Yu Youyao found many old farmers who were good at animal husbandry and wrote books containing their precious and rare experiences with them. She hired a bookstore to print them in large quantities and sold them for 80 copper coins each.
As printing was widely used, the price of books decreased. An ordinary book cost about 200 copper coins, and would cost no less than 100 copper coins. It also depended on the quality of the paper used and the number of words.
The "Records of Feeding" that Princess Shaoyi had implemented was divided into three volumes. It summarized the merits of the Great Zhou and the Northern Barbarians and was praised by many people. The price of 80 copper coins was really too low.
Eldest Princess Shaoyi encouraged the development of animal husbandry and wanted to expand the scale of livestock so that the commoners would not suffer.