An antitrust class action accuses Tyson Foods Inc. of harming competition in the chicken farmers market of southeastern Missouri one month after the giant poultry company filed a federal lawsuit seeking preemptive exoneration of these state-law claims.

Tyson is alleged to have “decimated all broiler chicken farmers” in Missouri’s Dexter area by selling a local chicken processing plant as part of an “anticompetitive scheme” that violated state antitrust laws.