In ancient China, the means of subsistence were scarce, and eating meat was basically the patent of the upper class. Ordinary people only have the opportunity to eat meat on holidays or birthdays.
As early as the pre-Qin period, the theory of "Six Livestock" appeared in China. The so-called "six animals" include horses, cows, sheep, pigs, dogs and chickens. The "Six Livestock" consists of five kinds of horses that are basically not Chinese, used for riding, and fish that constitute the main part of ancient meat in China. Among them, cattle, sheep and You Zhu occupy a particularly important position.
The Book of Rites of the Zhou Dynasty called cattle, sheep and pigs "prisons", which are the best products that only monarchs and great doctors can enjoy. As for the people at the bottom, as the salt and iron theory of the Han Dynasty said, "people who don't drink in their hometown, eat fat, and sacrifice no wine and meat" can usually only enjoy it on holidays and celebrations.