Swine Farms Research Articles

Reduction in Antimicrobial Resistance Prevalence in Escherichia coli and Enterococcus Species from a Swine Farm in Korea following All-In/All-Out Management

Reduction in Antimicrobial Resistance Prevalence in Escherichia coli and Enterococcus Species from a Swine Farm in Korea following All-In/All-Out Management

Enhancing Swine Husbandry: The IoT-Integrated Hog Feeding Assistant

IoT-Integrated Hog Feeding Assistant revolutionizes swine husbandry, offering hog raisers crucial insights into feed consumption and operational costs, thereby enhancing overall efficiency and comfort. This paper elucidates the system's development process, methodology, and usability assessment. Employing the Rapid Application Development model ensured a swift and flexible creation of the Hog Feeding Assistant, guaranteeing the timely deployment of a fully functional system. Essential data for system design and features were acquired through document analysis and surveys. The system's usability was systematically evaluated using the ISO 25010 software quality standard tool, assessing functional suitability, performance efficiency, compatibility, usability, reliability, security, and maintainability. This comprehensive evaluation provides a profound understanding of the system's capabilities and user-friendliness. The Hog Feeding Assistant with IoT Integration is strongly recommended for hog raisers due to its remarkable efficiency, convenience, and exceptional usability. Seamlessly integrating into daily operations, the system not only streamlines feeding processes but also furnishes valuable insights, empowering more informed decision-making in swine husbandry.

Economic-Financial Analysis of a swine farm in Rosales Chihuahua

Pig cattle are characterized by their high productive capacity and adaptability to different environmental and climatic conditions. The present work was carried out in the Municipality of Rosales, Chihuahua with the purpose of knowing the economic and financial feasibility of an investment project for a small backyard pig farm with six females of the Landrace breed and one male of the Duroc breed. The marketing of pork will be through local butcher shops and chorizo processors in nearby communities. The management of the herd was designed with emphasis on nutrition and health. The results of the economic and financial analysis showed a positive evaluation of the IRR and the NPV, and the benefit-cost relationship was obtained, which also yielded a viable result for its implementation.

Tackling African swine fever in India

Abstract Globally, African swine fever (ASF) is the most feared swine viral disease, associated with a mortality rate of up to 100%. More than half of the world’s swine population is located in Asia. ASF outbreaks in Asia have a significant impact on the global pig industry. Pig industry’s economic losses have been huge because of ASF outbreaks. Swine husbandry in India is in a flourishing phase to meet food security demands, but the losses associated with ASF greatly hamper its expansion. ASF in India can be controlled and eradicated through strict biosecurity measures and vaccination. Development of penside point-of-care (POC) rapid diagnostics and effective indigenous vaccines are prerequisites to tackle ASF in India. Sensitization of veterinary professionals, researchers, and pig farmers about disease pathogenesis, transmission, and impact are crucial part of ASF control. This review presents the status of ASF in India in comparison to other parts of the world, and current approaches in India to deal with ASF. Further roadmap to combat this calamitous swine infection in India.

Identification of sulfamethazine degraders in swine farm-impacted river and farmland: A comparative study of aerobic and anaerobic environments

Sulfonamides (SAs) are extensively used antibiotics in the prevention and treatment of animal diseases, leading to significant SAs pollution in surrounding environments. Microbial degradation has been proposed as a crucial mechanism for removing SAs, but the taxonomic identification of microbial functional guilds responsible for SAs degradation in nature remain largely unexplored. Here, we employed 13C-sulfamethazine (SMZ)-based DNA-stable isotope probing (SIP) and metagenomic sequencing to investigate SMZ degraders in three distinct swine farm wastewater-receiving environments within an agricultural ecosystem. These environments include the aerobic riparian wetland soil, agricultural soil, and anaerobic river sediment. SMZ mineralization activities exhibited significant variation, with the highest rate observed in aerobic riparian wetland soil. SMZ had a substantial impact on the microbial community compositions across all samples. DNA-SIP analysis demonstrated that Thiobacillus, Auicella, Sphingomonas, and Rhodobacter were dominant active SMZ degraders in the wetland soil, whereas Ellin6067, Ilumatobacter, Dongia, and Steroidobacter predominated in the agricultural soil. The genus MND1 and family Vicinamibacteraceae were identified as SMZ degrader in both soils. In contrast, anaerobic SMZ degradation in the river sediment was mainly performed by genera Microvirga, Flavobacterium, Dechlorobacter, Atopostipes, and families Nocardioidaceae, Micrococcaceae, Anaerolineaceae. Metagenomic analysis of 13C-DNA identified key SAs degradation genes (sadA and sadC), and various of dioxygenases, and aromatic hydrocarbon degradation-related functional genes, indicating their involvement in degradation of SMZ and its intermediate products. These findings highlight the variations of indigenous SAs oxidizers in complex natural habitats and emphasize the consideration of applying these naturally active degraders in future antibiotic bioremediation.

Assessment of a Novel Real-Time Bio-Liquor Circulation System for Manure Management and Mitigation of Odor Potential in Swine Farming.

Recently, circulating biologically treated manure in slurry pits has been used as an odor reduction technology, but few successful results have been reported, due to the lack of proper control strategies for bioreactors. This study was conducted to investigate the performance of the developed real-time controlled bio-liquor circulation system (BCS) at farm scale. The BCS was operated sequentially as per swine manure inflow (anoxic, aerobic, and settling) circulation to the slurry pit. Each operational phase was self-adjusted in real-time using a novel algorithm for detecting the control point on the oxidation reduction potential (ORP) and pH (mV)-time profiles, the nitrogen break point (NBP), and the nitrate knee point (NKP) in the aerobic and anoxic phases, respectively. The NH4-N in the slurry manure was thoroughly removed (100%) in the bioreactor, optimizing the duration of each operational phase by accurately detecting real-time control points. The newly developed real-time BCS decreased the nitrogen and organic matter in the slurry pit by >70%, and the potential ammonia and methane emissions by 75% and 95%, respectively. This study highlights that improved BCS that utilizes ORP tracking and pH (mV)-time profiles can effectively optimize BCS operation, and thereby reduce malodor and GHG emissions from swine farms.

Molecular Characterization of Porcine Epidemic Diarrhea Virus from Field Samples in South Korea.

Porcine epidemic diarrhea virus (PEDV) is a highly contagious enteric pathogen of swine. PEDV has been a major problem in the pig industry since its first identification in 1992. The aim of this study was to investigate the diversity, molecular characteristics, and phylogenetic relationships of PEDVs in field samples from Korea. Six PEDVs were identified from the field samples, and the full spike (S) glycoprotein gene sequences were analyzed. A phylogenetic analysis of the S gene sequences from the six isolates revealed that they were clustered into the G2b subgroup with genetic distance. The genetic identity of the nucleotide sequences and deduced amino acid sequences of the S genes of those isolates was 97.9-100% and 97.4-100%, respectively. A BLAST search for new PEDVs revealed an identity greater than 99.5% compared to the highest similarity of two different Korean strains. The CO-26K equivalent (COE) epitope had a 521H→Y/Q amino acid substitution compared to the subgroup G2b reference strain (KNU-1305). The CNU-22S11 had 28 amino acid substitutions compared to the KNU-1305 strain, which included two newly identified amino acid substitutions: 562S→F and 763P→L in the COE and SS6 epitopes, respectively. Furthermore, the addition and loss of N-linked glycosylation were observed in the CNU-22S11. The results suggest that various strains of PEDV are prevalent and undergoing evolution at swine farms in South Korea and can affect receptor specificity, virus pathogenicity, and host immune system evasion. Overall, this study provides an increased understanding of the prevalence and control of PEDV in South Korea.

Satureja hortensis L. and Calendula officinalis L., Two Romanian Plants, with In Vivo Antiparasitic Potential against Digestive Parasites of Swine.

Internal parasitic diseases of swine constitute a major welfare and health concern in low-input livestock farming. Due to an increase in chemical resistance, phytotherapeutic remedies have become an alternative for the prophylaxis and therapy of digestive parasitosis, albeit few remedies have been subjected to scientific validation. Low-input swine farming in Romania has adopted the traditional use of phytotherapy for controlling pathogens in livestock. The current study aimed to assess the antiparasitic potential of Calendula officinalis and Satureja hortensis against digestive parasites of swine in two low-input farms. The fecal samples were collected from sows, fatteners, and weaners, and were tested using the following coproparasitological methods: centrifugal sedimentation, flotation (Willis, McMaster egg counting technique), Ziehl-Neelsen stain modified by Henricksen, modified Blagg method, and in vitro nematode larvae/protozoan oocyst cultures. Six species of digestive parasites were diagnosed, namely Ascaris suum, Trichuris suis, Oesophagostomum spp., Balantioides coli, Eimeria spp., and Cryptosporidium spp., in various combinations, dependent on the swine category. A dose of 140 mg/kg bw/day of C. officinalis and 100 mg/kg bw/day of S. hortensis powders administered for 10 consecutive days revealed a strong antiprotozoal and anthelmintic activity on the aforementioned parasites. The curative efficacy can be attributed to the presence of polyphenols, sterols, tocopherols, and methoxylated flavones. In conclusion, our results indicate that S. hortensis and C. officinalis are promising alternatives to the commercially available antiparasitics, enabling their use as natural antiparasitic products against gastrointestinal parasites in pigs.

Environmental macroscopic analysis of shallow wells containing water for human consumption in rural properties in Brazil

Water is an essential natural resource for maintaining life and its quality is influenced by the land use and occupation within a watershed. Furthermore, water quality has a direct impact on the health and well-being of a population. The present study aimed to carry out a macroscopic environmental analysis in shallow wells found in rural properties distributed in the states of Rio Grande do Sul and Santa Catarina, including the Uruguay River Basin. The evaluation period of the macroscopic parameters took place in April 2021. The physical characteristics of the water and the state of preservation of the shallow wells and their surroundings were visually evaluated in rural properties with predominant land use and occupation through dairy production, swine farming activity and seasonal crops (agricultural crops). As results obtained for the environmental macroscopic analysis, through the weighting of the characteristics observed in each parameter about the state of preservation of the shallow wells, it was verified that they presented different classifications, ranging from the Very Good class to the Poor, being possible to identify the main sources that cause negative impacts on the evaluated locations (state of vegetation, use by animals, protection of the area and proximity to residences). Therefore, rural producers were advised to carry out protection and care measures around these wells that presented lower classifications, Fair (38,10%) and Poor (19,09%) to improve the conditions and aspects that directly influence the quality of water for human consumption.

Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Feces and Wastewater Treatment System in Swine Farms, Thailand

The antimicrobial resistance (AMR) problem is one that demands urgent interventions to minimize the rapid spread in humans, animals and the environment. Extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) could spread from livestock farms to environment or circulate in farms via wastewater. This study aimed to quantify and characterize ESBL-Ec in swine feces and wastewater samples collected from 2 conventional swine farms with wastewater treatment systems. Microbiological analysis was performed on fecal and wastewater samples, and the concentration of cefotaxime (CTX)-resistant bacteria, indicative of ESBL-Ec, was determined across different stages of wastewater treatment. Additionally, ESBL-Ec was isolated and identified from fresh feces, swine house wastewater, and treated wastewater from covered lagoons and photosynthetic ponds. Results indicated a higher concentration of CTX-resistant bacteria in the wastewater in the early process of wastewater treatment. However, CTX-resistant bacteria were not detected in the final photosynthetic pond in one of the 2 farms. ESBL-Ec was identified in fresh feces from swine houses and wastewater treatment plants in both farms. Further antimicrobial susceptibility testing revealed diverse resistance patterns among the ESBL-Ec isolates, with tetracycline and gentamicin demonstrated the highest resistance rates. The ESBL genes identified belonged to the CTX-M-14, CTX-M-17 and CTX-M-55. This study demonstrated the presence of ESBL-Ec in swine feces and wastewater, emphasizing the importance of effective wastewater treatment before discharging to limit the spread of AMR bacteria. HIGHLIGHTS ESBL producers was isolated from fecal and wastewater samples from swine farms The wastewater treatment system could reduce cefotaxime-resistant bacteria CTX-M-14, CTX-M-17 and CTX-M-55 genes were detected in swine farms, Thailand GRAPHICAL ABSTRACT

Epidemiological investigation, determination of related factors, and spatial-temporal cluster analysis of wild type pseudorabies virus seroprevalence in China during 2022.

Pseudorabies virus (PRV) is a linear DNA virus with a double-stranded structure, capable of infecting a diverse array of animal species, including humans. This study sought to ascertain the seroprevalence of Pseudorabies Virus (PRV) in China by conducting a comprehensive collection of blood samples from 16 provinces over the course of 2022. The presence of PRV gE antibodies was detected through the utilization of an enzyme-linked immunosorbent assay (ELISA) technique. Logistic regression analysis was conducted to identify potential related factors associated with the serologic status of PRV gE at the animal level. Additionally, the SaTScan 10.1 software was used to analyze the spatial and temporal clusters of PRV gE seroprevalence. A comprehensive collection of 161,880 samples was conducted, encompassing 556 swine farms throughout the country. The analysis revealed that the seroprevalence of PRV gE antibodies was 12.36% (95% confidence interval [CI], 12.20% to 12.52%) at the individual animal level. However, at the swine farm level, the seroprevalence was considerably higher, reaching 46.22% (95% CI, 42.08% to 50.37%). Related factors for PRV infection at the farm level included the geographic distribution of farms and seasonal variables. Moreover, five distinct high seroprevalence clusters of PRV gE were identified across China, with the peak prevalence observed during the months of April through June 2022. Our findings serve as a valuable addition to existing research on the seroprevalence, related factors, and temporal clustering of PRV gE in China. Furthermore, our study provides a reference point for the development of effective strategies for the prevention and control of pseudorabies and wild virus outbreaks.

Epidemiology and genetic diversity of Streptococcus suis in smallhold swine farms in the Philippines

This study aimed to determine the presence and characteristics of locally circulating strains of Streptococcus suis, the most important streptococcal pathogen in swine. Oral swab samples were collected from pigs from 664 representative smallhold farms across nine provinces in the Philippines. Isolates were identified and characterized using PCR assays. The study revealed an isolation rate of 15.8% (105/664, 95% CI: 13.0–18.6) among the sampled farms. Two hundred sixty-nine (269) S. suis isolates were recovered from 119 unique samples. Serotype 31 was the most prevalent (50/269, 95% CI: 13.9–23.2) among the other serotypes identified: 5, 6, 8, 9, 10, 11, 15, 16, 17, 21, 27, 28, and 29. The detection of the three ‘classical’ S. suis virulence-associated genes showed that 90.7% (244/269, 95% CI: 87.2–94.2) were mrp-/epf-/sly-. Multilocus sequence typing (MLST) analysis further revealed 70 novel sequence types (STs). Notably, several local isolates belonging to these novel STs formed clonal complexes (CC) with S. suis strains recovered from Spain and USA, which are major pork-exporting countries to the Philippines. This study functionally marks the national baseline knowledge of S. suis in Philippines.

Characterization of the family economy of the La Hermosa farm in the village of La Libertad in Florencia - Caquetá

The peasant family economy in the La Hermosa farm, located in the La Libertad hamlet of Florencia, Caquetá, faces significant challenges due to the disarticulation of the community and the lack of inclusion of plot holders in communal projects. This study analyzes the family economy of the farm, characterized by the multifunctionality of its activities, including swine, poultry and agricultural production. The main economic activity is swine farming, which generates income in the short and medium term, allowing for continuous production cycles. Poultry production, divided between egg and chicken production, contributes additional income, while bread crops are essential for family nutrition and food sovereignty. The peasant economy on the farm is characterized by the active participation of family labor and its articulation with local markets. However, marketing faces obstacles such as the poor condition of tertiary roads and increased transportation costs. Short marketing circuits allow a direct relationship between producers and consumers, favoring the sale of fresh and organic products. This work highlights the importance of implementing agroecological practices and sustainable production systems that preserve biodiversity and contribute to food security and sovereignty. It also emphasizes the need for policies that strengthen the peasant family economy, guaranteeing its economic viability and its capacity to adapt to environmental changes. The research also underlines the relevance of community participation and the integration of producers in local development projects to improve the living conditions of peasant families.

Mitigating the Environmental Impacts from Pig and Broiler Chicken Productions: Case Study on a Citrus Extract Feed Additive

The rapid expansion of the livestock production sector to meet the world population’s demand is posing a big challenge to environmental sustainability. Plant-based feed additives extracted from agro-food byproducts could potentially result in multiple outcomes: reducing food-processing wastes and improving animal growth performances, hence mitigating environmental impacts of meat production chains. This presented study was carried out to assess the environmental impacts of the use of a commercial citrus extract feed additive (CEFA) in swine and broiler chicken farming. Life-cycle assessment (LCA) was applied to assess the impact of manufacturing and distributing one 25 kg bag of CEFA and its use in feed in broiler chicken and swine productions. With regards to CEFA manufacturing and distribution, results showed that most of the impact came from the production of CEFA ingredients, accounting for 70% of the impact generated. The remaining 30% effect was divided between transportation to the customer (25%), CEFA packaging (3%), and CEFA manufacturing and production loss (2%). When enlarging the scope, the use of the CEFA in pigs and broilers’ diets was shown to improve the measured environmental indicators, compared to such standard systems. Indeed, CEFA-added feeds have demonstrated enhanced growth performances, hence reducing the required amount of consumed feed to achieve the same level of growth. Consequently, this helped reduce environmental issues from animal feed ingredients’ agriculture. To be more specific, the use of one 25 kg bag of CEFA in feed at 250 g per ton of feed led to a reduction of 6 tons of CO2 equivalent (CO2 eq) emitted along the life cycle of poultry production and 5 tons in the case of fattening pigs. The inclusion of this CEFA in the diet also led to a reduction in the land use footprint by 0.7 hectares and reductions in water consumption by 201 m3 and 82 m3 for broiler chicken and swine production, respectively. The environmental performance assessment thus showed the interest in using this CEFA in swine and broiler chicken diets to mitigate the environmental impacts.

Swine farming shifted the gut antibiotic resistome of local people

Antibiotic resistance genes (ARGs) are prevalent in the livestock environment, but little is known about impacts of animal farming on the gut antibiotic resistome of local people. Here we conducted metagenomic sequencing to investigate gut microbiome and resistome of residents in a swine farming village as well as environmental relevance by comparing with a nearby non-farming village. Results showed a shift of gut microbiome towards unhealthy status in the residents of swine farming village, with an increased abundance and diversity in pathogens and ARGs. The resistome composition in human guts was more similar with that in swine feces and air than that in soil and water. Mobile gene elements were closely associated with the prevalence of gut resistome. Some plasmid-borne ARGs were colocalized in similar genetic contexts in gut and environmental samples. Metagenomic binning obtained 47 ARGs-carrying families in human guts, and therein Enterobacteriaceae posed the highest threats in antibiotic resistance and virulence. Several ARGs-carrying families were shared by gut and environmental samples (mainly in swine feces and air), and the ARGs were evolutionarily conservative within genera. The findings highlight that swine farming can shape gut resistome of local people with close linkage to farm environmental exposures.

Molecular epidemiology, phenotypic and genomic characterization of antibiotic-resistant enterococcal isolates from diverse farm animals in Xinjiang, China

Multidrug-resistant (MDR) bacteria in farm environments can be transferred to humans through the food chain and occupational exposure. Enterococcus infections caused by linezolid resistant enterococci (LRE) are becoming more challenging to treat as their resistance to antibiotics intensifies. Therefore, this study investigated the molecular epidemiology, phenotypic and genomic characterization of enterococci in seven species of farm animals (sheep, chicken, swine, camel, cattle, equine, pigeon) anal swab from Xinjiang, China by agar dilution method, polymerase chain reaction (PCR), whole-genome sequencing (WGS) and bioinformatics analysis. A total of 771 samples were collected, 599 (78 %) were contaminated with Enterococcus spp., among which Enterococcus faecalis (350/599) was dominant. Antimicrobial susceptibility testing showed that high resistance was observed in rifampicin (80 %), tetracycline (71 %), doxycycline (71 %), and erythromycin (69 %). The results of PCR showed the highest prevalent antibiotic resistance genes (ARGs) were aac(6′)-aph(2″) (85 %), followed by tet(M) (73 %), erm(B) (62 %), and aph(3′)-IIIa (61 %). Besides, 29 optrA-carrying E. faecalis isolates belonging to 13 STs (including 3 new alleles) were detected, with ST714 (31 %, 9/29) being the dominant ST type. The phylogenetic tree showed that optrA-carrying E. faecalis prevalent in the intensive swine farm is mainly caused by clonal transmission. Notably, optrA gene in Enterococcus spp. isolate from camel was first characterized here. WGS of E. faecalis F109 isolate from camel confirmed the colocalization of optrA with other five ARGs in the same plasmid (pAFL-109F). The optrA-harboring genetic context is IS1216E-fexA-optrA-erm(A)-IS1216E. This study highlights the prevalence of MDR Enterococcus (≥88 %) and four ARGs (≥75 %) in swine (intensive farming), cattle (commercial farming), and chickens (backyard farming) are high and also highlights that optrA-carrying E. faecalis of farm animals incur a transmission risk to humans through environment, food consumption and others. Therefore, antibiotic-resistant bacteria (ARB) monitoring and effective control measures should be strengthened and implemented in diverse animals.

Market prospects for biogas-to-energy projects in the U.S.A. based on a techno-economic assessment of major biogas sources in North Carolina

Current market potential for biogas-to-energy projects in the United States is analyzed based on levelized cost of energy (LCOE) estimates for producing renewable electricity, compressed natural gas (bio-CNG) and renewable natural gas at 2,837 landfills, wastewater treatment plants and swine farms in North Carolina having biogas resource potentials of 13 m3/d to > 380,000 m3/d. The LCOE estimates are generated using new approaches for modeling biogas collection from multiple sources via physical pipeline networks or tanker truck transport (a.k.a. “virtual” pipelines) in combination with recent production and cost functions published elsewhere. Whereas the LCOE estimates end up being significantly higher than 2022–23 prices for electricity and natural gas in regional U.S. energy markets, bio-CNG projects collecting > 100 MMBtu/d (1 MMBtu ∼ 1 GJ) of biomethane yield LCOEs on par with recent prices for CNG for transportation of $26–$51/MMBtu. When incentives available through federal and certain state government programs are considered, sites in pipeline networks or in virtual pipelines with biomethane collection rates as low as 45 MMBtu/d could become economically viable. The results of this study help quantify the potential for monetizing an underutilized energy resource in the U.S. that can contribute to decarbonizing the nation’s energy production.

Molecular-level insights into the transformation and degradation pathways of dissolved organic matter during full-scale swine wastewater treatment

The rapid development of swine farming has resulted in the generation of a large amount of swine wastewater (SW), and dissolved organic matter (DOM) has a crucial role in determining the efficiency and safety of SW treatment. In this study, the transformation and influential mechanisms of DOM on the quality of SW effluent during full-scale SW treatment in actual engineering were systematically investigated using multispectral analysis and the Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) technique. The results showed that S-containing, reduced, saturated, and less aromatic molecules were preferentially removed in the C-AF, while C-S preferentially removed reduced, unsaturated, and aromatic molecules, as well as molecules with large molecular weights. And in the two-stage A/O, the degradation of organic matter and DOM transformation occurred mainly in the A/O-1, with the A/O-2 acting as a supplement to further enhance the humification of DOM. Furthermore, the AOP preferentially removed lignin-like and highly unsaturated compounds, replacing them with a new generation of substances such as proteins and tannins with low aromaticity and unsaturation. More deeply, oxygen addition reactions dominate in both A/O and AOP. Specifically, the most common types of reactions in the A/O were the corresponding potential precursor-product pairs based on methyl to carboxylic acid (-H2 + O2) and alcohol to carboxylic acid (-H2 + O), while tri-hydroxylation (+O3) and di-hydroxylation (+H2O2) reactions were predominant in the AOP. Finally, the study's findings might suggest improving the actual engineering by prioritizing the AOP before the A/O-2 and using the C-S for safeguard treatment of the A/O-2 effluent. It is reliable that this kind of adjustment guarantees safe drainage indications and raises each process unit's efficiency in purifying.

Comparison of deep-litter bedding materials and analysis of semen traits in Piétrain boars: A randomized controlled field study

External factors can affect reproductive traits of breeding boars and especially the sensitive process of spermatogenesis. The aim of this study was to investigate probable influences of bedding materials (chipsy wood shavings (CWS), hemp straw (HS), linen straw (LS), spelt husks (SH), and regional wood shavings (RWS)) on semen traits of 40 randomly selected Piétrain boars (8 boars per group, age: 2.35 ± 1.23 years). After a six-week adaptation period, 40 fresh semen samples were collected weekly for four weeks and diluted in BTS (4 consecutive ejaculates per boar, 32 samples per group, 160 samples in total). Semen samples were analyzed using an extended range of spermatological methods (e.g., computer-assisted sperm analysis and flow cytometry). Generalized linear mixed models for each sperm parameter as well as the area under the curve for total sperm motility and thermo-resistance test were calculated. Materials LS and SH exceeded the standard maximum level for pesticide residues (VO (EG) No. 396/2005). Materials HS and LS presented the highest water-binding capacity of 413 % and 357 %, respectively, while SH showed the lowest value of 250 %. There were no significant (P > 0.05) differences between groups in any sperm characteristic, therefore indicating that bedding material had no influence on sperm quality. For most semen traits, however, we found significant (P ≤ 0.001) differences between sampling weeks. Based on pesticide results, we suggest CWS, RWS, or HS as possible bedding materials for pig production farms in the future. Furthermore, we strongly recommend a quality analysis of any new bedding material before use in swine husbandry.

A Longitudinal Study of NADC34-Like Strains in an Intensive Farm Unravels Divergent Evolution

NADC34-like porcine reproductive and respiratory virus (PRRSV) has had a significant impact on the pig industry, particularly in China. However, the evolutionary characteristics and pathogenicity of NADC34-like PRRSV strains within intensive farming systems are not well understood, particularly regarding the biological characteristic variation of successive outbreaks on a farm. In this study, we conducted continuous surveillance in an intensive farm that experienced a PRRSV outbreak. Two PRRSV strains, GDHZ109/2020 and GDYS162/2022, were isolated and fully sequenced from the same swine farm in Guangdong Province in 2020 and 2022, respectively. Evolutionary analysis based on the ORF5 gene revealed that both strains clustered with NADC34-like strains and shared 96.5% homology. Analysis of the full-length genome and NSP2 gene classified the strains into lineage 1.8, represented by the NADC30 strain. Recombination analysis suggested complex recombination patterns for both strains, involving NADC30-like, NADC34-like, and JXA1-like strains. Although many recombinant regions were nearly identical, there were differences observed in the NSP5–NSP7 region. Pathogenicity experiments conducted on piglets demonstrated that GDHZ109/2020 exhibited higher pathogenicity compared to GDYS162/2022. Piglets in the GDHZ109/2020 infected group had more severe clinical signs and higher mortality. Moreover, analysis of respiratory microbial diversity indicated a significant increase in the abundance of potentially pathogenic microbiota, such as Klebsiella and Erysipelothrix contributing to the respiratory tract of PRRSV-infected piglets, suggesting secondary infections due to differences in immune defense. These findings highlight the importance of NADC34-like recombinant strains’ evolution during the farm’s epidemic period, which may have contributed to changes in pathogenicity. This study improves our understanding of the current prevalence of PRRSV and provides novel insights into the prevention and control of PRRSV.