Effects of dietary inclusion of condensed tannins from Schinopsis lorentzii and age on the physicochemical properties, and the content of minerals and amino acids content of meat in Eimeria-challenged broilers

The aim of the study was to evaluate the dietary effect of condensed tannins (CT) from red quebracho (Schinopsis lorentzii) and broiler age on the physicochemical properties, mineral composition, and amino acid content in the meat of broilers challenged with Eimeria spp. Broilers were randomly assigned to four dietary groups: CT1 and CT2 received 10 and 20 g CT/kg, respectively; the control (C) group received a basal diet; and the R group received a basal diet with a coccidiostat. Meat quality indicators were assessed at 35 and 42 days of age. Supplementation with the higher CT level (2%) reduced carcass weight, particularly at 42 days (P < 0.05), and affected physical meat quality indicators, including cooking loss, pH, and shear force, although the relationships among individual indicators were not fully consistent. Broiler age significantly influenced most of the physical traits, with older birds showing higher cooking loss and shear force in breast meat and altered meat colour (P < 0.05). Both CT and age modified mineral composition, with significant differences in macro- and microelements depending on muscle type and fattening duration (P < 0.05; P < 0.01). CT supplementation consistently increased total essential (EAA) and non-essential amino acids (NEAA) in leg meat (P < 0.05), whereas in breast meat, a significant effect was observed only for NEAA in the CT1 group at 42 days of age. Extending fattening from 35 to 42 days did not affect total EAA or NEAA in either muscle (P > 0.05), although minor age-related differences were detected for several individual amino acids (P < 0.05; P < 0.01). Overall, dietary CT supplementation and broiler age significantly influenced meat quality, including mineral content, amino acid composition, and functional physical properties.