The administrator of USDA’s Grain Inspection, Packers and Stockyards Administration (GIPSA) has announced that he is leaving his post next week.

J. Dudley Butler was in charge of key parts of the Obama administration’s effort to pass sweeping antitrust reforms affecting the meat packing industry.

Proposed regulations saw small farming groups in a battle with large meat packing firms; that conflict ended late last year after Congress killed funding.

Those meat packing firms and a large segment of Congress voiced displeasure at the proposed GIPSA rules because they overstepped the intentions of Congress as outlined in the last farm bill.

Among the biggest concerns was the lack of a published economic analysis of the proposed GIPSA rule that could be reviewed by the livestock industry. Congressional estimates last fall placed the GIPSA rule among 219 economically significant regulations in the pipeline that would cost $100 million annually, according to a report by the American Meat Institute (AMI).

Agriculture Secretary Tom Vilsack says Butler’s resignation won’t change antitrust enforcement at the Department of Agriculture.

“President Obama and I believe fair and competitive markets are critical to the success of American agriculture, and Dudley has worked tirelessly to advance this cause. USDA looks forward to continuing this work on behalf of our nation’s producers,” Vilasck said in an e-mail to the Associated Press.

The USDA said Alan Christian, deputy administrator for the Packers and Stockyards Administration, will serve as GIPSA’s acting administrator until a replacement can be found.