African swine fever in wild boar ecology and biosecurity
- African swine fever (ASF) is a devastating hemorrhagic viral disease of pigs, affecting domestic and wild pigs of all ages and sexes. The disease is the cause of major economic losses, threatens food security and safe trade, and challenges sustained swine production in affected countries. Since ASF emergence in Georgia in 2007, the disease has spread to many countries in Europe and in 2018 was detected in East Asia, where over 60 percent of global domestic pig inventories are found. The spread of the African swine virus genotype II into the Eurasiatic wild pig population was unprecedented; the increased densities in wild pig that had taken place in eastern and central Europe over the past few decades was a prime environment for the ASF virus to expand its geographical distributional range. Climate change and extensive cereal production enhanced local wild pig densities and expanded their geographical distribution. Besides these general tendencies, hunting management boosted wildlife abundance by curbing the hunting of wild sows thereby maintaining or increasing the localreproductive stock. They created winter feeding areas aimed at preventing the once-typical demographic crashes of the wild pig populations due to scarce food availability determined by the forest tree seed (mast) cycles. These areas promoted higher fecundity and fertility parameters. As a result, in most of Eurasia, wild pig management practices have artificially increased both abundance and geographical distribution of wild boars by bypassing the natural carrying capacity of the environment.