The aim of this study was to compare recommendations for vitamin E supplementation regarding high polyunsaturated fatty acid intake and to compare th

The present study was conducted to investigate the effects of dietary supplementation with vitamin E, vitamin C, and Se, alone or in combination, on carcass characteristics, oxidative stability and meat quality parameters of breast meat from broilers exposed to cyclic heat stress (HS), and stored under different conditions. A total of 120 one-day-old male Ross 308 broilers were randomly assigned to six dietary treatments: NRC (minimal nutrition requirements), AVI (commercial nutritional recommendations for Ross 308 broilers), AVI + vitE (as AVI + 200 IU vitamin E/kg feed), AVI + vitC (as AVI + 250 mg vitamin C/kg feed), AVI + Se (as AVI + 0.2 mg Se/kg feed), and AVI + ECSe (as AVI + vitE + vitC + Se). From day 26 onwards, all birds were exposed to a high ambient temperature (31 °C) for 8 h per day. The results showed that dietary vitamin E alone or in combination with vitamin C and Se significantly increased the α-tocopherol content and decreased the malondialdehyde (MDA) content in breast meat. Although no obvious synergistic effects of the added antioxidants were observed, the addition of higher levels of vitamin E, vitamin C and Se to broiler diets had no adverse effects on carcass traits, oxidative stability and meat quality parameters when supplemented either alone or in combination.

A trial was conducted to investigate whether, and if so to what extent, the combined supplementation of vitamin E, vitamin C, and selenium was superi

1. This study examined the effect of α-tocopherol (α-T), sweet chestnut wood extract (SCW) and their combination on oxidative stress in vivo and oxidative stability of meat in broilers given diets rich in PUFA. 2. A total of 60 male broilers were individually caged and divided into 6 groups of 10. The C-PALM group received a diet with 7·5% palm fat and the other 5 groups with 7·5% linseed oil. The linseed oil groups were either un-supplemented (C-LIN) or supplemented with α-T or/and SCW as follows: αT-85 (C-LIN diet + 68 IU vit E as all-rac-α-T/kg), αT-200 (C-LIN diet + 183 IU vit E as all-rac-α-T/kg), SCW (C-LIN diet + 3 g SCW/kg) and αT-SCW (C-LIN diet + 68 IU vit E as all-rac-α-T/kg + 3 g SCW/kg). Different parameters of oxidative stress were measured. 3. Linseed oil induced DNA fragmentation and malondialdehyde (MDA) formation, while α-T reduced both parameters, and SCW reduced the DNA damage. A combination (αT-SCW) also reduced plasma MDA. Larger antioxidant capacity of lipid soluble compounds were recorded in groups αT-85, αT-200 and αT-SCW than in the controls but there were no differences between these groups in antioxidant enzymes and total antioxidant status. A combination (αT-SCW) increased tocopherol concentrations in breast muscle and in comparison to the C-LIN group MDA concentrations were reduced in groups αT-85, αT-200 and αT-SCW. 4. It can be concluded that neither of the α-T concentrations were able to prevent all the negative effects of lipid oxidation in vivo and only high concentrations of α-T improved the stability of meat. With the exception of DNA damage, SCW had no impact on in vivo and in vitro measured markers of oxidative stress but may have a sparing or regenerating effect on α-T.

The aim of the current study was to assess the antioxidative effects of the dietary supplementation of olive leaf extract (OLE) in different concentrations compared to those of vitamin E in piglets under conditions of dietary n-3 PUFA-induced oxidative stress. Forty-eight castrated male piglets (10.6 ± 0.99 kg) were fed the following experimental diets: Cont− (low-fat diet, no supplement), Cont+ (high linseed oil diet, no supplement), Vit-E (as Cont+, 105 IU vitamin E/day), OLE-1 (as Cont+, 3.84 mg hydroxytyrosol equivalents (HEQs)/day), OLE-2 (as Cont+, 38.4 mg HEQ/day), and OLE-3 (as Cont+, 96 mg HEQ/day). After 21 days of feeding, the experimental diets, blood and urine samples were collected to assess the extent of the oxidative stress. Results indicated that diet OLE-1 lowered the activity of gamma-glutamyl transferase, protected DNA (measured as DNA tail %) and altered urinary 8-hydroxy-2’-deoxyguanosine (8-OHdG). Dietary vitamin E lowered the levels of urinary F₂-isoprostanes, as well as of plasma malondialdehyde and γ-tocopherol, but raised the plasmatic α-tocopherol and altered the level of urinary 8-OHdG. In conclusion, only minor positive effects of dietary OLE on the oxidative stress parameters were observed. Additionally, OLE did not show concentration dependence.