Antioxidative effects of supplementing linseed oil-enriched diets with α-tocopherol, ascorbic acid, selenium, or their combination on carcass and meat quality in broilers.

In a previous study, we examined the synergistic effects of the dietary supranutritional supplementation with vitamin E, vitamin C, and Se on the in vivo antioxidative status of broilers under conditions of dietary oxidative stress induced by feeding a diet high in n-3 PUFA. In this study, we examined the effect of their inclusion on the quality characteristics and oxidative stability of raw or cooked meat, both fresh or after a long-term frozen storage. Four hundred 21-day-old Ross 308 male broilers were allocated to 5 experimental groups fed 5% linseed oil-enriched finisher diets (days 21 to 40): Cont (recommended levels of vitamin E, C, and selenium), +E (200 IU vitamin E/kg feed), +C (250 mg vitamin C/kg feed), +Se (0.2 mg selenium/kg feed), or +ECSe (concentrations as in the sole supplementation, combined). Animal performance and carcass characteristics were monitored at the age of 40 D. Breast meat samples of 12 chickens per group were analysed fresh, fresh after frozen storage, cooked fresh, and cooked after frozen storage (2 × 2 factorial design) for parameters of meat quality (water-holding capacity-WHC, pH, and color) and oxidative stability (concentrations of vitamin E, malondialdehyde-MDA, antioxidant capacity of the water-soluble compounds-ACW, and fatty acid composition). Vitamin E alone (+E) and combined with Se and vitamin C (+ECSe) increased the α-tocopherol concentration in breast muscle, and showed similar protective effects against lipid peroxidation measured as MDA regardless of the frozen storage or cooking. The sole supplementation of vitamin C or selenium showed no effects on the meat quality parameters. In conclusion, the dietary supranutritional inclusion of vitamin E inhibited the lipid peroxidation in fresh, frozen stored, cooked fresh, and frozen stored meat in broilers fed with diets rich in n-3 PUFAs. Even though no clear synergistic effects of the supranutritional supplementation of vitamin C and Se with vitamin E were detected, their dietary inclusion did not negatively affect broilers carcass and meat quality parameters.

Fe bioavailability from Fe-enriched yeast biomass in growing rats.

The Fe content in animal feeds is highly variable. The availability of Fe in feeds varies with the feed and the form in which Fe is present. The present study reports the effect of the addition of different concentrations of Fe from yeast biomass on Fe bioavailability and Fe level in rat liver, compared with a diet containing Fe-sulphate (Fe-sulphate) addition (control) and with a diet without any addition of Fe. Male Wistar rats were fed ad libitum for 10 days a diet with different levels of Fe-enriched yeast biomass (20, 35 and 50 mg of Fe), or Fe-sulphate diet (50 mg of Fe) or without Fe addition. Faeces and urine were collected for Fe analyses during the last 5 days of the test period. The results clearly showed a highly significant (P < 0.001) better bioavailability of Fe from Fe-enriched yeast biomass, independent of the level of Fe in the diet. This was on average 36% higher than the availability of Fe from the Fe-sulphate-enriched diet. Liver Fe storage depended on the level of Fe in the diet from yeast biomass. A significantly lower amount of Fe was found to be incorporated in the liver in the group with an inorganic source of Fe (Fe-sulphate) in the diet.