Domestic Pig Farms Research Articles

Standardized Risk Analysis Approach Aimed to Evaluate the Last African Swine Fever Eradication Program Performance, in Sardinia.

From more than 40 years African swine fever (ASF) is endemic in Sardinia. Historically, areas at higher risk are located throughout some inland parts of this island where domestic pigs are still illegally kept in semi-wild conditions, living in contact with the local wild boar population, thereby creating perfect conditions for disease endemicity. A new eradication plan (EP-ASF15-18) has been ongoing for the past 3 years, based on a comprehensive strategy adapted to the local situation and focused on strong actions on domestic pig farms, wild boars (WB), and the third Sardinian typical involved population [illegal free-ranging pigs (FRPs)]. A fundamental aspect of the plan is the classification of pig farms as “controlled” or “certified,” based on clinical, structural, and biosecurity characteristics. The eradication plan also provides for strong action against illegal farms and pig meat marketing channels. In addition, this plan establishes specific control measures for WB hunting and ASF checks. Each control strategy is specifically based on municipality risk level, to focus actions and resources on areas at higher risk of endemic or re-emerging ASF. Thus, precise risk classification is fundamental to this goal. The aim of the present work was to establish an ASF risk index, to provide a summary measure of the risk level in the Sardinian municipalities. This synthetic measure can express the different aspects of a multidimensional phenomenon with a single numerical value, facilitating territorial and temporal comparisons. To this end, retrospective data (years 2011–2018) were used. The ASF risk index is the result of the algorithmic combination of numerical elementary indicators: disease prevalence in the suid populations, WB compliance with EP-ASF15-18, domestic pig compliance with EP-ASF15-18, and presence of FRPs. A negative binomial regression model has been applied and predictors calculated to obtain a risk index for each municipality. The result of the risk analysis was discussed and considered according to expert opinion and consensus. The results of this study, expressed as risk score and classified into five risk levels, can be used to help define actions to be carried out in each Sardinian municipality, according to the risk assessment for the territory.

Investigating the impact of environmental factors on the African Swine Fever epidemic in Belgium

Investigating the impact of environmental factors on the African Swine Fever epidemic in Belgium

Epidemiological analysis of the 2015–2017 African swine fever outbreaks in Estonia

African swine fever (ASF) was first detected in the Estonian wild boar population in September 2014, while the first domestic pig farm was affected in July 2015. In the present study, we aimed to analyse, retrospectively, the epidemiology of the disease in all 26 outbreaks in domestic pig herds that occurred in Estonia during the period 2015–2017. Formal interviews were conducted to estimate the high-risk period for every farm, and to identify the possible origin of the ASF virus and the mode of virus introduction. Furthermore, the clinical manifestation of the disease as well as the course of the disease within the farm were investigated. Survival analysis was used to calculate herd incidence and to estimate outbreak risk. A hierarchical Bayesian space–time model was used to analyse the associations between outbreaks and ASF occurrence in wild boar. The spatial and temporal distribution of outbreaks was analysed to characterise the ASF epidemic in the Estonian domestic pig population from 2015 to 2017.The estimated high-risk period varied from seven to 20 days with a median of 11 days. On most of the affected farms, the first clinical signs were mild and not specific to ASF despite the high virulence of the circulating virus. Morbidity and mortality were often limited to a single pen or unit of the farm. The highest mortality (29.7%) was seen on backyard farms with 1–10 pigs and the lowest (0.7%) on large commercial farms (>1000 pigs). The spread of the virus within affected farms has been slow and the contagiousness of the virus has been relatively low. Farms of all sizes and types have been at risk, including large commercial farms operating at a high biosecurity level. In none of the affected farms could the specific route of introduction be verified. However, the findings suggested that virus introduction occurred via indirect transmission routes due to insufficient biosecurity. The total herd incidence of outbreaks was similar across all three years, being 2.4% in 2015 and 2016, and 2.0% in 2017. All outbreaks occurred from June to September, during the warmest period of the year. The results suggest that the increase in ASF cases in local wild boar populations is the main risk factor leading to the infection of farms; 88% of outbreaks occurred in areas where ASF virus was detected in wild boar prior to the outbreak, within a radius of 15 km from the outbreak farm.

Genomic and antigenic characterization of porcine epidemic diarrhoea virus strains isolated from South Korea, 2017.

SummaryPorcine epidemic diarrhoea virus (PEDV) is a globally emerging and re‐emerging enteric coronavirus in pigs causing serious economic threats to the world swine industry. Since the re‐emergence of massive PEDV outbreaks in South Korea in 2013−2014, domestic pig farms have continued to experience PED epidemics or endemics. This study represents the molecular characterization of PEDV isolates identified in diarrhoeic animals collected across the country in 2017. Initial sequencing analysis of the full‐length S genes revealed that 70% of the 2017 isolates (7/10) belong to the G2b subgroup, while the remaining isolates were classified as G1b. The data indicated that both variant G1b and global epidemic G2b strains were responsible for current PED outbreaks in South Korea. The 2017 G1b and G2b isolates shared 98.7%–99.4% and 98.1%–99.2% amino acid sequence identity at the S gene level and 99.3% and 99.0%–99.6% nucleotide sequence homology at the genome level compared to the corresponding Korean prototype G1b and G2b strains, respectively. In an interesting manner, one G2b‐like KNU‐1705 strain was found to possess a large 39‐nucleotide deletion in the ORF1a region theoretically encoding nonstructural protein 3. Phylogenetic analysis based on the entire genome and spike protein sequences indicated that the 2017 isolates were most closely related to other global G1b or G2b strains but formed different branches within the same genogroup. These results indicate that PEDVs undergo continuous evolution in the field. In addition, one 2017 PEDV strain, KOR/KNU‐1705/2017, was successfully isolated and propagated in Vero cells. The antisera raised against the Korean prototype 2014 G2b strain efficiently neutralized KNU‐1705 virus infection, suggesting antigenic homology between the 2014 and 2017 PEDV strains. Our data advance the understanding of the molecular epidemiology and antigenicity of PEDV circulating in South Korea.

Relevant Measures to Prevent the Spread of African Swine Fever in the European Union Domestic Pig Sector.

During the past decade, African swine fever (ASF) has spread from the Caucasus region to eastern European Union countries affecting domestic pig and wild boar populations. In order to avert ASF spread, mitigation measures targeting both populations have been established. However, despite these efforts, ASF has been reported in thirteen different countries (Georgia, Azerbaijan, Armenia, the Russian Federation, Ukraine, Belarus, Estonia, Latvia, Lithuania, Poland, Moldova, Czech Republic, and Romania). In the absence of an effective vaccine or treatment to ASF, introduction and spread of ASF onto domestic pig farms can only be prevented by strict compliance to control measures. This study systematically reviewed available measures to prevent the spread of ASF in the EU domestic pig sector distinguishing between commercial, non-commercial, and outdoor farms. The search was performed in PubMed and using a common browser. A total of 52 documents were selected for the final review process, which included scientific articles, reports, EU documents and official recommendations, among others. From this literature review, 37 measures were identified as preventive measures for the introduction and spread of ASF. Subsequently, these measures were assessed by ASF experts for their relevance in the mitigation of ASF spread on the three mentioned types of farms. All experts agreed that some of the important preventive measures for all three types of farms were: the identification of animals and farm records; strict enforcement of the ban on swill feeding; and containment of pigs, so as to not allow direct or indirect pig–pig and/or pig–wild boar contacts. Other important preventive measures for all farms were education of farmers, workers, and operators; no contact between farmers and farm staff and external pigs; appropriate removal of carcasses, slaughter residues, and food waste; proper disposal of manure and dead animals, and abstaining from hunting activities during the previous 48 h (allowing a 48 h interval between hunting and being in contact with domestic pigs). Finally, all experts identified that the important preventive measures for non-commercial and outdoor farms is to improve access of those farms to veterinarians and health services.

Characterisation of Bergeyella spp. isolated from the nasal cavities of piglets

The aim of this study was to characterise bacteria in the genus Bergeyella isolated from the nasal passages of healthy piglets. Nasal swabs from 3 to 4 week-old piglets from eight commercial domestic pig farms and one wild boar farm were cultured under aerobic conditions. Twenty-nine Bergeyella spp. isolates were identified by partial 16S rRNA gene sequencing and 11 genotypes were discriminated by enterobacterial repetitive intergenic consensus (ERIC)-PCR. Bergeyella zoohelcum and Bergeyella porcorum were identified within the 11 genotypes. Bergeyella spp. isolates exhibited resistance to serum complement and phagocytosis, poor capacity to form biofilms and were able to adhere to epithelial cells. Maneval staining was consistent with the presence of a capsule. Multiple drug resistance (resistance to three or more classes of antimicrobial agents) was present in 9/11 genotypes, including one genotype isolated from wild boar with no history of antimicrobial use. In conclusion, Bergeyella spp. isolates from the nasal cavities of piglets showed some in vitro features indicative of a potential for virulence. Further studies are necessary to identify the role of Bergeyella spp. in disease and within the nasal microbiota of pigs.

First detection and genetic characterization of porcine parvovirus 7 from Korean domestic pig farms.

Porcine parvovirus 7 (PPV7) was first detected in Korean pig farms in 2017. The detection rate of PPV7 DNA was 24.0% (30/125) in aborted pig fetuses and 74.9% (262/350) in finishing pigs, suggesting that PPV7 has circulated among Korean domestic pig farms. Phylogenetic analysis based on capsid protein amino acid sequences demonstrated that the nine isolated Korean strains (PPV-KA1-3 and PPV-KF1-6) were closely related to the previously reported USA and Chinese PPV7 strains. In addition, the Korean strains exhibit genetic diversity with both insertion and deletion mutations. This study contributes to the understanding of the molecular epidemiology of PPV7 in Korea.

Multiplex real-time polymerase chain reaction for the differential detection of porcine circovirus 2 and 3

A multiplex quantitative real-time polymerase chain reaction (mqPCR) assay was developed for the rapid and differential detection of porcine circovirus 2 (PCV2) and PCV3. Each of the capsid genes of PCV2 and PCV3 were amplified using specific primers and probe sets, while no other porcine pathogen genes were detected. Limit of detection of the assay was below 50 copies of the target genes of PCV2 and PCV3, and was comparable to that of previously described methods The assay showed high repeatability and reproducibility, with coefficients of intra-assay and inter-assay variation of less than 4.0%. Clinical evaluation using tissue samples from a domestic pig farm showed that PCV2 and PCV3 co-circulated at the farm. Moreover, singular infection rates of PCV2 or PCV3 were 21.7% (10/46) or 6.5% (3/46), respectively, while the co-infection rate of PCV3 with PCV2 was 28.3% (13/46). PCV3 DNA was detected by the mqPCR in respiratory diseased piglet tissue samples and aborted fetal tissue samples, suggesting that PCV3 infection is associated with porcine respiratory disease and reproductive failure in the pig farm. This mqPCR method is a rapid and reliable differential diagnostic tool for the monitoring and surveillance of PCV2 and PCV3 in the field.

The Incidence of Hepatitis E Virus in Domestic Pigs

Abstract Hepatitis E virus (HEV) is the causative agent of hepatitis E — an emerging zoonotic disease distributed worldwide. The aim of this study was to determine the prevalence of HEV in Slovakian domestic pigs, as this has not been studied yet. Clinical samples (n = 269) from fourteen randomly selected domestic pig farms for three different age categories of pigs were analysed and the subsequently detected isolates were genetically characterized. The reverse transcriptase polymerase chain reaction (RT-PCR) analysis revealed that 32 pigs (11.9 %) of all age categories were HEV RNA positive. The highest occurrence was detected in fattening pigs (14.8 %) and the lowest in weaning pigs (12.5 %). The HEV RNA was not observed at all in the youngest category (the suckling piglets). The phylogenetic analysis revealed that all Slovak HEV isolates clustered into two genetic groups of the genotype HEV-3.

Anthropogenic factors predict movement of an invasive species

AbstractHumans are playing an increasingly large role in the expansion of invasive species' distributions, but few (if any) studies have evaluated anthropogenic factors associated with intentional translocation of invasives. The wild pig (Sus scrofa) is an extremely destructive and rapidly expanding invasive species whose movement is thought to be facilitated by humans. We sought to (1) identify a suite of genetic markers that can be applied to population genetic analyses of wild pigs, (2) find quantitative evidence of human‐mediated dispersal of wild pigs, and (3) determine which anthropogenic factors were associated with their translocation. We identified 43 polymorphic microsatellite loci and employed population genetic analyses to evaluate population structure and movement of wild pigs among populations in California, USA. Hierarchical Bayesian models were used to evaluate the influence of anthropogenic covariates on wild pig movement, and to predict migration risk. Natural dispersal of wild pigs among populations was low, as indicated by a large number of genetic clusters (K = 21), significant population differentiation, and low rates of recent migration. This suggests that the observed movement resulted from human‐mediated translocation. Movement of pigs was positively predicted by the number of domestic pig farms, the number of captive game hunting farms, the amount of public land, the number of wild pigs harvested by hunters, and the number of game outfitters. While hunting has been hypothesized to play a role in wild pig movement, our study is the first to provide quantitative evidence of such a relationship. We argue that future efforts to manage invasive species must consider the potential role of humans in their dispersal.

Identification of Tick Species Collected from Wild Boars and Habitats of Wild Boars and Domestic Pigs in the Republic of Korea.

Tick is one of the most important arthropods in the transmission of vector-borne diseases. In this study, we investigated the abundance and species of ticks associated with swine and their habitats to assess the risk of spread of tick-borne diseases in host species, such as wild boars. Ticks were collected from 24 grazing or traditionally reared domestic pig farms and 8 habitats of wild boars in 8 provinces and 1 city in the Republic of Korea, by using the dragging and flagging methods. Ticks were also collected directly from 49 wild boars by using fine forceps. A total of 9,846 hard ticks were collected, including 4,977 Haemaphysalis longicornis, 4,313 Haemaphysalis flava, 508 Ixodes nipponensis, 1 Ixodes turdus, and 47 Amblyomma testudinarium. A total of 240 hard ticks were collected from 49 wild boars, including 109 H. flava, 84 H. longicornis, and 47 A. testudinarium. A total of 578 hard ticks were collected from areas around domestic pig farms. Only 2 hard tick species, 546 H. longicornis and 32 H. flava, were collected from these areas. A total of 9,028 hard ticks were collected from wild boars of 8 habitats, including 4,347 H. longicornis, 4,172 H. flava, 508 I. nipponensis, and 1 I. turdus. A. testudinarium was collected only from wild boars, and I. nipponensis and I. turdus were collected only from the habitats of wild boars.

Understanding African Swine Fever infection dynamics in Sardinia using a spatially explicit transmission model in domestic pig farms.

African swine fever virus (ASFV) has been endemic in Sardinia since 1978, resulting in severe losses for local pig producers and creating important problems for the island's veterinary authorities. This study used a spatially explicit stochastic transmission model followed by two regression models to investigate the dynamics of ASFV spread amongst domestic pig farms, to identify geographic areas at highest risk and determine the role of different susceptible pig populations (registered domestic pigs, non-registered domestic pigs [brado] and wild boar) in ASF occurrence. We simulated transmission within and between farms using an adapted version of the previously described model known as Be-FAST. Results from the model revealed a generally low diffusion of ASF in Sardinia, with only 24% of the simulations resulting in disease spread, and for each simulated outbreak on average only four farms and 66 pigs were affected. Overall, local spread (indirect transmission between farms within a 2km radius through fomites) was the most common route of transmission, being responsible for 98.6% of secondary cases. The risk of ASF occurrence for each domestic pig farm was estimated from the spread model results and integrated in two regression models together with available data for brado and wild boar populations. There was a significant association between the density of all three populations (domestic pigs, brado, and wild boar) and ASF occurrence in Sardinia. The most significant risk factors were the high densities of brado (OR=2.2) and wild boar (OR=2.1). The results of both analyses demonstrated that ASF epidemiology and infection dynamics in Sardinia create a complex and multifactorial disease situation, where all susceptible populations play an important role. To stop ASF transmission in Sardinia, three main factors (improving biosecurity on domestic pig farms, eliminating brado practices and better management of wild boars) need to be addressed.

養豚場における食肉検査結果の決定要因の主成分分析による解析法

食肉検査結果を生産者に還元し，衛生的な食肉生産を促進する事業が複数の自治体で進められているが，食肉検査結果と家畜の飼養条件の関係に関する報告は少ない．両者は多次元のデータであるため関係の解析が困難であることが問題となるが，主成分分析を用いれば多次元データを低次元のデータに縮約でき，この問題を克服できる．そこで，食肉検査データを含む多次元データから主成分分析により，肥育豚の廃棄，産子数及び子豚死亡率に係る3つの指標を作成し，それぞれとアンケート調査によって得た家畜の飼養条件との関係を重回帰分析した．重回帰分析で有意差が認められた飼養条件につき，縮約前のデータと飼養条件の関係を一般化線形混合モデル（GLMM）で分析した結果，オールイン・オールアウト，出荷日齢，断尾など6種の決定要因が示唆された．

A Cartographic Tool for Managing African Swine Fever in Eurasia: Mapping Wild Boar Distribution Based on the Quality of Available Habitats.

The current African swine fever (ASF) epidemic in Eurasia represents a risk for the swine industry with devastating socio-economic and political consequences. Wild boar appears to be a key factor in maintaining the disease in endemic areas (mainly the Russian Federation) and spreading the disease across borders, including within the European Union. To help predict and interpret the dynamics of ASF infection, we developed a standardized distribution map based on global land cover vegetation (GLOBCOVER) that quantifies the quality of available habitats (QAH) for wild boar across Eurasia as an indirect index for quantifying numbers of wild boar. QAHs were estimated using a seven-level scale based on expert opinion and found to correlate closely with georeferenced presence of wild boar (n=22362): the highest wild boar densities (74.47%) were found in areas at the two highest QAH levels, while the lowest densities (5.66%) were found in areas at the lowest QAH levels. Mapping notifications from 2007 to 2016 onto the QAH map showed that in endemic areas, 60% of ASF notifications occurred in domestic pigs, mostly in agricultural landscapes (QAHs 1.75 and 1) containing low-biosecurity domestic pig farms. In the EU, in contrast, 95% of ASF notifications occurred in wild boar, within natural landscapes (QAH 2). These results suggest that the QAH map can be a useful epi-tool for defining risk scenarios and identifying potential travel corridors for ASF. This tool will help inform resource allocation decisions and improve prevention, control and surveillance of ASF and potentially of other diseases affecting swine and wild boar in Eurasia.

오목점과 에지 정보를 이용한 돼지의 경계 구분

To reduce huge losses in pig farms, weaning pigs with weak immune systems are required to be carefully supervised. Even if various researches have been performed for pig monitoring environment, segmenting each pig from touching-pigs is still entrenched as a difficult problem. In this paper, we propose a segmentation method for touching-pigs by using concave-points and edge information in a video surveillance system. Especially, we interpret the segmentation problem as a time-series analysis problem in order to identify the concave-points generated by touching-pigs. Based on the experimental results with the videos obtained from a domestic pig farm, we believe that the proposed method can accurately segment the touching-pigs.

이유자돈사에서 개별 돼지 모니터링을 위한 실시간 돼지 구분

To reduce huge losses in pig farms, weaning pigs with weak immune systems are required to be carefully supervised. Even if various researches have been performed for livestock monitoring environment, segmenting each pig from touching pigs is still entrenched as a difficult problem. In this paper, we propose a real-time segmentation method for moving pigs by using motion information in a 24-h video surveillance system. The experimental results with the videos obtained from a domestic pig farm illustrated the possibility for segmenting by using our proposed method in real-time.

Lung parasites of the genus Metastrongylus Molin, 1861 (Nematoda: Metastrongilidae) in wild boar (Sus scrofa L., 1758) in Central-Italy: An eco-epidemiological study

The respiratory tracts of 57 wild boars (Sus scrofa L. 1758) hunted in central Italy during the 2011/2012 hunting season were examined to detect the presence of lung worms. Fifty-five out of 57 animals (96,5%) were positive. Five species of Metastrongylus were detected and their prevalence was as follows: Metastrongylus asymmetricus Noda, 1973 (91.2%), Metastrongylus confusus Jansen, 1964 and Metastrongylus salmi Gedoelst, 1923 (87.7%), Metastrongylus apri Gmelin, 1790 (80.7%), Metastrongylus pudendotectus Vostokov, 1905 (70.2%). In most cases multi-species infection was observed. The highest parasite load was found in young animals (<1 year old). The Metastrongylus genus sex ratio (M/F) had a range from 1:4.8 to 1:1.5 in favor of females. The Simpson and Shannon–Wiener indices showed a moderate uniformity in parasite community composition. The Fager index highlighted a high degree of affinity among all pairs of selected parasites. The whole parasite population showed an aggregate distribution. Our findings confirm that these parasites are widespread in the wild boar population. The establishment of outdoor domestic pig farming in the same area of the game preserve could pose the risk of infection to domestic animals. Further studies will be needed to understand the factors involved in the presence and prevalence of the intermediate host as well as the population dynamics of Metastrongylus spp.

Comparison of antibiotic resistance profiles for Escherichia coli isolated from wild boar and domestic pig fecal samples

Increasing presence of wild boar around cities and suburban areas is a growing concern with respect to agronomy, environmental ecology, and public safety. In this study, antibiotic resistance profiles of Escherichia (E.) coli isolated from wild boar and domestic pig fecal samples were compared. Eighty E. coli samples were isolated from wild boars. Resistance of the bacteria to 14 common antimicrobial agents used in human and veterinary medicine was evaluated. Ninety-five E. coli isolates from domestic pig farms were used for comparison. Common and distinct antibiotic resistance patterns were observed when comparing wild boar and domestic pig isolates, indicating that wild boars may significantly influence environmental microbiology.

The Consequences of the Imposition of Restrictions on Pork Imports in 2014 and the Import Substitution Prospects for Russia's Domestic Pig Farming Sector

The short-term consequences of the bans imposed in 2014 on pork imports into Russia from the countries that used to be major suppliers of meat to this country are as follows: an altered geography of import supplies, rising prices on the pork market and related markets, and plummeting consumer demand for meat and meat products. At the same time, the medium-term perspective offers some favorable opportunities for turning the domestic pig farming sector into the main source of import substitution. The present course towards boosting import substitution is fraught with the risk of overinvestment into that sector with the resulting market oversaturation, while the rate of return on investment in the sector is too low to ensure loan repayment.

Evaluation of Methane Yield on Mesophilic-Dry Anaerobic Digestion of Piggery Manure Mixed with Chaff for Agricultural Area

A mesophilic-dry anaerobic digestion process is valid in treating high-concentration substrates containing low moisture content. It has merits of lower wastewater discharge and lower heat capacity required in maintaining reactor temperature as compared with a thermophilic-wet anaerobic digestion process. In fact, chaff can be easily obtained in farming areas and used as a mixture substrate as one of bulking agents for controlling moisture and supplying carbon. For this reason, this study applies the chaff to improve livestock manure, which contains high moisture content and is discharged from domestic pig farms. This study aims at verifying its feasibility for improving methane production efficiency on a basis of BMP (Biochemical Methane Potential) assay obtained through a series of experiments. Finding results were methane gas production and gas production per volatile solid (VS) added, and methane gas production among biogas production were increased as the chaff added in the piggery manure was increased. According to experimental results for improving the methane production efficiency, mixture of the chaff and the piggery manure played an important role in controlling the moisture content and improving the methane gas production rate, and also verified its feasibility in the mesophilic-dry anaerobic digestion process indicating relatively less difficulty for operation and management.