Histologic changes of porcine portal vein anastomosis after electrochemotherapy with bleomycin.

Electrochemotherapy (ECT1) is used for treatment of unresectable abdominal malignancies. This study aims to show that ECT of porcine portal vein anastomosis is safe and feasible in order to extend the indications for margin attenuation after resection of locally advanced pancreatic carcinoma. No marked differences were found between the control group and ECT treated groups. Electroporation thus caused irreversible damage to the vascular smooth muscle cells in tunica media that could bedue to the narrow irreversible electroporation zone that may occur near the electrodes, or due to vasa vasorum thrombosis in the tunica externa. Based on the absence of vascular complications, and similar histological changes in lienal veinanastomosis, we can conclude that ECT of portal vein anastomosis is safe and feasible.

Risk Factor Impact on African Swine Fever Transmission in Different Extensive Pig Production Settings in Serbia.

The first case of ASF in a domestic pig population in Serbia was confirmed in 2019 in a backyard population. Today, outbreaks in wild boar and, more importantly, in domestic pigs are still occurring, although the government measures for ASF prevention are in place. The aim of this study was to determine critical risk factors and identify the possible reasons for ASF introduction into different extensive pig farms. The study was conducted on 26 extensive pig farms with confirmed ASF outbreaks, with data collected from beginning of 2020 to the end of 2022. Collected epidemiological data were divided into 21 main categories. After identifying specific values of variables as critical for ASF transmission, we identified nine important ASF transmission indicators as those variables for which at least 2/3 of the observed farms reported values critical for ASF transmission. Among them were type of holding, distance to hunting ground, farm/yard fencing, and home slaughtering; however, the hunting activity of pig holders, swill feeding, and feeding with mowed green mass were not included. We represented the data in the form of contingency tables to study associations between pairs of variables using Fisher's exact test. All pairs of variables in the group including type of holding, farm/yard fencing, domestic pig-wild boar contact, and hunting activity were significantly related; hunting activity of pig holders, holding pigs in backyards, unfenced yards, and domestic pig-wild boar contact were observed on the same farms. Free-range pig farming led to observed domestic pig-wild boar contact on all farms. The identified critical risk factors need to be strictly addressed to prevent the further spread of ASF to extensive farms and backyards in Serbia and elsewhere.

Evaluation of Biosecurity Measures in Pig Holdings in Slovenia as a Risk Assessment for the Introduction of African Swine Fever Virus.

African Swine Fever (ASF) is persistently spreading and hindering pork production in Europe. Slovenia is one of the last countries in Central Europe without a confirmed ASF case in domestic pigs or in wild boar. The aim of this study was to assess the current biosecurity implementation on different types of pig farms. Internal and external biosecurity status was determined in 17 commercial (CF), 15 non-commercial (NC), and 15 outdoor (O) farms. Data were collected using the Biocheck.UGent questionnaire and assessed in combination with the latest information on the wild boar population in Slovenia. Biosecurity was compared between farm types based on the assessment of 12 subcategories. Statistically significant differences (p < 0.05) were found in six subcategories: (i) purchase of pigs and semen, (ii) visitors and farmworkers, (iii) vermin and bird control, (iv) finishing unit, (v) measures between compartments and use of equipment, and (vi) cleaning and disinfection. The highest total biosecurity score (0-100%) was determined on CF with 64.59 ± 16.47%, followed by NC with 55.73 ± 10.67%, and O with 48.47 ± 8.20%. The density of the wild boar population was estimated from the number of wild boars per km2 per year, with 3 or more hunted wild boars per unit representing the highest density. Geolocation of farms on the wild boar population map showed that two O farms are at high risk and seven farms (1 O, 5 NC, and 1 CF) are at medium risk for disease transmission from wild to domestic pigs. Biosecurity measures must be tightened in some subcategories, especially in areas with a high density of wild boar.

Discrepancies between farmers' perceptions and actual animal welfare conditions on commercial pig farms.

Animal welfare is a multiparameteral concept that encompasses the physical and mental health of animals and includes various aspects such as physical wellbeing, absence of hunger and thirst, and ability to express motivated behavior, to which farmers usually attach different importance. The objectives of this study were to evaluate animal welfare on Slovenian commercial pig farms, to determine whether farmers' perceived importance of animal welfare differ from actual animal welfare on farms and to determine, if farmer's age, gender, their level of education and participation in vocational training have an influence. For that purpose, we created an Animal Welfare Protocol/Questionnaire for Pig Farms (AWQ/P-P) that assessed several parameters of animal welfare: (1) general status, (2) animal behavior, (3) health status, (4) living conditions, and (5) environmental conditions. Each parameter included at least five observation points and was scored on a 5-point scale. The same observation points were used to measure farmers' perceived importance of animal welfare and for observational assessment. Consequently, we were able to compare both statistically. Farmers from 14 (N = 14) large Slovenian pig farms participated in the study. Results show that farmers rate all parameters of animal welfare very highly. For them, animal health status is the most important, and environmental conditions are the least important factors for animal welfare. Observational inspections yielded significantly lower scores for animal welfare conditions than those obtained from farmer ratings. The highest correlations between farmers' perceptions and observational inspections were found for the parameters of animal behavior and environmental conditions. The results of this study also suggest that vocational training is a significant variable in increasing levels of pig welfare. Age, gender, and education level are not significant variables, however, farms led by older male farmers with lower level of education but involved in vocational training from different sources had slightly better welfare on the farm. This should be further investigated before making conclusions, due to our small sample size. The significance of the study is to identify deficiencies in pig welfare as perceived by farmers and consequently improve pig welfare.

Safety and Feasibility of Electrochemotherapy of the Pancreas in a Porcine Model.

OBJECTIVES: The use of thermal ablative therapies in the pancreatic tumors is limited because of the risk of the vessel injury and potential pancreatitis or fistula formation. Electrochemotherapy (ECT) is an ablative therapy with an established role in the treatment of cutaneous and liver tumors. This study was designed to evaluate the safety and feasibility of ECT of the pancreas in a porcine survival model. METHODS: In the first group, 4 animals underwent computed tomography (CT)-guided percutaneous ECT with bleomycin of the pancreatic tail. In the second group (4 animals), the intraoperative ECT with bleomycin of pancreatic tail and head was performed. Animals were followed for 7 days and then killed. Clinical parameters, CT imaging, laboratory, and histologic analysis were performed. RESULTS: All pigs survived the ECT procedure and none of them developed clinical signs of acute pancreatitis or related complications. There were no signs of acute pancreatitis or damage to the large vessels present in the follow-up CT scans. No significant change in laboratory parameters was obtained after procedure. CONCLUSIONS: This study shows that ECT with bleomycin is feasible and safe in the pancreatic parenchyma. Clinical studies are needed to evaluate the efficacy of ECT in pancreatic cancer.

A molecular survey and phylogenetic analysis of porcine circovirus type 3 using oral fluid, faeces and serum.

BACKGROUND: Porcine circovirus type 3 is the most recently discovered porcine circovirus, and an emerging pathogen. In this study the status of its presence on some Slovenian farms is reported. The effectiveness of the vaccine against porcine circovirus type 2 was assessed against porcine circovirus type 3. Group samples of oral fluid, faeces and individual serum samples were taken from six different pig categories and tested for presence of viral DNA, using both real time and conventional PCR. Positive samples were subjected to direct Sanger sequencing. Nucleotide sequences were analyzed and compared to GenBank PCV3 sequences. RESULTS: Positive samples were sent for genome sequencing, which confirmed the presence of virus in all different pig categories on five farms. A high to moderate correlation of strong statistical significance was found between individual serum samples, oral fluid and faeces. Slovenian PCV3 was found to be distributed in a way similar to that of other countries. Slovenian PCV3 nt sequences are highly related, sharing more than 99.5% nt identity. On one farm a commercially available vaccine against porcine circovirus type 2 was used on 3-week-old pigs. It did not affect the presence of porcine circovirus type 3 in oral fluid or sera of any of the seven age groups of pigs, each with two control groups. CONCLUSIONS: The results constitute the first discovery of the virus in Slovenia. Genome sequencing has revealed a high degree of similarity between Slovenian and GenBank isolates.

Molecular detection of porcine reproductive and respiratory syndrome virus, porcine circovirus 2 and hepatitis E virus in oral fluid compared to their detection in faeces and serum.

BACKGROUND: Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), Porcine Circovirus Type 2 (PCV2) and Hepatitis E virus (HEV) are common and economically important viral disease causative agents detected in pig oral fluid (OF), faeces and serum at some infection stages. The purpose of this study was to detect PRRSV, PCV2 and HEV on six pig farms to determine which of the three sample types, OF, faeces or serum is appropriate for the diagnosis of these viruses in different pig categories. The following pig categories were included: 5 weeks-old (w/o), 7 w/o, 9 w/o, 11 w/o weaners, fatteners and breeding sows. Pursuant to the preliminary detection of each pathogen at the selected farms, OF samples, faeces, serum pools and 10 individual sera were examined, using PCR, for each age category. If any of the viruses were found in pools of faeces and OF, then faeces and OF from positive farms were tested separately for each pig category. The viral nucleic acids were detected using RT-PCR, PCR and real-time RT-PCR, for PRRSV, PCV2 and HEV respectively. RESULTS: PRRSV and HEV were detected on one farm and PCV2 on three others, positive results being more often obtained from the OF than from the faeces of the same animals. Ten individual serum samples from pigs from the same group of animals were also tested. The viruses were detected in almost all individual sera and OF in the same pig category with some exceptions: PRRSV was detected in the OF of fatteners but was absent in their sera; on Farm 2, PCV2 was detected in sera of 11 w/o pigs and fatteners but absent in group samples of their OF and, vice versa, in case of 9 w/o animals; HEV was detected in the OF of the youngest, 5 w/o weaners and absent in sera of the same age group. CONCLUSIONS: The primary finding of the study is that OF is a welfare-friendly, non-invasive and highly efficient matrix for pathogen detection, thus evidencing the usefulness of pig OF as a matrix in which each of the three viruses considered can be detected with the highest probability.

Radiological findings of porcine liver after electrochemotherapy with bleomycin.

Background Radiologic findings after electrochemotherapy of large hepatic blood vessels and healthy hepatic parenchyma have not yet been described. Materials and methods We performed a prospective animal model study with regulatory approval, including nine grower pigs. In each animal, four ultrasound-guided electroporated regions were created; in three regions, electrodes were inserted into the lumen of large hepatic vessels. Two types of electrodes were tested; variable linear- and fixed hexagonal-geometry electrodes. Ultrasonographic examinations were performed immediately and up to 20 minutes after the procedure. Dynamic computed tomography was performed before and at 60 to 90 minutes and one week after the procedure. Results Radiologic examinations of the treated areas showed intact vessel walls and patency; no hemorrhage or thrombi were noted. Ultrasonographic findings were dynamic and evolved from hyperechogenic microbubbles along electrode tracks to hypoechogenicity of treated parenchyma, diffusion of hyperechogenic microbubbles, and hypoechogenicity fading. Contrast-enhanced ultrasound showed decreased perfusion of the treated area. Dynamic computed tomography at 60 to 90 minutes after the procedure showed hypoenhancing areas. The total hypoenhancing area was smaller after treatment with fixed hexagonal electrodes than after treatment with variable linear geometry electrodes. Conclusions Radiologic findings of porcine liver after electrochemotherapy with bleomycin did not show clinically significant damage to the liver, even if a hazardous treatment strategy, such as large vessel intraluminal electrode insertion, was employed, and thus further support safety and clinical use of electrochemotherapy for treatment of hepatic neoplasia.

Large Liver Blood Vessels and Bile Ducts Are Not Damaged by Electrochemotherapy with Bleomycin in Pigs.

The first clinical studies on the use of electrochemotherapy to treat liver tumours that were not amenable to surgery or thermal ablation techniques have recently been published. However, there is still a lack of data on the effects of electrochemotherapy on normal liver tissue. Therefore, we designed a translational animal model study to test whether electrochemotherapy with bleomycin causes clinically significant damage to normal liver tissue, with emphasis on large blood vessels and bile ducts. We performed electrochemotherapy with bleomycin or delivered electric pulses alone using a potentially risky treatment strategy in eight pigs. Two and seven days after treatment, livers were explanted, and histological analysis was performed. Blood samples were collected before treatment and again before euthanasia to evaluate blood biomarkers of liver function and systemic inflammatory response. We found no thrombosis or other clinically significant damage to large blood vessels and bile ducts in the liver. No clinical or laboratory findings suggested impaired liver function or systemic inflammatory response. Electrochemotherapy with bleomycin does not cause clinically significant damage to normal liver tissue. Our study provides further evidence that electrochemotherapy with bleomycin is safe for treatment of patients with tumours near large blood vessels in the liver.

Variations in the detection of anti-PEDV antibodies in serum samples using three diagnostic tests - short communication.

Over the last few years several porcine epidemic diarrhoea (PED) outbreaks have been discovered in Europe including the first PED case in Slovenia in January 2015. The aim of this study was to determine when PED virus (PEDV) infection started in Slovenia. Serum samples collected between 2012 and 2016 were tested. Three hundred and seventy-five serum samples were collected from 132 Slovenian small, one-site pig farms. Samples were tested for PEDV antibodies utilising three different serological methods: commercially-available indirect ELISA, in-house blocking ELISA test and Immunoperoxidase Monolayer Assay (IPMA) test. One hundred and seventy (45.33%) tested samples were found positive by the commercially-available ELISA test kit, and 10 (5.68%) of these 170 samples found positive were positive by the in-house blocking ELISA. Only these 10 samples were collected from a farm where clinical signs of PED infection had been observed and PEDV was confirmed by RT-PCR methodology; the other 160 samples were collected randomly. Thirty-two samples with the highest S/P value obtained with the commercial ELISA were all negative with IPMA. Reasons for the high variance in the results obtained remain unclear; more research is required to ensure higher sensitivity and specificity in terms of PEDV antibody tests and other PED diagnostic methods.

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.

Serum inoculation as a possibility for elimination of porcine reproductive and respiratory syndrome (PRRS) from a farrow-to-finish pig farm.

The large heterogeneity among porcine reproductive and respiratory syndrome virus (PRRSV) isolates is probably the main obstacle to its effective control using current commercial vaccines. Intentionally exposing all breeding pigs to PRRSV circulating on the farm could eliminate porcine reproductive and respiratory syndrome (PRRS) from the herd. The objective of this study was to eliminate PRRS from a farrow-to-finish pig farm by serum inoculation. The owner was acquainted with the strict biosecurity measures. Breeding pigs were immunised with serum, which was obtained from PRRSV-positive weaners from the same farm. The percent of antibody high positive breeding pigs decreased six months after serum inoculation, while 34 months after serum inoculation no more antibody high positive pigs were detected and 56.8% of breeding pigs and all other categories were free of antibodies. In the breeding herd no virus was detected during all testing while PRRSV circulated in 2-month-old weaners until 12 months after serum inoculation. Later all tested samples from weaners, growers and fatteners were negative. Herd closure and the adoption of strict biosecurity measures are essential. Serum inoculation of the breeding herd proved to be a successful measure for eliminating PRRS from this farrow-to-finish farm.

The effect of the combination of acids and tannin in diet on the performance and selected biochemical, haematological and antioxidant enzyme parameters in grower pigs.

BACKGROUND: The abolition of in-feed antibiotics or chemotherapeutics as growth promoters have stimulated the swine industry to look for alternatives such as organic acids, botanicals, probiotics and tannin. The objective of the present study was to compare the effects of a combination of acids and tannin with diet with organic acids and diet without growth promoters on the growth performance and selected biochemical, haematological and antioxidant enzyme parameters in grower pigs. Tannin is more natural and cheaper but possibly with the same effectiveness as organic acids with regard to growth performance. METHODS: Thirty-six 7 week old grower pigs, divided into three equal groups, were used in a three week feeding trial. Group I was fed basal diet, group II basal diet with added organic acids and group III basal diet with added organic and inorganic acids and tannin. Pigs were weighed before and after feeding and observed daily. Blood was collected before and after the feeding trial for the determination of selected biochemical, haematological and antioxidant enzyme parameters. One-way ANOVA was used to assess any diet related changes of all the parameters. Paired t-test was used to evaluate changes of blood parameters individually in each group of growers before and after feeding. RESULTS: No clinical health problems related to diet were noted during the three week feeding trial. The average daily gain (ADG) and selected blood parameters were not affected by the addition to basal diet of either acids and tannin or of organic acids alone. Selected blood parameters remained within the reference range before and after the feeding trial, with the exception of total serum proteins that were below the lower value of reference range at both times. The significant changes (paired t-test) observed in individual groups before and after the feeding trial are related to the growth of pigs. CONCLUSION: Diet with acids and tannin did not improve the growth performance of grower pigs but had no deleterious effects on selected blood parameters. The possibility of beneficial effects of adding acids and tannin in diets on growth performance over a longer period, however, could not be excluded.