Effects of dietary natural antioxidant supplementation on broiler chicken and Muscovy duck meat quality

A total of 150 one-day-old male broiler chicks (Ross 308) and 120 one-day-old female Muscovy ducklings were distributed over 15 and 12 pens, respectively. All birds received the same diet during the first period of life. Throughout the second period (36-56 days for broiler chickens and 43-69 days for Muscovy ducks) different source plant extracts were supplemented to the basal diet for each species; dietary treatments were assigned to three pens each. In the chicken (CK) trial the following dry extracts were tested: tomato (Solanum lycopersicum) skin (200 mg lycopene kg-1 feed; CK-L200 group), orange (Citrus aurantium) peel (200 mg hesperidin kg-1 feed; CK-O200 group), and green tea (Camellia sinensis) leaves (200 mg catechins kg-1 feed; CK-T200 group). For the Muscovy duck (DK) trial the tested extracts were produced from rosemary (Rosmarinus officinalis) leaves (200 mg carnosic acid kg-1 feed; DK-R200 group) and orange (Citrus aurantium) peel (200 mg hesperidin kg-1 feed; DK-O200 group). The effects in both species were compared with those for the unsupplemented diet (CK-C and DK-C) and the diet supplemented with 200 mg of alpha-tocopheryl acetate (CK-E200 and DK-E200). At the end of each trial three birds per pen were slaughtered. Growth performance,pH and meat proximate composition in both species were not affected by dietary treatments. The TBARS value of chicken leg meat from the unsupplemented group was 3.86, while on average in CK-E200, CK-L200 and CK-O200 it was by 60, 55 and 63% lower (P<0.05), whereas in CK-T200 it was by 25% higher (P<0.05). Dietary treatments did not exert any antioxidant effects on chicken breast meat. The TBARS value of duck breast meat and leg meat from the control was 1.39 and 4.51,respectively, while on average in the DK-E200, DK-O200 and DK-R200 groups it was by 82 and 71%, 33 and 46%, and 66 and 47% lower (P<0.05), respectively. The magnitude of the antioxidant action of vegetable dry extract in this trial was lower than that of alpha-tocopheryl acetate.