China has unveiled regulations that aim to more tightly control the world’s largest pig population, after a recent growth in herd numbers weighed heavily on pork prices.

The country’s agriculture ministry said in a notice on Monday that its guidelines on herd sizes should be “better used” to “prevent large fluctuations in pig production capacity” after a period of volatility.

China’s pig herds, which make up about half of the global total, were devastated by an outbreak of African swine fever from 2018 to 2021, leading to widespread culling, higher prices and a push for more production that in subsequent years resulted in volumes recovering to the point of overcapacity. China’s pig population was 434mn in 2023, up significantly from a low of 310mn in 2019.