Effect of slaughter weights on some meat quality traits of Santa Inês lambs in a feedlot

Context The growing demand for more tender and healthy meat requires more precise parameters. Therefore, defining the ideal slaughter weight for sheep is crucial to strike a balance between productive performance and meat quality. Aims In this context, we aimed to evaluate the effect of different slaughter weights of lamb on the physicochemical, sensory and fatty acid characteristics of the meat. Methods Twenty-four uncastrated Santa Inês male lambs, 80 days old and with an initial bodyweight of 16.52 ± 1.92 kg, were distributed into individual pens. A completely randomized experimental design was used, with four slaughter weights (26, 32, 38 and 44 kg) and six replicates per treatment. Results The ether extract content increased linearly with slaughter weight. A quadratic effect of slaughter weight was observed on water-holding capacity, with a maximum estimated at approximately 41.84% at 34.98 kg, and on cooking losses, with a minimum estimated at approximately 34.95% at 34.49 kg. Shear force and pH after storage increased linearly. Meat lightness (L*) and hue angle decreased linearly. Higher slaughter weights resulted in higher concentrations of stearic and oleic acid, and the n6:n3 ratio was highest at 38 kg. The thrombogenic index was lowest in lambs slaughtered at 38 kg, and the concentrations of polyunsaturated fatty acids and some individual fatty acids were also higher at this weight. Flavor, color, aroma and overall acceptance were not affected by slaughter weight. The meat from lambs slaughtered at 38 kg had lower hardness, whereas greater succulence was observed in those slaughtered at 32 kg, with no difference from lambs slaughtered at 38 and 44 kg. Conclusion Slaughter weight influences the physicochemical and sensory characteristics of Santa Inês lamb meat. Slaughter at 38–44 kg was associated with a more favorable fatty acid profile, whereas 34–35 kg appears to provide a better balance of physicochemical and sensory characteristics. Implication These findings may support slaughter-weight decisions according to the desired balance between meat quality characteristics and fatty acid profile.