Assessment of the factors for the presence of wild boar near outdoor and extensive pig farms in two areas of Eastern Europe

Abstract

Expanding wild boar populations associate to conflicts with human activities, being a threat to livestock and public health. Particularly, the emergence of African Swine Fever (ASF) in Europe is of major importance. To better understanding the dynamics at the interface between wild boar and domestic pigs in Europe, which is essential to prevent the risk for ASF spread, this report describes (i) the use of extensive pig farm resources by wildlife (wild boar and other mammals) and domestic pigs, and (ii) the factors involved. We studied two regions of Central‐Eastern Europe with different farm management of pigs in Serbia, in low biosecurity farms in forest/bushland habitats, and Hungary, characterized by more industrial and professional farming in fenced pastures. Camera traps (CTs) were placed at a priori risk points for interspecies interactions and in random points in 4 representative outdoor pig farms in different seasons during 2022 (2 farms in Serbia and 2 in Hungary). Also, questionnaires were distributed to 37 farms (17 in Serbia and 20 in Hungary, respectively) to describe the main features and risk factors for wildlife‐pigs interaction on outdoor pig farms. CTs revealed that the wild species that more frequently used the study farms resources were golden jackal (Canis aureus) and wild boar in Serbia, and red fox (Vulpes vulpes) and red deer (Cervus elaphus) in Hungary (at the periphery of fenced farms). The use of extensive farm resources by wild boar was frequent and widespread throughout the study area of Serbia (over 33 % of daily presence per farm, 3.70 visits detected per week) whereas it was rarely detected in our sampled Hungarian farms. Wild boar visit frequency (Serbia) peaked during spring (7.5 visits per CT and day, CT*day), mainly associated with water point use (2.1 visits per CT*day). In Hungary, the greater number of direct interactions occurred between pigs and red deer during summer. Even when a higher average number of risk points were identified inside Hungarian farms, they were less permeable due to effective perimeter fencing, which prevented the entrance of wild boar and other big sized terrestrial wildlife. The study exemplifies contrasted outdoor pig farm managements, and associated risks for interaction with wild boar in ASF infected or at‐risk regions. Management, characterized by almost absence of external biosecurity in the specific type of production in Serbia raise health concerns, and indicates the need to develop efforts to improve biosecurity. Several strategies and specific measures adapted to environmental conditions and farm management could reduce the interactions at the wild boar‐pig interface in Serbia (and similar production systems in Eastern Europe). This should be materialized in farm‐specific biosecurity programs and protocols, which requires the evaluation of their effectiveness, costs, and practical value. The type of farming practiced in marginal agricultural/forest lands in Eastern Europe, often connected to backyards production, is a highly priori...

Investigation of PRRS Virus Infection in Hungarian Wild Boar Populations during Its Eradication from Domestic Pig Herds

“…The spatial distribution of the wild boar and domestic pig population densities in all 19 counties in the year of the beginning of the PRRS eradication (2014), in the year of the ASF outbreak (2018), and in the year after the end of the PRRS eradication (2023) shows an overall reduction in the wild boar density and little change in the domestic pig density ( Figure 2 and Figure 3 ). While in 2014 and 2018, the wild boar density per km 2 was 1.13 at the national level, this number decreased to 0.6 wild boar/km 2 by 2023 in the context of the National Action Plan requirements published in 2021 [ 32 ].…”

Evaluation of the Risk of African Swine Fever Virus Transmission at the Interface between Feral and Domestic Pigs in Lombardy, with a View to Establishing Preventive Measures for Domestic Pigs

“…However, a recent study in Serbia reported a frequency of 3.70 weekly visits of wild boars to pig farms, with a higher frequency observed in spring (7.5 visits). Wild boar visits to pig farms were mainly associated with the use of farm resources, such as food and water points [6]. Other studies have found that the proximity of forest to the farm and the distance between pig enclosures and houses (where farmers live) were factors that could influence wild-boar intrusions [7,8], as well as the presence of sows in estrus.…”