Browsing by Author "Zhou, Huaijun"

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Antibody response, viral load, viral clearance and growth rate in Tanzanian free-range local chickens infected with lentogenic Newcastle disease virus
(Academic Journals, 2021-04-15) Gallardo, Rodrigo; Kelly, Terra; Lamont, Susan; Dekkers, Jack; Zhou, Huaijun; Muhairwa, Amandus; Mushi, James Richard; Chiwanga, Gaspar Honorati; Mollel, Esther Lemburis; Walugembe, Muhammed; Max, Robert Arsen; Msoffe, Peter Makenga; Rodrigo Gallardo
This study is aimed at evaluating antibody responses, viral loads, viral clearance and growth rate of Tanzanian free-range local chicken (FRLC) challenged with LaSota strain of Newcastle disease virus (NDV) as indicator traits for selection of chickens for breeding with enhanced resistance to the disease and economic value. Three popular free-range local chicken ecotypes: Kuchi, Ching’wekwe and Morogoro-medium from three ecological zones of Tanzania were used for the experiments. Progenies from the breeder chickens were challenged with 10 7 titer of 50% egg infectious dose (EID 50 ) of the virus at 28 days of age. The viral loads and viral clearance rates evaluated by qRT-PCR from tear samples collected at 2- and 6-days post infection (dpi) showed that Kuchi could clear NDV better than Morogoro- medium and Ching’wekwe. Anti-NDV antibody levels determined from blood samples collected at 10 dpi using ELISA showed that Kuchi ecotype expressed higher mean anti-NDV antibodies compared to Morogoro-medium and Ching’wekwe. Growth rates determined from body weights collected for 38 days from day of hatch (D0) to 10 dpi showed higher growth rate for Kuchi than Morogoro-medium and Ching’wekwe chickens. Kuchi chickens were potentially more resistant to ND compared to Morogoro- medium and Ching’wekwe.
Phenotypic variability and population structure analysis of Tanzanian free-range local chickens
(BMC Veterinary Research, 2020) Mushi, James R; Chiwanga, Gaspar H; Amuzu-Aweh, Esinam N; Walugembe, Muhammed; Max, Robert A; Lamont, Susan J; Kelly, Terra R; Mollel, Esther L; Msoffe, Peter L; Dekkers, Jack; Gallardo, Rodrigo; Zhou, Huaijun; Muhairwa, Amandus P
Background: Free-range local chickens (FRLC) farming is an important activity in Tanzania, however, they have not been well-characterized. This study aimed to phenotypically characterize three Tanzanian FRLCs and to determine their population structure. A total of 389 mature breeder chickens (324 females and 65 males) from three popular Tanzanian FRLC ecotypes (Kuchi, Morogoro-medium and Ching’wekwe) were used for the phenotypic characterization. Progenies of these chickens were utilized to assess population structure. The ecotypes were collected from four geographical zones across Tanzania: Lake, Central, Northern and Coastal zones. Body weights and linear measurements were obtained from the mature breeders, including body, neck, shanks, wingspan, chest girth, and shank girth. Descriptive statistics were utilized to characterize the chickens. Correlations between the linear measurements and differences among the means of measured linear traits between ecotypes and between sexes were assessed. A total of 1399 progeny chicks were genotyped using a chicken 600 K high density single nucleotide polymorphism (SNP) panel for determination of population structure. Results: The means for most traits were significantly higher in Kuchi relative to Ching’wekwe and Morogoro- medium. However, shank length and shank girth were similar between Kuchi and Morogoro-medium females. All traits were correlated with the exception of shank girth in Morogoro-medium. Admixture analyses revealed that Morogoro-medium and Ching’wekwe clustered together as one population, separate from Kuchi. Conclusions: Phenotypic traits could be used to characterize FRLCs, however, there were variations in traits among individuals within ecotypes; therefore, complementary genomic methods should be considered to improve the characterization for selective breeding.