The price of live pigs in every region is so uniform. Who set this price?

The price of live pigs in every region is so uniform. This price is set by slaughterhouses, large-scale farming and animal husbandry enterprises, Shuanghui, Yurun and other enterprises. According to relevant public information, the price of live pigs depends entirely on the floating pricing of both suppliers. The purchase price of live pigs is reported by slaughter enterprises every night according to demand, and released by large agricultural and animal husbandry enterprises, Shuanghui, Yurun and other enterprises.