The pig industry is the pillar industry of animal husbandry in China, and epidemics can lead to drastic changes in pig supply, affecting the healthy development of the pig industry and residents’ quality of life. This study analyzed the mechanism of the effect of swine epidemics on nonlinear shocks to pig supply, and monthly data on pig supply from January 2012 to June 2020 were applied to study the threshold effect of swine epidemics on pig stock and slaughter in China empirically, using the index of swine epidemics’ width (ISEW) as the threshold variable. The results of this study were as follows: (1) The influence of the ISEW over 7 months on pig stock in China was divided into two ranges, and the pig stock did not change significantly when the ISEW was less than 0.25. Swine epidemics had a significantly negative impact on the pig stock when the ISEW was larger than 0.25. (2) The influence of the ISEW over 8 months on pig slaughter was also divided into two ranges. When the ISEW was less than 0.33, epidemics had a positive and significant effect on pig slaughter, while epidemics had a marked negative impact on pig slaughter when the ISEW was greater than 0.33. Based on these conclusions, this study proposed relevant measures for the prevention and control of swine epidemics.

The rural population aging poses a great challenge to China’s agricultural production, which is dominated by small farmers. Based on the panel data of 30 provinces or cities (except Tibet) in China from 2005 to 2020, the DEA-Malmquist index is employed to measure the agricultural total factor productivity (ATFP) in each province (city), and then the mediation effect model is used to reveal the mechanism by which the rural population aging affects the ATFP through farmland transfer, agricultural social services, and agricultural machinery. The results show that the rural population aging has made a significant contribution to the ATFP, and farmland transfer, agricultural socialized services and agricultural machinery have a intermediary effect on the increase of the ATFP. Further decomposition of ATFP reveals that the rural population aging can significantly contribute to the scale efficiency and technical progress rate through farmland transfer, agricultural socialization services and agricultural machinery, but does not have a significant effect on pure technical efficiency. In order to promote the high-quality and high-efficiency development of agriculture in the context of population aging, it is necessary to optimize the market environment for farmland transfer, improve the agricultural socialized service system, and continue to strengthen agricultural science and technology innovation.