The effect of transport distance, lairage temperature and electrical stunning current type on slaughter performance and breast meat quality traits of slow- and fast-growing broilers

This study examined the effects of genotype (G), transport distance (TD), lairage temperature (LT) and electrical stunning current type (CT) on slaughter performance, carcass defects and breast meat quality of broilers. A total of 320 broilers (equally mixed-sex), belonging to two different genotypes were used: 160 slow-growing (SG, 62 days old) and 160 fast-growing (FG, 42 days old). Birds were transported to the slaughterhouse at short or long distances, kept at 22 °C or 35 °C for 2 h, stunned and slaughtered using alternating current or pulsed direct current. The results showed that the G × TD interaction significantly affected body weight loss (BWL) and the heterophil:lymphocyte (H:L) ratio. SG broilers had higher BWL (5.20%) and H:L ratio (0.81) than FG broilers (BWL 3.24%, H:L 0.51) at short distance, but differences between genotypes were not significant at long distance. SG broilers showed higher body resistance during stunning. Haemorrhages were more intense in the wings and pygostyle in FG broilers and in the breast meat in SG broilers. Blood loss and some meat quality traits were significantly influenced by binary interactions between G, TD, LT and CT. The H:L ratio and BWL results indicate that TD should be taken into consideration in genotype selection for broiler production.