Recent nutrigenomic studies have shown that animal nutrition can have a major influence on tissue gene expression. Dietary antioxidant supplements can enhance the quality of meat through modification of tissue metabolic processes. This study investigated the influence of dietary antioxidants and quality of oil on the oxidative and enzymatic properties of chicken broiler breast meat stored in an oxygen-enriched package (HiOx: 80% O2/20% CO2) in comparison with air-permeable polyvinylchloride (PVC) or skin packaging systems during retail display at 2 to 4°C for up to 21 d. Broilers were fed either a diet with a low-oxidized (peroxide value 23 mEq of O2/kg) or high-oxidized (peroxide value 121 mEq of O2/kg) oil, supplemented with or without an algae-based Se yeast and organic mineral antioxidant pack for 42 d. Lipid and protein oxidation and tissue enzymatic activity were analyzed. In all packaging systems, lipid oxidation (TBA reactive substances) was inhibited by up to 32.5% (P < 0.05) with an antioxidant-supplemented diet when compared with diets without antioxidants, particularly in the HiOx and PVC systems. Protein sulfhydryls were significantly protected by antioxidant diets (e.g., by 14.6 and 17.8% for low-and high-oxidized dietary groups, respectively, in PVC d 7 samples). Glutathione peroxidase, catalase, and superoxide dismutase activities were significantly higher (P < 0.05) in antioxidant-supplemented diets compared with the basal diet, regardless of oil quality. Also, serum carbonyls were lower in broilers fed a low-oxidized antioxidant-supplemented treatment. The results demonstrate that dietary antioxidants can minimize the oxidative instability of proteins and lipids, and the protection may be linked to improved cellular antioxidant enzymatic activity.

Two experiments were conducted to examine the effects of alpha-galactosidase supplementation and acidification of diets on nutrient digestibility and growth performance of broiler chicks. In experiment 1, dietary treatments consisted of feeding a low-energy basal diet (2.74 Mcal of ME/kg) alone, the basal diet supplemented with 1,724 units of alpha-galactosidase per kg, the basal diet supplemented with 2% citric acid, or the basal diet supplemented with both. alpha-Galactosidase significantly increased feed intake, weight gain, AME(n) of the diets, and retention of CP and neutral detergent fiber (NDF) (P < 0.05). Citric acid significantly increased the retention of DM, CP, and NDF, but decreased feed intake and weight gain. The greatest values for DM and NDF retention and for AME(n) were obtained with the combination of alpha-galactosidase plus citric acid. In experiment 2, chicks were fed diets with 2 levels of energy (2.74 or 3.11 Mcal/kg), 2 levels of citric acid (0 or 1.5%), and 2 levels of alpha-galactosidase (0 or 1,724 units/kg) in a 2 x 2 x 2 factorial arrangement of treatments. alpha-Galactosidase significantly increased the reducing sugar concentration in the crop content, whereas citric acid decreased the pH and increased the reducing sugar concentration in the crop content. Citric acid decreased the gain to feed ratio in the absence but not in the presence of alpha-galactosidase. The data from these studies indicate that acidification of diet improves the efficacy of alpha-galactosidase.

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