Effect of lairage on lamb welfare and meat quality

Abstract

The study analysed the effect of lairage on some indicators of welfare and meat quality in lambs. Forty-eight lambs were divided into two treatments: T1 without lairage and T2 with 12 h of lairage. Blood samples were collected at slaughter to analyse cortisol, lactate, glucose, creatinine kinase, non-esterified fatty acid, white blood cells, red blood cells, haematocrit and ratio of neutrophil : lymphocytes. Meat from the M. longissimus was analysed in terms of pH 24 h post-mortem, water-holding capacity, texture and colour. Sensory analyses were performed by a trained panel. Lairage had a significant effect on stress response, but had no effect on haematological variables. The lambs with a lairage period before slaughter (T2) had significantly (P ≤ 0.001) lower values of cortisol at the time of slaughter. A similar result was observed for lactate and glucose, with T1 lambs showing significantly (P ≤ 0.05) higher values than T2 lambs. The creatinine kinase activity and non-esterified fatty acid concentrations were highest in T2 lambs (P ≤ 0.05). Instrumental and sensory meat quality were not affected, with the exception of water-holding capacity and some meat colour indicators. The water-holding capacity was significantly higher for T2 (P ≤ 0.05), while T1 lambs had a higher yellow index (P ≤ 0.05) and hue (P ≤ 0.05). The results obtained in this study suggest that animals will be less stressed at the time of slaughter with an overnight lairage compared with slaughter on arrival at the abattoir. While stress at the time of slaughter can influence meat quality, these changes were small and always within the normal commercial range.