Effects of organically-complexed minerals on meat quality in chickens

The impact of combined lower concentrations of organically-complexed versus inorganic copper, zinc and manganese on meat quality in chickens was investigated. A total of 200 male broiler chicks (Ross-308), 1-d-old and weighing approximately 40 g, were divided into 4 groups comprising three experimental groups and one control group, with each consisting of 50 chicks. All groups were also divided into 5 subgroups, with each containing 10 broiler chicks. All birds were given a starter diet from d 1 to d 21, and a grower diet from d 22 to d 49. The diets were formulated according to the NRC recommendations. The mineral contents of the control diet were supplied using a standard inorganic mineral premix (containing 8 mg Cu as CuSO₄, 40 mg Zn as ZnSO₄, and 60 mg Mn as MnO, per kg). For the experimental diets, a mineral premix was prepared using organically complexed forms of those minerals at 1/3 (L1), 2/3 (L2) and 3/3 (L3) proportions. After slaughtering and evisceration, the carcases were stored at 3 ± 0·5°C for 10-12 h, and then the breast fillets removed from the carcases, and stored in a deep-freezer (-86°C) until analysis (for 30 d). For analyses, the breast muscles were then thawed at 4-6°C for 24 h. 6. The concentration of organically complexed mineral in the diet had no statistically significant effect on pH values of breast fillets. Treatments significantly affected the Thiobarbituric Acid Reactive Substances (TBARS) values. Lightness (L* value) of the fillet from broilers fed the diet containing inorganic minerals was significantly lower than that for broilers fed on the diets containing organically complexed minerals. The redness (a* value) and Chroma (C* value) significantly decreased while Hues (H* value) were higher in the fillet from broilers fed organically complexed minerals compared with those fed inorganic minerals. The yellowness (b* value) was not changed by dietary treatment.