Effect Of Dietary Vitamin Research Articles

Effect of dietary vitamin E supplementation on fertilising ability of pheasant semen following artificial insemination

Effect of dietary vitamin E supplementation on fertilising ability of pheasant semen following artificial insemination

Effect of dietary vitamin E supplementation on fertilising ability of pheasant semen following artificial insemination

Effect of dietary vitamin E supplementation on fertilising ability of pheasant semen following artificial insemination

Effect of supplementation of vitamin E, selenium and their different combinations on the performance and immune response of broilers

1. The effect of dietary vitamin E, selenium (Se) and their different combinations on body weight gain, food consumption, food conversion efficiency, leukocyte migration inhibition and antibody production was determined in broilers. 2. Chicks were fed on maize-soya bean based diets with concentrations of supplemental vitamin E varying from 0 to 300 IU/kg and selenium concentrations varying from 0 to 1 mg/kg either alone or in combination from 1 to 42 d of age. 3. The chicks were immunised for Newcastle Disease Virus (NDV) vaccine at 21 d. Per cent leukocyte migration inhibition (LMI) was studied on 42 d. Antibodies to NDV in serum were determined at 10 and 21 d post immunisation (PI). 4. Chicks receiving Se, 1 mg/kg and vitamin E 300 IU/kg had significantly higher cellular immune responses in terms of per cent LMI. 5. Maximum body weight gain and best efficiency of food utilisation were obtained in chicks fed diets containing 0.50 mg/kg Se and 300 IU/kg vitamin E. 6. Significantly higher antibody titres (HI and ELISA) at 10 d PI were attributed to 0.06 mg/kg and 150 IU/kg Se and vitamin E, respectively. 7. These data suggest that optimum growth and immune response may be achieved at supplemental level of Se of 0.06 mg/kg and vitamin E at 150 IU/kg. The vitamin E level is higher than that recommended by NRC (1984, 1994).

Immune Competence of Chicks from Two Lines Divergently Selected for Antibody Response to Sheep Red Blood Cells as Affected by Supplemental Vitamin E

Effects of dietary vitamin E on responses to SRBC antigens and Escherichia coli infection were studied in chicks from White Leghorn lines selected for 24 generations for high (HAS) and low (LAS) antibody responses to SRBC. Chicks were fed corn-soybean diets consisting of either high (300 IU per kg feed) or low (10 IU per kg feed) concentrations of vitamin E from the day of hatch through the end of experiment. The LAS chicks were heavier than the HAS chicks at 14 d of age and thereafter; there was no difference in BW between vitamin E concentrations. At 37 d of age, chicks were inoculated via the brachial vein with 0.1 mL of 0.25% SRBC suspension. Antibody titers at 6 and 10 d after inoculation were higher in HAS than in LAS chicks. At 6 and 10 d after inoculation with SRBC, antibody responses were lower in LAS chicks fed the diet containing the higher vitamin E concentration than in those fed the diet containing the lower concentration of vitamin E. At 64 d of age, chicks were injected in the posterior thoracic air sac with 0.1 mL of 10−2 or 10−4 dilution of Escherichia coli and scored for pericardial and air sac lesions. The HAS chicks were more susceptible to E. coli infection than LAS chicks as measured by lesion scores and BW changes. Although dietary vitamin E had no effect on lesion scores in either line, BW loss at 24 h after E. coli inoculation was significantly reduced in HAS chicks fed the higher concentration of vitamin E. The dosage of E. coli had no effect on lesion scores and BW changes. These results suggest that genetic selection might have changed immune competence in relation to responses to dietary vitamin E, and the optimum dietary concentration of vitamin E depends on genotype, among other factors.

Effect of dietary vitamin E supplementation, fat level and packaging on colour stability and lipid oxidation in minced beef

The effect of addition of vitamin E (2025 IU animal −1 day −1) to the diet of beef bulls on the colour stability and lipid oxidation of minced beef was studied. Control and enriched diets were provided for the last 136 days before slaughter. Batches of freshly minced meat were prepared containing approximately 1.3 and 22.2 wt% fat, respectively. Half of the samples of minced meat from control (CON) and supplemented (SUP) beef were packaged on trays with oxygen-permeable over wraps and half in modified atmosphere (MA) packs (initial gas mixture: O 2/CO 2/N 2=65/25/10). The minced beef was stored for 10 days at 7°C in an illuminated environment. The SUP meat at both fat levels was consistently more resistant to lipid oxidation than was the CON meat. The additional vitamin E had a greater anti-oxidant effect for the lean meat product. MA packaging in comparison to the oxygen-permeable foil over-wrap did increase lipid oxidation, the effect being most pronounced for the CON meat. A sensory panel considered the colour of the lean SUP meat during display as more attractive than that of lean CON meat, irrespective of packaging. A similar effect was observed occasionally for the relatively fat minced meat. These subjective findings were confirmed by objective assessment of colour. The stability of the colour of the MA packed meat was better than that of the oxygen-permeable foil-wrapped meat. Microbial growth patterns of enriched and control meat were similar. MA packaging retards the multiplication of mesophilic aerobic spoilage micro-organisms and Enterobacteriaceae.

Effect of induced hyperoxia on the antioxidant status of Atlantic salmon Salmo salar L. fed three different levels of dietary vitamin E

Atlantic salmon smolt (64 g) were fed 40, 300 or 1100 mg kg−1 all-rac-α-tocopheryl acetate feed under normoxic and moderate hyperoxic conditions for 12 weeks. After 7 weeks, however, the hyperoxic fish were subjected to a temporary severe supersaturation of dissolved oxygen with development of gas bubble disease and substantial mortality as a result. Liver α-tocopherol (α-TOH) levels reflected the dietary input after 6 and 12 weeks of feeding. Increased levels of thiobarbituric-reactive substances (TBARS) in the liver of hyperoxygenated fish after 6 weeks indicate that moderate hyperoxic conditions may represent an oxidative challenge to the fish. After 12 weeks, liver ascorbic acid (AA) content was reduced in hyperoxygenated fish, and a decreasing tendency was also found in the liver content of α-TOH. Effects of oxygen supersaturation were also observed on liver antioxidant enzyme activities, content of glutathione and total mercapthans in liver, phagocytic chemiluminescent response and total plasma protein level, indicating a disturbed redox balance. No effects of dietary vitamin E were observed on any of the measured parameters, indicating that high levels of dietary vitamin E under these circumstances did not protect the fish against oxidative stress.

Effects of dietary vitamin E on the quality of table eggs enriched with n-3 long-chain fatty acids

Because of the proposed cardioprotective benefits of n-3 fatty acids and vitamin E, a trial was carried out to investigate the possibility of enriching eggs with n-3 fatty acid and vitamin E added to the hen's diet. One hundred ninety-two Hy-Line Brown hens, 39-wk-old, were divided into eight groups: four groups received the basal diet supplemented with 3% lard and four doses of dl-alpha-tocopheryl acetate (0, 50, 100, and 200 ppm), whereas the diets of the other groups were supplemented with 3% of fish oil and the same doses of vitamin E. The performances of the hens and egg weights were not affected either by the type of lipid supplement or by the vitamin level. The treatment with fish oil caused a dramatic increase (P < 0.01) of all n-3 fatty acids of the yolk, particularly EPA (19.53 vs. 0.74 mg/egg) and DHA (143.70 vs. 43.66 mg/egg), and an appreciable decrease of arachidonic acid (25.54 vs. 67.72 mg/egg). The different levels of dietary vitamin E slightly affected the fatty acid composition of the yolk. Yolk alpha-tocopherol increased linearly as dietary dl-alpha-tocopheryl acetate increased (P < 0.01) from the control level of 90.93 microg/g of yolk to 313.84 microg/g of yolk when 200 ppm were added to the hen diets. Twenty-eight days of storage at room temperature (20 to 25 C) did not alter the yolk fatty acid profile, and, moreover, the levels of vitamin E remained still very close to those observed in fresh egg.

Effect of dietary vitamin E on apoptosis and proliferation of murine splenocytes

Vitamin E (Vit E) is one of the most potent natural lipophilic antioxidants shown to inhibit proliferation of cancer cells and influence apoptosis in in-vitro systems. In the present investigation, we studied the effect of dietary Vit E on splenocyte proliferation, apoptosis, and necrosis. Two-month old male ICR mice were fed an AIN tm 76 formula diet for three months with 10% (W/W) corn oil, supplemented with Vit E at normal (75 IU/kg) or higher (500 IU/kg) levels, or without Vit E as zero Vit E group. In vivo analysis revealed both serum lipid peroxides (MDA) and splenocyte peroxides (dichlorofluorescein staining) were found to be reduced with increased dietary Vit E levels in a dose-dependent manner; whereas, serum Vit E levels were found to be augmented with increased levels of dietary Vit E. Also, apoptosis and necrosis were measured in splenocytes incubated with and without 1 μM dexamethasone (DEX) in RPMI media for eight and 21 hours. Cells were stained with Annexin V and Propidium Iodide (PI), and both apoptotic and necrotic cells were analyzed simultaneously by a FACScan desktop flow cytometer using the Cell Quest Program. High and normal levels of Vit E increased necrosis by 29 and 18% in the cells placed in media, and 67 and 34% in cells incubated with DEX for eight hours, respectively, in comparison to that in the zero Vit E-fed group. However, in splenocytes from the high Vit E group apoptosis was decreased by 32 and 49.5% in cells incubated for eight hours in media alone or with DEX, respectively. Furthermore, in the high Vit E group necrosis was increased by 25% and apoptosis was decreased by 17% in cells incubated for 21 hr in media alone, compared to that of the zero Vit E group. In addition, proliferation of splenocytes, either stimulated or unstimulated with mitogens, was also found to be decreased with increasing levels of dietary Vit E. In conclusion, our results indicate that dietary Vit E appears to alter both cell proliferation and programmed cell death (apoptosis vs. necrosis), by lowering lipid peroxides.

Effect of dietary vitamin E supplementation on cholesterol oxidation in vacuum packaged cooked beef steaks

The effect of dietary vitamin E supplementation on cholesterol oxidation in vacuum packaged, cooked, refrigerated and frozen beef steaks, was investigated. Steers (Friesian×Charolais×Black Hereford) were fed diets providing 20 or 3000 mg α-tocopheryl acetate/head/day for 135 days prior to slaughter. α-Tocopherol concentrations in M. psoas major (PM) and M. longissimus dorsi (LD) were significantly ( p<0.05) increased by supplementation and were significantly ( p<0.05) higher in PM than LD. Cholesterol oxidation (monitored by measuring 7-ketocholesterol formation) increased during refrigerated and frozen storage in some, but not all, groups, and tended to be higher in PM than LD. Dietary vitamin E did not affect 7-ketocholesterol formation in LD, but significantly ( p<0.05) reduced concentrations in PM during refrigerated and frozen storage. Supplementation significantly ( p<0.05) reduced TBARS in PM and LD, indicating that vitamin E improved oxidative stability in both muscles. The results show that dietary vitamin E supplementation inhibits cholesterol oxidation in vacuum packaged, cooked beef during refrigerated and frozen storage, but may be influenced by muscle type.

Effect of dietary vitamin E supplementation on beef colour stability

The effect of dietary vitamin E upon colour, waterholding capacity, bacterial growth and lipid oxidation of beef longissimus thoracis (LT) and psoas major (PM) muscle were examined during aerobic display of fresh muscle and after aging in vacuum for 26 days. Forty crossbred beef bulls received a whole crop corn silage, supplemented with concentrate. Twenty bulls were each supplemented with 2025 mg vit E per day (added to the concentrate) for 136 day prior to slaughter and compared with non-supplemented control animals ( n=20). In fresh LT muscle drip loss did not differ between treatment groups, while in PM muscle drip loss was significantly higher for the supplemented group. The treatment did not affect bacterial growth in fresh and aged muscles. Lipid oxidation during 12 day storage of fresh muscle was significantly lower for the supplemented group, as indicated by the lower TBA-values. No effect of the vitamin E treatment was observed on a ∗ -values of both fresh and aged LT muscle during display for 8 and 5 days, respectively. In PM muscle, supplemented beef had lower a ∗ -values in fresh (at day 1) and aged (at days 1 and 2) muscle, due to a lower oxygenation. The reason for this lower oxygenation is unclear. After aging, colour stability was decreased and more variable than in fresh muscle. Similar results were obtained when the difference in reflection values at 630 and 580 nm (R630-580), instead of the a ∗ value, was used as a parameter for colour stability. The absence of an effect of vit. E on the rate of discoloration, might possibly be explained from the observation that α-tocopherol levels in control muscle were relatively high (LT: 2.1 and PM: 3.2 μg/g muscle), compared with data from literature. Analysis of the feed for vit. E suggests that this was due to a relatively high natural vit. E uptake from the feed, which was calculated to be approx. 330 mg vit. E per animal per day for the control group.

Effects of dietary vitamin C on tissue ascorbate and collagen status in sturgeon hybrids (Acipenser ruthenus L. x Acipenser baeri Brandt)

Summary The aim of this study was to determine the vitamin C status of various tissues, and collagen concentration in cartilage, of a sterlet (Acipenser ruthenus L.) x Siberian sturgeon (Acipenser baerii Brandt) hybrid fed different dietary vitamin C rations. Growth, vitamin C status and collagen concentration were measured in groups fed diets supplemented with 150, 300, 600 mg.kg-1 ascorbate-2-polyphosphate (APP); 100, 200, 400 mg.kg-1 ascorbate-2-monophosphate (AMP), 1000 mg.kg-1 L-ascorbic acid (AA) and with an almost ascorbate free diet (Total AA > 5 mg.kg-1), as a control. No significant differences in growth were observed, and no external symptoms of scurvy developed in the vitamin C-free group. No reduction in total vitamin C concentration was revealed in the tissues examined, as compared with initial concentrations. Ascorbate-2-phosphate esters were only found in kidney or hepatopancreas of fish fed with these vitamin C derivatives. Significantly (p<0.05) lower contents of collagen were observed in the control group after 8 weeks feeding. No significant differences were found among the groups after 16 weeks although the collagen concentration in the cartilage was slightly lower in the control group without vitamin C supplementation.

Influence of dietary selenium and vitamin E on the levels of fatty acids in brain and liver tissues of lambs.

In this study, the effects of dietary vitamin E, selenium, and their combination on the levels of fatty acid composition of the brain and liver tissues were examined. In brain tissue, the amounts of most fatty acids increased in vitamin E, combination and selenium groups compared with control group values. While the proportions of myristic, pentadecanoic, palmitic, linoleic, and total saturated fatty acids were decreased in vitamin E, Se and combination groups, eicosapentaenoic, total unsaturated and MUFA were increased in the same groups. In addition, the proportions arachidonic, eicosapentaenoic, total unsaturated, omega 6 and MUFA in the combination group were higher than in the control group. In liver tissue, the amounts of myristic, pentadecanoic, palmitic, eicosedienoic, eicosapentaenoic, docosahexaenoic, omega 3 and PUFA were higher in the combination group than in the control group. Also the proportions of eicosapentaenoic, docosahexaenoic acids in supplemented groups were higher than those in the control group. We conclude that dietary vitamin E and selenium have an influence on the levels of fatty acids in the brain and liver.

Toxicological and Antioxidant Effects of Short-term Dehydroepiandrosterone Injection in Young Rats Fed Diets Deficient or Adequate in Vitamin E

This study examined the in vivo antioxidant and/or prooxidant effect of short-term dehydroepiandrosterone (DHEA) injection and the effect of dietary vitamin E. Male Sprague–Dawley rats (4 wk old) were fed vitamin E-deficient or vitamin E-adequate (30 mg dl- α-tocopheryl acetate/kg) diet for 4 weeks followed by intraperitoneal injection of DHEA for 1 week. The results showed that DHEA injection caused a dose-dependent decrease in body weight, and this effect was more pronounced in vitamin E-deficient rats. In contrast, DHEA injection significantly increased liver, kidney and adrenal weights. Hepatic vitamin E content was significantly lowered by vitamin E deficiency, which led to significantly increased ex vivo and iron-induced lipid peroxidation. DHEA injection did not affect hepatic vitamin E content but significantly decreased ex vivo and iron-induced lipid peroxidation in vitamin E-deficient rats. Hepatic total sulfhydryl (SH) groups and non-protein SH contents were not affected by vitamin E but were significantly increased by DHEA injection, which at 100 mg/kg was not more effective than at 50 mg/kg. Hepatic glutathione S-transferase (GST) activity was significantly decreased by DHEA, but vitamin E alleviated such a decrease. DHEA injection significantly increased hepatic glucose 6-phosphate dehydrogenase (G6PD) activity, and the effect was dose dependent in vitamin E-deficient rats. Thus, DHEA may compensate for vitamin E deficiency in vivo, and this effect is masked when dietary vitamin E is adequate. The antioxidant effect of DHEA is accompanied by decreased body weights, enlarged (fat-laden) tissues and altered activities of hepatic GST and G6PD.

Antioxidant defence system and lipid peroxidation in lactating rats: Effect of dietary vitamin E during gestation and lactation

The purpose of this study was to investigate the influence of a low vitamin E diet given to rat dams during gestation and lactation on the antioxidant defence enzymes and lipid peroxidation in their pups. Wistar rats were fed two different diets during gestation and lactation: a) Low vitamin E diet containing 65.8 mg Vit. E per kg of food, and b) Control diet containing 215.8 mg Vit.E per kg of food. Plasma concentration of vitamin E and in vitro spontaneous red blood cell hemolysis were determined in dams and their pups. Liver and brain superoxide dismutase, selenium-dependent glutathione peroxidase and catalase activities were evaluated in pups. Malondialdehyde production was measured in both brain and liver homogenates from pups. The low vitamin E diet decreased significantly the plasma concentration of the vitamin both in mothers (6.1 ± 3.3 vs. 13.1 ± 0.9 μM) and pups (2.5 ± 2.3 vs. 7.4 ± 1.6 μM). The treatment decreased the activities of superoxide dismutase (0.16 ± 0.02 vs 0.26 ± 0.05 ΔAbs/4min./mg,protein) and catalase (0.31 ± 0.06 vs 0.49 ± 0.13 k/mg protein) in pups liver. This diet had no influence on selenium-dependent glutathione peroxidase activity. Brain selenium-dependent glutathione peroxidase and catalase activities could not be detected and superoxide dismutase activity was not modified by the diet. Red blood cells from lactating rats whose mothers had received the low diet were essentially hemolysed. The production of malondialdehyde in both brain and liver from lactating rats was higher than in the control group (p<0.01). These data suggest that an inadequate supply of vitamin E during gestation and lactation has a significant impact on the antioxidant defence system and peroxidative status of pups tissues.

Effects of dietary vitamin E supplementation on pulmonary morphology and collagen deposition in amiodarone- and vehicle-treated hamsters

Amiodarone (AM) is a potent antidysrhythmic agent that is limited in clinical use by its adverse effects, including potentially life-threatening AM-induced pulmonary toxicity (AIPT). The present study tested the ability of dietary supplementation with vitamin E (500 IU d,l-α-tocopherol acetate/kg chow) to protect against pulmonary damage following intratracheal administration of AM (1.83 μmol) to the male golden Syrian hamster. At 21 days post-dosing, animals treated with AM had increased lung hydroxyproline content and histological disease index values compared to control ( P<0.05), which were indicative of fibrosis. Dietary vitamin E supplementation for 6 weeks resulted in a 234% increase in lung vitamin E content at the time of AM dosing, and maintenance on the diet prevented AM-induced elevation of hydroxyproline content and disease index 21 days post-dosing. Dietary vitamin E supplementation also decreased hydroxyproline content and disease index values in hamsters treated intratracheally with distilled water, the AM vehicle. These results demonstrate a protective role for vitamin E in an in vivo model of AIPT, and suggest that this antioxidant may have non-specific antifibrotic effects in the lung.

Effect of dietary vitamin E supplementation on the colour and lipid stability of fresh, frozen and vacuum-packaged beef

The effects of dietary vitamin E supplementation on tissue α-tocopherol (α-Toc) levels and on the susceptibility of fresh, frozen and vacuum-packaged beef to lipid oxidation and colour deterioration were investigated. Friesian cattle were fed diets containing 20 (basal, n=5) or 2000 (supplemented, n=5) IU (α-tocopheryl acetate/kg feed/day for approximately 50 days prior to slaughter. α-Toc levels were higher ( p < 0.05) in muscles from supplemented animals than from those on a basal diet. Significant differences in α-Toc levels were also observed between muscles from different treatment groups, the order of the supplemented group was: M. psoas major (PM) > M. longissimus dorsi (LD) > M. gluteus medius (GM) ( p < 0.05), and in the basal group the order was: PM > GM > LD ( p < 0.05). Supplemented fresh, frozen and vacuum packed beef showed greater colour and lipid oxidative stability than meat from the basal group after 7 days retail display at 4°C ( p < 0.05). Thus, dietary (α-Toc supplementation appeared to retard metmyoglobin and TBARS formation in LD, GM and PM and increased the colour shelf life of these muscles.

Vitamin K intake and hip fractures in women: a prospective study

Vitamin K mediates the gamma-carboxylation of glutamyl residues on several bone proteins, notably osteocalcin. High serum concentrations of undercarboxylated osteocalcin and low serum concentrations of vitamin K are associated with lower bone mineral density and increased risk of hip fracture. However, data are limited on the effects of dietary vitamin K. We investigated the hypothesis that high intakes of vitamin K are associated with a lower risk of hip fracture in women. We conducted a prospective analysis within the Nurses' Health Study cohort. Diet was assessed in 72327 women aged 38-63 y with a food-frequency questionnaire in 1984 (baseline). During the subsequent 10 y of follow-up, 270 hip fractures resulting from low or moderate trauma were reported. Women in quintiles 2-5 of vitamin K intake had a significantly lower age-adjusted relative risk (RR: 0.70; 95% CI: 0.53, 0.93) of hip fracture than women in the lowest quintile (< 109 microg/d). Risk did not decrease between quintiles 2 and 5 and risk estimates were not altered when other risk factors for osteoporosis, including calcium and vitamin D intakes, were added to the models. Risk of hip fracture was also inversely associated with lettuce consumption (RR: 0.55; 95% CI: 0.40, 0.78) for one or more servings per day compared with one or fewer servings per week), the food that contributed the most to dietary vitamin K intakes. Low intakes of vitamin K may increase the risk of hip fracture in women. The data support the suggestion for a reassessment of the vitamin K requirements that are based on bone health and blood coagulation.

Effects of Dietary Vitamin E Supplementation and Packaging on the Quality of Minced Beef

Friesian cattle, aged 26–27 months, were fed a diet supplemented with 2000 IU α-tocopheryl acetate/kg feed/day and another group was fed a basal diet (20 IU/kg feed/day) for approximately 50 days prior to slaughter. Following frozen storage (−20°C for 8 weeks) semimembranosus muscles from basal and α-tocopheryl acetate supplemented cattle were minced and vacuum packaged, aerobically packaged or packaged under modified atmospheres (MAP) (30% O 2: 70% CO 2; 70% O 2: 30% CO 2; 80% O 2: 20% CO 2). Samples were held under refrigerated (4°C) display (fluorescent lighting, 616 lux) for eight days. Vacuum-packaged samples were held under similar conditions but in complete darkness and allowed to bloom for a minimum of 4 hr prior to taking colour readings. TBARS values and Hunter a values in minced beef were measured every two days. α-Tocopherol concentrations were significantly ( p<0·05) higher in minced meat samples from the supplemented group than in the basal group. Significant ( p<0·05) reductions in α-tocopherol concentrations in supplemented meat samples were observed with increased concentrations of oxygen in different packaging systems after eight days of refrigerated storage. TBARS values were reduced over the whole retail display period for all packaging systems when α-tocopheryl acetate supplemented beef was used. TBARS values increased as oxygen levels increased in MAP. Hunter a values showed that vitamin E supplementation in combination with vacuum packaging and MAP improved the colour stability of meat during the first 4 days of storage, however, the failure of MAP to extend meat colour for longer periods of time was probably the result of prior storage at −20°C for 8 weeks.

Effect of Dietary Vitamin E on the Oxidative Stability of Raw and Cooked Rabbit Meat

The effect of dietary α-tocopheryl acetate supplementation (200 mg/kg diet) on plasma and muscle levels of α-tocopherol and the oxidative stability of raw and cooked rabbit meat was determined. Two groups of 20 male hybrid rabbits were fed the experimental diets from 35 to 80 days of age. Feed intake, live weight, feed efficiency and qualitative traits of the carcass and meat were recorded. The α-tocopherol levels in plasma and muscle were significantly higher ( p≤0·01) in the supplemented group, which also showed an increase in oxidative stability in both raw and cooked meat. The higher α-tocopherol level improved the physical traits of the meat, significantly reducing shear value and increasing water-holding capacity; n-3 fatty acids in raw and cooked meat increased ( p≤0·05) and the thrombogenic index decreased ( p≤0·05). Dietary vitamin E did not influence weight gain, feed intake and dressing yield.

Effect of dietary vitamin E supplementation for one week before slaughter on drip, colour and lipid stability during display in Japanese Black steer beef

Effects of dietary vitamin E supplementation for one week on drip, colour and lipid stability in raw beef steaks were studied. Four Japanese Black steers were fed no supplemental vitamin E and four were supplemented with 5000 mg of dl-α-tocopherol per animal daily for one week before slaughter. Steak samples from psoas major and longissimus thoracis muscles were over-wrapped with PVC film and displayed under fluorescent lights at 4 °C for 10 days. Drip loss percentages, L ∗, a ∗ and b ∗ values, metmyoglobin percentages, and 2-thiobarbituric acid reactive substances values were determined at day 1, 4, 7 and 10. Dietary vitamin E supplementation increased ( p < 0.01) α-tocopherol concentration in the plasma, liver and muscles. Vitamin E supplementation reduced ( p < 0.001) drip loss compared to the control. Vitamin E supplementation maintained ( p < 0.001) redness and retarded ( p < 0.01) metmyoglobin formation in beef steak from day 4 to day 10 of display compared to the control. Vitamin E supplementation delayed ( p < 0.001) lipid oxidation during 10 days of display compared to the control. The data indicated that dietary vitamin E supplementation for one week prior to slaughter improved lipid stability better than drip and colour stability in beef steak during 10 days of display.