Mo. Rev. Stat. § 416.425: Sales by retailers at less than cost — evidence.

1. No nonprocessing retailer shall, with the intent or with the effect of unfairly diverting trade from a competitor, or otherwise injuring a competitor, or of destroying competition, or of creating a monopoly, advertise, offer to sell or sell within the state of Missouri, any milk product for less than cost to the retailer.

2. Proof of the advertising, offer to sell or sale of milk products by a nonprocessing retailer is prima facie evidence of a violation of this section.