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1.
Objective To compare the effectiveness of combined selenium and α-tocopherol acetate treatments in preventing lupinosis-associated myopathy in sheep.
Design Measurement of plasma muscle and liver enzymes, and histopathological examination of muscle and liver in the treatment groups.
Procedure The treatments were: subcutaneous injections of selenomethionine and vitamin E (sc(SeM+E)) , an intraruminal selenium pellet and oral doses of vitamin E and intramuscular injections of selenomethionine combined with either oral doses of vitamin E (imSeM+orE) or intramuscular injections of vitamin E in an oily carrier. Another group received no supplements, while a control group was given selenium pellets on day 0 and fortnightly oral doses of vitamin E from day 0 to 72. To produce lupinosis-associated myopathy, the sheep were fed a diet low in vitamin E and given repeated injections of a crude extract of Diaphorthe toxica. Groups sc(SeM+E) and imSeM+orE were stressed by dosing with protected polyunsaturated fatty acids from day 56 onwards.
Results Lupinosis-associated myopathy was induced in all unsupplemented sheep. In these sheep the storage of Se increased and that of vitamin E decreased. The subcutaneous treatment was highly effective in preventing lupinosis-associated myopathy and also produced the highest vitamin E concentrations in plasma and liver. Supplemental vitamin E was more efficacious than supplemental Se. Concentrations of vitamin E in the livers of sheep given intramuscular vitamin E were higher than expected based on plasma concentrations. Oral doses of vitamin E proved the least effective method of increasing concentrations in liver. Lupinosis did not affect Se concentrations in liver or muscle.
Conclusion The sc(SeM+E) treatment is highly effective in preventing lupinosis-associated myopathy but needs to be further assessed when selenium and vitamin E are both limiting in the diet.  相似文献   

2.
The effectiveness of various treatments upon, and pathological and biochemical changes in, ovine weaner nutritional myopathy were observed. Clinical myopathy was already apparent in the sheep at the start of the study, and they were fed decreasing amounts of a ration containing low levels of selenium and alpha-tocopherol, and periodically deprived of water. In spite of this management there was a spontaneous remission of the clinical myopathy in the sheep, but a subclinical myopathy was identified in some of the sheep at the end of the trail. The conclusions were that the myopathy was not caused by a low dietary intake of selenium and/or alpha-tocopherol alone, that alpha-tocopherol was involved in the aetiology, that alpha-tocopherol was completely effective and selenium possibly partially effective in treating it, and that the condition may be a Type II muscle fibre disease. Data on plasma creatine phosphokinase and erythrocyte glutathione peroxidase activities, and terminal liver selenium and alpha-tocopherol concentrations are presented, and their roles in the diagnosis of ovine weaner nutritional myopathy discussed.  相似文献   

3.
Changes in the plasma and liver concentrations of alpha-tocopherol in sheep kept in an animal house, grazed on pasture, grazed on pasture and fed an oat/lupin grain supplement, or grazed on toxic lupin stubble were monitored following no, oral or intramuscular administration of alpha-tocopherol. It was concluded that intramuscular administration was most effective because it caused longer periods of elevated plasma alpha-tocopherol concentrations in most situations investigated and consistently higher concentrations of alpha-tocopherol in the liver, compared to oral administration. The dose rates of alpha-tocopherol given, the vehicle for alpha-tocopherol in the injectable preparation, the different diets consumed and the concurrent occurrence of lupinosis all influenced the results. In spite of this a significant positive correlation existed between the terminal liver and plasma alpha-tocopherol concentrations.  相似文献   

4.
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.  相似文献   

5.
Fourteen calves, 14 weeks old, fed a low vitamin E and selenium diet based on sodium hydroxide-treated, selenium-deficient barley showed a rapid decline in plasma alpha-tocopherol, a gradual decline in erythrocyte glutathione peroxidase (GSHPX) activity, elevated plasma creatine kinase (CK) activity, teeth grinding and (in three cases) electrocardiographic changes, but no clinical abnormalities after 127 to 137 days. Necropsy of six depleted calves at that stage revealed pale muscles in two animals and mild histopathological lesions of skeletal myopathy in all six calves. Ten control calves were fed a similar diet supplemented with alpha-tocopherol and selenium. Plasma alpha-tocopherol and erythrocyte GSHPX activity remained high in these calves and no clinical abnormalities or evidence of myodegeneration were observed. When protected linseed oil was fed as a source of polyunsaturated fatty acids to the remaining eight depleted calves, rapid elevations in plasma CK activity and linolenic acid associated with a variety of cardiopulmonary and locomotory signs, electrocardiographic changes and myoglobinuria occurred within six to 11 days. Necropsy revealed widespread severe skeletal myodegeneration (eight calves) and myocardial lesions (five calves) with preferential involvement of the left ventricular myocardium. Clinical signs and pathological changes were similar to those reported in field outbreaks of nutritional degenerative myopathy in ruminant cattle and establish the experimental regime as the first successful model for reproduction of this disease.  相似文献   

6.
The relationship between in vitro erythrocyte 75Se uptake (75Se uptake) and erythrocyte glutathione peroxidase (EGSHPx) activity was examined in weaner sheep during periods of selenium depletion and repletion, to determine whether 75Se uptake was better correlated than EGSHPx activity to the development of weaner nutritional myopathy. In the 2 trials conducted, only 3 of 45 Merino wether weaners developed clinical myopathy and histological lesions in skeletal muscles. The 75Se uptake values and EGSHPx activities in these 3 sheep were no different from those in the unaffected sheep. There was a significant negative correlation between 75Se uptake values and EGSHPx activities over the entire period of the trials. It could not be demonstrated that 75Se uptake was any better correlated than EGSHPx activity to the development of nutritional myopathy, and it was concluded that EGSHPx activity indicated selenium status better than 75Se uptake in weaner sheep.  相似文献   

7.
Unacceptably high mortalities in rainbow trout fry (Oncorhynchus mykiss) six to 10 weeks after they started to feed were recorded in two spring water trout hatcheries in Northern Ireland in May 1989. Muscle degeneration and necrosis were consistent with histopathological findings in both outbreaks, and this myopathy was similar to that previously described in salmonids and other species associated with vitamin E and selenium deficiency. A feed trial was designed to investigate the hypothesis that the vitamin E requirement of rainbow trout fry on these farms was higher than the current minimum recommendations. Three groups of fry were fed diets containing 147, 239 and 532 iu/kg alpha-tocopherol. The mortality in the groups was inversely related to the dietary alpha-tocopherol concentration, and there was severe myopathy in fry fed the diet containing 147 iu/kg alpha-tocopherol, mild myopathy in fry fed 239 iu/kg alpha-tocopherol but no myopathy in fry fed 532 iu/kg alpha-tocopherol.  相似文献   

8.
Mean selenium and vitamin E (alpha-tocopherol) concentrations in the liver, myocardium and skeletal muscle of nine goat kids with nutritional myodegeneration (NMD) were significantly lower than those in a group of nine kids dying from other causes. Each of the 18 kids was from a different property in the southern half of the North Island. The polyunsaturated fatty acid composition of the liver, myocardium and skeletal muscle was not significantly different between the two groups, but the overall level of peroxidisable polyunsaturated fatty acids appeared high in both groups. A further 21 kids with confirmed NMD and live 'controls', submitted as routine cases to Palmerston North Animal Health Laboratory, were included with the above 18 kids in a comparison of liver selenium and alpha-tocopherol concentrations. Kids with NMD had liver selenium concentrations ranging from 170-1100 (mean = 380) nmol/kg and alpha-tocopherol from 0.7-11.0 (mean =2.2) micromol/kg. In control kids, the liver selenium concentration ranged from 530-4300 (mean = 1220) nmol/kg and a-tocopherol from 1.7-14.0 (mean = 5.6) pmollkg. Although these ranges overlapped, the results suggest that liver selenium concentrations <500 nmol/kg and alpha-tocopherol concentrations <2.5 micromol/kg should be regarded as deficient. Liver selenium concentrations from 500-1100 nmol/kg and alpha-tocopherol concentrations from 2.5-10 micromol/kg should be considered marginal. Goat kids appear to require more selenium than lambs or calves which may explain the higher prevalence of NMD in kids. In some cases, however, the disease is associated with low alpha-tocopherol suggesting that supplementation with selenium alone may not always be sufficient.  相似文献   

9.
OBJECTIVE: To assess changes in serum concentrations of thyroid hormones associated with selenium deficiency myopathy in lambs. ANIMALS: 35 lambs with selenium deficiency myopathy and 30 healthy lambs. PROCEDURES: Blood samples were collected via jugular venipuncture from lambs with selenium deficiency myopathy and healthy lambs. Activities of markers of selenium deficiency myopathy (erythrocyte glutathione peroxidase [GSH-Px] and plasma creatine kinase [CK]) and serum thyroid-stimulating hormone (TSH) and total thyroxine (tT(4)) and total triiodothyronine (tT(3)) concentrations were assessed; values in affected lambs were compared with those in healthy lambs. Correlations of erythrocyte GSH-Px and plasma CK activities with serum concentrations of TSH, tT(4), and tT(3) were investigated, and the tT(3):tT(4) concentration ratio was evaluated. RESULTS: Compared with findings in healthy lambs, erythrocyte GSH-Px activity, serum tT(3) concentration, and tT(3):tT(4) concentration ratio were significantly decreased and serum concentrations of tT(4) and TSH and the activity of plasma CK were significantly increased in affected lambs. Analysis revealed a significant negative correlation in the affected group between erythrocyte GSH-Px activity and each of the following: plasma CK activity (r = -0.443), serum TSH concentration (r = -0.599), serum tT(4) concentration (r = -0.577), and serum tT(3) concentration (r = -0.621). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that notable changes in circulating amounts of thyroid hormones develop in association with selenium deficiency in lambs. Such alterations in thyroid hormone metabolism may be involved in the high incidence of disorders, such as stillbirths and neonatal deaths, in selenium-deficient flocks.  相似文献   

10.
Plasma concentrations of vitamins A and E were examined in sheep, and a transitory decrease was observed after a single massive dose of vitamin D3 (5 X 10(6) IU) was administered orally or parenterally. Administration of a large dose of vitamin E to sheep decreased plasma retinol concentrations within 72 hours, but thereafter, the plasma retinol concentrations returned to near baseline values. Oral administration of a single pharmacologic dose of dl-alpha-tocopherol (5 g) to sheep caused a slow increase of this vitamin in the blood plasma. In cattle, a single IM administration of 3 liposoluble vitamins (A, D3, and E) at acceptable concentrations had no detectable influence on plasma alpha-tocopherol concentrations with the sampling intervals used. Plasma concentrations of alpha-tocopherol in these cattle showed a marked seasonal pattern; the concentrations increased from January to a peak in July, with a subsequent decrease in the fall. Also reported are estimates of inter- and intraindividual variation in plasma liposoluble vitamin concentrations.  相似文献   

11.
The objective of this experiment was to establish the validity of using plasma alpha-tocopherol values as an index of alpha-tocopherol status in sheep. alpha-tocopherol values were obtained for tissues and blood of 40 sheep given four different dietary intakes of dl-alpha-tocopheryl acetate. Group 1 sheep were given a basal diet containing 25 to 32 mg dl-alpha-tocopheryl acetate kg-1 while groups 2, 3 and 4, comprising 10 sheep each, received the basal diet plus 200, 400 and 600 mg dl-alpha-tocopheryl acetate per sheep, respectively. Blood samples were obtained at zero time and then twice weekly for eight weeks, at which time sheep were killed and organs retrieved for tissue alpha-tocopherol analysis. Tocopherol concentrations were higher in all tissues (P less than 0.001) of sheep fed the vitamin E supplemented diets than the basal diet. Vitamin E stored in the liver of sheep at the end of the experiment (eight weeks) showed a linear response to the level of vitamin E in the diet. Blood plasma vitamin E concentrations increased following vitamin E supplementation, but no direct relationship was found between vitamin E intake and plasma vitamin E content.  相似文献   

12.
SUMMARY Subclinical nutritional myopathy was induced in 5-month-old sheep by feeding them a diet low in vitamin E and selenium. Subsequently clinical myopathy was induced by dosing with protected polyunsaturated fatty acids. Plasma activities of creatine kinase (CK), pyruvate kinase, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase and aldolase, enzymes of muscle origin, all remained above their reference ranges in clinically affected sheep, but fluctuated widely. Similar fluctuations occurred in subclinically affected animals, resulting in some activities being within the reference ranges and some above, at different times. Plasma malondialdehyde, an indicator of lipid peroxidation, proved of no diagnostic value. Terminal plasma CK activities were significantly correlated with microscopic damage in the vastus lateralis (VL), but not the vastus intermedius (VI) or the tensor fascia lata (TFL) muscles. AST was the most highly correlated with damage in VI and VL. In two clinically affected sheep successfully treated with an oral dose of α-tocopherol actetate all enzymes decreased steadily to within their reference ranges, at rates probably related to their plasma half-lives. These results suggest that measurement of plasma CK activity would be useful in monitoring recovery of treated sheep.  相似文献   

13.
Blood plasma and tissue Vitamin E concentrations were determined in 20 sheep following a single i.p. dose of 5 g of dl-alpha-tocopherol. In addition, five sheep were used as controls (no treatment and killed at d 0). From the 20 vitamin E-dosed sheep, 4 were slaughtered on d 3, 6, 10, 15 and 28 after dosing. There was a significant time effect in alpha-tocopherol concentrations in all tissues. In most tissues, the peak alpha-tocopherol concentration was at 3 d postdosing. Uptake varied among the different tissues examined. Three days postdosing, a large uptake of vitamin E by the liver was observed; this supports the concept that hepatic tissues are a target organ for vitamin E action. Also at 3 d uptake was pronounced in spleen and lung. Vitamin E concentrations in the other body tissues at d 3 postdosing increased considerably, but to a lesser degree than those in liver, spleen and lung. Vitamin E concentration in all tissues declined 3 d after i.p. dosing.  相似文献   

14.
An experiment was conducted to compare the bioavailability of dl-alpha-tocopherol acetate (TA) with that of dl-alpha-tocopherol nicotinate (TN) when administered to sheep, as a single dose, either into the rumen or the peritoneal cavity. A total of 16 sheep were used in a factorial design, with 4 sheep/treatment at the interaction level. In addition, 5 sheep that received no supplemental alpha-tocopherol, were euthanatized at the end of the trial to provide base-line data for tissue alpha-tocopherol concentrations. Curves were fitted to the plasma alpha-tocopherol concentration values, taken over 180 hours after administration of the esters. Availability of TA was greater than TN, as evidenced by the significantly higher curve parameter values (P less than 0.05) and tissue concentrations (P less than 0.05). Route of administration had a marked effect on availability of TA (P less than 0.001), but not of TN.  相似文献   

15.
A myopathy of horses at grass in east and south east Scotland was recognised in the autumn and winter of 1984 and the spring of 1985. The clinical signs resembled those of paralytic myoglobinuria. Grossly increased creatine kinase activities and the passage of dark brown urine were consistent features. However, the horses were not in training, most of them died and the muscles affected were those of posture and respiration rather than movement. The condition may be unrelated to nutritional myopathy because all the cases had adequate levels of alpha-tocopherol although their selenium status varied from normal to deficient. The clinical and pathological findings in 12 cases are presented and the differential diagnosis and possible aetiologies discussed.  相似文献   

16.
The effect of 5 different copper supplements on copper status of Merino sheep at pasture was examined. Transient increases in plasma copper concentrations occurred following treatment with copper calcium EDTA, copper sulphate, and glass bullets impregnated with copper, cobalt and selenium, but these increases were not considered to be a reliable indication of changes in liver copper reserves. Sheep receiving the glass bullet or 2.5 g oxidised copper wire particles orally or 50 mg copper as copper calcium EDTA parenterally had liver copper concentrations significantly greater than those of untreated sheep for periods up to 51 weeks. Oral doses of 30 mg copper as copper oxychloride, or 300 mg copper as copper sulphate did not alter the liver copper reserves at any stage. The bodyweight and greasy fleece weights were not significantly altered by any of the copper supplements. Plasma vitamin B12 concentrations in sheep given the glass bullet were increased for about 5 months. Thereafter increased plasma vitamin B12 concentrations were observed in all sheep. Blood selenium concentrations were also high during the experiment thereby preventing the evaluation of the glass bullet as a source of selenium.  相似文献   

17.
A trial was devised to assess whether the administration of selenium and cobalt together with the anthelmintic mebendazole (Ovitelmin S&C) was safe and could improve the supplies of selenium and cobalt for adult sheep fed a whole grain diet, low in both elements, which produced a steady decrease in blood glutathione peroxidase (GSHPx) and plasma vitamin B12 concentrations. Ovitelmin S&C, when given orally in a single dose as a suspension containing 0.34 mg selenium/ml, and 0.44 mg cobalt/ml (to provide 0.11 mg selenium and 0.15 mg cobalt/kg liveweight) significantly increased the GSHPx activity in blood. After a second dose given 28 days later the rate of change increased from 2.5 to 3.5 u/g haemoglobin/day. The responses in GSHPx were similar for a preparation which contained twice the concentration of selenium. Ovitelmin S&C increased the concentration of vitamin B12 in the plasma by about 1000 pg/ml for four to seven days after each dose and the increases were similar to those observed in sheep treated with an Ovitelmin preparation containing 45 times more cobalt (providing 6.7 mg cobalt/kg liveweight). After 63 days, liver vitamin B12 concentrations were 43 per cent higher in the cobalt treated than in the untreated groups (P less than 0.01) with no differences among the groups given cobalt. Neither adverse reactions nor signs of toxicity followed the administration of Ovitelmin S&C or Ovitelmin containing the higher concentrations of selenium and cobalt.  相似文献   

18.
Merino wether weaners were exposed to toxic lupin stubbles for periods of one, two and six to nine weeks, and the effect on their liver copper, selenium and zinc concentrations studied. After the one week period there was a slight decrease in liver copper and selenium concentrations in sheep severely affected with lupinosis. This was attributed to loss of these elements from necrotic cells, and greatly increased quantities of fat in the liver. In the same period liver zinc concentrations declined and were negatively correlated with the degree of liver injury. After two weeks or more of exposure to toxic lupins a positive correlation existed between both the liver copper and selenium concentrations, and the degree of liver injury. Furthermore, total liver copper and selenium levels were also positively correlated with the degree of liver injury. Liver zinc concentrations were negatively correlated with the degree of liver injury. It is suggested that when the liver is under the influence of the toxins causing lupinosis for more than two weeks, it stores copper and selenium, and loses zinc.  相似文献   

19.
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.  相似文献   

20.
From a study of approximately 1000 New Zealand Romney ewes from different areas of New Zealand it was found that the mean packed cell volume of sheep of haemoglobin type B Hb B was significantly lower than for haemoglobin type A (Hb A) sheep. The mean Hb A gene frequency was 0.60.

The concentrations of reduced glutathione (GSH) in the erythrocytes of these Romneys followed a normal distribution, the mean being 67.1 ± 12.4 mg GSH per 100 ml erythrocytes. The concentration of GSH in selenium deficient sheep was significantly higher than for selenium adequate sheep. The concentrations of the selenium-containing enzyme, glutathione peroxidase in the erythrocytes and of copper in the plasma of Hb B sheep were significantly higher than for Hb A sheep.

When different breeds of sheep on Mana Island were compared, the Finnish Landrace had significantly less ferroxidase in their plasma than did other breeds.  相似文献   

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