Complex sentence: In 2008, the Government Accountability Office concluded BLM was not in compliance with the 2004 amendment, as the department had imposed limitations on the sale of excess horses to help ensure that they were not slaughtered (thus avoiding a public outcry).
Split into simpler sentences: In 2008, the Government Accountability Office concluded BLM was not in compliance with the 2004 amendment. BLM had imposed limitations on the sale of excess horses to help ensure that they were not slaughtered (thus avoiding a public outcry).