Animal Welfare Assessment in Antibiotic-Free and Conventional Broiler Chicken

The poultry sector is moving towards antibiotic-free production, both to challenge the increasing spread of the antibiotic resistance phenomenon and to meet market demands. This could negatively impact the health and welfare of the animals. In this study, the welfare of 14 batches of 41-47-day-old broilers raised by the same integrated company with and without antibiotics was assessed using the Welfare Quality^® protocol. The total welfare score did not significantly differ between the two systems: the good-feeding principle was, on average, higher in the conventional batches, with statistical significance (t = -2.45; p = 0.024), while the other welfare principles (good housing, good health and appropriate behaviour) were slightly better in the antibiotic-free batches. Despite stocking densities averagely higher in the antibiotic-free batches, the absence of antibiotics did not seem to impact the good-health principle; in particular, hock burns, foot pad dermatitis and lameness were significantly less severe in the antibiotic-free batches (p < 0.0001, p = 0.018, p < 0.0001, respectively), which showed also a lower death rate (2.34% vs. 2.50%). Better management of antibiotic-free batches was reported, particularly concerning litter conditions. Further studies would be required to identify and standardise a set of managerial methodologies in order to improve the health of broilers raised without antibiotics.