Seroprevalence of Viral Enzootic Diseases in Swine Backyard Farms in Serbia

SIMPLE SUMMARY: Infectious diseases are considered one of the main challenges to pig production despite continuous health management and biosecurity improvement. Hard to control, backyard farms are considered a high-risk infection source for commercial farms. However, as some consumers are concerned about animal welfare in intensive production systems, backyard farms are becoming popular as they respect environmental protection and animal welfare more than commercial farms. Though we discovered that Porcine Parvovirus and Aujeszky’s disease are widely present in backyard pigs from Serbia, almost half are free from the four tested diseases. Being the mirror of wild boar health and the link between wild boars and commercial farms, backyard farms must be controlled as they can interfere with countries’ eradication programs. ABSTRACT: Contrary to pig farming in developed Western countries, in a large part of the world, pigs are still traditionally kept in small backyard farms, usually for family needs. Their main characteristics are low biosecurity, swill feeding, natural breeding and uncontrolled trade. Given the high number of backyard farms in Serbia and the risk they are thought to pose to intensive pig farming, the main aim of this study was to evaluate the prevalence of major viral diseases of swine among traditionally kept pigs in small holdings with low biosecurity. For this investigation, 222 serum samples from 69 backyard holdings were randomly selected and tested for antibodies to Porcine Reproductive and Respiratory Syndrome virus (PRRSV), Aujeszky’s disease virus (ADV), Porcine Parvovirus (PPV) and Swine influenza Virus (SIV) by enzyme-linked immunosorbent assay (ELISA). The herd-level seroprevalence of PRRS, Aujeszky’s disease and PPV was 2.9%, 27.5% and 37.7%, respectively. Swine influenza seroconversion was not confirmed in any of the tested holdings. Despite widely distributed PPV and AD in backyard farms in Serbia, almost 50% of them are still negative for all the tested diseases. The backyard farms must be monitored, and owners must be educated as their role in eradication programs and obtaining country-free status may be crucial.