Porcine epidemic diarrhoea virus (PEDV) of the Coronaviridae family causes significant economic losses in the pig industry worldwide. Wild boars contribute to the transmission of different viral, bacterial and parasitic infections to livestock animals and humans. However, their role in the maintenance and transmission of PEDV has not been established. In this study, blood and faecal samples from 157 wild boars were collected from 14 provinces of Poland during the 2017–2018 hunting season. RNA was extracted from the faecal homogenate supernatant and subjected to quantitative RT-PCR (RT-qPCR), while clotted blood samples were used for detection of antibodies against PEDV by ELISA. Five blood samples (3.2%) were seropositive in ELISA, while none of the faecal samples were found positive using RT-qPCR assays. The results of this analysis indicate the need for additional studies incorporating a larger number of samples and preferably comparing different serological methods, to confirm whether wild boars in Poland act as PEDV reservoirs.

Porcine epidemic diarrhoea virus (PEDV) of the Coronaviridae family causes significant economic losses in the pig industry worldwide. Wild boars contribute to the transmission of different viral, bacterial and parasitic infections to livestock animals and humans. However, their role in the maintenance and transmission of PEDV has not been established.

Introduction of highly pathogenic avian influenza virus (HPAIV) into a country and its further spread may have a devastating impact on the poultry industry and lead to serious economic consequences. Various risk factors may increase the probability of HPAI outbreak occurrence but their relative influence is often difficult to determine. The study evaluates how the densities of selected poultry species and proximity to the areas inhabited by wild birds impacted HPAI outbreak occurrence during the recently reported epidemics in Poland. The analysis was developed using these risk factors in the locations of affected and randomly chosen unaffected commercial farms. Generalised linear and non-linear models, specifically logistic regression, classification tree and random forest, were used to indicate the most relevant risk factors, to quantify their association with HPAI outbreak occurrence, and to develop a map depicting spatial risk distribution. The most important risk factors comprised the densities of turkeys, geese and ducks. The abundance of these species of poultry in an area increased the probability of HPAI occurrence, and their farming intensity in several areas of central, western, eastern and northern Poland put these areas at the highest risk. The results may improve the targeting of active surveillance, strengthen biosecurity in the areas at risk and contribute to early detection of HPAI in outbreak reoccurrences.

Introduction of highly pathogenic avian influenza virus (HPAIV) into a country and its further spread may have a devastating impact on the poultry industry and lead to serious economic consequences. Various risk factors may increase the probability of HPAI outbreak occurrence but their relative influence is often difficult to determine. The study evaluates how the densities of selected poultry species and proximity to the areas inhabited by wild birds impacted HPAI outbreak occurrence during the recently reported epidemics in Poland.

The aim of the study was to carry out epizootic assessment of male roe deer to detect the presence of Cephenemyia stimulator larvae and determine the influence of the parasite on the carcass and antler weight in animals living in different habitats. The investigations were based on post-mortem analysis of Cephenemyia stimulator infestations of the nasal passages and throat of 177 male roe deer culled between May 11 and September 30, 2020 in hunting districts of the Lublin region in Poland. The individual quality of the animals was assessed by weighing the gutted carcasses after cooling, and the antlers were weighed after dissection and their total weight was determined. The parasite prevalence ranged from18 to 48% according to habitat type, with a mean value of 33%. The highest prevalence was detected in bucks living in grassland ecosystems. The presence of the parasites exerted influence on the individual condition of the animals, which was reflected in reduced carcass and antler weight. The differences were found both in young individuals and in somatically fully developed animals, but they were not statistically significant in all age groups. Although the parasitic infestations impaired the individual condition traits, their parametric values in most cases were not lower than those reported from other regions of Poland. Despite the Cephenemyia stimulator infestation, male roe deer from the Lublin region are characterised by high carcass and antler weight.

The aim of the study was to carry out epizootic assessment of male roe deer to detect the presence of Cephenemyia stimulator larvae and determine the influence of the parasite on the carcass and antler weight in animals living in different habitats.

Since April 2020, when the first SARS-CoV-2 infection was reported in mink and subsequently in mink farm workers in the Netherlands, it has been confirmed that human-to-mink and mink-to-human transmission can occur. Later, SARS-CoV-2 infections in mink were reported in many European and North American countries. Samples from 590 mink from a total of 28 farms were tested by real-time RT-PCR. Whole genome sequences from one positive farm were generated and genetic relatedness was established. SARS-CoV-2 RNA was detected on a breeder farm with stock of 5,850 mink. Active viraemia was confirmed in individually tested samples with Ct values respectively between 19.4 and 29.6 for E and N gene fragments. Further testing of samples from culled animals revealed 70% positivity in throat swabs and 30% seropositivity in blood samples. Phylogenetic analysis of full-length nucleotide sequences of two SARS-CoV-2 isolates revealed that they belong to the 20B Nextstrain clade. Several nucleotide mutations were found in analysed samples compared to the reference Wuhan HU-1 strain and some of them were nonsynonymous. We report the infection of mink with SARS-CoV-2 on one farm in Poland and the results of subsequent analysis of virus sequences from two isolates. These data can be useful for assessment of the epidemiological situation of SARS-CoV-2 in Poland and how it endangers public health.

Since April 2020, when the first SARS-CoV-2 infection was reported in mink and subsequently in mink farm workers in the Netherlands, it has been confirmed that human-to-mink and mink-to-human transmission can occur. Later, SARS-CoV-2 infections in mink were reported in many European and North American countries.

Silage quality deteriorates with Clostridium spp. contamination, and if consumed, such silage jeopardises herd health and productivity. Minimising its occurrence reduces economic and animal welfare risks. The study investigated the influence of environmental and technological determinants on the Clostridium genus’ occurrence in silage. Analyses were conducted on 305 silage samples directly collected from farms located in all Polish provinces. Cultures and isolates were evaluated phenotypically and examined for occurrence of Clostridium spp., particularly C. perfringens and C. botulinum using PCR techniques. The results were statistically analysed using the ᵡ² test for continuous and Student’s t-test for non-continuous values. The most influential effect on Clostridium spp. occurrence is exerted by factors potentially associated with primary production, like the type of fertilisation and the contamination level of the ensiled feed material. Clostridium spp. was detected in 232 (76%) samples, and C. perfringens strains, predominantly toxinotype A, in 79 (26%). C. botulinum occurrence was not detected. Deterioration of silage by clostridia could be prevented by a properly conducted ensiling process with the addition of starter cultures, but the presence of spores mainly depends on primary production and the extent of contamination of the feed material.

Silage quality deteriorates with Clostridium spp. contamination, and if consumed, such silage jeopardises herd health and productivity. Minimising its occurrence reduces economic and animal welfare risks. The study investigated the influence of environmental and technological determinants on the Clostridium genus’ occurrence in silage.

Repeated incursions of highly pathogenic avian influenza virus (HPAIV) H5 subtype of Gs/GD lineage pose a serious threat to poultry worldwide. We provide a detailed analysis of the spatio-temporal spread and genetic characteristics of HPAIV Gs/GD H5N8 from the 2019/20 epidemic in Poland. Samples from poultry and free-living birds were tested by real-time RT-PCR. Whole genome sequences from 24 (out of 35) outbreaks were generated and genetic relatedness was established. The clinical status of birds and possible pathways of spread were analysed based on the information provided by veterinary inspections combined with the results of phylogenetic studies. Between 31 December 2019 and 31 March 2020, 35 outbreaks in commercial and backyard poultry holdings and 1 case in a wild bird were confirmed in nine provinces of Poland. Most of the outbreaks were detected in meat turkeys and ducks. All characterised viruses were closely related and belonged to a previously unrecognised genotype of HPAIV H5N8 clade 2.3.4.4b. Wild birds and human activity were identified as the major modes of HPAIV spread. The unprecedentedly late introduction of the HPAI virus urges for re-evaluation of current risk assessments. Continuous vigilance, strengthening biosecurity and intensifying surveillance in wild birds are needed to better manage the risk of HPAI occurrence in the future.

Repeated incursions of highly pathogenic avian influenza virus (HPAIV) H5 subtype of Gs/GD lineage pose a serious threat to poultry worldwide. We provide a detailed analysis of the spatio-temporal spread and genetic characteristics of HPAIV Gs/GD H5N8 from the 2019/20 epidemic in Poland.

A significant threat to public health is presented by antibiotic-resistant strains of bacteria, selective pressure on which results from antibiotic use. Colistin is an antibiotic commonly used in veterinary medicine, but also one of last resort in human medicine. Since the 2015 discovery in China of the mcr-1 gene encoding colistin resistance in Enterobacteriaceae, other countries have noted its presence. This study was to find the mcr-1 gene prevalence in E. coli isolated from poultry slaughtered in Poland. Cloacal swabs were taken from December 2017 to October 2018 from broiler chickens in three regions. The samples (n = 158) were grouped as flocks treated with colistin sulphate (n = 87) and those not treated (n = 71). Resistance to antimicrobials commonly used in poultry was evaluated by minimum inhibitory concentration. The presence of the mcr-1 gene was confirmed by PCR. Isolates containing the mcr-1 gene were yielded by 11.27% of the samples from not treated flocks and 19.54% of those from treated flocks, but no statistically significant difference in the prevalence of the gene was seen between the groups. The results clearly preclude intensification of selective pressure for colistin resistance due to colistin sulphate treatment because they show that the avian gastrointestinal tract was already inhabited by colistin-resistant E. coli by the time the chickens came to the poultry house.

A significant threat to public health is presented by antibiotic-resistant strains of bacteria, selective pressure on which results from antibiotic use. Colistin is an antibiotic commonly used in veterinary medicine, but also one of last resort in human medicine. Since the 2015 discovery in China of the mcr-1 gene encoding colistin resistance in Enterobacteriaceae, other countries have noted its presence. This study was to find the mcr-1 gene prevalence in E. coli isolated from poultry slaughtered in Poland.

Due to the widespread occurrence of acrylamide in the environment, its likely carcinogen status, and the suitability of the pig model as a human analogue, the authors decided to evaluate the impact of high and low doses of this compound on the processes of erythropoiesis in swine bone marrow. The experiment was carried out on Danish Landrace pigs at the age of eight weeks and body weight about 20 kg. The animals were divided into three equal groups consisting of five pigs in each. Control animals received empty gelatin capsules (placebos). Animals from the first experimental group received a low dose of acrylamide of 0.5 μg/kg b.w./day (> 99% purity; Sigma-Aldrich, Poland), and animals from the second experimental group received a dose 10 times higher. Placebos and acrylamide capsules were administered with feed every morning for 28 days. After anaesthetisation of the animals, bone marrow from the femur was collected into tubes without an anticoagulant on days 0 and 28. After drying and staining, bone marrow smears were subjected to detailed cytological evaluation using a light microscope. This study showed that high and low doses of acrylamide affected the process of porcine erythropoiesis. The cytotoxic effect of acrylamide on this process was demonstrated in a change of the polychromatic erythroblasts/normochromatic erythroblasts ratio. Both doses of acrylamide caused a decrease in the number of ortho- and polychromatic erythroblasts.

Due to the widespread occurrence of acrylamide in the environment, its likely carcinogen status, and the suitability of the pig model as a human analogue, the authors decided to evaluate the impact of high and low doses of this compound on the processes of erythropoiesis in swine bone marrow.