glutathione peroxidase activity and selenium in the blood of dairy cows.

The distribution of glutathione peroxidase (GSH-Px) activity and selenium concentrations among several components in the blood of dairy cows was examined. Approximately 98% of the GSH-Px activity in peripheral blood was associated with the erythrocytes when enzyme activity was expressed as units per milliliter of blood. The GSH-Px activity expressed per cell was approximately fourfold greater for peripheral leukocytes than for erythrocytes. The cellular component contained a greater proportion (approx 73%) of whole blood selenium than did the plasma. A positive linear relationship (r = 0.958) between blood GSH-Px activity and blood selenium concentrations was found in dairy cattle under practical field conditions.     

Effect of intraruminally administered, selenium soluble-glass boluses on selenium status in cows and their calves

Intraruminal selenium soluble-glass boluses were administered by balling gun to 65 of 125 crossbred beef cows (Shorthorn X Charolais) during the last trimester of pregnancy. Elevated (P less than .01) whole blood glutathione peroxidase (GSH-Px) concentrations were observed monthly for the next 10 mo following initiation of treatment, reaching the maximum magnitude (263 vs 41) at the fourth month. Monthly milk samples showed elevated selenium concentrations (P less than .01, April through August; P less than .05 through September). Intraruminal, selenium soluble-glass bolus administration to gestating cows was highly effective in raising the selenium status of their progeny. Although the control calves were in low-selenium status, no acute cases of nutritional muscular dystrophy were observed during this experiment.     

Contribution to the Understanding of Unexplained Death of Pasturing Horses in the North of Spain: A Retrospective Case Series

The aim of this work was to study a retrospective case series of acute degenerative myopathy, which caused high mortality in adult horses grazing in a specific region of Spain, in relation to a possible etiopathogenesis. Outbreaks of myopathy occurred in December of 1999, 2003, 2009, and 2011 after an abrupt fall in temperatures and the first snowfalls. Ten horses were necropsied, and an exhaustive gross and histopathological examination was performed using specific histochemical stainings to evaluate muscle and cardiac damage. Intense myodegeneration, affecting the postural and respiratory muscles and the muscles involved in swallowing, was the main finding. A further consistent finding was necrosis of Purkinje fibers in the myocardium. Serum concentration values of creatine kinase, selenium, and vitamin E, as well as blood concentration values of glutathione peroxidase activity, were determined in 10 horses clinically affected and in another 12 horses with no clinical signs. In the affected horses, creatine kinase was high and reached values over 10,000 U/L. Selenium values were deficient in the horses affected, ranging from 4.2 to 10.5 μg/g (reference range: >50 μg/L) in selenium-untreated horses, and also, selenium values in 11 horses with no clinical signs were below the reference range. Glutathione peroxidase activity was below the reference range in all the analyzed sera, and vitamin E values were also below the reference range in four horses. The severe selenium deficiency together with a sudden arrival of unfavorable weather conditions seemed to provoke the arising of this disease. The presence of Eupatorium cannabinum in this valley is discussed as a possible source of the phytotoxin associated with rhabdomyolysis.     

A review of selenium deficiency in grazing ruminants. Part 1: new roles for selenium in ruminant metabolism

SELENIUM AVAILABILITY: Selenium deficiency has been an important source of loss to the pastoral industries of New Zealand. About 30% of farmed land in New Zealand is considered to be selenium-deficient and continued development of soils and pasture will tend to further decrease the concentration of selenium in pasture. BIOLOGICAL FUNCTIONS: Formerly it was believed that all biological functions of selenium in animals could be attributed to the antioxidant activity of the enzyme glutathione peroxidase. More recently, it has been shown that selenoproteins have roles in immune function and thyroid hormone metabolism. RESPONSES TO SUPPLEMENTATION: Following supplementation of ruminants grazing pastures deficient in selenium, milk production and growth responses are likely to occur in cattle, while in sheep improvements in growth and fertility are most likely. Reproductive dysfunction may not be as important as previously thought in cattle grazing pasture moderately deficient in selenium. The relationship between selenium intake and disease resistance deserves further study. CLINICAL RELEVANCE: Management of selenium deficiency will continue to be important in grazing ruminants. Veterinarians should be aware that many selenoenzymes exist, some with functions quite distinct from the antioxidant role of glutathione peroxidase.     

Effects of Selenium Administration on Erythrocyte and Blood Plasma Glutathione Peroxidase Activity in Goats

The activity of glutathione peroxidase (GSH-Px, E.G. 1.11.1.9.) was determined in heparinized whole blood, blood plasma and washed erythrocytes from goats before and up to 4 weeks after the administration of selenium (0.4 mg/10 kg BW) and vitamin E (20 mg/10 kg BW) or only vit. E (20 mg/10 kg BW). It was found that Se administration caused a significant increase in enzyme activity in whole blood and washed erythrocytes first detected 2 weeks after the intramuscular injection of Se. No changes were observed in plasma from the treated animals. Minor and insignificant changes were seen in the vit. E treated control animals. It is concluded that GSH-Px activity in blood plasma or serum is of no value as a short-term indicator of the selenium status of goats but whole blood is a good indicator of the long-term status.     

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.     

Studies on serum tocopherol and selenium levels and blood glutathione peroxidase activities in lambs with white muscle disease

For the investigation of the cause of white muscle disease (WMD), tocopherol (Toc) and selenium (Se) levels and blood glutathione peroxidase (GSH-Px) activities were examined using lambs with WMD and their ewes. Serum Se levels of 4 lambs with WMD were low under 30 ppb, lambs showing very low levels below 15 ppb. The serum Se level was correlated with blood GSH-Px activity showing remarkably low activities in the lambs with WMD. Se contents in the organs of lambs with WMD were lower than those of control lambs, and particularly liver Se contents were deficient levels below 50 ppb. Serum Toc levels were normal, but alpha-Toc contents in organs showed very low levels, especially in the liver. The serum Toc and Se levels and blood GSH-Px activities of their ewes and other sheep kept in the same farm revealed similar results to those of lambs with WMD. Feedstuffs supplied on the farm showed the deficient level of the Se content below 50 ppb and a very low level of alpha-Toc. It was concluded that WMD of lambs in Hokkaido was nutritional muscular dystrophy resulted from deficiencies of Toc and Se to their ewes.     

Effect of age on liver enzyme activities in serum of healthy quarter horses

Serum alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), 5'nucleotidase (5'NT), sorbitol dehydrogenase (SDH), and aspartate transaminase activities were measured in 10 clinically healthy foals, 10 yearlings, and 10 two-year-old Quarter Horses. Enzyme activities in foals at 0.5 to 3 days, 2 to 3 weeks, and 5 to 7 weeks of age were compared with enzyme activities from yearling and 2-year-old horses. Multivariate analyses of variance revealed significantly higher enzyme values in foals (P less than 0.002). This increase was mainly a result of higher ALP and GGT activities, with lesser effects due to higher SDH and 5'NT activities. Standard deviations for ALP and GGT were also larger in foals than in adult horses. The wide variation of ALP and GGT activities may limit their usefulness in the diagnosis of hepatic disease in foals. Standard deviations for serum AST, SDH, and 5'NT activities were smaller. These enzymes may be indicators of hepatobiliary disease in foals. The high serum enzyme activities in healthy foals may reflect a physiologic difference between foals and adult horses. Relative hepatic mass (as a percentage of body weight) and enzyme activity per gram of hepatic tissue are high in young animals, indicating that the high serum enzyme activities in foals are due partly to a high rate of enzyme production and release.     

LOW RELEASE OF SELENIUM FROM RECOVERED RUMINAL PELLETS

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.     

快速斑点实验法在测定绵羊血中谷胱甘肽过氧化物酶和硒的浓度上的应用

本实验利用一种经改进的“斑点实验”法来测定外源NADPH的荧光消失时间,并计算出动物血中谷胱甘肽过氧化物酶(GSHPX,下同)的活性和羊血中硒的浓度。其灵敏度和可重复性实验表明,此种方法可用于牧场上对大量放牧家畜进行血硒水平的快速测定。     

Influence of selenium status in merino weaners on resistance to trichostrongylid infection

Weaned merino lambs, grazing pastures low in selenium, were used to investigate the effect of selenium status on immunity to trichostrongylids. Six weeks following selenium supplementation to 14 of the 27 sheep using intraruminal selenium pellets, 5000 Ostertagia circumcincta and 5000 Trichostrongylus colubriformis larvae were administered orally to all sheep. At four weeks after infection, the mean total worm burden in the selenium supplemented sheep (5537 +/- 343, n = 14) was not significantly different (P greater than 0.05) from that in the unsupplemented sheep (5614 +/- 374, n = 12) and faecal worm egg concentrations were also similar in the two treatment groups. At this time, mean red cell glutathione peroxidase activities in the supplemented and unsupplemented groups were 430 and 11 U g-1 haemoglobin, respectively, and clinical white muscle disease had been observed in the latter group. These results suggest that increasing selenium status of selenium deficient sheep by the use of intraruminal selenium supplementation, has a negligible effect on resistance to an artificial challenge infection of O circumcincta and T colubriformis.