Insights and progress on epidemic characteristics, pathogenesis, and preventive measures of African swine fever virus: A review

The African swine fever virus (ASFV) is the only giant double-stranded DNA virus known to be transmitted by insect vectors. It can infect pigs and cause clinical signs such as high fever, bleeding, and splenomegaly, which has been classified as a reportable disease by the WOAH. In 2018, African swine fever (ASF) was introduced into China and rapidly spread to several countries in the Asia-Pacific region, with morbidity and mortality rates reaching 100 percent, resulting in significant economic losses to the global pig industry. Because ASFV has large genomes and a complex escape host mechanism, there are currently no safe and effective drugs or vaccines against it. Therefore, it is necessary to optimize vaccination procedures and find effective treatments by studying the epidemiology of ASFV to reduce economic losses. This article reviews research progress on pathogenesis, genome, proteome and transcriptome, pathogenic mechanisms, and comprehensive control measures of ASFV infection.

A lineage 1 branch porcine reproductive and respiratory syndrome virus live vaccine candidate provides broad cross-protection against HP-like PRRSV in piglets

Multiple porcine reproductive and respiratory syndrome virus (PRRSV) subtypes coinfect numerous pig farms in China, and commercial PRRSV vaccines offer limited cross-protection against heterologous strains. Our previous research confirmed that a PRRSV lineage 1 branch attenuated live vaccine (SD-R) provides cross-protection against HP-PRRSV, NADC30-like PRRSV and NADC34-like PRRSV. HP-PRRSV has undergone significant genetic variation following nearly two decades of evolution and has transformed into a subtype referred to as HP-like PRRSV, which also exhibits high pathogenicity. The effectiveness of immunising piglets with the SD-R strain to provide protection against infection with HP-like PRRSV remains uncertain. In the present study, we evaluated the protective effects of SD-R vaccine strains on DLF-challenged piglets. The results revealed that piglets challenged with DLF presented clinical symptoms such as continuous high fever and an obvious decrease in daily weight gain. Importantly, the piglets immunised with SD-R exhibited notable reductions in pathological damage, especially of decreases in DLF-induced thymic atrophy. Moreover, the serum of SD-R-immunised piglets strongly neutralised DLF, and the number of SD-R-vaccinated piglets demonstrating viraemia was greatly reduced. These results suggest that the PRRSV lineage 1 branch live vaccine candidate provides broad cross-protection against HP-like PRRSV in piglets.

An attenuated African swine fever virus expressing the E2 glycoprotein of classical swine fever virus protects pigs against challenge of both viruses

African swine fever (ASF) and classical swine fever (CSF) are highly contagious diseases with high morbidity and mortality rates resulting in an enormous impact on the global pig industry. A bivalent vaccine that simultaneously protects against both ASF and CSF is highly desirable. We previously developed a seven-gene-deleted African swine fever virus (ASFV) attenuated vaccine candidate (HLJ/18-7GD) that provides complete protection against homologous strains. Herein, we constructed a recombinant virus HLJ/18-7GD-E2 by inserting the classical swine fever virus (CSFV) E2 gene into the HLJ/18-7GD via homologous recombination. After continuous in vitro passaging, Western blotting analysis showed that the E2 gene was expressed and stably maintained within the ASFV genome. Next, the immunogenicity and protective efficacy of the recombinant HLJ/18-7GD-E2 virus was evaluated in pigs. The results revealed that a single dose of 106 TCID50 of HLJ/18-7GD-E2 induced an efficient immune response and provided complete protection against lethal challenges with ASFV or CSFV. These results demonstrate that recombinant ASFV expressing the CSFV E2 protein has potential as a bivalent live attenuated vaccine, providing solid protection against ASFV and CSFV infection in pigs.

Pig survival, average daily gain, and individual antimicrobial treatments from birth to slaughter in Finland

Birth weight appears to be a key indicator for survival and average daily gain (ADG) in piglets. However, parameters associated with piglet antimicrobial treatment are less explored. We assessed the factors influencing piglet survival, ADG, and first individual antimicrobial treatment. Data were collected on sex, weight, litter details, and medication throughout the lifespan of 3991 ear tagged pigs in Finland. Discrete-time survival models were performed for piglet survival and individual antimicrobial treatment as well as a linear regression model for piglet ADG from birth to slaughter. Medium (1 - 1.49 kg) and lightweight (< 1.0 kg) piglets at day 4 had 2.26 and 4.04 times higher odds of dying (in terms of odds for discrete hazards), respectively, than heavyweight (≥ 1.5 kg) piglets. Barrows and antimicrobial-treated suckling piglets had 1.81 and 1.67 times, respectively, higher odds of dying than females and unmedicated piglets. The mean average daily gain from birth to slaughter was 714 g (SD 70.2 g). Pigs born to sows grew 29.2 g/day more than pigs born to gilts, and barrows grew 13.3 g/day better than females, but these results should be interpreted with caution because a considerable number of ear tags lost during the study could have led to selection bias of the pigs with a measured ADG. Altogether 756 piglets received at least one individual parenteral antimicrobial treatment. Antimicrobial-treated pigs were to a considerable extent medicated before weaning mainly for diarrhea and leg problems during two treatment peaks: before day 8 and around weaning. Lightweight piglets at day 4 had 2.35 and piglets born to gilts 1.56 times higher odds of becoming medicated with antimicrobials than heavyweight piglets and piglets born to sows, respectively. Half of the study piglets receiving antimicrobials were treated again later. In summary, our results show that lightweight piglets at day 4 had poorer survival, and they received more antimicrobial treatments than their heavier littermates. Further, gilt offspring were medicated more frequently. This emphasizes the need to direct extra attention to litters born to gilts.

Global prevalence of Porcine Astrovirus: A systematic review and meta-analysis

Porcine astrovirus (PAstV) is a widespread enteric virus in pigs, often co-infecting with other enteric viruses and contributing to diarrhea, leading to significant economic losses in the global swine industry. This study aims to identify the factors influencing PAstV prevalence by conducting a statistical meta-analysis of global data and evaluating heterogeneity across various subgroups. A systematic literature search was performed across PubMed, Web of Science, CNKI, Wanfang, and VIP databases, covering studies from the inception of the databases up to December 2023. A random-effects model was employed to estimate the global pooled prevalence of PAstV infection, and subgroup analyses were performed to evaluate the impact of different continents, years, detection methods, and sample types on the prevalence. Publication bias was assessed using a funnel plot and Egger's test. A total of 45 studies from 10 countries across three continents, involving 376 articles, were included in the meta-analysis. The global pooled prevalence of PAstV infection was found to be 28.19 % (95 % CI, 21.94 %-34.89 %). Subgroup analysis indicated significant differences in PAstV prevalence across continents, with Asia at 26.25 % (95 % CI, 25.41 %-27.09 %), Europe at 36.19 % (95 % CI, 34.09 %-38.33 %), and North America at 63.24 %. The prevalence of PAstV was highest between 2012 and 2014 (49.86 %, 95 % CI, 47.21 %-52.51 %), followed by a decreasing trend that stabilized below 30 % from 2015 to 2023. The analysis showed no significant influence of detection methods on PAstV prevalence. However, the prevalence in non-fecal samples (43.09 %, 95 % CI: 41.05 %-45.15 %) was significantly higher than in fecal samples (22.92 %, 95 % CI: 21.87 %-23.99 %). Additionally, the prevalence of PAstV in asymptomatic pigs (36.71 %, 95 % CI, 34.97 %-38.48 %) exceeded that in diarrheic pigs (28.18 %, 95 % CI, 26.94 %-29.44 %). Among different age groups, nursery pigs(6-10 weeks) exhibited the highest infection rate (63.19 %, 95 % CI, 58.45 %-67.75 %), followed by weaning pigs(3-6 weeks) (60.00 %, 95 % CI, 56.48 %-63.45 %), finisher pigs(>10 weeks) (49.89 %, 95 % CI, 46.59 %-53.19 %), sows (35.33 %, 95 % CI, 31.45 %-39.37 %), with suckling pigs(0-3 weeks) showing the lowest rate (31.93 %, 95 % CI, 30.23 %-33.68 %). This study highlights the widespread nature of PAstV infection in pig populations globally, with notable variations in prevalence across regions, years, and sample types. The high prevalence of asymptomatic infections underscores the need for enhanced PAstV surveillance and control measures.

Evaluating slaughterhouse findings for lung and tail lesions in fattening pigs from secondary data

Using slaughterhouse findings to monitor animal health and welfare is not a new idea. The German Federal Veterinary Surgeon's Association even calls for the establishment of an animal health database that combines slaughterhouse findings with health and farm data from already existing monitoring programs to create a comprehensive monitoring and surveillance tool. In an attempt to combine secondary health data from slaughterhouse findings, antibiotic use monitoring as well as biosecurity and husbandry evaluations into an integrated dataset, data from 18,593 fattening pig farms across Germany participating in the private sector Quality scheme for food (from 2018 to 2020) were harmonized at the half-year level and combined. As an example, the combined data was used to evaluate lung and tail lesion findings from abattoirs as indicators of animal health and welfare with descriptive analysis and mixed model approaches. Differences between abattoirs due to different data collection methods were taken into account by either considering the abattoir as a random effect or standardizing the prevalence data using abattoir means. The mean prevalence of lung lesions per half-year varied between 8.69 % and 9.78 %. The mean prevalence of tail lesion increased continuously from 0.65 % in the first half of 2018-1.04 % in the second half of 2020. Farm size, agricultural region, half-year and antibiotic treatment frequency were found to be associated (p < 0.000001) with the prevalence of both lung and tail lesions. A lack of variance and specificity of the secondary biosecurity and husbandry evaluation data restricts the use of individual assessment criteria as well as biosecurity and husbandry indices (calculated from a subset of assessment criteria) in our analyses. We therefore used the data for a broad categorization of farms and it could be found, that the occurrence of a lower rating in any assessment criteria during farm evaluations is associated (p < 0.000001) with a higher prevalence of lung and tail lesions, but the interpretation remains uncertain. The already existing data in the fattening pig sector can be used for the evaluation of animal health and welfare indicators to a large extent. Nonetheless, missing information, differences and changes (over time) in data collection methods introduce biases into the dataset. By improving the data quality and harmonizing collection methods, secondary animal health data could prove to be a useful tool in promoting animal health and welfare.

The resilience of the Dutch pork supply chain to Toxoplasma gondii

Toxoplasma gondii (T. gondii) is a parasite leading to a substantial disease burden. An important source of toxoplasmosis is raw or undercooked pork. Our aim is to develop a model that can assess the resilience of the Dutch pork supply chain to T. gondii shocks, measured in Disability adjusted life years (DALYs), and the cost-effectiveness ratio (CER) of control measures that improve the resilience of the supply chain. We developed a farm-to-fork model to simulate T. gondii through the pork supply chain. We modelled two shocks: 1) young cats on the farm, a long-term shock, and 2) feeding pigs a batch of contaminated goat whey, a short-term shock, and two control measures: 1) sterilising cats at farm level, and 2) freezing meat at processing level. When facing shock 1, all control measures can be considered cost-effective with a CER between k€3 and k€24 per DALY in the first year and between k€1 and k€13 per DALY in subsequent years. When facing shock 2, freezing unheated meat, or freezing unheated meat and large pork cuts, or freezing all pork products led to a CER of respectively k€21, k€10, and k€46 per DALY in the first year. However, in subsequent years, the CER ranged from k€162 to k€820 per DALY, which cannot be considered cost-effective anymore. Control measures are more cost-effective in case of a long-term shock than in case of an isolated short-term shock. In the latter case, a control measure can be cost-effective if applied only for a limited time after the shock has been detected. The developed model can be used by decision makers to select effective control measures against toxoplasmosis caused by pork consumption.

Rapid on-site diagnosis of PEDV and PoRV co-infection by gold magnetic nanoparticles-based SERS immunochromatography

Porcine epidemic diarrhea virus (PEDV) and porcine rotavirus (PoRV) are the two main pathogens causing porcine diarrhea, which are characterized by high morbidity and mortality. Most of the diagnostic methods available are limited to the laboratory or fail to highlight their advantages in terms of target species, detection time, sensitivity, and stability. To meet the demand for rapid on-site diagnosis of PEDV and PoRV co-infection, a surface-enhanced Raman scattering (SERS) immunochromatographic sensor based on gold magnetic nanoparticles (MNPs) was developed. The sensor is dual-mode, detecting on the basis of color signals by the naked eye and Raman signals. After a series of optimizations, the constructed sensor could perform simultaneous qualitative and quantitative detection of PEDV and PoRV in just 18 min, with visualized (color signals observed by the naked eye) limits of detection (LOD) of 3.13 × 102 TCID50/mL and 4.69 × 102 copies/μL, respectively. The LOD based on Raman signal analysis was as low as 4.63 × 101 TCID50/mL and 3.30 × 102 copies/μL for PEDV and PoRV, respectively. In addition, the sensor exhibited excellent specificity without cross-reactivity with common pathogens. The overall compliance rate with RT-PCR was 92.1 % (35/38) for 38 clinical samples. Therefore, the sensor is characterized by high sensitivity, specificity, reproducibility, and accuracy, making it suitable for the simultaneous rapid on-site detection of PEDV and PoRV.

Industry stakeholders attitudes and beliefs about tail biting and docking in pigs - A case study in Switzerland and Spain

BACKGROUND

Tail docking is still widely used in major European pig-producing countries despite efforts to ban it. The present study aimed to understand the attitudes and beliefs of pig farming professionals in Spain and Switzerland regarding tail biting and tail docking. For this, n = 275 Swiss, and n = 87 Spanish participants completed an online questionnaire regarding the issue of tail biting and docking in pigs and their attitudes and beliefs.

RESULTS

Spanish participants predominantly kept docked pigs (n = 70, 80 %), whereas Swiss participants kept undocked pigs (n = 271, 99 %). While tail biting occurrences in the last two years were reported by most participants (n = 301, 83 %), the attitudes towards them differed: Spanish participants found the management of tail biting more challenging than Swiss participants. In addition, Spanish participants considered welfare to be better for docked pigs than for undocked pigs, whereas Swiss participants perceived the welfare of undocked pigs to be better. Similarly, Spanish participants showed a strong perception of lower production risks for docked pigs than for undocked pigs, a perception that could not be found in Swiss participants. Overall, Swiss participants saw more advantages in keeping long-tailed pigs and more possibilities to prevent tail biting than Spanish participants.

CONCLUSIONS

The results suggest that Spanish pig-farming professionals' attitudes towards tail docking are dominated by the conviction that docking is a necessity that lowers production risks and ensures animal welfare. Future efforts attempting to enforce the prohibition on tail docking should not only attempt to overcome structural barriers, but also focus on communicating with and changing the perceptions of pig farming professionals. By tackling the reluctance to try non-docking, producers can gain more experience and confidence with raising long-tailed pigs. To create sustainable changes in tail-docking practices, in addition to optimising the environment for pigs, communication should focus on changing attitudes and reducing risk perceptions.

Large heterogeneity in biosecurity legislation in the intensive pig production across Europe

Implementing biosecurity measures in the pig production is crucial to optimize animal health and reduce antimicrobial usage. A legal framework may help to ensure all stakeholders understand the need of biosecurity measures and to implement them correctly. Limited knowledge is available about how implementation of biosecurity measures is regulated in European countries. Therefore, the aim of this study was to identify which biosecurity measures were mandatory by national legislation and/or by pig sector organizations of European countries for the intensive pig production under normal circumstances (i.e. no (threat of) disease outbreaks). A questionnaire including 51 biosecurity measures, 32 on external and 19 on internal, was developed and sent to national country representatives. Twenty-four European countries, of which 18 belonging to the European Union, indicated which biosecurity measures were mandatory by law. Four countries, France, Spain, Italy and Romania had a single national pig-specific biosecurity legislation, while in the other countries multiple legislations had to be consulted to complete the questionnaire. In general, there was a high heterogeneity in the number of measures that were mandatory by law per country. Most biosecurity measures addressed in the national legislation focused on external biosecurity and were measures that can be easily audited when conducting a farm visit such as the presence of a hygiene lock, fencing around the farm and the existence of documentation. A significant (p < 0.001) positive correlation was observed between the presence of external and internal biosecurity measures in the legislation. Yet, no significant association was observed between the number of biosecurity measures present in the national legislation and the size of the pig production. Fourteen countries indicated which biosecurity measures were required by pig sector organizations for intensive pig farms. The median number of biosecurity measures mandatory by pig sector organizations but not by law was 13 with a minimum of one measure in Germany and a maximum of 24 in Croatia. Different countries apply different strategies to increase the level of biosecurity. Further research is needed to investigate the impact of the different strategies on the implementation of biosecurity on intensive pig farms in the countries.

Utero-placental adaptations in response to intrauterine growth restriction in swine

Intrauterine growth restriction (IUGR) is a common condition in swine associated with high piglet mortality and morbidity that develops in early gestation. This review article explores differences in uterine and placental tissues associated with IUGR fetuses compared to their normally-grown littermates at different stages of gestation. Specifically, we will review the available knowledge to date describing differences in 1) structure, 2) cellular apoptosis and proliferation, 3) adhesion, and 4) angiogenesis in endometrial and placental tissues associated with IUGR fetuses across gestation. Improved understanding of the mechanisms regulating IUGR is essential for the development of strategies to minimize the impact of IUGR in swine operations, thus improving reproductive efficiency and animal welfare.

Active immunization with a novel recombinant GnRH vaccine inhibits reproductive function in male goats

Gonadotropin-releasing hormone (GnRH) vaccines have been widely used to effectively inhibit gonadal development and reproductive function. To improve the immunogenicity of GnRH, we developed and evaluated the effects of GnRH6-kisspeptin-CRM197 immunization on the reproductive function in male goats. Thirty 3-month-old male goats (n = 30) were randomly assigned to control, surgical, and immunized groups. The immunized group received a 2 mL injection of the GnRH6-kisspeptin-CRM197 with a booster administered four weeks later. The control group was administered a white oil adjuvant. Blood samples were collected at regular intervals, and at week 20, the animals were euthanized for tissue collection. Serum antibody titers and testosterone levels were measured using ELISA and CLIA, respectively. Testicular parameters and histology were evaluated. The mRNA levels of reproductive-related genes in the HPG axis were measured using RT-qPCR. The results showed that the immunized goats had significantly increased serum GnRH and kisspeptin antibodies (P < 0.05) but decreased testosterone concentrations (P < 0.05) compared to the control group. Testicular size and histology were significantly affected in the immunized group, with notable reductions in testicular weight and dimensions (P < 0.01), and evidence of vacuolar degeneration and suppressed sperm production. The mRNA levels of FSHβ and LHβ in the pituitary, as well as FSHR, LHR, 3βHSD, and 17βHSD in the testis, were significantly lower in the immunized group compared to controls (P < 0.05). These findings suggest that GnRH6-kisspeptin-CRM197 is a safe antigen and a promising immunocastration vaccine with enhanced efficacy.

Evaluation of porcine epidemic diarrhea virus RNA contamination on swine industry transportation vehicles

Porcine epidemic diarrhea virus (PEDV) is one of the most devastating pathogens of global swine health and welfare. It is well known that contaminated fomites and vehicle movements play an important role in farm-to-farm PEDV spread, but the efficacy of cleaning and disinfection (C&D) protocols on the reduction in dissemination risk via vehicles and trailers remains unclear. This study used swine industry data to determine how frequently vehicles and trailers were contaminated with PEDV RNA before and after C&D. Environmental RNA samples were collected at three eastern North Carolina C&D sites from four different vehicle types: crew trucks, feed trucks, pigs-to-farm trucks and trailers, and pigs-to-market trucks and trailers. A total of 2004 samples were collected from truck cabins, trailers, and tires before and after C&D with two commercial disinfectants at two different concentrations. An in-house RT-qPCR assay was used to detect the presence of PEDV RNA only (not infectivity status). Results suggest that pigs-to-market trucks hauling live pigs were the most likely to be contaminated with PEDV (79.17 % of trailers tested positive before C&D and 88.52 % tested positive after C&D), while feed trucks were the least likely contaminated (8.19 % of tires testing positive before C&D and 15.12 % testing positive after C&D). Based on PEDV RNA detection, we demonstrated that quaternary ammonium and glutaraldehyde is a more effective disinfectant compared to advanced hydrogen peroxide in eliminating detectable PEDV RNA. Results also show that truck cabins are just as contaminated as the exterior of their vehicles. Based on these results, vehicle biosecurity measures should be evaluated and modified to prevent the spread of PEDV.

Overcoming ice: cutting-edge materials and advanced strategies for effective cryopreservation of biosample

Cryopreservation techniques have been widely used, especially in biomedical applications and preservation of germplasm resources. Ideally, biological materials would maintain functional integrity as well as a normal structure and can be recovered when needed. However, this tool does not work all the time. Ice formation and growth are the key challenges. The other major reason is that the cryoprotective agents (CPAs) currently used do not meet these needs and are always accompanied by their cytotoxicity. A comprehensive and synergistic approach that focuses on the overall frozen biological system is crucial for the evolution of cryopreservation methods. In this review, we first summarize the fundamental damage mechanisms during cryopreservation, as well as common cryoprotectants and their limitations. Next, we discuss materials that interact with ice to improve cryopreservation outcomes. We evaluated natural and synthetic materials, including sugars and polymers, AFPs and mimics, ice nucleators, and hydrogels. In addition, biochemical regulation, which enhances the tolerance of biosamples to cryopreservation-induced stresses, was also mentioned. Nanotechnology, cell encapsulation, cryomesh, and isochoric freezing, such scalable approaches, are further discussed for cryopreservation. Finally, future research directions in this field for efficient cryopreservation are proposed. We emphasized the need for multidisciplinary progress to address these challenges. The combination of cryobiology mechanisms with technologies, such as synthetic biology, nanotechnology, microfluidics, and 3D bioprinting, is highlighted.

Cross-sectional study of Mycoplasma hyopharyngis, Mycoplasma hyopneumoniae, Mycoplasma hyorhinis and Mycoplasma hyosynoviae in the tonsils of fattening pigs from Central-Eastern Europe

BACKGROUND

Mycoplasma (M.) hyopharyngis, M. hyopneumoniae, M. hyorhinis, and M. hyosynoviae can all be transiently present in the swine tonsils without causing any clinical signs or lesions. M. hyopharyngis is considered a commensal bacterium, however, our knowledge about its prevalence and pathogenic capabilities is lacking. M. hyopneumoniae, M. hyorhinis and M. hyosynoviae are widespread pathogens, responsible for significant economic losses. M. hyopneumoniae is known as the causative agent of porcine enzootic pneumonia, while M. hyorhinis and M. hyosynoviae are associated with arthritis and polyserositis. The objective of this study was to evaluate the detection rates of these mycoplasmas in Central-Eastern Europe (Croatia, the Czech Republic, Hungary, and Slovakia) through a cross-sectional investigation. In parallel, a novel quantitative polymerase chain reaction (qPCR) assay was designed targeting M. hyopharyngis to facilitate the identification of this bacterium.

RESULTS

Tonsils of 15 animals per herd were sampled from six-month-old fattening pigs, and a total of 150 herds were examined. Tonsils form each herd were divided into three pools, each comprising five tonsils. The samples were submitted for species-specific TaqMan assay and isolation. M. hyopharyngis was identified in 92.67% (139/150, 95% confidence interval: 87.35-95.86%) of the stocks, with successful isolation from 20 herds. Besides, M. hyopneumoniae was detected in 51.33% (77/150, 95% confidence interval: 43.40-59.19%) of the stocks. Additionally, M. hyorhinis was identified in all herds (100.00%; 150/150, 95% confidence interval: 97.50-100.00%) by qPCR examination and was successfully isolated from 107 stocks. Regarding the occurrence of M. hyosynoviae, 88.00% (132/150, 95% confidence interval: 81.83-92.27) of the herds showed positive PCR results, and the pathogen was successfully isolated in 122 cases. Moreover, the newly developed M. hyopharyngis qPCR assay proved to be a reliable and sensitive method.

CONCLUSIONS

This study determined the detection rates of several porcine mycoplasmas (M. hyopharyngis, M. hyopneumoniae, M. hyorhinis, and M. hyosynoviae) in fattening pigs in Central-Eastern Europe. Additionally, the developed M. hyopharyngis qPCR assay may facilitate future prevalence studies and diagnostic procedures concerning this neglected bacterium.

Mammalian Species-Specific Resistance to Mammary Cancer

Tumorigenesis in mammals is driven by inherited genetic variants, environmental factors and random errors during normal DNA replication that lead to cancer-causing mutations. These factors initiate uncontrolled cellular proliferation and disrupt the regulation of critical checkpoints. A few mammalian species possess unique protective mechanisms that enable them to resist widespread cancer development and achieve longevity. Tissue-specific tumor protection adds another layer of complexity to this diversity. Breast cancer is a leading cause of human mortality, particularly among females. Driven by the need for new strategies in treatment and prevention, this opinion article explores and supports the idea that herbivores are more resistant to mammary cancer than carnivores and omnivores. This diversity has occurred despite the remarkably similar basic mammary biology. Herbivores' meatless diet cannot explain the differences in cancer resistance, which have accompanied species segregation since the Jurassic era. To investigate the causes of this diversity, the characteristics of tumorigenesis in the human breast-and to a lesser extent in other carnivores-have been compared with data from retrospective analyses of bovine mammary tumor development across various locations over the past century. Well-established genomic, cellular, and systemic triggers of breast cancer exhibit different, or less pronounced tissue-specific activity in the bovine mammary gland, accompanied by novel bovine-specific protective mechanisms. Together, these factors contribute to the near absence of breast cancer in bovines and offer a basis for developing future anticancer strategies.

Subunit vaccine of PCV3 capsid protein produced by sf9 cells with double knockout of Caspase-1 and Dronc induces strong immune response in mice

Porcine circovirus type 3 (PCV3) associated with multisystemic clinicopathological diseases in swine herds has caused economic losses and there is no available commercial vaccine. Production of PCV3 capsid protein (Cap) by Spodoptera frugiperda 9 (sf9) cells using baculovirus expression vector system (BEVS) is a valid strategy to develop vaccines. Here, we report that subunit vaccine of PCV3 produced by sf9 cells with double knockout of Caspase-1 and Dronc genes induces strong immune response in mice. Three kinds of knockout sf9 cells aimed at Caspase-1 gene, Dronc gene and both genes were successfully generated by clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR-Cas9) system, and sequence analysis confirmed this. The anti-apoptosis ability of three kinds of knockout sf9 cells was assessed, and double knockout sf9 cells are the best. The expression of PCV3 Cap was enhanced in double knockout sf9 cells compared to wild type sf9 cells, and subunit vaccines were produced by PCV3 Cap expressed from double knockout sf9 cells and wild type cells, respectively. Results of immunological experiment in mice showed subunit vaccine of PCV3 Cap from double knockout sf9 cells induces higher level of serum antibody, stimulates lymphocyte proliferation and enhances expression of IL-2, IFN-γ, IL-4 and IL-10 compared to wild type cells. These results present knockout sf9 cells to enhance the expression of protein in BEVS, and provide a technical platform for vaccine development of PCV3.

Advances in porcine epidemic diarrhea virus research: genome, epidemiology, vaccines, and detection methods

Porcine epidemic diarrhea (PED) is a highly contagious intestinal disease caused by the porcine epidemic diarrhea virus (PEDV). The economic impact of PEDV on the global pig industry has been significant, resulting in considerable losses. This paper presents a review of the latest research progress on PEDV genome, molecular epidemiology, vaccine development, and molecular detection methods. It was determined that the genetic diversity of the PEDV spike (S) gene was closely associated with the epidemiological trend of PEDV. The prevalence of S gene variants of different genotypes exhibited variability across regions and pig populations. Epidemiological analyses have demonstrated that PEDV can be transmitted via multiple routes, including direct contact, airborne aerosol, and water source contamination. With regard to vaccine research, the available vaccines can be classified into several categories, including live-attenuated vaccines, inactivated vaccines, subunit vaccines, bacterial vector vaccines, viral vector vaccines, mRNA vaccines, etc. Each of these has distinctive characteristics in terms of immunogenicity, protection efficiency, and safety. Molecular detection methods, including PCR-based methods, isothermal amplification techniques, immunological assays, and biosensors, play an important role in the diagnosis and monitoring of PEDV. Furthermore, this paper examines the current developments in PEDV research and identifies the key areas of future investigation. The objective of this paper is to establish a theoretical foundation for the prevention and control strategies of PED, and to provide a point of reference for further research on the genomics, epidemiology, vaccine development and detection methods of PEDV.

Assessment of individual and population-based sampling for detection of influenza A virus RNA in breeding swine herds

Sample types currently used for Influenza A virus (IAV) surveillance in swine farms vary in sensitivity, convenience of collection, and herd representativeness. Family oral fluids are an effective population-based sample type for detecting porcine reproductive and respiratory syndrome virus (PRRSV) (ribonucleic acid) RNA by real-time reverse transcription-polymerase chain reaction (RT-rtPCR) in breeding herds. However, little is known about the efficacy of family oral fluids samples for detecting IAV RNA in these herds. This study compared the probability of IAV RNA detection among individual and population-based samples. A 3,500-sow breeding herd was sampled for matched sets (n = 57) of family oral fluids, udder wipes, sow nasal wipes, individual piglet nasal wipes, and drinker wipes, tested by RT-rtPCR for IAV RNA. Overall, 57.9 % (33/57) of family oral fluids, 49.1 % (28/57) of udder wipes, 28.1 % (16/57) of sow nasal wipes, 15.8 % (9/57) of drinker wipes, and 66.6 % (38/57) of individual piglet nasal wipes were positive. Family oral fluids showed a Kappa value of 0.81, indicating near-perfect agreement with individual piglet nasal wipes, while udder wipes had a substantial agreement (Kappa = 0.65). Other sample types showed fair agreement (Kappa < 0.28). These results validate family oral fluids as an efficient alternative population-based sample for IAV surveillance in breeding herds. The proportion of positive piglets within litters by room was 91 % in room A (20/22), 70 % in room B (17/24), and 9 % in room C (1/11). This study also highlights the importance of sampling different farrowing rooms within the same breeding herd to enhance IAV surveillance.

In vitro effect of omentin-1 on level of other adipokines in granulosa cells from ovaries of Large White and Meishan pigs

Omentin-1, also known as intelectin-1 (ITLN1), is an adipokine produced by visceral adipose tissue and effect on improve insulin sensitivity, regulate energy metabolism and reproduction. Our previously data has shown that ITLN1 expression in porcine ovarian follicles is influenced by both the level of adiposity and the phase of the estrous cycle. Additionally, recent studies have indicated variations in the serum levels of adipokines in pigs with higher fat content, suggest their common interaction. It was therefore hypothesized that ITLN1 regulates the levels of other adipokines and their receptors in the ovary of pigs with different fat content. The aim of this study was to investigate the in vitro effect of ITLN1 (10-100 ng/mL) on the levels of other adipokines, namely adiponectin, apelin, leptin, chemerin, resistin, visfatin, and vaspin in the culture medium, assessed by ELISA. In addition, the effect of ITLN1 on the mRNA expression of the above-mentioned adipokines with their receptors was investigated using RT-qPCR in granulosa cells (Gc) from normal weight Large White (LW) and fat Meishan (MS) pigs on days 10-12 of the estrous cycle. The results showed that ITLN1 reduced apelin levels, increased leptin, and had no effect on vaspin in the culture medium. ITLN1 was found to have a modulating effect on the mRNA expression of the other adipokines with their receptors in porcine Gc. It can, therefore, be proposed that ITLN1 represents a previously unidentified auto- and paracrine regulator of the functions of ovarian microenvironmental compartments in different types of pig breeds.

Factors affecting the intracytoplasmic sperm cell injection outcomes: A meta-analysis of porcine studies

BACKGROUND

Intracytoplasmic sperm cell injection (ICSI) has the potential to produce gene-edited (GE) pigs for biomedical research, but its success is limited. The factors impeding ICSI in pigs are impractical in-vivo oocyte production, incomplete cytoplasmic maturation of in-vitro matured (IVM) oocytes, inefficient methods for sperm selection and membrane removal, abnormal sperm nucleus decondensation, substandard protocols for oocyte stimulation, suboptimal in-vitro culture (IVC) systems, and high embryonic/fetal losses.

AIM OF REVIEW

The aim of this review is to investigate the effects of interventions in ICSI on oocyte activation, fertilization, cleavage, blastocyst, blastomere count, and live birth by means of robust statistical meta-analytical methods.

KEY SCIENTIFIC CONCEPTS OF REVIEW

A total of 61 studies published between 1905 ∼ 2024 met the inclusion criteria. The results of the meta-analysis suggested that manipulation in the IVM media did not improve oocyte developmental competency to blastocysts but increased the blastomere count, especially with the addition of thiol compounds. Consistently, manipulation with sperm was beneficial only for increasing the cleavage and blastomere count. Exogenous stimulation increased the relative risk (RR) for oocyte activation (10 %), fertilization (33 %), cleavage (18 %), and blastocyst formation (71 %) but did not affect the blastomere count. Chemical stimulation either pre- or post-ICSI was more beneficial than electrical stimulation. Manipulation of the culture increased the RR for oocyte activation (14 %) and fertilization (37 %) but did not benefit cleavage, blastocyst formation, or blastomere count. The subgroup analyses revealed that supplementation with thiol compounds was indeed beneficial. Our network meta-analysis also supported the findings of classical meta-analyses showing that cysteine, cysteamine, epidermal growth factor, amino acid supplementation in maturation and culture media, and Triton treatment of sperm improved blastocyst formation. The overall success rate of live births from total embryos transferred after ICSI was not greater than 2 %. Although, manipulations that were beneficial for ICSI outcomes were identified in this meta-analysis, however, areas where more robust data are needed to reach a conclusive decision are highlighted.

Modification of African classical swine fever p30 protein with magnetic nanoparticles and establishment of a novel rapid detection method

African swine fever has caused huge losses to the global pig industry. In the absence of effective vaccines, reliable detection methods are crucial. The p30 protein of ASFV is often used as a target for detection due to its high antigenicity in the early stage of virus replication. In this study, we modified the p30 protein using magnetic nanoparticles to increase its specific surface area and suspension in solution. Based on this modified p30 protein, we optimized the experimental steps to determine the best reaction conditions and then established a double probe competitive ELISA method. The established detection method can produce results within 45 min, with repeatability between and within batches <15 %, and it does not react with other pathogens, which demonstrates high specificity. In conclusion, we modified the ASFV p30 protein with magnetic nanoparticles and established a rapid, ultra-sensitive, and convenient detection method for ASF based on the modified p30. This also provides a new reference for the rapid detection of other veterinary diseases.

Effect of dietary supplementation of Bacillus subtilis QST 713 on constipation, reproductive performance and offspring growth performance of sows

The experiment aimed to investigate the effects of dietary supplementation with Bacillus subtilis QST 713 (BS) on the reproductive performance, perinatal constipation, and offspring growth performance of sows. 78 multiparous Landrace-Yorkshire sows with same parity and backfat thickness were divided into 2 groups: a basal diet group (CON) and a basal diet supplemented with 1.5 × 109 CFU/kg BS. The experiment was conducted from day 85 of gestation to day 21 of lactation. Reproductive performance, lactation performance, and perinatal fecal scores of sows were recorded. Samples were collected for subsequent analysis, including the feces of sows on day 110 of gestation, colostrum within 2 hours of parturition, milk on day 21 of lactation and feces from sows on day 21 of lactation. The results showed that, compared with the CON group, the BS group significantly shortened the duration of parturition (P < 0.01) and the average birth interval of piglets (P < 0.05), reduced stillbirth rate (P < 0.05) and invalid piglet rate (P < 0.05). Additionally, the BS group increased the content of protein (P < 0.05) and level of IgM in colostrum (P < 0.05), as well as the average daily gain (P < 0.05) of weaned piglets. The BS group increased the perinatal fecal score (P < 0.05) of sows, decreased the incidence of post-partum constipation (P < 0.05), and increased the relative abundance of Lactobacillus (P < 0.05) in feces on day 110 of gestation. In summary, a maternal diet supplemented with BS reduced the stillbirth rate by shortening the duration of parturition, alleviated perinatal constipation, and improved intestinal microbiota, meanwhile improving the growth performance of piglets by increasing nutrients and immunoglobulins in colostrum.

The clinical characteristics of Streptococcus equi ssp. zooepidemicus causing acute death in pigs and its prevention with chimeric monoclonal antibodies

Streptococcus equi subsp.zooepidemicus (SEZ) causes acute death in pigs and severely impacts the pig industry; however, comprehensive records of the clinical signs of SEZ from a bacteriological perspective are lacking. In this study, we found that piglets developed fever and a reduced appetite within 24 hours-post-infection (hpi) with SEZ and that sudden death usually started at 36 hpi. The mortality rate reached 100 % within 48 hpi. The moribund piglets presented prominent gross lesions, including swollen lungs with peripheral consolidation, enlarged and congested spleens, turbid cerebrospinal fluid (CSF), and hemorrhagic lymph nodes. Histopathologic analysis revealed widespread septicemia. The liver and spleen harbored the highest CFU burden in moribund piglets, and more SEZ proliferated in the CSF than in the brain parenchyma, suggesting an adaptation of SEZ in the CSF. By using genetically engineered chimeric McAbs with a porcine Fc region that targets the variant region of SzM (vSzM), we efficiently eliminated the SEZ burden and protected organs from gross pathological lesions in piglets. Collectively, these data provide more details concerning the systemic infection of SEZ and the potential preventive and therapeutic effects of McAbs against SEZ infection.

Molecular genetic characterization of porcine reproductive and respiratory syndrome virus outbreak in Assam, India and neighbouring regions

Porcine reproductive and respiratory syndrome (PRRS) is a significant swine disease with no effective vaccine due to high viral mutation rates. This study investigates a natural PRRS outbreak through molecular, pathological, and serological analyses. Nineteen affected pigs were clinically examined, and 10 underwent post-mortem examination. PRRS virus (PRRSV) presence was confirmed in all tissue samples by RT-PCR targeting open reading frame (ORF) 5 and ORF7 genes. Clinical signs, especially in boars and sows, included fever, appetite loss, movement reluctance, erythematous skin patches, vomiting, and abortions in sows. Post-mortem findings highlighted lung consolidation, severe lymph node enlargement, interstitial pneumonia with mononuclear cells, macrophage accumulation and necrotic cells in alveolar spaces. Multifocal myocarditis, lymphoid follicular degeneration, and follicular necrosis were observed in the tonsil, spleen, and lymph nodes. PRRSV-specific antibodies were detected in 32.75% of serum samples, confirming the outbreak. Phylogenetic analysis of the PRRSV-ORF5 and ORF7 genes revealed a close genetic relationship between the outbreak samples from Assam and recent outbreaks in Idukki, Kerala, India (2018), and neighbouring country China, indicating the circulation of Genotype 2 virus in Assam. However, the sequences showed some differences from the isolates of Mizoram, India. In conclusion, this study provides molecular and pathological evidence of a PRRSV outbreak, confirms the presence of PRRSV-specific antibodies and viral RNA, and shed light on the virus's genetic characteristics in India.

Biosecurity and Biocontainment for Ruminant Respiratory Disease

Respiratory disease in cattle and small ruminants is caused by various factors, including inadequate biosecurity and biocontainment. Biosecurity and biocontainment depend on good husbandry. Testing on arrival and quarantining for 42 to 56 days could improve biosecurity. Controlling visitors and vehicles, maintaining good air quality, and ensuring optimal passive immunity transfer are critical. Endemic respiratory agents are unlikely to transmit beyond 10 m, but environmental factors can affect this. Endemic viruses have a high R0, so achieving high herd immunity is important to limit transmission. While vaccination is an important biosecurity tool, it is not a substitute for other practices.

Refining genetic classification of global porcine reproductive and respiratory syndrome virus type 1 (PRRSV-1) and investigating their geographic and temporal distributions

Porcine reproductive and respiratory syndrome virus type 1 (PRRSV-1) primarily circulates in Europe but is also detected in North America and Asia. Based on ORF5 sequences, previous studies classified PRRSV-1 into four subtypes. Subtype 1 was further classified into 12 clades (A-L) or into three lineages with lineage 1 including clades 1A-1G and lineage 3 including clades 3A-3G, but the systems are inconsistent and have not been adopted. In this study, we proposed a statistically supported PRRSV-1 genetic classification system based on 10,446 global PRRSV-1 ORF5 sequences spanning 1991-2023. We replaced the colloquial "subtype" designation with "lineage" to reflect evolutionary history and, subsequently, PRRSV-1 was classified into four lineages (L1-L4) with L1 including 18 sublineages (L1.1 to L1.18). The proposed classification system is flexible and may be amended if additional lineages, sublineages, or more granular classifications are needed to reflect contemporary PRRSV-1 detections and evolution. Geographic distributions of PRRSV-1 at lineage and sublineage levels were distinct, with L1 globally distributed and L2, L3 and L4 more restricted. Temporal dynamic changes in some countries were quantified. Classification and ORF5 nucleotide identity of six commercial PRRSV-1 vaccines to each lineage and sublineage and detection frequency of vaccine-like viruses were determined. The phylogenies based on whole-genome and ORF5 sequences demonstrated slightly different tree topologies. Recombination of PRRSV-1 was observed at within-sublineage and between-sublineage levels. A set of ORF5 reference sequences representing the refined classification is available for future diagnostic and epidemiological applications. This study provides a benchmark delineating the current genetic diversity of PRRSV-1 and introduces a refined classification system to support the global standardization and application of ORF5-based genetic classification for PRRSV-1.

Spatiotemporal analysis of African swine fever in wild boar in Serbia from 2020 to 2024

African swine fever (ASF) is a highly fatal viral haemorrhagic disease affecting pigs. This study uses official surveillance data to investigate the persistence and spread of ASF in wild boar populations in Serbia from 2020 to 2024. A total of 480 ASF cases were analysed, with spatiotemporal clustering conducted via SaTScan™ and proximity analyses performed in the Quantum Geographic Information System. The yearly prevalence of ASF in wild boar rose steadily from 0.66% in 2020 to 1.47% in 2023. Seasonal trends showed a significant increase in cases during winter (68%) and spring (24%). Five distinct clusters were identified, predominantly near the borders with North Macedonia and Bulgaria, suggesting potential cross-border transmission. Proximity to major roads was significantly associated with ASF case distribution (p  0.01), while proximity to water bodies and elevation showed no consistent pattern. The findings highlight critical gaps in current passive surveillance systems, which likely underestimate ASF prevalence. The study underscores the need for enhanced surveillance in remote and wooded areas and proposes strategies to improve ASF monitoring and control in wild boar populations.Contribution: This study highlights the feasibility of cost-effective, non-invasive surveillance methods for ASF detection, offering critical insights for low-income countries where resources for intensive disease monitoring are limited. By demonstrating how environmental and anthropogenic factors drive ASF dynamics, this research provides actionable strategies for improving regional and global ASF control efforts.

Detection of Antibiotic-Resistant Airborne Bacteria in Restaurant Environments in Riyadh City

The spread of bacteria that cause illness is a critical problem facing the restaurant industry worldwide. These bacteria can proliferate in various restaurants areas through airborne transmission mechanisms, increasing the risk of food contamination. In this study, our aim was to detect the presence of potential foodborne pathogenic bacteria-Escherichia coli, Staphylococcus aureus, and aerobic bacteria-in aerosols of different restaurants zones in Riyadh city in the Kingdom of Saudi Arabia. We focused on 3 important zones: preparation (Zone A), food packaging (Zone B), and handwashing (Zone C). The bacteria of interest were isolated, identified, and characterized by using selective media, biochemical, and antibiotic susceptibility tests. The results showed that all 40 of the studied restaurants were contaminated with aerobic bacteria, with a total count of 3,978 colony-forming units (CFU) in Zone C, 1,323 in Zone B, and 525 in Zone A. E coli was identified as the most prevalent illness-causing bacteria in Zone A-derived aerosols (721 CFU), while S aureus had the highest occurrence in aerosols in Zone C (528 CFU). Pertaining to the antibiotic resistance phenotype of assessed isolates, our findings revealed that Zone C-derived E coli isolates showed resistance ranging from 25% to 100% toward 8 of the 15 tested antibiotics. S aureus isolates originating from Zone B exhibited between 25% and 75% resistance to 2 antibiotics, while isolates from Zone C showed resistance ranging from 5.88% to 47.05% to 4 antibiotics. Findings from this study illustrate that restaurants' aerosols are highly contaminated with different antibiotic-resistant bacteria, which increases the risk of food poisoning and threats food security.

Complete genome analysis of Bacillus velezensis HF-14,109 with potential for broad-spectrum antimicrobial activity and high enzyme-producing ability from common carp (Cyprinus carpio L.)

Bacillus velezensis (B. velezensis) HF-14,109 is an aerobic Gram-positive bacterium isolated from the gut of healthy carp (Cyprinus carpio L.). Here, we sequenced and annotated the genome of HF-14,109, identified and classified its enzyme-producing genes and secondary metabolite biosynthesis gene clusters (BGCs), and verified the inhibitory effects on pathogenic bacteria in vitro. Results suggested that HF-14,109 had a circular 4,214,172 bp genome that contains 4,392 predicted genes with an average length and GC content of 851.56 bp and 46.94%, respectively. A total of 210 non-coding RNAs, 8 CRISPR sequences, and 152 tandem repeats were predicted. Based on a CAZy database analysis, HF-14,109 contains 93 genes encoding enzymes for carbohydrate-related processes, 38 of which were glycoside hydrolase genes and divided into 20 families. Based on enzyme predictions, HF-14,109 had the capability to hydrolyze high molecular carbohydrates such as starch, disaccharides such as lactose and sucrose, and non-starch polysaccharides such as β-glucan, mannan, fructan and xylan. Twelve BGCs for producting secondary metabolites were identified by antiSMASH analysis, 5 of which were predicted to encode polyketide synthases (PKSs) and non-ribosomal peptide synthetases (NRPSs), indicating that HF-14,109 could produce multiple secondary metabolites. The genome of HF-14,109 contained numerous genes encoding glycoside hydrolases and BGCs for producting secondary metabolites. Besides, the HF-14,109 could inhibit pathogenic bacteria such as E. tarda, A. hydrophila, S. aurenus, and E. coli in vitro. In conclusion, our results demonstrate that HF-14,109 has the effects of hydrolyzing non-starch polysaccharides and inhibiting pathogenic bacteria, which lays a solid foundation for elucidating its antibacterial and enzyme-producing mechanisms, and is expected to be developed as a probiotic for aquaculture feed in the future.

A bioinspired polymeric membrane-enclosed insulin crystal achieves long-term, self-regulated drug release for type 1 diabetes therapy

The nuclear envelope serves as a highly regulated gateway for macromolecule exchange between the nucleus and cytoplasm in eukaryotes. Here we have developed a cell nucleus-mimicking polymeric membrane-enclosed system for long and self-regulated therapy. A polymeric nano-membrane with nanopores is conformally synthesized in situ on the surface of each insulin crystal, ensuring sustained, adjustable and zero-order drug release kinetics. Glucose- and β-hydroxybutyrate-dually sensitive microdomains are integrated into the nano-membranes. Under a normal state, the microdomains are uncharged and the channel is narrow enough to block insulin outflow. Under hyperglycaemia and ketonaemia, microdomains convert the high glucose and β-hydroxybutyrate concentration signals to the negative electric potential of membranes, widening the nanopores with rapid insulin outflow. In type 1 diabetic mice and minipigs, this system can maintain normoglycaemia for longer than 1 month and 3 weeks, respectively, with validated glucose- and β-hydroxybutyrate-triggered insulin release. Such membrane-enclosed drug crystal/powder formulation provides a broad platform for long-acting controlled release.

Pig tail length is associated with the prevalence of tail malformations but not with inflammation of the tail

BACKGROUND

Assuming that tail length is associated with the prevalence of tail biting, attempts are being made to shorten tails by genetic selection in order to avoid the painful procedure of docking. However, undesirable side effects such as kinky tails and inflammatory changes may occur. The aim of the present study was to clinically quantify in a population with known segregation of tail length, i) its variability, ii) possible associations with kinked tails and iii) possible associations of tail length and kinks with inflammation of the tail using 348 piglets at day 3 (undocked) and 39 (docked tails) of life.

RESULTS

The relative tail length (tail tip to tail base/tail tip to ear base × 100) varied between 20.3 and 31.3%. A reduced tail length was associated with kinked tails. Piglets with the shortest tails had 28% kinked tails, 5.6 times more than the piglets with the longest tails. The tails showed high prevalence of inflammation both on day 3 and on the docked tails on day 39. Overall, these were not associated with tail length or kinked tails. Only necrosis of the tail was significantly more frequent in the kinked tails than in the normal tails. Sow line, sow ID and boar ID significantly affected relative tail length, which may suggest a genetic cause.

CONCLUSION

Based on the phenotypic variation found in the present study, it seems possible to influence tail length through breeding. It remains to be seen whether the available potential is sufficient to actually reduce tail biting. At the same time, a higher incidence of kinked tails and necrosis is to be expected.

Discovery of small molecules against porcine reproductive and respiratory syndrome virus replication by targeting NendoU activity

Porcine reproductive and respiratory syndrome (PRRS) remains a major threat to animal health and causes substantial economic losses worldwide. The nonstructural protein 11 (NSP11) of the causative agent, PRRS virus (PRRSV), contains a highly conserved nidoviral uridylate-specific endoribonuclease (NendoU) domain essential for viral replication and immune evasion. Targeting NSP11 offers a novel approach to antiviral intervention. Through in silico virtual screening followed by a fluorescence resonance energy transfer assay , we identified A8-A2 as a promising candidate that effectively inhibits NendoU activity. Molecular docking and mutational analysis revealed that A8-A2 and its analogs target the key catalytic residues His144 and Thr217 of NSP11, located within the NendoU enzyme activity loop and pocket region, respectively. A8-A2 demonstrated dose-dependent inhibition of PRRSV replication in porcine alveolar macrophages. Notably, the NendoU is conserved across PRRSV strains and other Nidoviruses, and A8-A2 exhibited antiviral activity against both type I and type II PRRSV strains, as well as the infectious bronchitis virus, a coronavirus in the order Nidovirales. Further investigations revealed that A8-A2 impedes viral replication early in infection and reverses NSP11-mediated suppression of Poly(I:C)-induced interferon production. However, this effect occurs independently of mRNA splicing inhibition. These findings indicate that A8-A2 could act as an effective antiviral agent against infections caused by diverse PRRSV strains and may serve as a broad-spectrum agent for other Nidoviruses.

IMPORTANCE

Porcine reproductive and respiratory syndrome virus (PRRSV) causes significant economic losses in the pig industry, and vaccination is the principal method to prevent this viral infection currently. However, vaccination often fails to provide protection against heterologous strains, highlighting the need for alternative strategies for broad protection. The nidoviral uridylate-specific endoribonuclease (NendoU) domain plays a crucial role in viral replication and evasion of host immune responses. In this study, we identified a group of new compounds with similar chemical structures that could interfere with NendoU enzyme activity. Among these compounds, A8-A2 significantly inhibited PRRSV replication in host cells with minimal cytotoxicity. Our findings provide a new direction for developing potent antiviral compounds that can offer broad protection against different PRRSV strains, thereby mitigating their impact on pig health and benefiting the husbandry industry.

L-Carnitine enhances porcine sperm quality, longevity, and zona pellucida binding in cooled semen

Porcine breeding industries typically ensure the viability of boar artificial insemination doses during a 5-day liquid storage period at 17 °C. This study aimed to investigate whether the addition of L-carnitine (LC) to boar semen doses on different days of cooled storage could extend their usability. In experiment 1, LC was added to porcine semen doses on the fifth day (d5) of cooled storage performing five treatments control (no LC), 0.5, 1-, 5- and 10-mM LC. On d6 and d8 of storage, semen samples were evaluated for sperm motility and kinematic parameters, membrane functionality, and hydrogen peroxide and nitrite concentrations. In experiment 2, the number of sperm bound to the zona pellucida (ZP) was determined, as a way to investigate sperm penetration capability from boar insemination doses, with co-incubation with porcine oocytes. LC concentration that produced the most favorable outcomes in Experiment 1 was chosen to experiments 2 and 3, performing two treatments in the absence and with the LC. In Experiment 3, LC was added to cooled porcine semen doses after one day of storage (d1), and the same evaluations of experiment 1 were conducted on days 5, 7, 9, and 12, including sperm membrane integrity. The addition of 10 mM LC on d5 and d1 of storage improved sperm motility, which was extended up to 8 and 12 days of cooled storage, respectively. LC addition on d5 of storage increased sperm membrane functionality, while when added to semen on d1 of storage, it decreased NO2 - concentration on d9. On d6 of cooled storage 10 mM LC increased the number of sperm bound to ZP compared to the control. In conclusion, adding 10 mM LC to porcine semen doses at 17 °C improved sperm characteristics and ZP binding, ultimately enhancing sperm viability for up to 12d.

Combined immunoinformatic approaches with computational biochemistry for development of subunit-based vaccine against Lawsonia intracellularis

Lawsonia intracellularis (LI) are obligate intracellular bacteria and the causative agent of proliferative hemorrhagic enteropathy that significantly impacts the health of piglets and the profitability of the swine industry. In this study, we used immunoinformatic and computational methodologies such as homology modelling, molecular docking, molecular dynamic (MD) simulation, and free energy calculations in a novel three stage approach to identify strong T and B cell epitopes in the LI proteome. From ∼ 1342 LI proteins, we narrowed our focus to 256 proteins that were either not well-identified (unknown role) or were expressed at a higher frequency in pathogenic strains relative to non-pathogenic strains. At stage 1, these proteins were analyzed for predicted virulence, antigenicity, solubility, and probability of residing within a membrane. At stage 2, we used NetMHCPan4-1 to identify over ten thousand cytotoxic T lymphocyte epitopes (CTLEs) and 286 CTLEs were ranked as having high predicted binding affinity for the SLA-1 and SLA-2 complexes. At stage 3, we used homology modeling to predict the structures of the top ranked CTLEs and we subjected each of them to molecular docking analysis with SLA-1*0401 and SLA-2*0402. The top ranked 25 SLA-CTLE complexes were selected to be an input for subsequent MD simulations to fully investigate the atomic-level dynamics of proteins under the natural thermal fluctuation of water and thus potentially provide deep insight into the CTLE-SLA interaction. We also performed free energy evaluation by Molecular Mechanics/Poisson-Boltzmann Surface Area to predict epitope interactions and binding affinities to the SLA-1 and SLA-2. We identified the top five CTLEs having the strongest binding energy to the indicated SLAs (-305.6 kJ/mol, -219.5 kJ/mol, -214.8 kJ/mol, -139.5 kJ/mol and -92.6 kJ/mol, respectively.) W also performed B-cell epitope prediction and the top-ranked 5 CTLEs and 3 B-cell epitopes were organized into a multi-epitope subunit antigen vaccine construct joined using EAAAK, AAY, KK, and GGGGG linkers with 40 residues of the LI DnaK protein attached to the N-terminus to further enhance the antigenicity of the vaccine construct. Blind docking studies showed strong interactions between our vaccine construct with swine Toll-like receptor 5. Collectively, these molecular modeling and immunoinformatic analyses present a useful in silico protocol for the discovery of candidate antigen in many viral and bacterial pathogens.

Experimental efficacy of vaccination of weaned piglets with a modified-live commercial PRRS virus vaccine against the challenge with a Spanish highly virulent PRRSV-1 strain

BACKGROUND

In 2020, a highly virulent PRRSV-1 strain emerged in Spain and rapidly spread across the country. The purpose of the present study was to test in a piglet model whether a commercial PRRSV-1 modified live vaccine was able to confer protection against strain R1, a representative of the emerging clade. For that purpose, two groups of 26 piglets were either vaccinated intradermally or kept as controls; 42 days later, half of the animals in each group were intranasally challenged with the R1 strain. Then, animals were followed to assess the development of clinical signs (until 14 days post-challenge), lung lesions (10- and 35-days post-challenge), weight gains, viremia and nasal shedding and the immune response (anti PRRS virus nucleoprotein antibodies) by ELISA and virus specific-interferon-γ secreting cells by ELISPOT).

RESULTS

Challenge of naïve pigs resulted in high fever (up to 41.9 °C), lethargy and severely retarded growth (0.748 kg/day). In contrast, vaccinated/challenged pigs had less fever and for a shorter period, lower clinical scores and a higher average daily weight gain (0.940 kg/day), comparable to the unchallenged animals. At 10 days-post challenge, in naïve animals on average 49.1% of the lung was pneumonic (range 8-81%) while in vaccinated animals the average was 15.7% (4-41%). Duration of viremia was reduced in vaccinated animals and after 14 days post-challenge, most were negative by RT-qPCR. In contrast, 50% of the naïve/challenged pigs remained viremic at 35 days post-challenge. Vaccination induced rapid seroconversion and challenge of naïve animals resulted in 100% of ELISA-positive pigs by day 14 post-challenge. Regarding the development of IFN-γ responses, for vaccinated animals the frequencies increased until day 35 post-vaccination. After challenge, in vaccinated pigs, the peak of the R1-specific IFN-γ response was reached at 14 days and then the viremia ceased, although nasal shedding persisted in some vaccinated animals.

CONCLUSIONS

In the present trial, vaccination resulted in improved clinical course, better weight gain and reduced viremia. At the peak of the infection, lung lesions were reduced in most animals although some individuals still had extensive pneumonia. In summary, vaccination was shown to provide partial but significant protection against the highly virulent R1 strain.

Influence of fermented milk permeate containing antimicrobial Lactobacillus and galactooligosaccharides on growth performance and health parameters in neonatal piglets

The study aimed to compare the effects of fermented milk permeate (MP) containing Pediococcus pentosaceus (MPPp) and P. acidilactici (MPPa) on growth performance, plasma parameters, and the faecal microbial, metataxonomic, and physicochemical characteristics of Topigs Norsvin Yorkshire piglets. A total of 36 1-day-old piglets were divided into three groups: (i) control group (C), (ii) MPPp group, and (iii) MPPa group. The treated groups, in addition to their full-fledged combined pre-starter diet, received 25 mL of MP daily. After the experiment, piglets in the MPPa group exhibited the highest weight gain, while piglets in the MPPp group showed the highest IgM concentration. Both experimental groups demonstrated increased Lactobacillus counts in the faeces. Although the numbers of Lactobacillus and Enterobacteria increased, these microbial changes did not show a direct correlation with growth performance. The feces of MPPa piglets had a unique volatile compound profile, characterized by higher levels of butanoic acid and indole levels, which may be linked to differences in their metataxonomic profile. The MPPp group showed a greater variety of bacterial patterns compared to the control and MPPa groups. Post-experiment, the MPPa group demonstrated the highest prevalence of specific bacterial species, Parabacteroides sp. 12,306, Terrisporobacter sp. 34,393, Holdemanella sp. 36,738, and Lachnospiraceae sp. In conclusion, feeding piglets with MPPa proved beneficial for achieving better weight gain while also promoting the proliferation of specific bacteria species and contributing to a distinctive VC profile in their faeces. These findings highlight the importance of further research into the metabolic pathways underlying these observations.

Outer Membrane Proteins as Vaccine Targets Against Lawsonia intracellularis in Piglets

BACKGROUND

Lawsonia intracellularis (LI) is the agent of proliferative enteropathy in swine, a common disease that affects pigs for up to eight weeks after weaning.

AIM

To evaluate the effectiveness of two novel subunit vaccines targeting outer membrane proteins on LI.

METHODS

The two vaccines included OMP2c.cVLP, where the OMP2c antigen was anchored on the surface of capsid virus-like particles (cVLP); and MBP.INVASc, where antigens were anchored to an MBP fusion protein. Groups of six mice, as proof of concept, and six piglets were immunized with either OMP2c.cVLP, MBP.INVASc., or PBS as a control using a prime-boost regime.

RESULTS

Both OMP2c.cVLP and MBP.INVASc subunit vaccines induced strong antigen-specific serum IgG and IgA responses. There were no significant differences in weight gain among the groups. Mild-to-moderate clinical signs of LI infection were observed, but vaccinated groups showed lower inflammatory scores and fewer animals tested positive for bacteria by immunohistochemistry. Although neither vaccine completely prevented clinical signs of LI infection, both effectively reduced inflammation and lowered the pathogen load, thereby mitigating the severity of the disease, particularly the MBP.INVASc vaccine.

CONCLUSIONS

These findings suggest that both vaccines have the potential for further development and optimization to enhance their protective efficacy against LI infections.

Dietary Short-Chain Fatty Acid Supplementation Improves Reproductive Performance and Gut Microbiota in Gilts

BACKGROUND

Short-chain fatty acids (SCFAs) have emerged as critical modulators of female reproductive function and host gut microbiota.

OBJECTIVES

This study aimed to investigate the impact of dietary SCFA supplementation on reproductive performance and gut microbiota in gilts, and to elucidate the underlying mechanisms.

METHODS

Eighty gilts (95 d old) were randomly assigned to either a control group (Ctrl, 40 gilts) receiving a basal diet, or a SCFAs treatment group (SCFAs, 40 gilts) receiving a basal diet supplemented with 0.13% sodium acetate, 0.11% sodium propionate, and 0.09% sodium butyrate. At third estrus, 13 gilts (6 from Ctrl and 7 from SCFAs) were killed for follicular development and gut microbiota analysis, whereas the remaining gilts completed gestation for reproductive performance assessment.

RESULTS

SCFA group had higher total number born (11.97 compared with 9.44) and total number born alive (11.28 compared with 9.34) compared with Ctrl group (P < 0.05). SCFA group had increased counts of secondary follicles (36.14 compared with 26.83), antral follicles (10.29 compared with 6.67), and corpus luteum (25.09 compared with 19.33), alongside had reduced atretic follicles (15.32 compared with 20.67) compared with Ctrl group (P < 0.05). Proteomic analysis revealed that SCFAs-induced differentially expressed proteins (DEPs) were significantly enriched in the follicular development-related pathways (P < 0.05). Apoptosis-related DEPs positively correlated with follicular development indices (P < 0.05), consistent with the reduced apoptosis observed in ovarian granulosa cells of the SCFA group. Additionally, SCFA supplementation improved both the composition and alpha-diversity (P < 0.05) of gilts' gut microbiota. Furthermore, both the SCFAs-enriched bacteria and plasma SCFAs concentrations showed positive associations with gilts' follicular development indices (P < 0.05).

CONCLUSIONS

Dietary SCFA supplementation enhances reproductive performance in gilts by promoting ovarian follicular maturation and optimizing gut microbiota composition.

From Microbes to Metabolites: Advances in Gut Microbiome Research in Type 1 Diabetes

Background: Type 1 diabetes (T1D) is a severe chronic T-cell mediated autoimmune disease that attacks the insulin-producing beta cells of the pancreas. The multifactorial nature of T1D involves both genetic and environmental components, with recent research focusing on the gut microbiome as a crucial environmental factor in T1D pathogenesis. The gut microbiome and its metabolites play an important role in modulating immunity and autoimmunity. In recent years, studies have revealed significant alterations in the taxonomic and functional composition of the gut microbiome associated with the development of islet autoimmunity and T1D. These changes include reduced production of short-chain fatty acids, altered bile acid and tryptophan metabolism, and increased intestinal permeability with consequent perturbations of host (auto)immune responses. Methods/Results: In this review, we summarize and discuss recent observational, mechanistic and etiological studies investigating the gut microbiome in T1D and elucidating the intricate role of gut microbes in T1D pathogenesis. Moreover, we highlight the recent advances in intervention studies targeting the microbiota for the prevention or treatment of human T1D. Conclusions: A deeper understanding of the evolution of the gut microbiome before and after T1D onset and of the microbial signals conditioning host immunity may provide us with essential insights for exploiting the microbiome as a prognostic and therapeutic tool.

Rapid visual detection of hepatitis E virus combining reverse transcription recombinase-aided amplification with lateral flow dipstick and real-time fluorescence

Hepatitis E virus (HEV) is a globally prevalent zoonotic pathogen that is primarily spread through the fecal-oral route, such as by consuming undercooked or contaminated pork. HEV infection leads to an estimated 3.3 million symptomatic cases of viral hepatitis and 70,000 deaths in human populations each year. Therefore, a rapid and accurate method for detecting HEV in serum or stool samples is essential. In this study, we aimed to develop and evaluate two methods for the rapid and convenient detection of HEV RNA: reverse transcription recombinase-aided amplification with lateral flow dipstick (RT-RAA-LFD) and quantitative real-time reverse transcription recombinase-aided amplification (qRT-RAA). We optimized the reaction conditions and assessed their sensitivity and specificity. The RT-RAA-LFD assay completed its reaction at 39°C within 15 minutes, achieving a 95% limit of detection (LOD) of 247 copies/μL. The qRT-RAA assay, completed at 42°C within 20 minutes, had a 95% LOD of 25 copies/μL. Both assays demonstrated no cross-reactivity with other porcine pathogens and exhibited strong specificity. In testing 245 porcine bile and fecal samples, the RT-RAA-LFD assay showed a kappa value of 0.943 (P < 0.001) with a 97.14% (238/245) coincidence rate compared with quantitative reverse transcription PCR. Similarly, the qRT-RAA assay achieved a kappa value of 0.976 (P < 0.001) with a 98.78% (242/245) coincidence rate. In conclusion, these two RT-RAA assays show promising potential as effective diagnostic tools for broad and efficient screening of swine HEV in veterinary clinics.

IMPORTANCE

Hepatitis E virus (HEV) is a globally widespread zoonotic pathogen that poses a significant public health risk. Swine serve as the primary natural host for zoonotic HEV. This study introduces a rapid and precise method for detecting swine HEV RNA, showcasing its potential as an effective diagnostic tool for comprehensive and efficient screening of swine HEV in veterinary clinics.

Simulation model to estimate the burden of disease due to hepatitis E virus in Dutch pig meat and cost-effectiveness of control measures

Hepatitis E virus (HEV) can lead to liver disease in humans. In the Netherlands, the consumption of pig meat is thought to be the main contributor to the total burden of disease caused by HEV. In this study, the number of cases and lost disability-adjusted-life-years (DALYs) due to HEV in pig meat were estimated by simulating HEV through the pig supply chain, including the farm, transport, lairage, slaughtering, processing, and consumption stages. The first four stages were modeled using a susceptible-exposed-infected-recovered (SEIR) model. For the last two stages, pig meat and liver products were divided into six product categories commonly consumed by Dutch consumers. Depending on the product category, different ways of heating and storing, leading to the reduction of infectious HEV genome copies, were assumed. Furthermore, the model was challenged by four selected control options at the pig farm: the cleaning of driving boards, the use of predatory flies, the use of rubber mats, and the vaccination of finishing pigs. Finally, the cost-effectiveness of these control measures was estimated by estimating the costs per avoided DALY. For the baseline situation, it was estimated that HEV in pig meat would lead to 70 cases and 21 DALYs per year. All control measures led to a decreased number of DALYs, with vaccination leading to the largest decrease: five DALYs per year. However, the costs per avoided DALY ranged from €0.5 to €7.5 million, making none of the control measures cost-effective unless the control measures are also effective against other pathogens.

Discovery of viruses and bacteria associated with swine respiratory disease on farms at a nationwide scale in China using metatranscriptomic and metagenomic sequencing

Respiratory disease (RD) is a worldwide leading threat to the pig industry, but there is still limited understanding of the pathogens associated with swine RD. In this study, we conducted a nationwide genomic surveillance on identifying viruses, bacteria, and antimicrobial resistance genes (ARGs) from the lungs of pigs with RD in China. By performing metatranscriptomic sequencing combined with metagenomic sequencing, we identified 21 viral species belonging to 12 viral families. Among them, porcine reproductive and respiratory syndrome virus, influenza A virus, herpes virus, adenovirus, and parvovirus were commonly identified. However, emerging viruses, such as Getah virus and porcine respiratory coronaviruses, were also characterized. Apart from viruses, a total of 164 bacterial species were identified, with Streptococcus suis, Mycoplasma hyorhinis, Mycoplasma hyopneumoniae, Glaesserella parasuis, and Pasteurella multocida being frequently detected in high abundances. Notably, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, and Klebsiella pneumoniae were also highly detected. Our further analysis revealed a complex interaction between the identified pathogens in swine RD. We also conducted retrospectively analyses to demonstrate the prevalent viral genotypes or bacterial serotypes associated with swine RD in China. Finally, we identified 48 ARGs, which conferred resistance to 13 predicted antimicrobial classes, and many of these ARGs were significantly associated with a substantial number of mobile genetic elements, including transposons (e.g., tnpAIS1, tnpA1353, int3, and ISCau1) and plasmids (e.g., Col(BS512), Col(YC)]. These findings will contribute to further understanding the etiology, epidemiology, and microbial interactions in swine RD, and may also shed a light on the development of effective vaccines.IMPORTANCEIn this study, we identified viruses and bacteria from the lungs of pigs with RD in China at a nationwide farm scale by performing metatranscriptomic sequencing combined with metagenomic sequencing. We also demonstrated the complex interactions between different viral and/or bacterial species in swine RD. Our work provides a comprehensive knowledge about the etiology, epidemiology, and microbial interactions in swine RD and data reference for the research and development of effective vaccines against the disease.

Integrated Convolution and Attention Enhancement-You Only Look Once: A Lightweight Model for False Estrus and Estrus Detection in Sows Using Small-Target Vulva Detection

Accurate estrus detection and optimal insemination timing are crucial for improving sow productivity and enhancing farm profitability in intensive pig farming. However, sows' estrus typically lasts only 48.4 ± 1.0 h, and interference from false estrus further complicates detection. This study proposes an enhanced YOLOv8 model, Integrated Convolution and Attention Enhancement (ICAE), for vulvar detection to identify the estrus stages. This model innovatively divides estrus into three phases (pre-estrus, estrus, and post-estrus) and distinguishes five different estrus states, including pseudo-estrus. ICAE-YOLO integrates the Convolution and Attention Fusion Module (CAFM) and Dual Dynamic Token Mixing (DDTM) for improved feature extraction, Dilation-wise Residual (DWR) for expanding the receptive field, and Focaler-Intersection over Union (Focaler-IoU) for boosting the performance across various detection tasks. To validate the model, it was trained and tested on a dataset of 6402 sow estrus images and compared with YOLOv8n, YOLOv5n, YOLOv7tiny, YOLOv9t, YOLOv10n, YOLOv11n, and the Faster R-CNN. The results show that ICAE-YOLO achieves an mAP of 93.4%, an F1-Score of 92.0%, GFLOPs of 8.0, and a model size of 4.97 M, reaching the highest recognition accuracy among the compared models, while maintaining a good balance between model size and performance. This model enables accurate, real-time estrus monitoring in complex, all-weather farming environments, providing a foundation for automated estrus detection in intensive pig farming.

Changes of metabolic parameters, antioxidant capacity, and gut microbiota in response to substitution of ferrous sulfate with iron hydroxy methionine analog chelate in weaned piglets

Introduction

Previous studies have suggested that dietary organic iron offers health advantages compared to its inorganic counterpart. However, the effects of iron hydroxy methionine analog chelate (Fe-HMA) supplementation in weaned piglets have not been fully explored. Therefore, this study aimed to investigate the effects of replacing ferrous sulfate with Fe-HMA as the iron source on serum biochemistry, antioxidant capacity, and gut microbiota in weaned piglets.

Methods

One hundred and twenty weaned piglets were randomly allocated to two treatment groups. Each group contained four replicates, with 15 pigs per replicate. Piglets were fed either 100 mg Fe/kg in the form of ferrous sulfate (Fe-sulfate group) or 50 mg Fe/kg in the form of Fe-HMA (Fe-HMA group) as the iron source for 28 days.

Results and discussion

Results showed that supplementing Fe-HMA as an iron source significantly increased the levels of triglycerides and glucose in portal venous serum, albumin in both serum and portal venous serum and decreased serum low-density lipoprotein level in weaned piglets. Additionally, Fe-HMA supplementation significantly reduced serum and liver malondialdehyde levels, while increasing catalase (CAT), glutathione peroxidase (GSH-Px), total superoxide dismutase, and manganese superoxide dismutase levels in serum, as well as GSH-Px and CAT levels in the liver. Moreover, Fe-HMA regulated the intestinal microbiota composition, notably increasing the relative abundance of Proteobacteria and decreasing microbes involved in aromatic_compound_degradation. In conclusion, dietary replacing inorganic iron with Fe-HMA improved metabolic parameters and antioxidant capacity, and regulated gut microbiota composition in weaned piglets.

PRRSV-1 outbreak in a farrowing farm caused by a vaccine derived strain: a case report

BACKGROUND

The benefits of porcine reproductive and respiratory syndrome (PRRS) modified live virus vaccines (MLV) have been largely proven, however, the safety of these vaccines is questioned since vaccine strains can revert to virulence due to random mutations or recombination events. Reversion to virulence has been previously described for PRRSV-2 MLVs and recently for PRRSV-1 MLV after recombination. This case report describes the introduction of a PRRSV-1 strain derived from a MLV associated with an outbreak of reproductive disorder in a 1000-sow farrow-to-wean farm in France.

CASE PRESENTATION

In January 2023, unusual fever and lethargy in sows, and premature farrowings were reported in a farm that was regularly controlled as PRRS stable, through mass vaccination of the sows. PRRSV-1 was detected by PCR in sows and suckling piglet samples. Sequencing of ORF5, ORF7, and whole genome (WGS) was performed. Time-to-baseline production and total production losses were calculated using statistical process control methods. ORF5 and ORF7 nucleotide sequences indicated that the strain isolated from the clinical samples was differentiable from the DV MLV strain used in the farm (94.1% and 95.9% respectively) but closely related to the VP-046 Bis MLV strain which was never used (99.0% and 99.2% respectively). WGS of the farm PRRSV strain confirmed the high nucleotide identity percentage with the VP-046 Bis MLV strain (98.6%) over the entire genome and no recombination events was detected with MLV strains authorized in France. After different investigations aiming to identify the source of contamination, we were able to detect a closely related strain (99.46% of identity with the case farm strain across the entire genome) in a wean-to-finish farm located 400 m further. It took 17 batches (34 weeks) to recover the baseline production of piglets after implementation of a PRRSV stabilization protocol, which represented a total loss of 812 weaned piglets.

CONCLUSION

This is the first case report of a PRRSV-1 MLV which might have reverted to virulence in France and has caused substantial economic losses.

Assessing the adoption of biosecurity measures among extensive livestock producers: a case study in the free-range pig sector of Corsica

BACKGROUND

Increasingly exposed to emerging sanitary risks, extensive livestock farming systems are confronted with the imperative of incorporating biosecurity measures in their production models in order to limit the risk of introduction and diffusion of animal pathogens. Yet, ex-ante assessment methods of the likelihood of biosecurity measures implementation are poorly documented. Our study aimed at comparing alternative methods of elicitation of preferences to assess the attitude of extensive livestock farmers towards biosecurity measures. We used, as a case study, the Regional Porcine Sanitary Plan (RPSP) elaborated for the free-range pig sector of Corsica Island to meet the newly established national disease prevention requirements of France in the face of risk of African Swine Fever introduction.

METHODS

The RPSP imposed (1) a fencing of the breeding pigs' area, (2) the neutering of the pigs not used for breeding, and (3) a management process of dead pigs' carcasses found on pastures. We evaluated four attributes of the sanitary plan, including (1) proportion of the implementation cost covered by state subsidies, (2) mandatory carcass management, (3) people allowed to neuter gilts, (4) the age limit for neutering. We performed interviews of a sample of free-range pig farmers using three methods in parallel, namely (1) direct qualitative elicitation, (2) attributed-based stated choices and (3) semi-quantitative ranking of attributes.

RESULTS

Farmers' preference for a high subsidization of the sanitary plan and for enforcing the neutering of pigs at an early age was consistent across all used methods. Participants expressed heterogeneous preferences for the two other attributes. Half of the respondents were reluctant to entrust veterinarians with neutering gilts while the other half deemed veterinarians' intervention compulsory. Contradictory preferences were obtained on rendering carcass management mandatory depending on the elicitation method.

CONCLUSION

Our study demonstrates the added value of using choice-based methods, where respondents weigh the individual costs and benefits associated with different options, in combination with qualitative or semi-quantitative ranking methods in which farmers express their opinions and give more consideration to their community interest. It also reveals potential issues of heterogeneities among farmers' preferences that need to be taken into consideration in similar surveys.

Effects of Dietary Mallotus oblongifolius Ultrafine Powder Supplementation on Quality of Pork from Hainan Pigs During the Late Fattening Period

The genus Mallotus oblongifolius (MO), a member of the Euphorbia family, exhibits a predominant distribution in Hainan Island and has been proven to possess diverse medicinal attributes. Research indicates that ultramicro-grinding fully exposes the active ingredients of Mallotus oblongifolius, enhancing bioavailability and efficacy, compared to before. Our study investigates the effects of ultrafine powder of Mallotus oblongifolius (MOUP) on Hainan pigs. A total of sixty-four healthy castrated pigs (ternary hybrid pigs, Duroc × Duroc × Tunchang) with comparable initial body weight (BW, 68.06 ± 1.03 kg, 150 days old) were allocated randomly into four groups: the control group (CONT), the antibiotic group (ANTI), the 0.1% MOUP group (PT1), and the 0.5% MOUP group (PT2). There were four replicate pens per treatment with four pigs per pen. The pre-test lasted for 7 days and the formal test lasted for 70 days. The CONT group was fed the basal diet, the ANTI group was fed the basal diet supplemented with 300 mg/kg colistin sulfate, the PT1 group was fed the basal diet supplemented with 0.1% MOUP, and the PT2 group was fed the basal diet supplemented with 0.5% MOUP. The findings of our study indicate that the inclusion of colistin sulfate and MOUP in the diet did not have any significant impact on the production performance or carcass indicators of Hainan pigs compared to the CONT group. However, it is noteworthy that the addition of MOUP to the diet resulted in a significant improvement in the lightness, tenderness, muscle fiber morphology, amino acid composition, and antioxidant activity of the longissimus dorsi muscle, particularly in the PT2 group, compared to the CONT group. In conclusion, the present study has demonstrated that the inclusion of MOUP in the dietary regimen yields enhancements in the meat quality of Hainan pigs, particularly when supplemented at a concentration of 0.5%.

Application of Behavior Change Techniques (BCTTv1) to Reduce Antimicrobial Use in Livestock: A Scoping Review

Antimicrobial resistance (AMR) is a critical global health threat, partly driven by the overuse of antimicrobials in livestock production. Addressing this issue requires targeted interventions to influence behavioral drivers behind AMU practices. Behavior change techniques (BCTs) offer a structured approach to designing such interventions, yet their application in reducing AMU on farms remains underexplored. This scoping review systematically maps the current applications of the Behavior Change Techniques Taxonomy version 1 (BCTTv1) in interventions aimed at reducing AMU in livestock, while also identifying gaps in the literature and opportunities for future research. A comprehensive search across academic databases identified 23 relevant studies. Findings revealed the use of 37 BCTs, with commonly applied techniques including goal setting, instruction on behavior, credible sources, problem-solving, feedback on behavior, and self-monitoring. While some studies explicitly referenced BCTs, many applied them implicitly, without alignment with standardized frameworks. Intervention outcomes were influenced by contextual factors including financial, logistical, cultural, and technical challenges. This review underscores the importance of explicitly integrating and systematically reporting BCTs to enhance transparency, replicability, and scalability. Future interventions should adopt tailored, context-specific approaches to address regional and sectoral challenges, ultimately contributing to global efforts in combating AMR through improved antimicrobial stewardship.

Use of Saliva Analytes as a Predictive Model to Detect Diseases in the Pig: A Pilot Study

BACKGROUND/OBJECTIVES

Saliva is gaining importance as a diagnostic sample in pigs. The aim of this research was to evaluate a panel of salivary analytes in three porcine diseases and establish predictive models to detect them.

METHODS

Saliva samples were obtained from healthy pigs (n = 97) and pigs affected by meningitis due to Streptococcus suis (n = 118), diarrhea due to enterotoxigenic Escherichia coli (ETEC, n = 77), and porcine reproductive and respiratory syndrome (PRRS, n = 52). The following biomarkers were analyzed: adenosine deaminase (ADA), haptoglobin (Hp), calprotectin (Calp), aldolase, alpha-amylase (sAA), lactate dehydrogenase (LDH), total protein (TP), and advanced oxidation protein products (AOPPs). Predictive models based on binary logistic regression and decision trees combining those analytes for detecting specific diseases were constructed.

RESULTS

The results showed a different biomarker profile between the groups. S. suis and ETEC pigs showed higher values of ADA, Hp, Calp, aldolase, sAA, LDH, and TP than healthy pigs. Pigs with PRRS showed higher values of Hp, Calp, sAA, and LDH than healthy animals. The constructed predictive models showed overall accuracies of over 78% and 87% for differentiating ETEC and PRRS, respectively, whereas the models did not accurately predict S. suis infection.

CONCLUSIONS

Salivary analytes show different changes in pigs depending on the disease, and the combination of these analytes can contribute to the prediction of different diseases. Further studies should be conducted in larger populations to confirm these findings and evaluate their possible practical applications.