Processing, products, and food safety - Comparison of bruises and mortality, stress parameters, and meat quality in manually and mechanically caught broilers

A field trial was conducted to compare manual catching of broilers with a mechanical catching method. Both methods were compared with respect to the incidence of bruises and dead on arrival, stress parameters, and meat quality. Also the dynamics of corticosterone, glucose, and lactate were investigated on the day broilers were killed. The broilers originated from 8 commercial broiler farms; visits were made on the day of catching during spring and autumn of 2001. Broilers of one house were caught manually, and those of the second house were caught mechanically. Plasma samples were taken before catching started, 30 min after the start of catching, 30 min before the end of catching, and at exsanguination of broilers from the first- and last-loaded transport vehicles. Postmortem measurements of pH, temperature, and water-holding capacity were made. Mechanical catching was associated with higher DOA percentages than manual catching in spring, although the difference was not significant in autumn. Catching method did not influence the percentage of bruises or meat quality. Moreover, corticosterone levels indicated that both methods induced the same amount of stress. The dynamics of corticosterone, glucose, and lactate levels showed a similar pattern. Plasma levels increased at the start of catching, and they further increased during transport, shackling, and stunning. However during catching itself, no large changes were observed. Our findings indicated that attempts to reduce stress in broilers during the last day of life could better be focused on factors other than catching.