Vitamin E and selenium supplementation to alleviate cold-stress-associated deterioration in egg quality and egg Yolk mineral concentrations of Japanese quails

The effects of vitamin E (dl-α-tocopheryl acetate) and selenium (Se; Na₂-SeO₃) on egg production, egg quality, and mineral content of egg yolk in Japanese quails reared under a low ambient temperature (6°C) were evaluated. Birds (n=300; 7 wk old) were randomly assigned to 12 treatment groups, 25 birds per group. The birds in a 3×2 factorial design received either three levels of vitamin E (125, 250, and 500 mg/kg diet) or two levels of selenium (0.1 or 0.2 mg/kg diet). After 2 wk on feed, six groups of the birds were maintained at 18°C (thermoneutral temperature [TN]), and the other half were acclimated over 3 d to a decreased environmental temperature of 6°C (cold stress [CS]). The performance, egg quality, and mineral content of egg yolk were not influenced by supplemental vitamin E and selenium in quails not exposed to cold stress (p≥0.09). Two hundred fifty and 500 mg vitamin E/kg diet compared with 125 mg/kg diet and higher dietary selenium inclusions (0.2 vs 0.1 mg/kg) resulted in a better body weight, egg production, and feed efficiency (p=0.01) in quails reared under CS. Similarly, egg weight, egg specific gravity, eggshell thickness, and Haugh unit were positively influenced with vitamin E (p=0.01) and selenium (p≤0.05) supplementation. Egg yolk concentrations of Zn, Fe, and Mn were higher with higher dietary vitamin E (p=0.01) and selenium (p=0.05). There was no interaction detected for parameters measured in the present study (p≥0.3). The results of the present study showed that a combination of 250 or 500 mg vitamin E and 0.2 mg selenium per kilogram of diet provides the greatest effects on performance and egg quality of Japanese quails reared under cold stress and suggest that such a supplementation can be considered as a protective management practice in Japanese quail diets to reduce the detrimental effects of cold stress.     

In vivo antioxidant properties of vitamin e and chromium in cold-stressed Japanese quails

An experiment was conducted to determine if vitamin E (α-tocopherol acetate) and chromium (chromium picolinate, Cr Pic) supplementation attenuate the negative effects of cold stress on egg production, egg quality, serum metabolites, and antioxidant status in Japanese quails (Coturnix coturnix japonica). One hundred and fifty laying Japanese quails (50-day-old) were divided into five groups, 30 birds per group. The laying quails kept at 6°C for 12 h/d (08.00 p.m. to 08.00 a.m.) were fed either a basal diet (low temperature-basal diet, CS group) or the basal diet supplemented with either 400 μg of Cr/kg of diet (Cr group), 250 mg of α-tocopherol-acetate per kg of diet (Vit. E group) or 400 μg of Cr plus 250 mg of α-tocopherol-acetate per kg of diet (Vit. E + Cr group) while quails kept at 18°C were fed a basal diet (thermo-neutral-basal diet, TN group). Performance and egg quality were significantly reduced in CS group compared with TN group. Supplemental chromium and vitamin E significantly increased live weight change, egg production, and improved feed efficiency in cold-stressed laying hens compared with the group fed the basal diet at 6°C. Egg production and egg weight were also greater (P < 0.05) in each supplemental group compared with the CS group. However, a combination of vitamin E and chromium, rather than each separately, provided the greatest performance. Supplemental vitamin E and chromium also increased serum vitamin C and E but, decreased malondialdehyde (MDA) concentrations (P < 0.05); the combination of vitamin E and chromium resulted in the highest levels of serum vitamin C and E within the cold-stressed quails. Results of the present study indicate that combined antioxidant supplements increased performance, egg quality and serum antioxidant levels while lowering MDA in cold-stressed quails.     

Effects of vitamin C and vitamin E on lipid peroxidation, blood serum metabolites, and mineral concentrations of laying hens reared at high ambient temperature

This study was conducted to determine the effects of vitamin C (L-ascorbic acid) and vitamin E (alpha-tocopherol acetate) on serum concentrations of lipid peroxidation (MDA) and triiodothyronine (T3), thyroxine (T4), adrenocorticotropic hormone (ACTH), and some metabolite and mineral in laying hens reared at high ambient temperatures ranging from 25 degrees C to 35 degrees C. One hundred twenty laying hens (18 wk old; Hy-Line) were divided into 4 groups, 30 hens per group. The laying hens were fed either a basal diet (control) or the basal diet supplemented with either 250 mg of L-ascorbic acid/kg of diet (vitamin C), 250 mg of alpha-tocopherol acetate/kg of diet (vitamin E), or 250 mg of L-ascorbic acid plus 250 mg alpha-tocopherol acetate/kg of diet (combination). Separately or as a combination vitamins C and E increased serum vitamin C and vitamin E concentrations (p < 0.001) but decreased serum MDA concentration (p < 0.05). Serum concentrations of vitamin E and vitamin C were found highest but serum MDA concentration was lowest in the combination group. Supplemental vitamins C and E either separately or in a combination increased serum T3 and T4 concentrations (p < 0.05), whereas decreased serum ACTH concentration (p < 0.01). Serum glucose and cholesterol concentrations decreased, whereas serum protein concentration increased (p < 0.05) when vitamins C and E singly or together were added to the diet. Vitamin C and vitamin E supplementation resulted in an increase in serum concentrations of Ca, P, and K (p < 0.01) but a decrease in serum concentration of Na (p < 0.05). The results of the present study suggest that supplemental vitamin C and vitamin E alter serum lipid peroxidation, vitamin C, vitamin E and metabolite status, and diets supplemented with a combination of these two vitamins offer a good management practice in laying hens reared at high temperatures. In addition, the results suggest that dietary vitamin C and vitamin E act synergistically.     

Effects of dietary combination of chromium and biotin on egg production, serum metabolites, and egg yolk mineral and cholesterol concentrations in heat-distressed laying quails

Chromium picolinate is used in the poultry diet because of its antistress effects in addition to the fact that the requirement for it is increased during stress. This study was conducted to determine if the negative effects of high ambient temperature (34°C) on egg production, egg quality, antioxidant status, and cholesterol and mineral content of egg yolk could be alleviated by combination of chromium picolinate and biotin (0.6/2.0; Diachrome^™, as formulated by Nutrition 21 Inc.), in laying Japanese quails (Coturnix coturnix japanica), Quails (n=240; 50 d old) were divided into 8 groups, 30 birds per group. The quails were fed either a basal diet or the basal diet supplemented with 2, 4, or 8 mg of Diachrome/kg diet. Birds were kept at 22°C and 53% relative humidity (RH). At 14 wk of age, the thermoneutral (TN) group remained in the same temperature as at the beginning of experiment, whereas the heat stress (HS) group was kept in an environment-controlled room (34°C and 41% RH) for 3 wk. Heat exposure decreased performance when the basal diet was fed (p=0.001). Diachrome supplementation at 4 and 8 mg/kg diet, increased feed intake (p=0.05), egg production (p=0.05), feed efficiency (p=0.01), egg weight (p=0.05), and Haugh unit (p=0.01) in quails reared under heat stress conditions. Heat exposure increased concentrations of serum malondialdehyde (MDA) (p=0.001), glucose, and cholesterol (p=0.01), which were elevated by supplemental Diachrome (p≤0.05). Egg yolk Cr, Zn, and Fe (p=0.01) concentrations increased linearly, whereas MDA and cholesterol concentrations decreased (p=0.05) as dietary Diachrome supplementation increased in HS groups. Similar effects of supplementation on serum levels of glucose and cholesterol (p=0.05) and egg yolk concentrations of cholesterol (p=0.05) and Cr (p=0.01) were observed in TN groups. No significant differences in other values were observed in the TN groups. Results of the present study suggest that supplementation with Diachrome protects the quail by reducing the negative effects of heat stress.     

The role of vitamin E or clay in growing Japanese quail fed diets polluted by cadmium at various levels

This study was conducted to verify whether vitamin (Vit) E or natural clay as feed additives has the potential to modulate the deleterious effects resulting from exposure to cadmium (Cd) in growing Japanese quail. 648 Japanese quail chicks (1 week old) were used to evaluate the effects of dietary Cd (0, 40, 80 and 120 mg/kg diet) and two levels of Vit E (0, 250 mg/kg diet) or two levels of natural clay (0 and 100 mg/kg diet) to study the influences of Cd, Vit E, clay or their different combinations on growth performance, carcass traits, some blood biochemical components and Cd residues in muscles and liver. Live BW and weight gain of quails were linearly decreased with increasing dietary Cd levels. Moreover, feed conversion was significantly worsened with increasing Cd level. Mortality percentage was linearly increased as dietary Cd level increased up to 120 mg/kg diet. Carcass percentage was linearly decreased as dietary Cd level increased. While, giblets percentage were linearly and quadratically differed as dietary Cd level increased. Cd caused significant changes in total plasma protein, albumin, globulin, A/G ratio, creatinine, urea-N and uric acid concentrations as well as ALT, AST and ALP activities. Increasing dietary Cd level was associated with its increase in the muscles and liver. Dietary supplementation with 250 mg of Vit E/kg diet or 100 mg clay/kg improved live BW, BW gain and feed conversion when compared with the un-supplemented diet. Quails fed diet contained 250 mg Vit E/kg and those fed 100 mg clay/kg had the highest percentages of carcass and dressing than those fed the un-supplemented diet. Blood plasma biochemical components studied were better when birds received 250 mg of Vit E/kg diet and those received 100 mg clay/kg. Cd residues in the muscles and liver were significantly less in the birds had 250 mg of Vit E/kg or those received 100 mg clay/kg diet than those un-supplemented with Vit E. Growth performance traits and blood plasma biochemical components studied were significantly affected linearly by the interactions among Cd and each of Vit E and clay levels. In conclusion, the present results indicate that the deleterious effects induced by Cd plays a role in decreasing the performance of Japanese quail and that dietary supplementation with natural clay or Vit E may be useful in partly alleviating the adverse effects of Cd.     

维生素E对中华鳖幼鳖生长、肝脏维生素E以及血清皮质醇含量的影响

为探讨维生素E(VE)对中华鳖(Pelodiscus sinensis)幼鳖的生长、肝脏VE和血清皮质醇的影响，通过特定生长率、高压液相色谱法和放免法，我们测定了中华鳖幼鳖的生长、肝脏VE和血清皮质醇含量。发现VE添加量为1000和5000mg／kg的两组，能明显降低中华鳖幼鳖的生长。维生素E添加量为500、1000和5000mg／kg的三组，肝脏维生素E含量明显高于对照组，VE添加量在0—1000mg／kg的范围时，肝脏VE的含量随着饲料中VE含量的增加呈指数式增加，并且在VE添加量为5000kg／kg的一组基本达到饱和。维生素E添加量为0和50mg／kg的2组，其血清皮质醇的平均值明显高于维生素E添加量为250、500、1000和5000mg／kg的4组的平均值。上述结果表明：高剂量的VE降低了中华鳖幼鳖的生长和血清皮质醇的含量；在一定剂量范围内，肝脏VE随着饲料中VE含量的增加而升高。     

Effects of dietary combination of chromium and biotin on growth performance, carcass characteristics, and oxidative stress markers in heat-distressed Japanese quail

Environmental stress causes adverse effects in performance and antioxidant status of poultry. Dietary chromium supplementation promotes the growth rate and feed efficiency of growing poultry and these beneficial effects of chromium appear to be greater under stress. Biotin, a member of the vitamin B complex, is involved in the metabolism of carbohydrates, fats, and proteins. In a previous experiment, we examined the effects of chromium picolinate (CrPic) as a chromium source in birds subjected to high environmental temperature and the data showed that supplementation with CrPic ameliorated the deletorious effect of stress. The study was conducted to determine the effects of a supplementation of combination of CrPic and biotin (Diachrome^TM) on performance, carcass characteristics, levels of oxidative stress markers, serum cholesterol, and glucose concentrations in Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature of 34°C. Two hundred forty Japanese quail (10 d old) were randomly assigned to 8 treatment groups consisting of 10 replicates of 3 birds. The birds were kept in a temperature-controlled room at 22°C (thermo-neutral [TN] groups) or 34°C (for 8h/d; 09.00 am to 05.00 pm; heat-stress [HS] groups). Birds were fed either a basal (control) diet (TN and HS) or the basal diet supplemented with either 1, 2 or 4 mg of Diachrome/kg of diet. Heat exposure decreased performance when the basal diet was fed (p=0.001). Diachrome supplementation increased feed intake (p=0.001), body weight (p=0.05), feed efficiency (p=0.01), and carcass traits (p≤0.05) variables linearly in birds reared under HS conditions. Serum vitamin C (p=0.05) and vitamin E (p=0.03) concentrations increased, whereas malondialdehyde (MDA) levels in serum and the liver (p=0.01), thigh muscle (p=0.05), and serum cholesterol and glucose concentrations (p=0.05) decreased in supplemented birds reared at a high temperature. It should be noted that when birds were kept at the thermo-neutral temperature, Diachrome supplementation did not affect (p>0.05) the variables measured, with the exception of a reduction in serum cholesterol and glucose. Results of the present study suggest that Diachrome can be considered a protective dietary supplement by reducing the negative effects of high environment temperature on performance and oxidative stress in quail.     

Effect of vitamin E supplementation on arsenic induced alteration in blood biochemical profile,oxidant/antioxidant status,serum cortisol level and retention of arsenic and selenium in goats

Arsenic (As) exerts oxidative stress with depletion of body selenium in monogastric animals. But in ruminants this fact is not yet verified. Vitamin E is an effective dietary antioxidant. Thus, in this experiment, the protective effect of vitamin E against arsenic toxicity induced by sodium arsenite (60 mg As/kg diet) was investigated in goat kids. For this, 21 male kids were divided into three equal groups and fed either basal diet as such (control), or supplemented with 60 mg As/kg diet and 60 mg As/kg diet + 250 IU vitamin E/kg diet for 180 days. Vitamin E supplementation alleviated the toxic effects caused by arsenic on serum alanine aminotransferase and aspartate aminotransferase and lipid peroxidation. It also prevented the depletion of reduced glutathione content and reduction in activity of catalase, superoxide dismutase and glutathione-s-transferase in erythrocytes resulted from arsenic intoxication. The elevated levels of arsenic and reduced levels of selenium in the serum and tissues in arsenic treated animals were attenuated by vitamin E supplementation, though not completely. However, serum cortisol level was not affected by arsenic. It was concluded that arsenic exerts cortisol independent stressor mechanism and supplementation of vitamin E at a level of 250 IU/kg diet was partially effective in reducing tissue accumulation of arsenic in the body and protect the kids from oxidative stress induced by arsenic.     

Influence of dietary vitamin E (DL-alpha-tocopheryl acetate) and diludine (diethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate) levels on growth and lipid peroxidation in rainbow trout,Oncorhynchus mykiss

We aimed to investigate the influence of dietary vitamin E and diludine on growth and lipid peroxidation (malondialdehyde; MDA) in rainbow trout. Fish (1.5 g) were fed different dietary levels of vitamin E (0, 50 and 100 mg/kg) and diludine (0, 0.5 and 1 g/kg) for 10 weeks. Growth performance and feed conversion ratio (FCR) were significantly affected by dietary vitamin E (p < .05) but not diludine. Fish fed 50 mg/kg dietary vitamin E with no diludine had significantly better growth and lower FCR than those fed vitamin E free diets. Liver vitamin E content was significantly influenced by dietary vitamin E and diludine (p < .05). The highest hepatic vitamin E was in fish fed the highest dietary vitamin E and diludine levels. Hepatic MDA level was significantly affected by dietary vitamin E and diludine (p < .05), decreasing with the increase in both dietary vitamin E and diludine. According to our results, diludine had no significant effect on growth; however, decreased hepatic lipid peroxidation independent of vitamin E. Our results reveal that 50 mg/kg vitamin E content is suitable for optimal growth and FCR in rainbow trout juveniles. However, dose dependent effects of dietary diludine remain uncertain and need further researches.     

Influence of vitamin E supplementation and basal diet on the vitamin E status, performance and tissue fatty acid concentration in lambs

In order to determine the effect of dietary vitamin E level and basal diet on vitamin E status, performance and tissue fatty acid content, five groups of eight Suffolk × Charollais wether lambs with an initial live weight of 28.4 (s.d. 1.6) kg were allocated to one of five concentrate-based diets supplemented with all-rac-α-tocopheryl acetate to contain 30 mg (C-30), 60 mg (C-60), 120 mg (C-120), 250 mg (C-250) or 500 mg (C-500) α-tocopheryl acetate/kg dry matter (DM), for 63 days. Two additional groups of eight lambs entered the study at 31.2 (s.d. 3.3) kg and were fed grass silage and 400 g/day concentrate for 56 days, with the whole diet providing the equivalent of 60 mg (S-60) or 500 mg (S-500) α-tocopheryl acetate/kg DM. Lambs were weighed and blood samples obtained by venipuncture weekly. Dietary vitamin E level did not affect performance (P > 0.05), but lambs fed grass silage grew more slowly (P < 0.001) and had a higher (P < 0.001) feed conversion ratio (kg feed/kg gain) than those fed concentrates. At day 0 plasma α-tocopherol concentrations were 0.8 μg/ml and did not differ between treatments (P > 0.05). Plasma α-tocopherol concentrations then decreased in all lambs except for those fed S-500, which increased, and at slaughter were (μg/ml) 0.07, 0.23, 0.39, 0.76 and 1.57 in C-30, C-60, C-120, C-250 and C-500 and 1.18 and 1.93 in S-60 and S-500, respectively. At slaughter, muscle and liver α-tocopherol concentrations were in the deficiency range for lambs fed C-30, C-60 or C-120, whereas plasma creatine kinase and tissue polyunsaturated fatty acids were unaffected by dietary vitamin E level, but creatine kinase levels were higher (P < 0.05) and glutathione peroxidise levels lower (P < 0.001) in lambs fed grass silage than concentrates alone. Muscle and liver α-tocopherol concentrations were 1.8- and 4.1-fold higher in lambs fed S-60 than C-60, but there was less of a difference between lambs fed S-500 or C-500 with muscle and liver differences of 0.4- and 0.7-fold, respectively. Tissue n-3 polyunsaturated fatty acid concentrations were higher (P < 0.05) and n-6 fatty acids lower in lambs receiving the grass silage compared to concentrate-based diets, but were not affected by dietary vitamin E level. It is concluded that lower plasma and tissue levels of α-tocopherol are present in lambs supplemented with all-rac-α-tocopheryl acetate on a concentrate compared to a mixed diet of silage and concentrates, and that normal growth can be achieved at tissue levels previously considered to represent deficiency.     

Supplemental zinc and vitamin A can alleviate negative effects of heat stress in broiler chickens

This experiment was conducted to evaluate the effects of zinc (ZnSO₄H₂O) and vitamin A (retinol) supplementation on performance, carcass characteristics, and serum concentrations of glucose, cholesterol, total protein, and malondialdehyde (MDA) as an indicator of lipid peroxidation in broiler chickens (Ross) reared at a high temperature (34°C). One hundred twenty 10-d-old male broilers were randomly assigned to 4 treatment groups, 3 replicates of 10 birds each. The birds were fed either a basal diet or the basal diet supplemented with either 30 mg Zn/kg diet, 4.5 mg (15,000 IU) retinol/kg diet, or 30 mg Zn+4.5 mg retinol/kg diet. Supplemental zinc and vitamin A significantly increased live weight gain and improved feed efficiency (p<0.05). However, a combination of zinc and vitamin A, rather than each separately, provided a greater performance. Hot and chilled carcass weights and yields and the weights of internal organs with the exception of abdominal fat were greater for each supplement (p<0.05) compared to the control group. Abdominal fat decreased (p<0.05) upon dietary zinc and vitamin A supplementation. Supplemental treatments resulted in an increased total serum protein but decreased glucose, cholesterol, and MDA concentrations. The results of the study show that, separtely or as a combination, zinc and vitamin A supplementation resulted in an improved live weight gain, feed efficiency, and carcass traits, as well as a decrease in serum MDA concentrations. The results of the present study also suggest that zinc and vitamin A have similar effects and that a combination of zinc and vitamin A may offer a potential protective management practice in preventing heat-stress-related depression in performance of broiler chickens.     

A comparative study of serum selenium and vitamin E levels in a population of male risk drinkers and abstainers

Depressed selenium and Vitamin E levels may contribute to hepatic injury through lipid peroxidation. To study the effect of moderate alcohol drinking (32.4±23.6 g ethanol/d) on serum selenium and serum vitamin E concentrations, we conducted a matched-pair study of 73 healthy, well-nourished risk drinkers and healthy controls with little or no alcohol consumption. Among risk drinkers, serum selenium was significantly lowered (1.49 vs 1.67 μmol/L;p<0.001) compared with controls. Difference in α-tocopherol concentrations did not, however, reach statistical significance (22.8 vs 24.9 μmol/L;p=0.06). Nutritional and life-style factors differed very little between the two groups. We conclude that even moderate alcohol consumption lowers selenium status. Selenium may thus represent a link joining the hepatotoxic and nutritional backgrounds of alcoholic liver disease.     

Protective role of intraperitoneally administered vitamin E and selenium in rats anesthetized with enflurane

The aim of this investigation was to determine levels of liver vitamins A and E and blood biochemical and hematological parameters in the enflurane anesthesia of rats. Fifty adult male Wistar rats were used in this study. All rats were randomly divided into five groups. The first and second groups were used as the control and anesthesia control groups, respectively, and only the placebo was intraperitoneally injected. The third group was intraperitoneally administered with vitamin E (dl/-α-tocopheryl acetate, 100 mg/kg body weight), the fourth group with Se (Na₂SeO₃ 1.5 mg/kg body weight), and the fifth group with vitamin E and Se (dl-α-tocopheryl acetate, 100 mg/kg body weight + Na₂SeO₃ 1.5 mg/kg body weight). This administration was done for three times with overday intervals and the second, third, forth, and fifth group rats were taken to enflurane anesthetise for 2 h. The liver vitamin E level was slightly lower in the anesthesia control group than in control group. However, the liver vitamin E content was significantly (p < 0.05 andp < 0.01) increased in vitamin E, Se, and combination groups, whereas the vitamin A level in liver was not statistically different. In general, plasma levels of alanine aminotransferase, creatin kinase, total bilirubin, urea, red blood cell counts, packet cell volume, and hemoglobulin values were significantly (p < 0.05 andp < 0.001) increased during the anesthesia and returned to near control values after the vitamin E plus selenium injection. However, administration of vitamin E had less effect on the hematological and biochemical parameters compared to that of selenium and their combination with vitamin E. However, the white blood cell count and levels of alkaline phosphatase, aspartate aminotransferase, total cholesterol, triglycerides, total protein, and creatinine were not statistically influenced by the anesthesia. In conclusion, we observed that plasma levels of some enzymes and metabolites were significantly increased in the enflurane anesthesia of rats, whereas the liver vitamin E levels were slightly decreased. Therefore, we observed that vitamin E and selenium have a protective effect against anesthesia complication, but the effect of selenium appears to be much greater than the vitamin E.     

Effects of Dietary Selenium, Vitamin E, and Their Combination on Growth, Serum Metabolites, and Antioxidant Defense System in Skeletal Muscle of Broilers Under Heat Stress

This experiment was conducted to evaluate the effects of dietary vitamin E, selenium (Se), and a combination of the two, on the performance, serum metabolites and oxidative stability of skeletal muscle of broilers during heat stress. The broilers raised in either a thermoneutral (23.9°C constant) or heat stress (23.9°C to 37°C cycling) environment were assigned to 6 dietary treatments (0, 0.5, or 1 mg/kg Se; 125 and 250 mg/kg vitamin E; or 0.5 mg/kg Se plus 125 mg/kg vitamin E) from 1 to 49 days of age. At the end of the experiment, blood samples were collected from chicks, the chicks sacrificed, and pectoralis superficialis muscle was used for measurement of malondialdehyde (MDA) concentration and enzyme activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD). The heat-stressed chicks consumed less feed, gained less weight, and had higher feed conversion ratio when compared to thermoneutral chicks (P<0.05). Serum concentrations of iron (Fe) and zinc (Zn) were decreased by heat stress (P<0.05), whereas the serum concentrations of copper (Cu), glucose, and uric acid were significantly increased under heat stress (P<0.05). The chicks that received supplemental of vitamin E exhibited significantly higher serum concentrations of Zn (P<0.05) and significantly lower concentrations of Cu, glucose, and uric acid (P<0.05) when exposed to heat stress. Dietary Se also caused a significant decrease in serum glucose, uric acid, and Cu concentrations of heat-stressed broilers (P<0.05), but had no significant effect on Zn concentration (P>0.05). The GPx activity remained relatively constant (P>0.05), though SOD activity and MDA levels in skeletal muscle were enhanced on exposure to heat stress (P<0.05). The heat-stressed chicks that received the combined supplementary level of vitamin E and Se had the lowest concentration of MDA and the highest activity of SOD in the skeletal muscle (P<0.05). Dietary Se also caused a significant increase in enzyme activity of GPx in the skeletal muscle (P<0.05). These results indicate that the derangement of blood parameters and oxidative stability in broilers under heat stress are improved by supplemental vitamin E and Se.     

The influence of dietary vitamin E, fat, and methionine on blood cholesterol profile, homocysteine levels, and oxidizability of low density lipoprotein in the gerbil

A 90-day feeding study with gerbils was conducted to evaluate the influence of dietary vitamin E levels (25 mg/kg diet, 75 mg/kg, 300 mg/kg, and 900 mg/kg), two levels of dietary methionione (casein or casein+L-methionine (1% w/w)) and two sources of lipid (soybean oil [20%] or soybean oil [4%]+coconut oil [16%, 1:4 w/w]) upon serum lipids (total cholesterol, HDL-cholesterol, LDL-cholesterol). In addition, this study examined the effects of diet-induced hyperhomocysteinemia and supplemental dietary vitamin E on the oxidation of low density lipoproteins. Tissue vitamin E (heart, liver, and plasma) demonstrated a dose response (P≤0.001) following the supplementation with increasing dietary vitamin E (25, 75, 300, and 900 mg/kg). In addition, tissue vitamin E levels were found to be higher (P≤0.001) in those animals receiving a combination of coconut oil+soybean oil as compared to the group receiving soybean oil solely. Blood cholesterol profiles indicated an increase (P≤0.001) in total cholesterol and LDL cholesterol by the influence of saturated fat and supplemental methionine. Low-density lipoprotein cholesterol profile demonstrated a reduction (P≤0.001) at the higher dietary vitamin E levels (300 and 900 mg/kg) as compared to the 25 mg/kg and 75 mg/kg dietary vitamin E. Plasma protein carbonyls were not influenced by dietary vitamin E nor by supplemental methionine intake. In vitro oxidation of LDL showed that vitamin E delayed the lag time of the oxidation phase (P≤0.001) and reduced total diene production (P≤0.001). On the contrary, supplemental methionine decreased (P≤0.001) the delay time of the lag phase, whereas total diene production was increased (P≤0.001). Plasma lipid hydroperoxides were significantly reduced (P≤0.05) with supplemental dietary vitamin E, whereas supplemental L-methionine (1%) resulted in a significant (P≤0.05) increase in lipid plasma hydroperoxide formation. Plasma homocysteine was elevated (P≤0.001) with supplemental dietary L-methionine (1%) as well as the inclusion of dietary saturated fat. The present data showed that 1) a combination of dietary lipids (saturated and unsaturated fatty acids) as well as vitamin E and methionine supplementation altered blood cholesterol lipoprotein profiles; 2) in vitro oxidation parameters including LDL (lag time and diene production) and plasma hydroperoxide formations were affected by vitamin E and methionine supplementation; and 3) plasma homocysteine concentrations were influenced by supplemental methionine and the inclusion of dietary saturated fat.     

Alterations in plasma total and high density lipoprotein cholesterol levels in hyperlipidemic rats fed diets with varied content of selenium and vitamin E

The effect of dietary selenium and vitamin E on plasma total (TC) and high density lipoprotein cholesterol (HDLC) was evaluated in 54 Sprague Dawley rats fed cholesterol/cholic acid enriched diets. Diets 1, 2, and 3 had no added selenium (low Se) and 0 (low), 60 (adequate), and 600 (high) mg/kg dL alpha tocopheryl acetate added respectively. Sodium selenite at 0.2 mg/kg (adequate Se) was added to diets 4, 5, and 6 and at 4.0 mg/kg (toxic Se) to diet 7, 8, and 9 with the same pattern of vitamin E added to the diet as described above. TC and HDLC were measured using the Kodak Ectachem system. Rats in the low and adequate Se groups fed high vitamin E had lower TC values than rats fed lower vitamin E levels but differences were not significant. In the toxic Se groups, rats fed high vitamin E had significantly (p<0.05) higher plasma TC values than did lower Vitamin E groups. Rats on the high vitamin E diets with low or adequate Se had significantly (p<0.05) higher mean plasma HDLC values when compared to rats fed low or adequate vitamin E diets. HDLC values for animals on Se toxic diets were significantly (p<0.05) lower in rats fed a low vitamin E diet. In rats fed Se deficient and adequate diets, a high vitamin E intake resulted in a decrease in TC and an increase in HDLC. In Se toxic rats, TC was elevated by a high dietary intake of vitamin E as was HDLC with both values being significantly higher than values found in the vitamin E deficient rats. Vitamin E deficiency resulted in a plasma lipid pattern that has been associated with greater cardiovascular disease risk.     

Effects of supplementation with vitamin E on the performance and the tissue peroxidation of broiler chicks and the stability of thigh meat against oxidative deterioration

Two experiments were conducted: Expt 1 determined the optimal allowance of vitamin E in the diet for broiler chicks aged 0–3 weeks; Expt 2 investigated the effects of different dietary levels of vitamin E (α-tocopherol) on the performance and the oxidative stability of thigh meat of broiler chicks during storage. In Expt 1, 1-day-old 900 broiler chicks were allocated to five treatments, each with six replicates (cages) of 22 as-hatched chicks for performance evaluation, and another cage of 45 male chicks for determining plasma and hepatic α-tocopherol and thiobarbituric acid reactive substances (TBARS) concentration in blood and liver. The basal dietary α-tocopherol concentration was 13 mg/kg, and the five α-tocopherol acetate supplementation levels were 0, 5, 10, 50 and 100 mg/kg. For 0–3-week-old broiler chicks fed with maize–soya bean meal–soya oil type diet, supplementation of vitamin E did not influence the feed intake, but tended to improve growth and feed utilization, however there was no significant correlation between performance and vitamin E supplementation level. Significant positive correlations existed between dietary supplemental vitamin E level and plasma or hepatic α-tocopherol concentrations (P<0.05), and a negative correlation with hepatic TBARS levels no matter at what age (11, 16 and 21 days). In Expt 2, 2200 broiler chicks were randomly allocated to five treatments with four replicates (pens) in each. Chicks were fed ad libitum five pellet diets supplemented with vitamin E at 5, 10, 20, 50 and 100 mg/kg of diet, respectively. The basal dietary α-tocopherol level of grower and finisher diets were 7 and 6 mg/kg, respectively. Supplementation of vitamin E tended to improve growth and feed utilization of birds during 0–3 weeks of age, but the performance from 0 to 6 weeks of age were not influenced. The hepatic α-tocopherol concentrations of 6-week-old chicks linearly increased with the dietary vitamin E levels (R²=0.98, P<0.001). The content of TBARS in the thigh meat over 4 days of storage under 4°C was significantly decreased by increasing dietary vitamin E level (P<0.05). There was a significant inverse relationship between TBARS value in the thigh meat and the dietary vitamin E level (R²=0.93, P<0.01). Supplementation of vitamin E significantly improved the meat quality stability substantially against oxidative deterioration. Comparing the hepatic α-tocopherol levels of chicks in Expts 1 and 2, total allowance of dietary α-tocopherol of 20–30 mg/kg could sustain relatively constant hepatic α-tocopherol level at round about 2–2.5 μg/kg.     

Effects of taurine supplementation on productive performance,nutrient digestibility and gene expression of nutrient transporters in quails reared under heat stress

This study was conducted to examine the effects of dietary taurine supplementation on productive performance, nutrient digestibility, antioxidant status, and the gene expression of ileal nutrient transporters in laying quails reared under heat stress (HS). One hundred and eighty laying Japanese quails (Coturnix coturnix japonica) were fed a basal diet or basal diet supplemented with either 2.5 or 5 g of taurine per kg of diet, and reared at either 22 ± 2 °C for 24 h/d (thermoneutral, TN) or 34 ± 2 °C for 8 h/d (HS) for 12 weeks. The quails reared under HS consumed less feed, produced less egg, and had lower dry matter, organic matter and crude protein apparent digestibilities compared with the quails reared under the TN condition (P = 0.001). However, increasing taurine concentrations in the diet improved feed intake and egg production (P = 0.001), but also the apparent digestibilities (P ≤ 0.027) in quails reared under HS. The greater doses (5 g/kg) of taurine resulted in more responses. The quails reared under HS had greater serum and liver MDA concentrations (P = 0.0001) which decreased with dietary taurine supplementations, particularly greater doses. The gene expressions of ileal PEPT1, EAAT3, CAT1, CAT2, SGLT1, SGLT5, GLUT2, and GLUT5 decreased under HS conditions (P = 0.001). However, supplementing taurine, in a dose-dependent fashion, to the diet of quails reared under HS resulted in increases in the gene expressions of the transporters (P < 0.05) except for CAT1. The results of the present work showed that taurine supplementation, particularly with greater doses (5 g/kg), to the diet of laying quails kept under HS acts as alleviating negative effects of HS, resulting in improvements in productive performance and nutrient digestion, and also upregulation of ileal nutrient transporters.     

Influence of dietary vitamin E and C supplementation on vitamin E and C content and thiobarbituric acid reactive substances (TBARS) in different tissues of growing pigs

To investigate the influence and possible interactions of dietary vitamin E and C supplementation on vitamin content of both vitamins and oxidative stability of different pork tissues 40 Large White barrows from 25?kg to 106?kg were allocated to four different cereal based diets: Basal diet (B), dl-α-tocopherylacetate?+?200?mg/kg (E), crystalline ascorbic acid?+?300?mg/kg (C) or both vitamins (EC). At slaughtering samples of liver, spleen, heart, kidney, backfat outer layer, ham and M. longissimus dorsi were obtained. Growth performance of the pigs and carcass characteristics were not influenced by feeding treatments. Dietary vitamin E supplementation had a significant effect on the vitamin E and α-tocopherol concentration in all investigated tissues. Backfat outer layer, liver, spleen, kidney and heart had higher vitamin E concentrations than ham and M. longissimus dorsi. Dietary vitamin C supplementation tended towards enhanced vitamin E levels except for ham samples. Therefore, some synergistic actions without dietary vitamin E supplementation between the two vitamins could be shown. The vitamin C concentration and TBARS were increased or at least equal in all tissues due to vitamin C supplementation. Dietary α-tocopherol supplementation resulted in lower TBARS in backfat outer layer (malondialdehyde 0.35?mg/kg in B vs. 0.28?mg/kg in E), but increased in heart and ham. When both vitamins were supplemented (EC) TBARS were lower in M. longissimus dorsi and backfat outer layer, equal in heart and higher in liver and ham compared to a single vitamin C supplementation. Rancimat induction time of backfat outer layer was 0.3?h higher in C compared to B and 0.17?h higher in EC than in E. Correlations between levels of both vitamins were positive for kidney (r?=?0.169), M. longissimus dorsi (r?=?0.499) and ham (r?=?0.361) and negative for heart (r?=???0.350). In liver and spleen no interaction could be found. In backfat outer layer vitamin E was positively correlated with rancimat induction time (r?=?0.550) and negatively with TBARS (r?=???0.202), but provided no evidence that dietary vitamin E supply led to better oxidative stability.     

Circulating levels of vitamin E in captive Asian elephants (Elephas maximus)

Circulating levels of α-tocopherol (vitamin E) were examined via high-performance liquid chromatography in four female Asian elephants (Elephas maximus) at the New York Zoological Park between 1983 and 1987. Plasma vitamin E averaged 0.08 μg/ml in 1983, and was considered deficient. Over a four-year period of dietary supplementation ranging from 0.7 to 3.7 IU vitamin E/kg body mass (approximately 50 to 250 IU/kg diet as fed), mean plasma α-tocopherol increased to 0.6 μg/ml. Plasma and dietary vitamin E were found to be significantly correlated (p < 0.025) in these animals. Serum or plasma vitamin E measured in an additional 20 elephants from eight other zoological institutions in the United States and Canada averaged 0.5 μg/ml, but values were not significantly correlated (p > 0.05) with calculated dietary levels of the vitamin. To achieve the mean value for circulating α-tocopherol in captive elephants (0.5 μg/ml), feed must provide at least 1.0, and more likely 2.0 to 2.5 IU vitamin E/kg body mass (approximately 130 to 167 IU/kg diet).