Whenever after full hearing upon a complaint made as provided in section
210 of this title, or after full hearing under an order for investigation and hearing made by the Secretary on his own initiative, either in extension of any pending complaint or without any complaint whatever, the Secretary is of the opinion that any rate, charge, regulation, or practice of a stockyard owner or market agency, for or in connection with the furnishing of stockyard services, is or will be violative of section
205,
206, or
208 of this title, the Secretary—