Porcine Circovirus Type 3 (PCV3) in Poland: Prevalence in Wild Boar Population in Connection with African Swine Fever (ASF).

Human health is dependent on food safety and, therefore, on the health of farm animals. One of the most significant threats in regard to swine diseases is African swine fever (ASF). Infections caused by porcine circoviruses (PCVs) represent another important swine disease. Due to the ubiquitous nature of PCV2, it is not surprising that this virus has been detected in ASFV-affected pigs. However, recent data indicate that coinfection of PCV3 and ASFV also occurs. It is still unclear whether PCV infection plays a role in ASFV infection, and that subject requires further analysis. The aim of this study was to assess whether PCV3 and PCV4 are present in the wild boar population in Poland (real-time PCR). The analysis was performed on wild boar samples collected for routine ASF surveillance in Poland, between 2018 and 2021. By extension, the obtained data were compared in regard to ASFV presence in these samples, thus investigating the odds of ASFV infection on the grounds of the PCV carrier state in free-ranging Suidae in Poland. In addition, sequencing of PCV3 and phylogenetic analysis were performed, based on a full genome and a capsid gene. In the current study, we demonstrated the high prevalence of PCV3 in the wild boar population in Poland; meanwhile, PCV4 was not detected. The odds of ASFV infection on the grounds of the PCV3 carrier state in free-ranging Suidae in Poland was more than twice as high. Ten full genome sequences of PCV3 were obtained, all of them belonging to clade 3a. The similarity between them was in the range of 98.78-99.80%.

Probiotic supplementation as an alternative to antibiotics in broiler chickens.

Introduction: The broiler chicken digestive tract microbiome maintains the bird's immunity. Its composition has been shown to be important not only for the immune system but also for the gastrointestinal function and productivity of broiler chickens. If the microbiome is populated by supplementation with Lactobacillus, Pediococcus and Saccharomyces spp. - microorganisms with probiotic properties and alternatives to antibiotics - the immune system is stimulated. The use of probiotic supplements in the broiler production cycle can boost bird immunity and prevent adenovirus infection. The resilience of broiler chickens in different feeding schemes including supplementation with these microorganisms was assessed. Material and Methods: Four groups of Ross 308 chickens vaccinated on the standard scheme were investigated over 42 days. Group P received probiotics, prebiotics and vitamins; group AO received antibiotics; group P&AO received probiotics, prebiotics, vitamins and antibiotics; and the control group C received none of these. The birds' immunocompetence against common viral poultry pathogens and their immune response to an experimental challenge with a field strain of infectious bronchitis was evaluated by ELISA and production parameters were recorded. Results: Mortality was only observed in the control group and was 10%. All birds from the P, P&AO and AO groups responded to the challenge as would be expected of appropriately immunised chickens. Conclusion: The obtained results indicated that supplementation with synbiotic products and vitamins can enhance broiler chicken immunity and result in better production parameters.