Search Results (304)

Avian colibacillosis, caused by Escherichia coli, remains a significant threat to poultry health and production, particularly in the context of rising antimicrobial resistance. Efficient and scalable vaccination strategies are needed to reduce economic losses and reliance on antibiotics. This study investigated the safety and immunogenicity of a novel single-dose in ovo vaccine candidate based on three inactivated E. coli strains formulated with cationic maltodextrin nanoparticles. The vaccine was evaluated in broilers under commercial hatchery conditions. In ovo administration was well tolerated and did not adversely affect hatchability, survival, growth performance, or feed efficiency. Vaccinated birds mounted a measurable serum immunoglobulin Y (IgY) response against E. coli from 14 days post-hatch, which persisted until slaughter age. Furthermore, when co-administered with routinely used live-attenuated viral vaccines, no interference with the immunogenicity of these vaccines was observed. These results demonstrate that the inactivated nanovaccine is safe, immunogenic, and compatible with an industrial-scale in ovo vaccination. The findings support its potential as a practical prophylactic approach to prevent avian colibacillosis in broiler production. Full article

Omega-3 polyunsaturated fatty acids are increasingly applied as functional nutrients to improve broiler health, metabolic resilience, and meat quality. However, studies remain inconsistent regarding optimal inclusion levels and their efficacy. This systematic review was conducted following PRISMA 2020 guidelines. This study included 69 experimental studies that met predefined eligibility criteria, requiring broiler-specific trials with clear reporting of omega-3 source, inclusion level, and measurable outcomes related to growth, immune or antioxidant function, gut morphology, fatty acid composition, or meat quality. Searches were performed in Scopus and Web of Science for peer-reviewed articles published between 2020 and 2025. Across studies, supplementation with fish oil, flaxseed, or algal oil consistently increased the deposition of long-chain omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in broiler tissues. Omega-3 inclusion improved immune modulation, gut morphology, and antioxidant enzyme activity while reducing inflammatory markers and lipid peroxidation. Meat quality benefits included lower n-6:n-3 ratios by improving tenderness and juiciness and enhanced oxidative stability with no detrimental effects on growth performance. Nevertheless, responses varied with broiler strain, dietary formulation, feeding phase, antioxidant protection, and environmental conditions. As high levels of marine oils remained susceptible to oxidative degradation. Overall, omega-3 supplementation represents a viable and scalable precision-nutrition strategy for enriching poultry meat and supporting broiler health. Future research should prioritize cost-effective algal sources, establish phase-specific inclusion thresholds across genetic lines, and evaluate synergy with natural antioxidants and bioactive compounds to optimize oxidative stability, shelf life, and consumer acceptance. Full article

In recent years, outbreaks of inclusion body hepatitis (IBH) have been reported with increasing frequency worldwide. In Austria, the presence of fowl aviadenoviruses (FAdVs) and/or IBH has been documented sporadically. The present report describes a surge of natural IBH cases in fifteen Ross 308 broiler flocks. The clinical picture was characterized by the sudden onset of increased mortality in birds 3 to 15 days of age, persisting for approximately one week, resulting in cumulative flock mortality ranging from 2% to 27%. The main pathological findings were hepatitis with diffuse necrotic foci and petechial hemorrhages with intranuclear inclusion bodies by histology. FAdV was detected in liver samples from all affected flocks. Based upon partial hexon sequence analysis, FAdV serotype-11, species-D (FAdV-11, FAdV-D) was identified, showing complete sequence identity among broiler-derived strains and high identity with previous isolates from Austria and globally IBH-associated isolates. Furthermore, FAdV-11 DNA was detected in dead-in-shell embryos collected during the ongoing outbreak, originating from one suspect broiler breeder flock, confirming vertical transmission. Serological investigations of the suspect breeders confirmed the FAdV-11 infections within the studied timeframe. In conclusion, investigations confirmed vertical transmission of FAdV-11 and subsequent manifestation of IBH in broilers under field conditions, highlighting the epidemiological importance of broiler breeders in IBH outbreaks. Full article

Broiler production efficiency depends on the capacity of different strains to utilize nutrients and minimize environmental losses. This study aimed to quantify the excretion and digestibility of dry matter, nitrogen, and phosphorus in Cobb 500, Ross 308, and Hubbard Flex strains at different ages under Southwest Piauí conditions. A total of 300 broilers of both sexes were distributed in a 3 × 2 factorial design (3 strains × 2 sexes) with five replicates, totaling 30 experimental units. The six-week trial included adaptation periods, excreta collection, and feed intake control each week. Dry matter, nitrogen, and phosphorus were analyzed in diets and excreta to calculate intake, excretion, and retention coefficients (DMR, NR, PR). Interactions between sex and strain were observed after 25 days for some variables. Males excreted 10.21% more phosphorus than females, and strain effects were mainly observed for phosphorus excretion, with Hubbard exhibiting lower excretion in the 32–35-day phase, Cobb presenting the highest, and Ross demonstrating intermediate excretion. Variations between sexes were observed within strains across ages. These results demonstrate that nutrient utilization is influenced by both strain and sex, highlighting the need for tailored nutritional strategies to improve feed efficiency and reduce environmental impact in broiler production. Full article

Infectious bronchitis virus (IBV) is a highly infectious disease of chickens posing a major threat to poultry production worldwide. Due to genetic and antigenic variability, it is difficult to establish one universal protocol for vaccination against IB. The protectotype vaccination strategy, combining antigenically distinct vaccine strains, offers broader cross-protection than homologous IBV vaccination approaches. This field study aimed to establish serological baseline values in broiler chickens in a protectotype vaccination program using Avishield IB H-120 and Avishield IB GI-13, and to evaluate the program’s efficacy under field conditions on commercial farms where heterologous IBV genotypes were detected. The study was conducted on 25 broiler farms in 2023–2024. Day-old chicks were vaccinated via coarse spray. Blood samples were taken from them at six weeks of age and analyzed using IDEXX and BioChek ELISAs, and cecal tonsils were tested by real-time RT-PCR. Production performance was assessed using the European production efficiency factor (EPEF), with a cut-off value of 360. No IB-related clinical signs were reported, and the mean EPEF of the included farms was 408.7. The detected IBV genotypes were Mass + 793B, 793B, and 793B + VAR2. The presence of heterologous VAR2 did not negatively impact flock health or performance. Preliminary serological baseline values for vaccinated, non-VAR2 farms were established at 891–1332 (in chicks tested with the IDEXX ELISA) and 4193–5204 (in those tested with the BioChek assay). The H-120 + GI-13 program demonstrated high field efficacy, reliable serological profiles, and cross-protection in the presence of heterologous IBV. Continuous monitoring of IBV genotypes remains essential. Full article

Maintaining intestinal health is fundamental to immune competence and disease resistance in broiler chickens; however, effective nutritional strategies that enhance gut barrier integrity and systemic health remain under investigation. This study evaluated the effects of a multi-strain probiotic composed of Lactobacillus buchneri, Lactobacillus casei, Lactobacillus fermentum, Lactiplantibacillus plantarum, and Bacillus subtilis on growth performance, meat quality, immune response, antioxidant capacity, and intestinal health in broilers. The research included 144 Ross 308 broilers aged one day, distributed randomly into two diet groups, each containing 6 replicates of 12 birds. During the 42 d trial, the control group (CON) was fed a basal diet composed of corn and soybean meal, with the compound probiotics (CP) diet additionally containing 0.3% compound microbial preparation. Growth performance, meat quality, serum immune and antioxidant indices, intestinal morphology, intestinal barrier-related genes and cecal microbiota were analyzed. Compared with the CON, CP supplementation significantly increased average daily gain, reduced feed conversion ratio, and improved eviscerated and breast muscle yields (p < 0.05). Meat quality was enhanced, as indicated by higher pH_45min, increased redness (a*), and reduced shear force and drip loss in breast muscle (p < 0.05). In addition, CP broilers exhibited improved amino acid and fatty acid profiles in breast muscle (p < 0.05). Serum analysis revealed elevated immunoglobulin G and interleukin-10 levels, reduced pro-inflammatory cytokines, and enhanced antioxidant capacity in the CP group (p < 0.05). Probiotic supplementation significantly improved intestinal morphology and upregulated barrier-related genes such as mucin-1 (MUC-1), claudin-1(CLDN-1), zonula occludens-1 (ZO-1), and occludin (OCLN) (p < 0.05). Moreover, cecal microbiota analysis demonstrated increased abundance of Bacteroidota and enrichment of beneficial genera, including Megamonas, Ruminococcus, and Prevotella (p < 0.05). Overall, dietary supplementation with 0.3% compound probiotics effectively enhanced growth performance, immune function, antioxidant capacity, and intestinal health in broilers. Full article

Background: Avian pathogenic Escherichia coli (APEC) are significant bacterial pathogens that cause economic losses in the poultry industry and can pose a potential foodborne zoonotic risk. Herein, we examined APEC distribution and antimicrobial resistance in E. coli isolated from slaughtered broiler chickens in northern Thailand. Methods: PCR was used to classify APEC as either virulent or avirulent on 108 stored E. coli strains, as well as to perform Clermont phylotyping. Antimicrobial susceptibility to ciprofloxacin, cefotaxime, ceftazidime, imipenem, and colistin was examined. Results: Of the 108 E. coli strains, 101 (93.5%) isolates were APEC, and the remaining isolates were non-APEC. Among the APEC isolates, 58.4% were classified as virulent APEC; these isolates showed a statistically significant association with phylogroups F and C and (n = 54, 56.8%) more frequently exhibited a ciprofloxacin-resistant phenotype than avirulent APEC (n = 35, 36.8%). Among the ten APEC virulence genes, hlyF, iroC, iroN, iutA, O78, and ompT were significantly associated with virulent APEC. Conclusions: This study reveals a high prevalence of virulent APEC with fluoroquinolone resistance in slaughtered broiler chickens. Almost all virulent APEC strains belong to phylogroups F and C. The prediction of virulent APEC using hlyF, iroC, iroN, iutA, O78, and ompT may be useful. Full article

Fowl adenoviruses are opportunistic emerging viruses that spread widely in fowls, infecting birds of all ages, including young broiler chicks. This study aims to genotype the current adenovirus strains associated with inclusion body hepatitis hydropericardium syndrome (IBH-HPS) among infected broilers in Upper Egypt and to evaluate their pathogenic features. In 2024, 100 tissue samples were collected across Assiut and Sohag governorates in Upper Egypt for genetic characterization and pathogenicity evaluation. FAdVs were detected in 22% (11/50) of flocks. Typical FAdV lesions of dead embryos were observed after seven days post egg inoculation. Regarding the PCR assay of the hexon gene, only 8 of 30 samples were confirmed positive at 897 bp, yielding a 26.6% positivity rate. The remaining samples were considered negative using established RT-qPCR protocols for other viral pathogens. Partial sequencing of the hexon gene revealed that FAdV isolates (n = 4) clustered within FAdV species-D serotype 2/11, as determined by phylogenetic analysis. The four isolates shared (98–99%) and (94–100%) nucleotide and amino-acid similarities to FAdV-D of Israeli strains (2019–2020) and contemporary Egyptian isolates (2022), respectively, and low genetic divergence (54–81%) in comparison with other documented species. The amino acid sequence alignment and 3D structure indicate that the four immunogenic HVRs are located in the L1 region of the hexon protein, and that the highly conserved ⁹¹GQMTT⁹⁵, a specific region for FAdV-D serotype 2/11, is present. Regarding pathogenicity, the gross and histopathological findings observed clearly demonstrate the systemic pathogenicity of FAdV-2/11 in the infected group, with a final mortality rate of 30% at seven days post-infection (dpi). The FAdV DNA in hepatic tissues and cloacal swabs was confirmed by the PCR method at 3 dpi and 5 dpi. These results emphasize the circulating of FAdV-2/11 species D in Upper Egypt and highlight the significant need for a single inactivated vaccine that effectively targets the relevant FAdV serotypes to achieve broader and more efficient protection. Full article

Salmonella Infantis is a recognized antimicrobial resistance threat, and in the compromised chicken gut, this pathogen penetrates weakened tight junctions, disrupts the microbiota balance, and triggers inflammation. This study evaluated the potential effects of a feed additive blend comprising short chain fatty acids including coated sodium and calcium butyrate, medium chain fatty acids, and phenolic compounds on broiler gut health and performance under a Salmonella challenge using a proprietary seeder model methodology. The foundation, led by a preliminary study as Part A, comprises a negative control and two treatment groups, ran to develop a seeder model, and 1056 day-old Ross 308 broiler chicks were allocated into three groups. On days 5–6, Salmonella Infantis 7570 was inducted via seeders in T2 (frozen strain) and T3 (live strain), while T1 remained unchallenged. No significant difference in infection development was observed between T2 and T3 (p > 0.05). In T1, Salmonella positivity checked via real time polymerase chain reaction (iQ-check II Biorad) remained below 50% at respective time points, indicating that complete isolation in the same room is not feasible. Henceforth, in the main experiment, Part B, 396 male day-old Ross 308 birds were randomly assigned to two further treatments: (1) a positive control group fed a commercial diet, and (2) a treatment group fed the same diet supplemented with 2.5 kg/t of an organic acid-based additive blend (Presan FY, Tilburg, The Netherlands) until day 28. On days 5 and 6, five birds per pen were orally inoculated with 10⁹ CFU/mL Salmonella Infantis 7570 obtained via Part A and placed as seeders in both treatments. A borderline tendency for lower Salmonella counts was observed in the treatment group on day 19 (p = 0.062). The control group had significantly higher lesion scores on day 13 (p = 0.0068), with no significant difference on day 19. Body weight was significantly higher in the treatment group on days 11 and 28 (p = 0.0157), with no difference on day 39 (p = 0.1857). Average daily gain improved significantly between days 11 and 28 (p = 0.0234), and feed intake was also significantly higher during this period (p = 0.0007). Feed conversion ratio showed a tendency to improve between days 5 and 11 (p = 0.0638). Overall, this study reveals that the seeder model can be adopted in Salmonella research, and the application of a blend showed a borderline tendency to reduce Salmonella counts, however significantly lower the lesion scores, thereby improving gut health in broilers under a Salmonella challenge. Full article

Mycoplasma synoviae (MS) is a major pathogen threatening China’s poultry industry, causing severe economic losses, and clarifying its epidemiology is pivotal for disease control and flock purification. In this study, a total of 3215 chicken samples collected from 643 broiler farms across 15 provinces in China in 2024 were analyzed. PCR detected 14% positivity (450 samples), and 18 isolates obtained from these positive samples (4.0% isolation rate). Multilocus sequence typing (MLST, 7 housekeeping genes) and neighbor-joining phylogenetic analysis (integrating 425 reference sequences from public databases) identified 13 distinct sequence types (STs), demonstrating considerable genetic diversity among circulating MS strains. Pathogenicity assessment of the five isolates revealed that the infected chickens exhibited varying degrees of infectious synovitis, while no respiratory signs were observed. In addition, antimicrobial susceptibility testing against 10 commonly used antibiotics was conducted on the 18 strains, providing urgently needed guidance for rational drug use in the clinical treatment of both breeder and broiler flocks. This large-scale epidemiological study yields crucial insights into the current prevalence and genetic diversity of MS in China and lays a scientific foundation for formulating targeted prevention strategies and optimizing management practices. Full article

Infectious Bronchitis Virus is one of several major viral infections in poultry, affecting the respiratory, reproductive, and renal systems and causing significant economic losses worldwide. Current vaccines, including the H120 strain, provide limited cross-protection against emerging variants, underscoring the need for improved vaccine strategies. In this study, the complete genome of IBV H120 was divided into 12 fragments, synthesized, and assembled using the Golden Gate Assembly (GGA) method. The recombinant virus (rH120) was successfully rescued in chicken fibroblast cells and propagated in embryonated specific-pathogen-free (SPF) chicken eggs. Growth kinetics in embryonated SPF chicken eggs revealed similar replication patterns between rH120 and the original H120 strain. In broiler chickens, rH120 replicated efficiently, as confirmed by viral RNA detection in throat and cloacal swabs, and induced a stronger antibody response by 14 days post-infection. The rH120 virus proved to be genetically stable, infectious, and immunogenic, indicating that GGA-based reverse genetics is an effective system for IBV vaccine development. Full article

The global shift toward antibiotic-free poultry production has created an urgent need for sustainable feed additives that promote gut health and productivity. This study aimed to develop and evaluate a novel double-layered microencapsulated phytosynbiotic (DMP) comprising Tiliacora triandra extract, probiotics, and cereal by-products using lyophilization. In Experiment 1, we investigated the effects of cell wall materials (corn, defatted rice bran, and wheat bran) and different particle sizes (0.6 and 1.0 mm) on the physicochemical characteristics and probiotic encapsulation efficiency. Results revealed that wheat bran, particularly at the smaller particle size of 0.6 mm, enhanced probiotic viability, probiotic stability under simulated gastrointestinal and thermal conditions, and nutrient retention. Compared with other materials, wheat bran also provided superior powder flowability, lower density, and favorable color attributes. In Experiment 2, we assessed the influence of probiotic strains (P. acidilactici, Lactiplantibacillus plantarum TISTR 926, and Streptococcus thermophilus TISTR 894) on functional properties of the DMP. All strains exhibited high encapsulation efficiency and stability during gastrointestinal simulation, thermal exposure, and storage. However, P. acidilactici had superior fermentation kinetics and produced greater levels of beneficial short-chain fatty acids, especially acetic and butyric acids. Antibacterial activity was strain-dependent, with notable inhibitory effects against Gram-positive pathogens, primarily through bacteriostatic mechanisms. Overall, these findings confirm that the developed DMP formulations effectively stabilize probiotics and bioactive phytochemicals, offering a promising strategy for enhancing gut health and performance in antibiotic-free broiler production systems. Full article

For several years, Infantis was the most common Salmonella serovar circulating in the Belgian broiler sector and persisting on broiler farms. To gain insight into its prevalence and circulation on broiler farms in Belgium, five farms (14 flocks) with a S. Infantis contamination history were monitored during two consecutive production rounds. In total, ten sampling events were conducted using moist sponge sticks after cleaning and disinfection, during the delivery of the one-day-old chicks and during production until slaughter or until positive for S. Infantis. Salmonella presence on samples was determined based on the ISO 6579:2017 standard, and the isolated strains were typed using PFGE. The results showed that current cleaning and disinfection practices were unable to completely remove S. Infantis from the farms. Cleaning equipment (3 out of 9 sample times) and the floor (5 out of 10 sample times) were particularly contaminated. Furthermore, external environmental samples were also frequently contaminated (e.g., mortality containers, concrete driveway). During production, 12 of the 28 sampled flocks were colonized with S. Infantis after one week, indicating that S. Infantis quickly spreads throughout the broiler house, which raises the hypothesis that feeding and/or drinking water systems play a critical role in the circulation of the bacteria. This study gives insights into the circulation and difficulty of controlling S. Infantis in persistently contaminated broiler farms, highlighting the importance of thorough cleaning and disinfection and biosecurity. Full article

Recent innovations in poultry feed technology have emphasized the role of postbiotics and phytogenics as promising strategies to strengthen gut health and improve overall performance in broilers. Within this context, the current study evaluated the effectiveness of Biostrong™ Dual (Cargill Inc., Cedar Rapids, IA, USA), a novel product that integrates Saccharomyces cerevisiae fermentation-derived postbiotic products (SCFPs) with a proprietary blend of essential oil compounds (EOCs). The objective was to determine whether this dual formulation could consistently enhance growth, feed efficiency, and carcass quality across multiple production phases. To test this, three independent trials were conducted using commercial broiler strains. Birds were allocated to either a control group (CON) receiving a basal diet or a treatment group (DUAL) receiving the same diet supplemented with 0.4 kg/MT of Biostrong™ Dual. Each trial employed a randomized block design with 24 replicates per treatment and 16–25 birds per replicate. Results consistently demonstrated that DUAL improved (p < 0.05) body weight and the cumulative feed conversion ratio (cFCR) at 42 days. Pooled analysis revealed body weight gains of 5.5%, a cFCR improvement of 5 points, increased feed intake, and a 0.86% rise in breast meat yield. Additionally, one trial showed reduced footpad lesion scores. Collectively, these findings highlight Biostrong™ Dual as a valuable nutritional intervention to optimize productivity and carcass quality in poultry production and further research is needed to understand the mode of action of the product. Full article

Infectious bronchitis virus (IBV) remains a common pathogen in poultry production. Although its clinical and economic impact in Europe has markedly declined in recent decades due to extensive vaccination, ongoing viral circulation continues to pose risks to animal health and provides opportunities for viral evolution. In this study, we investigated the molecular epidemiology of GI-19 and related strains in Spain using samples collected between 2008 and 2025. Partial S1 sequencing revealed a complex scenario involving three major clades and several minor ones, the latter likely resulting from independent introduction events from north-western Europe, particularly Denmark. Six distinct recombination events involving GI-13 and GI-19 parental strains—some apparently vaccine derived—were also identified, several of which showed wide geographical spread and long-term persistence. Both recombinant and non-recombinant variants were detected across multiple regions and production systems, indicating strong epidemiological connectivity among broilers, layers, and breeders. Although overall viral population size appeared stable over time, shifts in the predominance of specific clades and recombinant groups were observed, possibly reflecting fitness advantages of newly introduced or evolved variants and reduced cross-protection from existing immunity. These findings highlight the susceptibility of the poultry sector to repeated introductions, mixing, and the dissemination of IBV variants. Strengthened molecular surveillance and tailored control strategies, together with the periodic evaluation of vaccination practices and population immunity, are needed to limit viral circulation, reduce recombination opportunities, and mitigate the impact of IBV. Full article