Effects of carvacrol- and thymol-based essential oil feed additives on carcass characteristics and breast meat quality of broilers with or without Salmonella challenge

This study evaluated the effects of essential oil-based feed additives on carcass characteristics and breast meat quality of broiler chickens with or without Salmonella challenge. A total of 1,800 one-day-old Ross 708 male broilers were randomly assigned to nine dietary treatments from day 0 to 42: a negative control diet without Salmonella inoculation and without essential oils (NC), NC supplemented with Salvix containing 50% carvacrol at 1,100 g/ton (NC+CAR1), NC supplemented with Esencial Premix containing 45% thymol at 250 g/ton (NC+THY1), a positive control diet with Salmonella inoculation without essential oils (PC), PC supplemented with Salvix at 1,100 g/ton (PC+CAR1) or 2,200 g/ton (PC+CAR2), PC supplemented with Esencial Premix at 250 g/ton (PC+THY1) or 500 g/ton (PC+THY2), and a combination of carvacrol and thymol (COMBO). Birds were processed on day 43, and carcass yield, cut-up part weights, breast meat quality traits, proximate composition, and the incidence of breast muscle myopathies were evaluated. Dietary treatment did not influence live body weight, hot or cold carcass weight, dressing percentage, or the absolute and relative yields of major carcass components, including breast, tenders, wings, and legs (P > 0.05). Similarly, breast meat pH, shear force, shear energy, drip loss at 48 h postmortem, lightness (L*), and yellowness (b*) were not influenced by treatment (P > 0.05). Breast meat redness (a*) differed among treatments (P = 0.035), with the highest values observed in the COMBO and NC treatments, whereas the lowest redness occurred in the Salmonella -challenged positive control group. Proximate analysis showed no treatment effects on moisture, crude protein, fat, salt, total collagen, soluble collagen, or insoluble collagen fractions of breast meat (P > 0.05). The incidence and severity of woody breast, white striping, and spaghetti meat were also similar across treatments (P > 0.05). Overall, dietary supplementation with carvacrol- and thymol-based essential oils had minimal effects on carcass yield and most meat quality parameters in broilers, while differences among treatments were observed in breast meat redness under the experimental conditions of this study.