An operator of a livestock market: Shall provide humane treatment of livestock in its custody; May not accept downers for sale at its market; In the case of livestock that become downers after acceptance for sale at the market, shall: Provide the needed equipment for handling, moving, and, if necessary, euthanizing these animals, Identify and mark the livestock in a distinctive manner, Separate and separately pen the livestock from healthy animals, and Notify the Department that an animal has become a downer; and Shall properly dispose of all animals that die or are euthanized after acceptance into the market. The operator of a livestock market is permitted to offer or sell 3-D livestock only to a slaughtering establishment for immediate slaughter. At the close of a livestock sale, if any downers remain unsold, the market operator immediately shall: Euthanize the livestock as provided under 9 CFR 313; or Place them in the care of a licensed veterinarian.