Salazar's announcement comes after reports about Tom Davis, a southern Colorado livestock hauler who has bought more than 1,700 horses from the Bureau of Land Management since 2009 but won't reveal the fate of the animals.
The Alamosa County district attorney is investigating the sales.
Salazar told The Gazette in an interview that buyers can be prosecuted for falsifying sales applications and for indirectly selling horses to slaughter by reselling to middlemen.
Salazar also said buyers will be limited to five horses every six months. Larger orders must be approved by the BLM's deputy director.
(Copyright 2012 by The Associated Press. All Rights Reserved.)