Mo. Rev. Stat. § 276.050
It is hereby declared unlawful for any two or more members of any association or organization organized or maintained by persons, firms or corporations buying, selling or exchanging cattle, hogs or sheep at such public market, to enter into any arrangement, understanding or agreement which shall limit, or have the effect of limiting, any member in the exercise of the right to distribute, in such manner and at such times as the member may desire, to the persons composing any partnership in which the member is financially interested or to the shareholders of any corporation or cooperative association in which such member is a shareholder, the profits of such member to the persons composing such partnership or to the shareholders of such corporation or cooperative association, in proportion to the quantity of cattle, hogs or sheep shipped to or from such member by the persons composing such partnership or the shareholders of such corporation or cooperative association, or which arrangement, understanding or agreement shall discriminate or have the effect of discriminating or which shall cause discrimination or tend to cause discrimination against such member because such member does so distribute the profits of such member; and the fact that any arrangement, understanding or agreement is made between two or more members of such association or organization which does or tends to discriminate against or which causes or tends to cause discrimination against any member who does so distribute the member's profits shall be prima facie evidence that such arrangement, understanding or agreement was made for the purpose of discriminating or causing discrimination against such member because such member does so distribute the profits of said member.
§ 276.050, RSMo