Sources of pain in farm animals

With the advent of intensive farming, farm animals are raised in production contexts where rearing conditions and enforcement of some practices, motivated by livestock, health and cultural considerations, may represent certain or potential sources of pain for the animals. These sources of pain may include 1) animal husbandry practices including routine interventions, such as the application of ear tags for identification, castration, tail docking, dehorning, teeth trimming, beak cutting or other mutilation; 2) production systems and farm management, which can induce or encourage the emergence of painful diseases with varied etiology (infectious, metabolic, locomotor, etc.); 3) protocols of genetic selection based on productivity criteria, which in some cases may promote animal susceptibility to certain diseases and hence to potential pain. These sources can add up to those related to the practice of animals slaughtering, both during the pre-cut (stay in the lairage, journey into the trap of restraint) and in the process of killing itself (restraint, stunning and slaughter).