Molecular phylogenetic identification and morphological characteristics of Raillietina echinobothrida (Cestoda: Cyclophyllidea: Davaineidae) in commercial chickens in North China.

Raillietina echinobothrida (R. echinobothrida) is one of the most pathogenic and prevalent tapeworms threat to the commercial chickens in China. However, there is a lack of research on their molecular identification and morphological characteristics. This study explored the molecular identification markers for R. echinobothrida in North China based on 18s ribosomal RNA (18s rRNA) gene and the ribosomal DNA second internal transcribed spacer (ITS-2) gene. The BLAST results of 18s rRNA (1643 bp) and ITS-2 (564 bp) gene sequences showed that the isolated intestinal tapeworms were R. echinobothrida. Phylogenetic trees obtained by maximum likelihood (ML) or neighbor-joining (NJ) method revealed that the R. echinobothrida in North China had the closest evolutionary relationship with the species found on the Qinghai-Tibet plateau, China. Morphological observations by hematoxylin staining and scanning electron microscope showed four round suckers and a retractable rostellum on the spherical scolex of R. echinobothrida. Two rows of alternately arranged hooks distributed around the rostellum. There were 30-40 testes in each mature segment. A well-developed cirrus pouch lied outside the excretory duct of mature segment. The gravid segment contained 200-400 eggs and there was a well-developed oncosphere in each egg. In addition, abundant ultrastructural features in mature proglottid of R. echinobothrida in North China were identified by transmission electron microscopy. In conclusion, the present study established ways of molecular phylogenetic identification for R. echinobothrida based on 18s rRNA and ITS-2 gene, and identified the morphological and ultrastructural characteristics of R. echinobothrida in North China.

Farm Stage, Bird Age, and Body Site Dominantly Affect the Quantity, Taxonomic Composition, and Dynamics of Respiratory and Gut Microbiota of Commercial Layer Chickens.

The digestive and respiratory tracts of chickens are colonized by bacteria that are believed to play important roles in the overall health and performance of the birds. Most of the current research on the commensal bacteria (microbiota) of chickens has focused on broilers and gut microbiota, and less attention has been given to layers and respiratory microbiota. This research bias has left significant gaps in our knowledge of the layer microbiome. This study was conducted to define the core microbiota colonizing the upper respiratory tract (URT) and lower intestinal tract (LIT) in commercial layers under field conditions. One hundred eighty-one chickens were sampled from a flock of >80,000 birds at nine times to collect samples for 16S rRNA gene-based bacterial metabarcoding. Generally, the body site and age/farm stage had very dominant effects on the quantity, taxonomic composition, and dynamics of core bacteria. Remarkably, ileal and URT microbiota were compositionally more related to each other than to that from the cecum. Unique taxa dominated in each body site yet some taxa overlapped between URT and LIT sites, demonstrating a common core. The overlapping bacteria also contained various levels of several genera with well-recognized avian pathogens. Our findings suggest that significant interaction exists between gut and respiratory microbiota, including potential pathogens, in all stages of the farm sequence. The baseline data generated in this study can be useful for the development of effective microbiome-based interventions to enhance production performance and to prevent and control disease in commercial chicken layers.IMPORTANCE The poultry industry is faced with numerous challenges associated with infectious diseases and suboptimal performance of flocks. As microbiome research continues to grow, it is becoming clear that poultry health and production performance are partly influenced by nonpathogenic symbionts that occupy different habitats within the bird. This study has defined the baseline composition and overlaps between respiratory and gut bacteria in healthy, optimally performing chicken layers across all stages of the commercial farm sequence. Consequently, the study has set the groundwork for the development of interventions that seek to enhance production performance and to prevent and control infectious diseases through the modulation of gut and respiratory bacteria.

Comparison of microsatellite variations between Red Junglefowl and a commercial chicken gene pool.

It is assumed that Red Junglefowl (Gallus gallus) is one of the main ancestors of domestic chickens (Gallus gallus domesticus). Differences in microsatellite polymorphisms between Red Junglefowl and modern commercial chickens, which are used for egg and meat production, have not been fully reported. A total of 361 individuals from 1 Red Junglefowl population that has been maintained as a closed flock, 5 final cross-bred commercial layer populations (white-, tinted-, and brown-egg layers), and 2 final cross-bred commercial broiler populations were genotyped for 40 autosomal microsatellite loci. We compared microsatellite variations in Red Junglefowl with those in a commercial chicken gene pool. The contribution of each population to the genetic diversity was also estimated based on the molecular coancestry. In total, 302 distinct alleles were detected in 1 Red Junglefowl and 7 commercial chicken populations, of which 31 alleles (10.3%) were unique to Red Junglefowl, most of which occurred at a high frequency. The genetic differentiation between Red Junglefowl and commercial chickens (pairwise FST) ranged from 0.32 to 0.47. According to the neighbor-joining tree based on the modified Cavalli-Sforza chord distances and the Bayesian clustering analysis, Red Junglefowl was genetically distant from the commercial chicken gene pool tested. In all of the populations analyzed, Red Junglefowl made the highest contribution to genetic diversity. These results suggest that Red Junglefowl has a distinct distribution of microsatellite alleles and that there is a high level of genetic divergence between Red Junglefowl and commercial chickens.

Low detection of H5N1 virus in commercial chickens with a low-level of vaccination coverage against H5N1 virus infection in Bangladesh.

BACKGROUND: Bangladesh has reported > 560 H5N1 outbreaks in poultry and eight human cases since 2007. Commercial chicken farms were mostly affected. Commercial chicken farms across the country use imported vaccines against H5N1 virus; however, these vaccines did not use local circulatory isolates of H5N1virus. Vaccination may have limited effectiveness in chicken because of the mismatch in terms of subtypes and clades. To test this, we conducted a mixed-method study to assess the impact of ongoing vaccination against H5N1 virus on H5N1 viral shedding through freshly dropped feces of chickens raised in commercial farms that exclusively vaccinated or did not vaccinate their chickens. METHODS: Initially, we collected vaccination coverage data from all active farms in a subdistrict of each of eight division. In each district, 25 vaccinated and 25 non-vaccinated chicken farms were selected randomly for sample collection. All samples were tested to detect avian influenza viruses using rRT-PCR. RESULTS: A total of 5092 poultry farms were surveyed; among them 1284 (25%) chicken farms administered vaccine against H5N1 virus. In total 21 of 400 tested farms (5%) had chicken feces samples that tested positive for AIVs; of these three were positive for H5N1 subtype of clade 2.3.2.1. Out of three H5N1 positive farms, 1 (33%) was vaccinated and 2 (67%) were unvaccinated. The chicken farms that administered vaccine against H5N1 was found protective for the detection of H5N1 viral RNA (aOR 0.39, 95% CI: 0.32-0.48). The H5N1 isolates of clade 2.3.2.1 sequenced in this study formed a cluster with the vaccine strain A/duck/Guangdong/S1322/2010 (H5N1) [Re-6]. CONCLUSIONS: The overall low vaccination coverage with low detection of H5N1 virus in commercial chickens makes it difficult to assess the effectiveness of the vaccine in reducing H5N1 viral shedding.

From the Backyard to Our Beds: The Spectrum of Care, Attitudes, Relationship Types, and Welfare in Non-Commercial Chicken Care.

Non-commercial chickens may be the third most numerous pets in Western countries. Yet, to date, there is limited research into their welfare or the care-taking practices and attitudes of their guardians. Using a quantitative questionnaire, this study investigated non-commercial chicken owners' care-taking practices, attitudes, and relationship types with their chickens. Additionally, the study investigated barriers to optimizing non-commercial chicken welfare. Specific questions were asked regarding niche care-taking practices, including the use of Suprelorin® implants. With 2000+ responses, this study found variable care-taking practices, yet largely positive attitudes towards chickens, and a "personal" (though not "close personal") owner-chicken relationship, as defined by the Owner-Bird Relationship Scale. The Chicken Attitude Scale, Owner-Bird Relationship Scale, and Care Series scores were found to be correlated with each other, with coefficients ranging from 0.176 to 0.543 (p < 0.001). "Preventing commercial chickens from going to slaughter" was a key motive for chicken care by 56.1% of respondents, with 69.6% of respondents stating they cared for ex-commercial chickens. This study found a higher prevalence of reported poor health conditions and number of deaths relative to prior studies, and egg yolk peritonitis emerged as a leading health condition and cause of death. Moreover, 68.0% had not heard of Suprelorin® implants, and only 6.3% used implants. Most (76.4%) chicken carers followed an omnivorous diet that includes chicken meat/eggs. The results reinforced previous findings concerning a need for more avian-specialist, locally available, and affordable veterinary care for chickens. Research into Suprelorin® implants, rooster-specific care, and tailored requirements of caring for ex-commercial chickens is recommended.

Antimicrobial resistance of avian pathogenic Escherichia coli isolated from broiler, layer, and breeder chickens.

Background and Aim: Antimicrobials are extensively used in poultry production for growth promotion as well as for the treatment and control of diseases, including avian pathogenic Escherichia coli (APEC). Poor selection, overuse, and misuse of antimicrobial agents may promote the emergence and dissemination of antimicrobial resistance (AMR) in APEC. This study aimed to assess antimicrobial susceptibility patterns and detect antibiotic resistance genes (ARGs) in APEC isolated from clinical cases of colibacillosis in commercial broiler, layer, and breeder chickens. Materials and Methods: A total of 487 APEC were isolated from 539 across 300 poultry farms in various regions of Nepal. Antimicrobial susceptibility patterns was determined using the Kirby-Bauer disk diffusion and broth microdilution methods. The index of AMR, such as multiple antibiotic resistance (MAR) index, resistance score (R-score), and multidrug resistance (MDR) profile, were determined. Polymerase chain reaction was employed to detect multiple ARGs and correlations between phenotypic and genotypic resistance were analyzed. Results: The prevalence of APEC was 91% (487/539). All of these isolates were found resistant to at least one antimicrobial agent, and 41.7% of the isolates were resistant against 8-9 different antimicrobials. The antibiogram of APEC isolates overall showed the highest resistance against ampicillin (99.4%), whereas the highest intermediate resistance was observed in enrofloxacin (92%). The MAR index and R-score showed significant differences between broiler and layers, as well as between broiler breeder and layers. The number of isolates that were resistant to at least one agent in three or more antimicrobial categories tested was 446 (91.6%) and were classified as MDR-positive isolates. The ARGs were identified in 439 (90.1%) APEC isolates, including the most detected mobilized colistin resistance (mcr1) which was detected in the highest (52.6%) isolates. Overall, resistance gene of beta-lactam (blaTEM), mcr1, resistance gene of sulphonamide (sul1) and resistance gene of tetracycline (tetB) (in broiler), were detected in significantly higher than other tested genes (p < 0.001). When examining the pair-wise correlations, a significant phenotype-phenotype correlation (p < 0.001) was observed between levofloxacin and ciprofloxacin, chloramphenicol and tetracycline with doxycycline. Similarly, a significant phenotype-genotype correlation (p < 0.001) was observed between chloramphenicol and the tetB, and colistin with blaTEM and resistance gene of quinolone (qnrA). Conclusion: In this study, the current state of APEC AMR in commercial chickens is revealed for the first time in Nepal. We deciphered the complex nature of AMR in APEC populations. This information of molecular surveillance is useful to combat AMR in APEC and to contribute to manage APEC associated diseases and develop policies and guidelines to enhance the commercial chicken production.

The attitude-behaviour gap in biosecurity: Applying social theories to understand the relationships between commercial chicken farmers' attitudes and behaviours.

Introduction: Traditionally, it is believed that people's behaviours align with their attitudes; however, during COVID-19 pandemic, an attitude-behaviour gap in relation to preventive measures has been observed in recent studies. As such, the mixed-methods research was used to examine the relationships between farmers' biosecurity attitudes and behaviours in Taiwan's chicken industry based on the cognitive consistency theory. Methods: Content analysis of face-to-face interviews with 15 commercial chicken farmers identified their biosecurity responses to infectious disease threats. Results: The results indicated the mismatch of farmers' attitudes and behaviours towards specific biosecurity measures, in that they act differently than they think. The findings of the qualitative research allowed the research team to conduct the subsequent quantitative, confirmatory assessment to investigate the mismatch of farmers' attitudes and behaviours in 303 commercial broiler farmers. Survey data were analyzed to discover the relationships between farmers' attitudes and behaviours in relation to 29 biosecurity measures. The results show a mixed picture. The percentage of the farmers who had the attitude-behaviour gap towards 29 biosecurity measures ranged from 13.9 to 58.7%. Additionally, at the 5% significant level, there is an association between farmers' attitudes and behaviours for 12 biosecurity measures. In contrast, a significant association does not exist for the other 17 biosecurity measures. Specifically, out of the 17 biosecurity measures, the disconnection of farmers' attitudes and behaviours was observed in three specific biosecurity measures such as using a carcass storage area. Discussion: Based on a fairly large sample of farmers in Taiwan, this study confirms the existence of an attitude-behaviour gap in context and applies social theories to provide an in-depth understanding of how infectious diseases are managed in the animal health context. As the results demonstrate the necessity of tailoring biosecurity strategies to address the gap, it is time to reconsider the current approach by understanding farmers' real attitudes and behaviours in relation to biosecurity for the success of animal disease prevention and control at the farm level.

Farm-Level Risk Factors Associated With Avian Influenza A (H5) and A (H9) Flock-Level Seroprevalence on Commercial Broiler and Layer Chicken Farms in Bangladesh.

A cross-sectional study was conducted to identify farm-level risk factors associated with avian influenza A H5 and H9 virus exposure on commercial chicken farms in Bangladesh. For broiler farms, both H5 and H9 seropositivity were associated with visits by workers from other commercial chicken farms [odds ratio (OR) for H5 = 15.1, 95% confidence interval (CI): 2.8-80.8; OR for H9 = 50.1, 95% CI: 4.5-552.7], H5 seropositivity was associated with access of backyard ducks (OR = 21.5, 95% CI: 2.3-201.1), and H9 seropositivity with a number of farm employees (OR = 9.4, 95% CI: 1.1-80.6). On layer farms, both H5 and H9 seropositivity were associated with presence of stray dogs (OR for H5 = 3.1, 95% CI: 1.1-9.1; OR for H9 = 4.0, 95% CI: 1.1-15.3), H5 seropositivity with hatcheries supplying chicks (OR = 0.0, 95% CI: 0.0-0.3), vehicles entering farms (OR = 5.8, 95% CI: 1.5-22.4), number of farm employees (OR = 5.8, 95% CI: 1.2-28.2), and burying of dead birds near farms (OR = 4.6, 95% CI: 1.2-17.3); H9 seropositivity with traders supplying feed (OR = 5.9, 95% CI: 1.0-33.9), visits conducted of other commercial poultry farms (OR = 4.7, 95% CI: 1.1-20.6), number of spent layers sold (OR = 24.0, 95% CI: 3.7-155.0), and frequency of replacing chicken droppings (OR = 28.3, 95% CI: 2.8-284.2). Policies addressing these risk factors will increase the effectiveness of prevention and control strategies reducing the risk of avian influenza on commercial chicken farms.

A Cross-Sectional Study of Antimicrobial Usage on Commercial Broiler and Layer Chicken Farms in Bangladesh.

Commercial poultry production is growing rapidly in Bangladesh to address the increasing demand for poultry meat and eggs. Challenges faced by producers include the occurrence of poultry diseases, which are usually treated or controlled by antimicrobials. A cross-sectional study was conducted on 57 commercial layer and 83 broiler farms in eight subdistricts of the Chattogram district, Bangladesh, to assess antimicrobial usage in relation to clinical signs observed in chicken flocks on these farms. Of the 140 commercial chicken farms, 137 (97.9%) used antimicrobials and 24 different antimicrobial agents were administered. On layer farms, the most commonly used antimicrobials were ciprofloxacin (37.0% of farms, 20/54), amoxicillin (33.3%, 18/54), and tiamulin (31.5%, 17/54), while on broiler farms, colistin (56.6%, 47/83), doxycycline (50.6%, 42/83), and neomycin (38.6%, 32/83) were most commonly administered. Only 15.3% (21/137) of farmers used antimicrobials exclusively for therapeutic purposes, while 84.7% (116/137) of farmers used them prophylactically, administering them either for prophylactic purposes only (22.6% of farmers, 31/137) or in combination with therapeutic purposes (62.1% of farmers, 85/137). About 83.3% (45/54) of layer farmers were selling eggs while antimicrobials were being administered compared to 36.1% (30/83) of the broiler farmers selling broiler chickens while administering antimicrobials. Overall, 75.2% (103/137) of farmers reported clinical signs for which they administered antimicrobials, while 24.8% (34/137) of farmers reported no clinical signs but still administered antimicrobials. Respiratory signs (71.8% of farms with clinical signs, 74/103) were most commonly reported, followed by enteric signs (32.0%, 33/103) and increased mortality (16.5%, 17/103). About 37.2% (51/137) of farmers bought antimicrobials exclusively from feed and chick traders, followed by veterinary medical stores (35.0%, 48/137). Purchasing antimicrobials from feed and chick traders was more common among broiler than layer farmers. It is recommended that commercial poultry farmers should keep records of antimicrobials used with dosage and duration of administration along with indication of use. This would allow farmers and veterinarians to review if antimicrobial usage had the desired effects and to evaluate the appropriate use of antimicrobial agents under an antimicrobial stewardship approach.

Molecular and serological prevalence of influenza A viruses in poultry and poultry farmers in the Ashanti region, Ghana.

For an analysis of the prevalence of influenza A viruses (IAVs) circulating in chickens and their farmers in the Ashanti region, Ghana, we examined 2,400 trachea and cloaca swabs (chickens) and 102 oropharyngeal swabs (farmers) by qRT-PCR. Sera from 1,200 (chickens) and 102 (farmers) were analysed for IAV antibodies by ELISA and haemagglutination inhibition (HI). Avian influenza virus (AIV) was detected in 0.2% (n = 5) of chickens but not farmers. Virus detection was more pronounced in the cloacal (n = 4, 0.3%) than in tracheal swabs (n = 1, 0.1%). AIV antibodies were not detected in chickens. Two farmers (2.0%) tested positive to human seasonal IAV H1N1pdm09. Sixteen (15.7%) farmers tested seropositive to IAV of which 68.8% (n = 11) were due to H1N1pdm09-specific antibodies. AIV H5- or H7-specific antibodies were not detected in the farmers. Questionnaire evaluation indicated the rare usage of basic personal protective equipment by farmers when handling poultry. In light of previous outbreaks of zoonotic AIV in poultry in Ghana the open human-animal interface raises concern from a OneHealth perspective and calls for continued targeted surveillance.