The U.S. Bureau of Land Management will implement new rules restricting the private sale of wild horses and burros.

The rules are in response to an investigation of Colorado livestock hauler Tom Davis, who has bought more than 1,700 horses since 2009. The Department of Interior's inspector general is investigating whether any of the horses sold to Davis were taken to slaughter. Wild horses are protected under federal law, and selling them for slaughter is illegal. Davis has denied any wrongdoing. The new BLM rules will limit the sale of wild mustangs and burros to no more than four within a six-month period unless prior approval is obtained from a BLM assistant director. Buyers also must describe where they intend to keep the animals. Nearly 37,000 wild horses roam Western states. About half are in Nevada. Steve Goldstein, KJZZ News.