State law says that livestock headed for slaughter must be removed , euthanized . But federal law lets farmers determine if they can still , be fit for consumption . Justices express concern that state law may go too far into federal arena . Case was brought by a meat trade group on behalf of dairy farmers in California .
California law says downed livestock headed for slaughter must be removed , euthanized . But federal law lets inspectors determine if livestock can recover , be fit for consumption . Justices express concern that state law may go too far into federal arena . Case was brought by a meat trade group on behalf of pig farmers in California .