Backyard Chickens Research Articles

Circulation of the reassorted very virulent genotype of infectious bursal disease virus isolated from vaccinated broiler chickens in Bangladesh

Objective: The methodology employed in this research was designed to identify and characterize the infectious bursal disease virus (IBDV) at the molecular level, originating from recent outbreaks in Bangladesh. Materials and Methods: The IBDV outbreak farm was investigated, and bursa of Fabricius (BF) specimens were acquired from infected chickens. Initially, viruses in the processed samples were detected in chicken embryo fibroblast (CEF) cells, and the RT-PCR method was used to confirm IBDV. The positive samples were injected through chorioallantoic membrane route into the embryo of a 10-day-old specific pathogen-free (SPF) egg for virus isolation and pathogenicity testing. Finally, we sequenced the VP2 gene to identify phylogenetic relationships and detect mutations. Results: From the 77 collected samples, 42.85% (33/77) were found positive for cytopathic effects in CEF cells, and IBDV was detected in 31.16% (24/77) of the samples by RT-PCR. IBDV was isolated in SPF chicken embryos. In the pathogenicity test, infectious bursal disease was evident in seronegative chickens with visible signs of disease. Sequence analysis shows that the broiler-isolated viruses clustered with genotype A3B2 and backyard chickens with genotype A1B1. The presence of amino acid motifs for virulence markers was revealed in the partially sequenced VP2 gene with a mutation at S254G in four IBDV isolates from broilers. However, amino acids for virulence markers were absent in two isolates from backyard chickens, which shows sequence homology with IBDV classic strains. Conclusion: In this study, we identified and characterized circulating reassorted IBDV from vaccinated broilers, which may be one of the major causes of vaccination failure in broilers.

Digestive tract impaction: An unusual cause of mortality in backyard chicken

Digestive tract impaction: An unusual cause of mortality in backyard chicken

Sub cellular alterations in natural infestation of intestinal coccidiosis in backyard chicken

Sub cellular alterations in natural infestation of intestinal coccidiosis in backyard chicken

Protective effectiveness of two vaccination schemes against the prevalent Egyptian strain of Newcastle disease virus genotype VII.

Despite the strict preventive immunization used in Egypt, Newcastle disease remained a prospective risk to the commercial and backyard chicken industries. The severe economic losses caused by the Newcastle disease virus (NDV) highlight the importance of the trials for the improvement and development of vaccines and vaccination programs. In the present study, we evaluated the effectiveness of two vaccination schemes for protection against the velogenic NDV (vNDV) challenge. Four groups (A-D) of commercial broiler chickens were used. Two groups (G-A and G-B) were vaccinated with priming live HB1 GII simultaneously with inactivated GVII vaccines at 5 days of age, then boosted with live LaSota GII vaccine in group A and live recombinant NDV GVII vaccine in group B on day 16. Groups A to C were challenged with NDV/Chicken/Egypt/ALEX/ZU-NM99/2019 strain (106 Embryo infective dose 50/0.1 ml) at 28 days of age. Two vaccination schemes achieved 93.3% clinical protection against NDV with body gain enhancement; whereas, 80% of the unvaccinated-challenged birds died. On day 28, the mean HI antibody titers were 4.3 ± 0.33 and 5.3 ± 0.33 log2 in groups A and B, respectively. As well as both programs remarkably reduced virus shedding. The two vaccination schemes displayed close protection efficacy against the vNDV challenge. Therefore, using the combination of a live attenuated vaccine with an inactivated genetically matched strain vaccine and then boosting it with one of the available live vaccines could be considered one of the most effective programs against current field vNDV infection in Egypt.

Molecular identification of the common viral respiratory viruses in backyard chickens in Basrah, Southern Iraq

Many viruses can infect different types of birds, with poultry being the most susceptible. These viral diseases have a direct negative impact on the poultry industry, with significant economic losses. This study examined a group of the most important viruses that infect backyard chickens in 2 specific areas of Basrah Governorate, south of Iraq. The study analyzed avian influenza viruses (AIVs), Newcastle disease virus (NDV), and infectious bronchitis virus (IBV). Two hundred and ninety oropharyngeal swabs, 150 from Abu Al-Khasib and 140 from Shatt Al-Arab regions in the Basrah governorate, were obtained from backyard chickens with clear respiratory signs. The samples were subjected to viral RNA extraction, and the viral nucleic acids were detected using an RT-PCR technique. The overall rate of viral infections was 74.8%, which varied depending on the type of virus: 15.8%, 31.3%, and 27.5% for AIV, NDV, and IBV, respectively. The NDV and IBV had much higher infection rates than that of AIV. In addition, the prevalence of AIV in the Shatt Al Arab district was significantly higher than in the Abul Khasib district. Moreover, there were no significant differences between the NDV and the IBV distributions in either of the targeted regions in this study.

Pharmacokinetics of intravenously and trans-dermally administered fluralaner in healthy laying shaver hens: fluralaner in chickens

Ectoparasite infestations negatively affect both backyard and commercial chicken flocks in the United States. Fluralaner is an isoxazoline shown to be efficacious in treating mite and bed bug infestations in poultry. Fluralaner is approved to treat fleas and ticks in dogs and cats in the United States and to treat mite infestations of chickens in Europe and Australia; however, the use of fluralaner in poultry is not yet approved in the United States. This study aimed to investigate the plasma fluralaner pharmacokinetic profile of intravenous and transdermal routes and apparent bioavailability of fluralaner administered trans-dermally in healthy shaver hens. A total of 12 individually housed healthy shaver hens received a single dose of either intravenous technical grade fluralaner at 0.5 mg/kg, or transdermal fluralaner (Bravecto (fluralaner transdermal solution) for dogs, 280 mg/mL, Merck Animal Health) at mean 58.7 mg/kg. Plasma from each hen was collected from the jugular, ulnar, or medial metatarsal vein at multiple intervals. Fluralaner concentrations in plasma were determined using Ultra Performance Liquid Chromatography with Mass Spectrometry (UPLC/MS). Noncompartmental analysis revealed that the geometric mean elimination half-life for intravenous and transdermal routes were 80.5 and 179.6 h, respectively. The geometric mean apparent bioavailability of transdermal routes was estimated as 3.4%. Prolonged fluralaner concentration in plasma above minimum inhibitory concentration of bed bugs following the single dose was observed in healthy shaver hens for both routes. It is important to understand the pharmacokinetic profile could be useful in determining the appropriate treatment strategy.

Adoption of TANUVAS Aseel backyard chicken adoption by ruralpoultry farmer of Dharmapuri district

Dharmapuri rural farmers were aware about TANUVAS Aseel strains of backyard poultry and had experience of rearing TANUVAS Aseel chicks trained by KVK, Dharmapuri. About 23.6% of the farmers have discontinued the practice due to lack of awareness about brooding and non-availability of chicks and 22.03% of the farmers did not followed the practice because of low preference andpredator attack. Farmers preferred TANUVAS Aseel strain of backyard poultry for meat and egg purpose, who fetch meat cost @ ₹400/kg. Therefore, KVK, VUTRC and Animal Husbandary sector should aid supportive services like brooding, vaccination, feeding, housing, marketing of these birds to the farmers in order to encourage backyard poultry farmers. Conclusively, extension activity should be strengthened for efficient transfer of technology from the laboratory to the farmer field.

An Analysis of the Challenges Faced by Small Scale Backyard Chicken Farmers of Dhemaji District of Assam

Aims: The present study was conducted to know the challenges faced by the small scale backyard chicken farmers of Dhemaji district of Assam.
 Study Design: The data obtained on various challenges faced by the farmers under the study were tabulated and analyzed statistically by using Garrett’s Ranking Technique.
 Place and Duration of Study: The study was conducted at Krishi Vigyan Kendra, Dhemaji, Assam Agricultural University, Simen Chapori, Dhemaji, Assam during the year, 2020-21.
 Methodology: For the purpose, a questionnaire was prepared for surveying and data were collected about various challenges in backyard chicken rearing faced by the farmers of the district. The farmers were asked to identify the challenges he or she and the fellow farmers of their villages faced with respect to rearing of local chickens in their locality and to rank the challenges from 1 to 20 according to the seriousness of the challenges faced by them.
 Results: Lack of suitable germplasm was found to be the major challenge of poultry farmers with mean score of 74.89 and ranked first among the constraints in backyard chicken rearing. Higher incidence of diseases (68.95), unavailability of feed and feed ingredients (66.55) and mortality of young chicks (63.00) were ranked second, third and fourth major challenges, respectively. On the other hand, non availability of vaccine, higher cost of feeds and feed ingredients, lack of extension training or service, high cost of farm equipments were ranked fifth, sixth, seventh and eighth, respectively, as challenges in backyard chicken rearing. Lack of organized marketing facilities, lack of knowledge on scientific poultry farming, high cost of chicks, presence of middle man, higher mortality during brooding period, inability to diagnose sick birds, inadequate veterinary facilities, seasonal price fluctuations, high cost of medicaments, lack of credit facilities, social problems like damaging of the standing crops by the birds and complaint by neighbours, loss of birds due to predators or thieves were some other constraints of lower importance as indicated by the respondents for the backyard chicken farmers surveyed during the study.
 Conclusion: From the study, it can be concluded that the small scale backyard poultry farmers of Dhemaji district of Assam have a lot many challenges in chicken rearing in village conditions, the major being the lack of suitable germplasm and higher incidence of diseases. To address such problems there should be proper initiatives from government level as well as in farmers’ collaborative approach to introduce some newly developed improved chicken breeds and awareness about proper disease prevention and bio-security measures and creation of other facilities.

Avian influenza and the Brazilian poultry production: Current situation and prevention strategies

Highly Pathogenic Avian Influenza (HPAI) presents a significant threat to global poultry, affecting trade and consumer trust. This analysis focuses on Brazil's preventive measures against HPAI to uphold its disease-free status recognized by the World Organization for Animal Health (WOAH). As of September 19th, 2023, Brazil confirmed 106 HPAI outbreaks, primarily in wild birds, with a few in backyard chickens. Despite most incidents occurring along the coast, a notable outbreak in Bonito-MS underlines the necessity for ongoing vigilance in key poultry regions. Brazil's HPAI prevention framework, initiated with the 1994 National Poultry Health Plan, has continually evolved. High biosecurity measures are emphasized in stringent regulations, surveillance, and rapid response strategies. The nation's vertically integrated poultry model supports centralized control, traceability, and consistent quality, fostering swift corrective actions and biosecurity guidelines. The private sector's commitment complements these efforts, often exceeding government regulations with rigorous biosecurity practices, highlighting Brazil's holistic approach to safeguarding its poultry sector from HPAI threats.

Virulent Newcastle disease virus genotypes V.3, VII.2, and XIII.1.1 and their coinfections with infectious bronchitis viruses and other avian pathogens in backyard chickens in Tanzania

Oropharyngeal (OP) and cloacal (CL) swabs from 2049 adult backyard chickens collected at 12 live bird markets, two each in Arusha, Dar es Salaam, Iringa, Mbeya, Morogoro and Tanga regions of Tanzania were screened for Newcastle disease virus (NDV) using reverse transcription real-time PCR (rRT-PCR). The virus was confirmed in 25.23% of the birds (n = 517; rRT-PCR CT ≤ 30), with the highest positivity rates observed in birds from Dar es Salaam region with higher prevalence during the dry season (September–November 2018) compared to the rainy season (January and April–May 2019). Next-generation sequencing of OP/CL samples of 20 out of 32 birds that had high amounts of viral RNAs (CT ≤ 25) resulted in the assembly of 18 complete and two partial genome sequences (15,192 bp and 15,045–15,190 bp in length, respectively) of NDV sub-genotypes V.3, VII.2 and XIII.1.1 (n = 1, 13 and 4 strains, respectively). Two birds had mixed NDV infections (V.3/VII.2 and VII.2/XIII.1.1), and nine were coinfected with viruses of families Astroviridae, Coronaviridae, Orthomyxoviridae, Picornaviridae, Pneumoviridae, and Reoviridae. Of the coinfecting viruses, complete genome sequences of two avastroviruses (a recombinant chicken astrovirus antigenic group-Aii and avian nephritis virus genogroup-5) and two infectious bronchitis viruses (a turkey coronavirus-like recombinant and a GI-19 virus) were determined. The fusion (F) protein F1/F2 cleavage sites of the Tanzanian NDVs have the consensus motifs 112 RRRKR↓F 117 (VII.2 strains) and 112 RRQKR↓F 117 (V.3 and XIII.1.1 strains) consistent with virulent virus; virulence was confirmed by intracerebral pathogenicity index scores of 1.66–1.88 in 1-day-old chicks using nine of the 20 isolates. Phylogenetically, the complete F-gene and full genome sequences regionally cluster the Tanzanian NDVs with, but distinctly from, other strains previously reported in eastern and southern African countries. These data contribute to the understanding of NDV epidemiology in Tanzania and the region.

Avian influenza and Brazilian poultry production – Current situation and prevention strategies. Proceeding of The First International Avian Influenza Summit, University of Arkansas- October 16-17, 2023"

Highly Pathogenic Avian Influenza (HPAI), particularly caused by the influenza virus A genus, is a paramount concern for global poultry health. The strains associated with HPAI are known to precipitate mortality rates exceeding 90\%. Beyond the immediate and catastrophic impact on poultry, the emergence of HPAI strains disrupts international poultry trade, leading countries to impose trade bans and shake consumer confidence. By September 19th, 2023, Brazil had reported 106 confirmed outbreaks of HPAI. Most of these incidents were linked to wild birds, totaling 103 cases, while backyard chickens accounted for the remaining three. Notably, most of these outbreaks are situated in coastal regions. However, an exception that demanded attention was the HPAI detection in backyard chickens in Bonito, Mato Grosso do Sul. State-wise analysis reveals differential prevalence patterns. São Paulo and Rio Grande do Sul have documented cases far from their primary poultry hubs. In juxtaposition, Espírito Santo's proximity to the outbreak areas heightens its risk profile. The southern broiler-producing regions, which account for a significant 64\% of Brazil's total production and a whopping 79\% of exports, currently face diminished immediate threats due to their inland geographies. Nevertheless, the episode in Bonito-MS underscores the escalating risks even in regions previously considered low-threat and amplifies the call for perpetual vigilance. Brazil's approach to HPAI defense is structured and well-planned, not a result of hasty improvisation or last-minute measures. It's a result of a long-standing commitment and rigorous planning. The country's legal framework for HPAI prevention has evolved since the 1994 introduction of the National Poultry Health Plan. Successive years saw further tightening of regulations, climaxing with the 2013 National Contingency Plan for Avian Influenza, which underwent revision in 2023. Brazil’s strategy to ward off HPAI is deeply rooted in stringent biosecurity measures. Farms are mandated to erect physical barriers, strictly regulate vehicular and human movement, and uphold rigorous cleaning and disinfection standards. Farm personnel are also trained in and adhere to meticulous personal hygiene protocols. Simultaneously, comprehensive waste management practices are firmly in place. Additionally, the Brazilian government plays a proactive role. Border surveillance, active monitoring of avian populations, and the deployment of passive surveillance within commercial flocks manifest the government's unwavering dedication to the poultry sector. One of Brazil's trump cards against diseases like HPAI is its vertically integrated poultry production model. This modus operandi permits companies and cooperatives to oversee every production stage. Such centralized oversight minimizes financial risks, guarantees consistent quality, and facilitates the swift roll-out of biosecurity directives. Traceability, a cornerstone for rapid disease containment, is inherently assured in this system. The private sector in Brazil not only meets governmental biosecurity standards but frequently surpasses them. It's common to see the integration of extended quarantine durations, intensified disinfection routines, and stringent farm access controls. The commitment to a tiered biosecurity mechanism across diverse poultry production stages is a testament to the industry's intent to ensure a holistic health foundation. Brazil's comprehensive and adaptive approach to HPAI is commendable. The country's strategic alignment between governmental regulations and private sector commitment, especially in the face of recent outbreaks, underscores Brazil's unwavering focus on safeguarding its poultry industry. While the road ahead demands continuous vigilance, Brazil's current strategies and learnings provide valuable insights for global stakeholders.

Determination of Heavy Metal Residue in Backyard Chicken at Various Region in Sulaymaniyah Province

Due to the accompanying hazards of cytotoxicity and systemic diseases following intake of such metals, especially in areas with rising industrial and agricultural activity, exposure to heavy metals through chicken consumption is a crucial issue for human health. In Kurdistan Region-Iraq, poultry meat and their products (especially local chicken) are widely consumed from population. On the point of view the present study was conducted to access the concentration levels of Cadmium (Cd), Copper (Cu) and Lead (Pb) heavy metals from some selected regions of Sulaymaniyah province (Bazyan, Dukan, Mergapan and Tanjaro) were measured in different body parts (breast and liver) of backyard chicken using Thermo Fisher Scientific inductively coupled plasma-mass spectrometry (ICP-OES). The results revealed that the residues of cadmium (Cd) in both samples (meat and liver) from all regions were within the permissible limit (0.3 mg/kg) by FAO/WHO, except Dukan region for liver sample, which recorded the value (0.355 mg/kg). The concentration of Copper (Cu) in meat and liver samples of all regions was exceeding than the permissible limit (0.3 mg/kg), levels proposed by FAO/WHO and the highest concentration was detected in of Dukan followed by Mergapan (11.541 and 11.372 mg/kg) respectively for liver sample. Lead (Pb) was found exceeding the permissible limit levels of 0.1 mg/kg in the liver samples of all the regions (0.147–0.729 mg/kg), except for Mergapan which recorded low value (0.091 mg/kg). Concerning Pb concentration in breast samples the value from Dukan and Tanjaro (0.118 and 0.149 mg/kg) was exceeding the permissible limit, while from Bazyan and Mergapan (0.082 and 0.022) the value was within permissible limit. As the most consumed section of the chicken has been determined to be among the tissues with the least contamination, liver, which is often less consumed by the local populace as compared to meat, was discovered to have relatively higher metal concentrations.

Molecular Characterization of Complete Genome Sequence of an Avian Coronavirus Identified in a Backyard Chicken from Tanzania.

A complete genome sequence of an avian coronavirus (AvCoV; 27,663 bp excluding 3' poly(A) tail) was determined using nontargeted next-generation sequencing (NGS) of an oropharyngeal swab from a backyard chicken in a live bird market in Arusha, Tanzania. The open reading frames (ORFs) of the Tanzanian strain TZ/CA127/19 are organized as typical of gammaCoVs (Coronaviridae family): 5'UTR-[ORFs 1a/1b encoding replicase complex (Rep1ab) non-structural peptides nsp2-16]-[spike (S) protein]-[ORFs 3a/3b]-[small envelop (E) protein]-[membrane (M) protein]-[ORFs 4a/4c]-[ORFs 5a/5b]-[nucleocapsid (N) protein]-[ORF6b]-3'UTR. The structural (S, E, M and N) and Rep1ab proteins of TZ/CA127/19 contain features typically conserved in AvCoVs, including the cleavage sites and functional motifs in Rep1ab and S. Its genome backbone (non-spike region) is closest to Asian GI-7 and GI-19 infectious bronchitis viruses (IBVs) with 87.2-89.7% nucleotide (nt) identities, but it has a S gene closest (98.9% nt identity) to the recombinant strain ck/CN/ahysx-1/16. Its 3a, 3b E and 4c sequences are closest to the duck CoV strain DK/GD/27/14 at 99.43%, 100%, 99.65% and 99.38% nt identities, respectively. Whereas its S gene phylogenetically cluster with North American TCoVs and French guineafowl COVs, all other viral genes group monophyletically with Eurasian GI-7/GI-19 IBVs and Chinese recombinant AvCoVs. Detection of a 4445 nt-long recombinant fragment with breakpoints at positions 19,961 and 24,405 (C- and N-terminus of nsp16 and E, respectively) strongly suggested that TZ/CA127/19 acquired its genome backbone from an LX4-type (GI-19) field strain via recombination with an unknown AvCoV. This is the first report of AvCoV in Tanzania and leaves unanswered the questions of its emergence and the biological significance.

Prevalence and Diversity of Blood Parasites (Plasmodium, Leucocytozoon and Trypanosoma) in Backyard Chickens (Gallus gallus domesticus) Raised in Southern Thailand.

Avian malaria and leucocytozoonosis can cause fatal diseases, whereas avian trypanosomiasis is reported to be harmless in chickens. Backyard chickens can be infected by several pathogens, including blood parasites, that may shed to industrial poultry production, with a consequently higher economic impact. This study aimed to investigate the presence of several blood parasites (Plasmodium, Leucocytozoon and Trypanosoma) in backyard chickens raised in Southern Thailand, using PCR-based detection and microscopic methods. From June 2021 to June 2022, 57 backyard chickens were sampled. Fresh thin blood smears were prepared from 11 individuals, and buffy coat smears were prepared from 55 of them. Both thin blood smears and buffy coat smears were used for microscopic analysis. Two nested PCR protocols that amplify a fragment of cytochrome b (cytb) and small subunit rRNA (SSU rRNA) genes were used to identify Haemosporida and Trypanosoma parasites, respectively. The number of positive samples was higher with the application of nested PCR than when buffy coat smears were used. Three new Plasmodium lineages (GALLUS47-49) and thirteen Leucocytozoon lineages (GALLUS50-62) were found. Trophozoites, meronts and gametocytes of Plasmodium gallinaceum (GALLUS01) were present in one thin blood smear. All thin blood smears revealed Leucocytozoon infections, but only three samples were a single infection. These three samples revealed the presence of fusiform host cell-parasite complexes, of which the morphological features resembled those of Leucocytozoon macleani (possible synonym is Leucocytozoon sabrazesi), while the cytb showed that this parasite is closely related to the lineage GALLUS06-07, described as Leucocytozoon schouteni. The Trypanosoma prevalence was 33.33%; it was present in only one of the thin blood smears, and it resembles Trypanosoma calmettei. This study showed the prevalence of a high diversity of Plasmodium (64.91%) and Leucocytozoon (89.47%) in Thai chickens. Both nested-PCR and buffy coat smear can be used as the diagnostic tool for the testing of Plasmodium, Leucocytozoon and Trypanosoma for parasitic control in backyard chickens and poultry farms. The information on the parasite species that can be found in chickens raised in Southern Thailand was also considered as the baseline information for further study.

Prevalence of major infectious diseases in backyard chickens from rural markets in Morocco.

Raising backyard chickens is a common practice in Morocco, mainly in rural or periurban areas. Constraints due to devastating avian diseases have been recognized as a major limiting factor in backyard poultry production. Consequently, these flocks could potentially be implicated as reservoirs for poultry diseases. However, there is a considerable lack of information on disease prevalence in this production system, and the risk represented by these small flocks remains under debate. This study aimed to estimate the seroprevalence and identify related risk factors of a range of bacterial and viral pathogens of outstanding importance for the economy and public health in backyard poultry in Morocco. A total of 712 sera samples and 258 cloacal swabs were collected from 712 backyard chickens from 15 rural markets in the Khemisset and Skhirat-Temara provinces. None of the sampled chickens received any vaccination. Sera samples were screened for antibodies against Newcastle disease virus (NDV) and low pathogenic avian influenza H9N2 subtype (LPAI H9N2) using a hemagglutination-inhibition test, against bursal infectious disease virus (IBDV) and infectious bronchitis virus (IBV) using enzyme-linked immunosorbent assay, and against Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) using a rapid serum agglutination test. Swab samples were compiled into 86 pools and submitted for molecular detection using real-time reverse-transcription-polymerase chain reaction (RT-PCR). The seroprevalences in backyard chickens for NDV, LPAI H9N2, IBDV, IBV, MG, and MS were 52.1% (371/712), 63.5% (452/712), 84.7% (603/712), 82.2% (585/712), 58% (413/712), and 74.8% (533/712), respectively. Based on the RT-PCR results, 2.3% (2/86), 62.8% (54/86), 2.3% (2/86), 63.9% (55/86), 40.7% (35/86), and 29.1% (25/86) of the pools were positive for NDV, H9N2 LPAI, IBDV, IBV, MG, and MS, respectively. Multiple coinfections (H9N2-IBV-MG), (H9N2-IBV-MS), or (IBV-MG-MS) were observed in 15.1%, 8.5%, and 8.5% of the tested samples, respectively. The results show that backyard chicken flocks and rural markets have the potential to serve as reservoirs or amplifiers for poultry pathogens and could pose a risk to the commercial poultry sector. This highlights the need for a comprehensive and adapted vaccination plan for backyard chickens, and extension of efforts to increase flock owners' awareness of avian diseases and incite the implementation of biosecurity measures at the farm level.

Avian encephalomyelitis virus in backyard chickens.

Avian viral diseases usually cause high economic losses because of high morbidity and mortality and poor growth. The rearing of chickens in backyards could have an important role in the spread of certain diseases, particularly those of viral origin. Infected birds might be prone to many viral infections for several reasons, including a lack of vaccination programs, the mixing of different bird species in the same location, and the close interactions of these birds with wild and migratory birds carrying various pathogens. This study aimed to conduct serological surveillance of avian encephalomyelitis virus (AEV) in some backyard chickens in the eastern region of Saudi Arabia. Serum samples (n = 368) were collected from domestic chickens reared in 10 backyards in the Eastern Province of Saudi Arabia. None of the domestic birds in these 10 backyards were vaccinated against the virus. In addition, 78 serum samples were collected from free-ranging birds belonging to Columbidae, such as pigeons and doves, in common areas near the domestic backyards. We tested these sera for specific antibodies against AEV. Our results revealed seroconversion to AEV among the examined chickens (14.6%). None of the tested pigeons and doves displayed seroconversion to AEV. Seroconversion of these non-vaccinated birds against AEV was suggestive of a recent natural infection by this virus. Further studies with a large number of birds are required to molecularly characterize the circulating strains of this virus in this area.

Uncovering changes in microbiome profiles across commercial and backyard poultry farming systems.

The microbiome profiles of poultry production systems significantly impact bird health, welfare, and the environment. This study investigated the influence of broiler-rearing systems on the microbiome composition of commercial and backyard chicken farms and their environment over time. Understanding these effects is vital for optimizing animal growth, enhancing welfare, and addressing human and environmental health implications. We collected and analyzed various samples from commercial and backyard farms, revealing significant differences in microbial diversity measurements between the two systems. Backyard farms exhibited higher alpha diversity measurements in soil and water samples, while commercial farms showed higher values for litter and feeder samples. The differences in microbial diversity were also reflected in the relative abundance of various microbial taxa. In backyard farms, Proteobacteria levels increased over time, while Firmicutes levels decreased. Campilobacterota, including the major poultry foodborne pathogen Campylobacter, increased over time in commercial farm environments. Furthermore, Bacteroides, associated with improved growth performance in chickens, were more abundant in backyard farms. Conversely, pathogenic Acinetobacter was significantly higher in backyard chicken fecal and feeder swab samples. The presence of Brevibacterium and Brachybacterium, associated with low-performing broiler flocks, was significantly higher in commercial farm samples. The observed differences in microbial composition and diversity suggest that farm management practices and environmental conditions significantly affect poultry health and welfare and have potential implications for human and environmental health. Understanding these relationships can inform targeted interventions to optimize poultry production, improve animal welfare, and mitigate foodborne pathogens and antimicrobial resistance risks. IMPORTANCE The microbiome of poultry production systems has garnered significant attention due to its implications on bird health, welfare, and overall performance. The present study investigates the impact of different broiler-rearing systems, namely, commercial (conventional) and backyard (non-conventional), on the microbiome profiles of chickens and their environment over time. Understanding the influence of these systems on microbiome composition is a critical aspect of the One-Health concept, which emphasizes the interconnectedness of animal, human, and environmental health. Our findings demonstrate that the type of broiler production system significantly affects both the birds and their environment, with distinct microbial communities associated with each system. This study reveals the presence of specific microbial taxa that differ in abundance between commercial and backyard poultry farms, providing valuable insights into the management practices that may alter the microbiome in these settings. Furthermore, the dynamic changes in microbial composition over time observed in our study highlight the complex interplay between the poultry gut microbiome, environmental factors, and production systems. By identifying the key microbial players and their fluctuations in commercial and backyard broiler production systems, this research offers a foundation for developing targeted strategies to optimize bird health and welfare while minimizing the potential risks to human and environmental health. The results contribute to a growing body of knowledge in the field of poultry microbiome research and have the potential to guide future improvements in poultry production practices that promote a sustainable and healthy balance between the birds, their environment, and the microbial communities they host.

Antibiotic Resistance Pattern and Distribution of Resistance Genes in Salmonella Isolated from Chicken and Duck Eggs in Chhattisgarh, India

Background: Salmonella is recognized as the most prevalent bacterial cause of foodborne diseases worldwide and animal-sourced foods have been reported as a common source of Salmonella infections among humans. Methods: The commercial chicken eggs, backyard chicken eggs, and duck eggs samples, 60 each, were processed for isolation and identification of Salmonella. All Salmonella isolates were further tested for resistance against six different antibiotics. The prevalence of virulence and antimicrobial resistance genes in the Salmonella isolates was determined by PCR. Result: A total of 28 Salmonella isolates were recovered with an overall prevalence of 15.6% and out of them, 11.1% and 4.4% were from eggshell and egg content, respectively. All the isolates were found sensitive to Gentamicin however maximum resistance was observed against Cefotaxime. PCR results revealed that 100% of the isolates were carrying the invA gene however stn gene was detected in 78.6% of isolates. Among presumptively identified β-lactam-resistant Salmonella isolates, 100% and 50% isolates harbored blaTEM and blaCTX-M genes, respectively whereas none of the isolates contained the blaSHV gene. All tetracycline-resistant isolates harbored the tetA gene whereas none of the isolates carried the tetB gene. 100% of fluoroquinolone-resistant isolates were carrying the gyrA gene however parC gene was present only in 60% of isolates. These results indicate that drug-resistant Salmonella spp. were prevalent in eggs sold in the study area which can pose a serious public health problem.

Avian Leukosis: Will We Be Able to Get Rid of It?

Avian leukosis viruses (ALVs) have been virtually eradicated from commercial poultry. However, some niches remain as pockets from which this group of viruses may reemerge and induce economic losses. Such is the case of fancy, hobby, backyard chickens and indigenous or native breeds, which are not as strictly inspected as commercial poultry and which have been found to harbor ALVs. In addition, the genome of both poultry and of several gamebird species contain endogenous retroviral sequences. Circumstances that support keeping up surveillance include the detection of several ALV natural recombinants between exogenous and endogenous ALV-related sequences which, combined with the well-known ability of retroviruses to mutate, facilitate the emergence of escape mutants. The subgroup most prevalent nowadays, ALV-J, has emerged as a multi-recombinant which uses a different receptor from the previously known subgroups, greatly increasing its cell tropism and pathogenicity and making it more transmissible. In this review we describe the ALVs, their different subgroups and which receptor they use to infect the cell, their routes of transmission and their presence in different bird collectivities, and the immune response against them. We analyze the different systems to control them, from vaccination to the progress made editing the bird genome to generate mutated ALV receptors or selecting certain haplotypes.

Phylogenetic and antigenic analysis of infectious bronchitis virus isolated from commercial and backyard chickens in Pakistan, 2015-2018.

Infectious bronchitis virus (IBV) is a rapidly evolving virus affecting both vaccinated and unvaccinated poultry flocks and is responsible for significant economic losses globally; hence, it is imperative to obtain a deeper understanding of this pathogen. In this study, seven IBV strains were isolated from commercial and backyard poultry flocks during 2015-2018. We obtained full-length IBV genomes of two viruses using the Illumina sequencing method, while five additional viruses were genetically characterized through full-length spike (S1) gene sequencing. Phylogenetic and distance analysis based on complete S1 gene and full-length genome sequences revealed that one IBV isolate belonged to genotype GI-1 and six viruses were clustered within genotype GI-13. Deduced amino acid sequences of GI-13 strains exhibited 31.8-37.2 % divergence with the commonly used classic vaccine strains (M41) and 2.7-12.6 % with variant vaccine strains (4/91) in Pakistan. High evolutionary distances suggest that the IBV viruses circulating in Pakistan are under continuous evolutionary pressure. Moreover, ch/IBV/Pak/AW-2/2017 was found to have originated from an intra-genotypic recombination event between the variant group (GI-23 lineage as a major parent) and variant vaccine strain (4/91-like as a minor parent) and is the first example of recombination within genotype GI-13 in Pakistan. Together, these findings provide genetic and evolutionary insights into the currently circulating IBV genotypes in Pakistan, which could help to better understand the origin, spread and evolution of IBVs, and to ascertain the importance of disease monitoring as well as re-evaluation forof currently used vaccines and vaccination programmes.