Search Results (1,512)

Respiratory diseases and welfare impairments impose substantial economic and ethical burdens on modern broiler production, driven by high stocking density, rapid pathogen transmission, and limited sensitivity of conventional monitoring methods. Because respiratory pathology and stress directly alter vocal behavior, acoustic monitoring has emerged as a promising non-invasive approach for continuous flock-level surveillance. This review synthesizes recent advances in audio classification and artificial intelligence for monitoring respiratory health and welfare in broiler chickens. We have reviewed the anatomical basis of sound production, characterized key vocal categories relevant to health and welfare, and summarized recording strategies, datasets, acoustic features, machine-learning and deep-learning models, and evaluation metrics used in poultry sound analysis. Evidence from experimental and commercial settings demonstrates that AI-based acoustic systems can detect respiratory sounds, stress, and welfare changes with high accuracy, often enabling earlier intervention than traditional methods. Finally, we discuss current limitations, including background noise, data imbalance, limited multi-farm validation, and challenges in interpretability and deployment, and outline future directions for scalable, robust, and practical sound-based monitoring systems in broiler production. Full article

Captive bird populations in zoological institutions face unique disease risks due to close interspecies contact and human interaction. Vaccination is widely used as a prophylactic measure. However, most available vaccines are developed for poultry and are used off-label in non-domesticated birds, often without species-specific safety and efficacy data. This review provides a comprehensive overview of vaccines reported in zoo-housed birds for major viral, bacterial, and fungal pathogens. This review highlights that for most vaccines, evidence of safety and effectiveness is limited. Vaccine use should therefore be guided by risk assessment, relevant legislation, and institutional priorities, and should integrate species-specific data on vaccine safety and effectiveness, disease susceptibility, and local epidemiology. Extensive research and species-specific validation are essential to improve preventive health strategies in avian conservation programs. Full article

The global poultry industry continues to face significant challenges due to Salmonella infections, which pose severe public health concerns and economic losses. Recently, the reemergence of antimicrobial resistance has led to the restriction of antibiotic use in poultry, especially as growth promoters, thus accelerating the search for sustainable alternatives. Among these, probiotics have gained attention as potential candidates for improving poultry health and mitigating Salmonella colonization in the gut. This review summarizes the key mechanisms through which probiotics exert anti-Salmonella effects, including competitive exclusion, production of antimicrobial substances, reinforcement of the intestinal barrier, and modulation of host immune responses. Commonly used probiotic strains in poultry such as Lactobacillus and Bacillus are discussed, alongside emerging candidates derived from non-poultry hosts that may offer additional functional benefits. Despite encouraging findings, the use of probiotics in poultry faces several challenges, including strain-specific efficacy, variation in results across studies, environmental influences, and regulatory limitations. Therefore, we further explore future directions that are aimed at improving probiotic application in poultry production, such as microbiome-guided strain selection, advanced delivery systems, and combination therapies. Advancing our understanding of probiotic-pathogen-host interactions will be essential for optimizing probiotic use to enhance poultry health, reduce zoonotic transmission of Salmonella, and contribute to safer and more sustainable food systems. Full article

Avian influenza (AI) significantly threatens poultry health and causes major economic losses in the poultry industry. Vaccination remains crucial for AI prevention and control. The major protective epitopes of influenza viruses are located on hemagglutinin (HA), a surface glycoprotein essential for viral infection. Most influenza vaccines induce neutralizing antibodies against HA to block viral entry. HA maturation requires the HA0 precursor to be proteolytically cleaved at a conserved site by host proteases to yield HA1 and HA2 subunits. A subsequent acidic condition triggers HA conformational changes, enabling viral–host membrane fusion. However, whether HA conformational variations affect immunogenicity remains unclear. In this study, the cleavage site of the HA gene from an H9N2 avian influenza virus was modified to block the proteolytic cleavage of the HA protein. Our results revealed distinct proteolytic patterns of certain mutants, which exhibited either increased or decreased cleavage efficiencies compared to the wild-type (WT) HA. However, none of the mutants exhibited completely abolished HA0 cleavage. To assess the immunogenicity of these variants, BALB/c mice were immunized with DNA vaccines expressing either WT or mutant HA proteins. Strikingly, the mutant HA protein with a 19-amino-acid deletion Dlt5 (P6~P1, P1’~P′13) at the cleavage site exhibited reduced cleavage efficiency and induced significantly higher HI antibody titers compared to the WT. These results offer valuable perspectives for enhancing avian influenza vaccine efficacy through strategic modification of HA cleavage properties. Full article

Although particulate matter (PM) is strongly associated with allergic reactions, the potential risk of the ability of PM derived from poultry houses to induce allergic reactions remains unclear. This study investigated the effects of duck housing PM on allergic reactions in mice. PM samples and fungi were collected from a duck farm. Ovalbumin (OVA) was used as a positive control, with ambient-level concentrations of PM, high-concentration PM (HPM), and fungal experimental groups. Aerosol exposure was performed on the mice. Serum IgE, allergic mediators (histamines and leukotrienes), cytokines, and pulmonary histopathology were analyzed. Furthermore, HPM-induced metabolic profiles in bronchoalveolar lavage fluid were measured. The results revealed that all the treatment groups of mice presented allergic symptoms, including sneezing and coughing; higher concentrations of IgE, His, and LTs in the serum; upregulation of allergic reaction-related cytokines, such as IL4, IL5, and IL33; and microscopic lesions of the lungs characterized by inflammatory cell infiltration were observed in all the treatment groups, indicating that PM and fungi can cause allergic reactions. Notably, allergic reactions were more pronounced in the HPM and fungal groups than in the PM group. In addition, metabolomics analyses revealed that HPM exposure caused metabolic disorders in mouse lungs. The key pathway with the highest correlation to metabolite differences was pyrimidine metabolism, which is associated with allergic reactions. In conclusion, this study demonstrated that exposure to PM in duck houses can cause allergic reactions in mice and significant metabolomic changes in the lungs, especially HPM. Moreover, the contribution of fungal components in the PM cannot be ignored. These findings highlight the potential health risks associated with PM from the poultry industry. Full article

Airborne organic dust has rarely been subject to immunotoxicological analysis. A pilot study was undertaken to link exposure metrics (respirable crystalline silica (RCS), bacteria, fungi, endotoxins (END), peptidoglycans (PGN), (1 → 3)-β-D-glucans (GLU)) with in vitro cytotoxicity and cytokine responses based on analysis of airborne organic dust samples collected during a single work shift at six different facilities. The A549 and BEAS-2B cell lines were used to assess cytotoxicity and proinflammatory cytokine release. The general linear model (GLM) and taxonomic linear ordering were used to identify key determinants and rank facilities by the hazard level they pose. The highest cytotoxicity of organic dust was observed at the sewage treatment plant, while the lowest was at the poultry farm. The most hazardous agents present in organic dust included RCS, aerobic bacteria, fungi, PGN, and GLU. They significantly affected cytokine release, particularly of IL-6 and IL-8. The use of a synthetic measure showed that inhalable organic dust from the composting plant presented the highest potential to induce adverse effects on human health, while the lowest one was characterized by the biomass-fired power plant samples. The open-ended statistical method can significantly increase awareness of occupational hazards and promote more responsible protection for exposed workers. Full article

Extended-spectrum β-lactamase-producing E. coli (ESBL-EC) threatens public health by driving widespread antimicrobial resistance transmission in environmental and agricultural settings. This study examined the prevalence, genetic determinants, and phylogenetic relationships of ESBL-EC isolated from municipal wastewater treatment plants (WWTPs) and farm environments in southeastern North Carolina. A cross-sectional survey was conducted between May and September 2025 across two WWTPs and two farms (cattle and poultry). We sampled influent and effluent wastewater, plus fecal and water specimens collected from chickens, ducks, and cattle. Antimicrobial susceptibility testing was performed using the Kirby–Bauer disk diffusion method against nine drugs, while PCR and sequencing were used for genotypic characterization. Phylogenetic analysis assessed genetic relatedness among isolates. ESBL-EC was detected in 27.4% (n = 124) of 452 samples, with the highest prevalence in chickens (31.5%), followed by WWTP influents (28.2%), ducks (18.5%), and cattle (12.1%). Dominant resistance genes included blaCMY-2 (71.8%), blaCTX-M-1 and blaOXA (54% each), and blaSHV (29.8%). Co-occurrence of blaCMY-2 with blaCTX-M-1 and blaOXA was observed in poultry isolates. Phylogenetic analysis revealed clonal relatedness between poultry and cattle isolates. These findings highlight poultry as a key reservoir and emphasize the need for One Health surveillance to mitigate cross-reservoir transmission of resistant E. coli. Full article

Food supply veterinarians, those who service the dairy, swine, poultry, small ruminant, and beef cattle industries, benefit society by protecting animal and public health and ensuring a safe, wholesome food supply. However, there are not enough entering the workforce to meet current and future demands. Non-formal learning environments can be used as a recruitment tool to provide participants with positive interactions and hands-on experiences. To build awareness of food supply veterinary medicine (FSVM) in youth, we developed an immersion program designed to provide high school students with hands-on experiences with food animal species. Day camps were held during the summers of 2022 and 2023, each coordinated with multiple partners at different locations in central Ohio. Year One camp utilized registration and post-test surveys and Year Two utilized matching pre- and post-test for analysis. Over the two programs, 110 participants engaged in hands-on experiences, including: outbreak investigations, measuring clinical parameters, performing diagnostics, and basic veterinarian procedures. Pre- and post-test evaluations were performed to measure changes in participants’ attitudes and perceptions, and a McNemars test was used to evaluate Year Two data. In Year One, we saw positive shifts in those interested in FSVM careers. In Year Two, we saw positive shifts in knowledge of FVSM careers, with biosecurity knowledge increasing. Outreach activities like day camps can be replicated in other locations to increase interest in FSVM careers. Full article

Fungal bioaerosols play a critical ecological and health role in intensive poultry production systems. However, their dynamic characteristics and community succession patterns in confined cage environments during winter remain poorly understood. This study investigated a typical confined broiler house in Hebei Province, China, during winter. A combined approach of Andersen six-stage sampling, colony counting, and Internal Transcribed Spacer (ITS) high-throughput sequencing was employed to comprehensively analyze the concentration, particle size distribution, diversity, and community composition of fungal bioaerosols across three key growth stages: 7 days (brooding phase), 21 days (growing phase), and 35 days (finishing phase). The results revealed a significant increasing trend in fungal aerosol concentration as the rearing cycle progressed, increasing from 1125 ± 125 CFU/m³ at day 7 to 3872 ± 565 CFU/m³ at day 35 (p < 0.001), reaching high-risk exposure levels in the later stages. Small-sized fungal bioaerosols (<4.7 μm) were dominant across all stages (54.35–65.50%), with the highest proportion observed at day 21, indicating their potential for deep respiratory deposition and long-distance airborne transmission. The number of Operational Taxonomic Units (OTUs), along with Chao1 and Shannon indices, increased significantly with bird age (p < 0.001), demonstrating a clear community succession from early-stage yeast-dominated forms (e.g., Diutina, Blumeria) to mid- and late-stage assemblages dominated by filamentous fungi (e.g., Aspergillus, Cladosporium, Alternaria). Notably, several zoonotic pathogenic genera were detected throughout all rearing stages, highlighting the potential risks of airborne fungi to animal health, occupational exposure, and environmental safety under winter ventilation restrictions. This study characterizes a stage-dependent pattern of increasing airborne fungal concentrations accompanied by shifts in particle size distribution and community composition under winter confined conditions. The findings provide a crucial scientific basis for optimizing winter ventilation and environmental management strategies, improving environmental control technologies, establishing airborne biosafety standards, and developing targeted fungal monitoring and prevention technologies. Full article

Background: Vancomycin is a critically important antimicrobial in human medicine, and vancomycin-non-susceptible enterococci represent a One Health concern when animal reservoirs contribute to the wider resistance ecology. We aimed to characterize vancomycin non-susceptibility among poultry-derived Enterococcus spp. from Hungary, using a combined phenotypic–genomic approach. Methods: Following a phenotypic pre-screen with antimicrobials authorized for poultry, 218 isolates with elevated minimum inhibitory concentrations (MICs) were selected for extended broth microdilution testing including vancomycin. Vancomycin susceptibility was interpreted using Clinical and Laboratory Standards Institute (CLSI) clinical breakpoints and European Committee on Antimicrobial Susceptibility Testing (EUCAST) epidemiological cut-off values (ECOFFs). Whole-genome sequencing was performed on a targeted multidrug resistant (MDR) subset (n = 42), enriched for elevated or borderline vancomycin MICs and stratified by region and host species (chicken, turkey), and resistance determinants were annotated against the Comprehensive Antibiotic Resistance Database (CARD) using stringent similarity/coverage thresholds. Results: Among the 218 pre-screened isolates (126 from chickens; 92 from turkeys), 196 (89.9%) met MDR criteria. For vancomycin, 15.6% of isolates were resistant and 9.2% intermediate by CLSI, while EUCAST ECOFF classification placed 34.9% in the non-wild-type group. The vancomycin MIC distribution was right shifted, with high-end MICs observed. In the sequenced subset, vancomycin-associated determinants consistent with the vanC pathway (including regulatory and auxiliary components) were detected in five isolates. Beyond vancomycin-related determinants, the WGS subset harbored common resistance genes consistent with the observed multidrug-resistant phenotypes. Conclusions: Vancomycin non-susceptibility was detected among pre-screened poultry-derived Enterococcus isolates in Hungary, and genomic analysis revealed vanC-associated and other peptide antibiotic resistance signatures. These findings support targeted One Health surveillance integrating MIC distributions with genomic resistance determinants in food animal reservoirs. Full article

Salmonellosis remains a persistent threat to global food safety and poultry productivity, compounded by rising antimicrobial resistance. Here, we report the in silico design and immunoinformatic validation of a broad-spectrum, edible multi-epitope vaccine targeting conserved adhesion and biofilm-associated proteins (FimH, AgfA, SefA, SefD, and MrkD) of Salmonella spp. Two constructs were engineered by integrating cytotoxic (CTL) and helper (HTL) epitopes with β-defensin-3 (HBD-3) or lipopolysaccharide (LPS) adjuvants, optimized for expression in Chlorella vulgaris. Structural modeling confirmed native-like folding (z-scores −2.58 and −5.22) and high stability indices. Molecular docking and dynamics revealed that the LPS-adjuvanted construct (Construct 2) forms a highly stable complex with Toll-like receptor 3 (HADDOCK score −63.4; desolvation energy −50.2 kcal/mol), indicating potent innate immune activation. Immune simulations predicted strong IgM-to-IgG class switching and durable humoral responses, consistent with effective antigen clearance. Codon optimization achieved high adaptability for algal expression (CAI = 0.93; GC ≈ 65%), supporting scalable microalgae-based production. Compared with current parenteral vaccines, offering a low-cost, non-invasive way to curb Salmonella in poultry, this edible vaccine platform reduces dependence on antibiotics. Our approach, which combines computational vaccinology with a safe-by-design sustainable biomanufacturing perspective, outlines a One Health framework for advancing antimicrobial stewardship and food safety. Full article

Food-borne diseases affect nearly 10% of the global population annually, with Salmonella being a major cause, particularly impacting children, the elderly, and populations in low- and middle-income countries. This study aimed to assess the prevalence, serotype distribution, antibiotic resistance profiles, and genetic determinants of resistance and virulence of Salmonella enterica in humans and poultry in the Nanoro health district. A community-based cross-sectional study involving humans and poultry was conducted in the Nanoro health district. Fresh stool samples (human and poultry cloacal/cecal) were collected, transported under sterile conditions, and processed within two hours using standard bacteriological methods. Phenotypic antibiotic resistance was determined by the Kirby–Bauer disk diffusion method, and whole-genome sequencing (Illumina) identified serotypes, resistance genes, and virulence factors. Logistic regression analyzed associations between Salmonella carriage and host or environmental factors. Salmonella enterica carriage was detected in 8.7% of humans and 7.2% of poultry. Human isolates showed 24% resistance to cephalosporins, while poultry isolates showed 36.8% resistance. Resistance genes, including fosA7, qnrB19, and a cryptic aminoglycoside resistance gene, and virulence genes encoding T3SS-1 and T3SS-2, were detected in both hosts. Logistic regression indicated that residence in Sitaon and Zimidin was associated with ~70% lower odds of carriage (aOR = 0.3), while individuals aged 11–20 and 51–60 years had 2.8-fold higher odds. Carriage was also 60% higher during the rainy season. These findings suggest possible cross-transmission of Salmonella between humans and poultry and the circulation of resistant, potentially virulent strains in the community. Seasonal and age-related variations highlight environmental and behavioral influences on asymptomatic carriage. Integrated One Health surveillance and targeted hygiene interventions are essential to reduce Salmonella transmission and antimicrobial resistance in rural settings. Full article

Histomonosis, caused by Histomonas meleagridis, leads to economic losses in the poultry and livestock industry. In recent years, studies on the role of intestinal microbiota in host physiological health have attracted growing attention. Understanding the changes in gut bacterial communities of chickens is crucial for improving poultry and livestock production. This study investigated the impact of Histomonas meleagridis infection on the growth performance, overall health, and cecal microbiota composition of chickens. Body weight changes and pathological alterations were assessed at different time points post-infection through animal experiments, with 7 days post-infection defined as the early stage and 14 days as the peak stage of infection. Cecal content samples were collected from the 7-day control group (G1), 7-day infected group (G2), 14-day control group (G3), and 14-day infected group (G4) for 16S rRNA sequencing analysis. The microbial diversity analysis revealed that H. meleagridis infection altered the number of microbial species in the cecal microbiota of chickens. The alpha diversity index was significantly reduced (p < 0.05), and principal coordinate analysis (PCoA) revealed significant structural differences between infected and control groups (p = 0.001). Taxonomic composition analysis showed that beneficial gut bacteria, such as Firmicutes and Lactobacillus spp., decreased in abundance, whereas Bacteroidota, Proteobacteria, Escherichia spp., and Fusobacterium mortiferum were enriched in the infected group. LEfSe analysis indicated that G1 was enriched with Oscillospiraceae and Blautia; G2 with Christensenellaceae; G3 with Verrucomicrobia and Lactobacillus aviarius; and G4 with Proteobacteria and Fusobacteria. In conclusion, H. meleagridis infection markedly altered the cecal microbiota composition by shifting the relative abundances of beneficial and pathogenic bacteria, resulting in reduced microbial diversity. Full article

Poultry production faces considerable challenges in terms of feed costs and sustainability, particularly regarding conventional protein sources such as fish meal (FM). Insect-based proteins, such as housefly larvae (HL) meal, offer sustainable alternatives. Therefore, this study aimed to investigate the effects of HL on growth, gut health, metabolizable energy, and gut microbiota of broilers to clarify the availability of HL meal for broiler diet. Experiment 1 was performed to investigate the effects of replacing FM with HL on growth performance, intestinal morphology, cecal short-chain fatty acids, and gut microbiota composition and diversity in male broilers. Experiment 2 was performed to assess the digestibility of broiler diets containing HL. HL addition effectively maintained growth and improved intestinal morphology. Blood analysis revealed that HL addition reduced TNF-α levels and improved protein utilization. Additionally, HL substitution induced significant changes in the gut microbiota community and metabolic pathways. In conclusion, HL are a viable alternative to FM with adequate energy content and beneficial effects on gut health, supporting their use as a sustainable protein source. Full article

Reproductive performance in livestock and poultry is a core determinant of economic efficiency in the animal industry. While traditional research has primarily focused on genetics, endocrinology, and immune regulation, emerging microbiome studies reveal that commensal microbiota within the gut and reproductive tracts play an underestimated yet pivotal role in host reproductive health. This review systematically synthesizes recent advances regarding the relationship between the microbiome and reproductive functions in major livestock species (cattle, pigs, sheep, and chickens). We first delineate the theoretical basis and mechanisms of the “gut-reproductive axis,” highlighting cross-system communication mediated by microbial metabolites, including short-chain fatty acids (SCFAs), indoles, and bile acids. Subsequently, we provide an in-depth comparative analysis of the microecological features of both female (vagina/uterus) and male (semen/epididymis) reproductive systems, examining their impacts on fertility, sperm quality, and pregnancy outcomes. Furthermore, we explore the molecular and systemic mechanisms governing microbial regulation of reproduction, encompassing the modulation of the hypothalamic-pituitary-gonadal (HPG) axis, the balance of local mucosal immunity and inflammation, and epigenetic regulation. Finally, we address current challenges—such as causal validation and the scarcity of multi-species databases—and propose future directions, including spatial multi-omics, AI-integrated analysis, and microbial intervention strategies. Ultimately, this review aims to offer a theoretical foundation and translational insights for elucidating reproductive regulatory networks and developing microbiome-driven precision strategies to enhance reproductive performance. Full article