The AVMA recommends that disabled livestock be handled humanely in all situations:
If an otherwise healthy animal has been recently injured, and the animal is ambulatory, it should be treated, shipped directly to a state or federally inspected slaughter plant, humanely slaughtered on the farm (where state laws permit), or euthanatized. Injured, ambulatory animals should not be commingled with other animals during transport.
Care should be taken during loading, unloading, and handling of these animals to prevent further injury or stress.
At no time is a nonambulatory animal to be dragged.
If an animal is down on a farm
If an animal is down at a nonterminal market (e.g., sale yard or auction)
If an animal is down at a terminal market (e.g., slaughterhouse or packing plant)
Animals that are down should be euthanatized immediately and not taken to slaughter. However, if swine are down, and are not in extreme distress or do not have an obviously irreversible condition, they may be allowed up to 2 hours to recover. Acceptable interventions to assist in this recovery include rest, cooling, or other treatments that do not create drug residue concerns.
2014 American Veterinary Medical Association