The Act's purpose at the time it was passed was to "regulate interstate and foreign commerce in live stock, live-stock produce, dairy products, poultry, poultry products, and eggs, and for other purposes." It prohibited packers from engaging in unfair and deceptive practices, giving undue preferences to persons or localities, apportioning supply among packers in restraint of commerce, manipulating prices, creating a monopoly or conspiring to aid in unlawful acts. The Act also made stockyards quasi-public utilities and required yard officers, agents and employees to register with the government. Stockyards were forbidden from dealing in the livestock they handled, and required them to maintain accurate weights and measures and pay shippers promptly. However, not all stockyards were under the jurisdiction of the Act. Only those with pen space larger than twenty thousand square feet were regulated.