Genetic Parameters and Genomic Regions Associated with Growth Rate and Response to Newcastle Disease in Local Chicken Ecotypes in Ghana and Tanzania

Local chicken enterprises in Africa are of great importance to household livelihoods but face major constraints with devastating disease outbreaks such as Newcastle disease (ND), which cause major economic losses. A study was conducted in two countries, Ghana and Tanzania, where three ecotypes in each country were challenged with a lentogenic (vaccine) strain of ND virus and various response phenotypes, including growth, anti-NDV antibody levels, and viral load from hatch to 38 days of age were taken. We estimated variance components and performed a genome-wide association study (GWAS) using ~2800 birds. Moderate heritabilities (0.14-0.55) of the above traits indicated that selection to improve these breeds/ecotypes for resistance to ND could be feasible. Genome-wide association analyses revealed several genomic regions that explained more than 0.5% of the genetic variance, including a candidate gene region for antibody response on chromosome 1. Future studies will characterize differences between the breeds/ecotypes, determine if large breed-specific quantitative trait loci can be identified, and evaluate the response of the same birds to endemic, velogenic ND virus strains

Prevalence, characterization and antimicrobial resistance profiles of Salmonella isolates from healthy broiler and free-range chickens in Morogoro, Tanzania

Abstract Background: Salmonella enterica is a group of bacteria that cause enteric and systemic infection in animals and human worldwide. Objectives:  The study was conducted to determine prevalence, characterization and antimicrobial susceptibility profiles of Non-Typhoidal Salmonella in indigenous free range and broiler chickens in Morogoro Municipality. Methodology: A cross-sectional study was conducted from November 2019 to May 2020 whereby 384 cloaca swab samples from health chickens from Magadu, Mzinga and Bigwa wards were collected. Identification was done by standard bacteriological methods, serotyping and genetically confirmed by PCR using Salmonella specific primers pair and Salmonella enterica primer pair (invA and iroB gene primers). Sensitivity test was done using Ampicillin, Tetracycline, Imipenem, Gentamycin, Ciprofloxacin, Sulfamethoxazole trimethoprim and Cefaclor antimicrobial discs. Descriptive statistic method was used for analysis, and paired t-test assuming unequal variance was used for comparing overall prevalence of Salmonella spp between free range and broiler chickens. Results: Out of 384 samples, 11 (2.9%) samples confirmed to be Salmonella of which 8(4%) were from broilers and 3(1.6%) were from free range chickens. Of the 11 isolates 8 were from group B serotypes and 3 isolates were from group D serotypes. Susceptibility results showed variable level of sensitivity to majority of antibiotics tested however, level of resistance were also found in 7/11 isolates resistant to Ampicillin, 4/11 isolates resistant to sulfamethoxazole-trimethoprim and 3/11 isolates resistant to tetracycline. Three isolates were found to harbor Sulfamethoxazole(sulII) resistant gene.Conclusion: This study revealed the presence of Salmonella carrier among chicken kept in Morogoro with antimicrobial resistances from both free range and broilers chickens. The results underline the importance of the biosecurity measures in the production and processing of chicken for human consumption, similarly improvement of management is recommended to stop transmission of Salmonella from natural carriers to chicken as indicated by fecal carriers found. &nbsp

Hipertrofična osteopatija kao posljedica stranoga tijela u jednjaku psa - prikaz slučaja

Hypertrophic osteopathy is a pathological disease process that occurs secondary to intra thoracic lesions that are either pulmonary or non pulmonary in origin. A 6-year-old female German shepherd cross was presented with complaints of losing body condition, anorexia, lameness, and swollen limbs. Clinical examination revealed swelling of all four limbs which were hard and painless on palpation. Radiographic examination of the limbs and the thoracic cavity revealed, irregular periosteal new bone formation along the shafts of most of the long bones and an oval-shaped 6 cm diameter radio dense caudal mediastinal mass. At post-mortem examination, an oesophageal diverticulum was found, filled with foul smelling creamy exudates and a bone foreign body firmly adherent to the wall. Hypertrophic osteopathy secondary to oesophageal foreign body was diagnosed based on history, clinical examination, radiography, post-mortem picture and histopathology.Hipertrofična osteopatija patološki je proces koji se javlja sekundarno kao posljedica intratorakalnih lezija plućnog ili neplućnog podrijetla. Njemačka ovčarka u dobi od šest godina bila je primljena sa znakovima gubitka težine, anoreksije, šepanja i otečenih nogu. Kliničkom pretragom ustanovljene su tvrde, na palpaciju bezbolne otekline nogu. Radiografskom pretragom nogu i prsne šupljine ustanovljene su nepravilne periostealne novotvorine u većine dugih kostiju i ovalna radiološki gusta masa promjera šest cm u kaudalnom medijastinumu. Pri razudbi je ustanovljen divertikul jednjaka ispunjen pjenušavim eksudatom neugodna mirisa i koštano strano tijelo koje je čvrsto prianjalo na stijenku. Na osnovi anamneze, kliničke pretrage, radiografije, razudbe trupla i patohistološkoga nalaza dijagnosticirana je sekundarna hipertrofična osteopatija kao posljedica stranoga tijela u jednjak

Estimating Genetic Parameters for Growth and Response to Infection with La Sota lentogenic Newcastle Disease Virus Strain in Local Chicken Breeds in Ghana and Tanzania

The local chicken industries in Ghana, Tanzania and several other African countries are greatly affected by mortalities due to Newcastle disease (ND). We tested local ecotypes/breeds in Ghana and Tanzania for genetic variation in growth rate and antibody levels after infection with a La Sota lentogenic ND virusstrain.We identifiedheritable variation in ND virus antibody levels, and in pre-, and post-infection growth rates, which implies that with selective breeding, genetic improvement is possible. One of the Ghanaian ecotypes had a faster growth rate than the otherecotypes, both pre-and post-infection. We however did not find significant differences between the Tanzanian breeds. Results from this study can be used to improveresistance to ND virus inthe local chicken breeds in Ghana and Tanzania, improving food security in these African countries

Innate Immune Genes Associated With Newcastle Disease Virus Load in Chick Embryos From Inbred and Outbred Lines

This research article was published by Frontiers in Microbiology in 2019Newcastle disease virus (NDV) causes substantial economic losses to smallholder farmers in low- and middle-income countries with high levels of morbidity and mortality in poultry flocks. Previous investigations have suggested differing levels of susceptibility to NDV between specific inbred lines and amongst breeds of chickens, however, the mechanisms contributing to this remain poorly understood. Studies have shown that some of these differences in levels of susceptibility to NDV infection may be accounted for by variability in the innate immune response amongst various breeds of poultry to NDV infection. Recent studies, in inbred Fayoumi and Leghorn lines, uncovered conserved, breed-dependent, and subline-dependent responses. To better understand the role of innate immune genes in engendering a protective immune response, we assessed the transcriptional responses to NDV of three highly outbred Tanzanian local chicken ecotypes, the Kuchi, the Morogoro Medium, and the Ching’wekwe. Hierarchical clustering and principal coordinate analysis of the gene expression profiles of 21-day old chick embryos infected with NDV clustered in an ecotype-dependent manner and was consistent with the relative viral loads for each of the three ecotypes. The Kuchi and Morogoro Medium exhibit significantly higher viral loads than the Ching’wekwe. The results show that the outbred ecotypes with increased levels of expression of CCL4, NOS2, and SOCS1 also had higher viral loads. The higher expression of SOCS1 is inconsistent with the expression in inbred lines. These differences may uncover new mechanisms or pathways in these populations that may have otherwise been overlooked when examining the response in highly inbred lines. Taken together, our findings provide insights on the specific conserved and differentially expressed innate immune-related genes involved the response of highly outbred chicken lines to NDV. This also suggests that several of the specific innate immunity related genes identified in the current investigation may serve as markers for the selection of chickens with reduced susceptibility to NDV

Genetic Analyses of Tanzanian Local Chicken Ecotypes Challenged with Newcastle Disease Virus

Newcastle Disease (ND) is a continuing global threat to domestic poultry, especially in developing countries, where severe outbreaks of velogenic ND virus (NDV) often cause major economic losses to households. Local chickens are of great importance to rural family livelihoods through provision of high-quality protein. To investigate the genetic basis of host response to NDV, three popular Tanzanian chicken ecotypes (regional populations) were challenged with a lentogenic (vaccine) strain of NDV at 28 days of age. Various host response phenotypes, including anti-NDV antibody levels (pre-infection and 10 days post-infection, dpi), and viral load (2 and 6 dpi) were measured, in addition to growth rate. We estimated genetic parameters and conducted genome-wide association study analyses by genotyping 1399 chickens using the Affymetrix 600K chicken SNP chip. Estimates of heritability of the evaluated traits were moderate (0.18–0.35). Five quantitative trait loci (QTL) associated with growth and/or response to NDV were identified by single-SNP analyses, with some regions explaining ≥1% of genetic variance based on the Bayes-B method. Immune related genes, such as ETS1, TIRAP, and KIRREL3, were located in regions associated with viral load at 6 dpi. The moderate estimates of heritability and identified QTL indicate that NDV response traits may be improved through selective breeding of chickens to enhance increased NDV resistance and vaccine efficacy in Tanzanian local ecotypes

Molecular characterization of Newcastle disease virus obtained from Mawenzi live bird market in Morogoro, Tanzania in 2020–2021

DATA AVAILABLILITY : All the data generated during this study are included in this manuscript.Newcastle disease (ND) is among the most important poultry diseases worldwide. It is the major threat to poultry production in Africa and causes major economic losses for both local and commercial chickens. To date, half of ND class II genotypes have been reported in Africa (I, IV, V, VI, VII, XI, XIII, XIV, XVII, XVIII, and XXI). The information on the circulating NDV genotypes is still scarce despite the endemic nature of ND in most countries on the African continent.A total of 659 oro-cloacal swabs were collected from local chickens in Mawenzi live bird market located in Morogoro, Tanzania, between June 2020 and May 2021. Newcastle disease virus was detected by using reverse transcription real-time polymerase chain reaction (RT-qPCR) and conventional PCR followed by sequencing of PCR products. The prevalence of NDV in the surveilled live bird markets was 23.5%. Sequencing and phylogenetic analysis revealed the presence of sub-genotype VII.2. The detected sub-genotype VII.2 has phylogenetic links to Zambian NDV strains implying a Southeast dissemination of the virus, considering that it was first detected in Mozambique. This study underscores the need of active NDV surveillance to determine the distribution of this NDV genotype in the country and monitor its spread and contribution to the emergence of new ND viruses.The American people through the United States Agency for International Development (USAID) Feed the Future Innovation Lab for Genomics to Improve Poultry. The RT-qPCR screening and Ion Torrent sequencing was provided by the South African National Research Foundation (NRF)/Department of Science and Innovation (DSI).https://link.springer.com/journal/42770am2024Production Animal StudiesSDG-02:Zero HungerSDG-03:Good heatlh and well-bein

Comparative effects of low energy diets on blood parameters and liver HSP70 and iNOS gene expressions among Tanzanian local chicken ecotypes

A study comparing effects of low energy diets on liver HSP70 and iNOS gene expressions and blood indices of three Tanzanian chicken ecotypes was conducted. Four weeks old hens belonging to Kuchi (KU), Ching’wekwe (CH) and Morogoro medium (MM) ecotypes were allocated to 9 pens in a 3 x 3 factorial design, with three replicates. They were fed 3 diets containing 40, 55 and 0% less energy than prescribed. Only KU 55% restriction groups had marked up-regulations (p<0.05) of HSP70 after 3 weeks. After 7 weeks, expression levels of HSP70 for KU and CH 55% restriction groups increased, while those for MM restriction groups remained unaltered. The iNOS levels were notably up-regulated for KU and CH 55% restriction groups after 3 and 7 weeks, respectively. Significant elevations (p<0.05) of serum corticosterone were only noted for KU restriction groups after 1 and 3 weeks. Serum uric acid was significantly increased (p<0.05) in all ecotypes and groups but triglycerides were markedly reduced as determined after 1, 3 and 7 weeks. There were no significant differences between controls and restricted groups in Hb and Hct levels except for CH ecotype, which showed lower (p<0.05) Hb and Hct levels after 5 and 7 weeks for both restricted groups. Results of this study show that low energy diets induced stress in chickens, and ecotype-specific tolerance was manifested through changes in liver HSP70, iNOS and blood parameters, with MM showing better tolerance at lowest energy levels and KU being least tolerant.Keywords: Corticosterone, Dietary energy, Ecotypes, Haemoglobin, Restriction, Stress, Tolerance, Haematocri

Genetic Parameters and Genomic Regions Associated with Growth Rate and Response to Newcastle Disease in Local Chicken Ecotypes in Ghana and Tanzania

Local chicken enterprises in Africa are of great importance to household livelihoods but face major constraints with devastating disease outbreaks such as Newcastle disease (ND), which cause major economic losses. A study was conducted in two countries, Ghana and Tanzania, where three ecotypes in each country were challenged with a lentogenic (vaccine) strain of ND virus and various response phenotypes, including growth, anti-NDV antibody levels, and viral load from hatch to 38 days of age were taken. We estimated variance components and performed a genome-wide association study (GWAS) using ~2800 birds. Moderate heritabilities (0.14-0.55) of the above traits indicated that selection to improve these breeds/ecotypes for resistance to ND could be feasible. Genome-wide association analyses revealed several genomic regions that explained more than 0.5% of the genetic variance, including a candidate gene region for antibody response on chromosome 1. Future studies will characterize differences between the breeds/ecotypes, determine if large breed-specific quantitative trait loci can be identified, and evaluate the response of the same birds to endemic, velogenic ND virus strains.</p