Search

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.

The rise in the spread of antibiotic-resistant pathogens such as Escherichia coli is one of the very important dynamics off-putting treatment and prophylaxis possibilities, hence posing a threat to the modern human medicine, veterinary medicine, and food safety. Therefore, the aim of this study was to determine antimicrobial resistance profiles in E. coli isolates obtained from broiler and layer chickens in Mwanza and Arusha regions in Tanzania. A cross-sectional study was carried out from February to March, 2021, in 402 poultry farms in Mwanza (201) and Arusha (201) regions in Tanzania. All samples that tested positive for E. coli were confirmed using MALDI-TOF MS, and two hundred and four (204) E. coli isolates were randomly chosen and subjected to antimicrobial susceptibility testing by disc diffusion method. Data were entered in Microsoft Excel® and analyzed using SPSS version 20. Isolates were tested against seven antimicrobial agents belonging to seven classes of antimicrobials. All the tested isolates (n = 204) were resistant to at least one antimicrobial agent. Overall, the highest resistance was observed in ampicillin (100%), whereas the lowest resistance was recorded for gentamicin (10.3%). Majority of the isolates (86.76%) were multidrug resistant. Antimicrobial resistance of E. coli to four classes of antimicrobial agents was the highest in this study (31.1%). Six of the 177 tested isolates (2.9%) were resistant to the seven classes of antimicrobial agents. 21 of the 204 (10.29%) isolates were ESBL producers where 21/21 (100%) isolates expressed blaTEM genes and only two isolates expressed (2/21) blaCTX-M gene. The isolates obtained in this study displayed high resistance to commonly used antimicrobial agents in veterinary and human medicine. This implies that there is existence of practices that accelerate antimicrobial resistance in the production of the sampled birds and therefore integration of appropriate use of antimicrobial agents and other measures that curb the spread of resistant genes is necessary.

A Newcastle disease virus was isolated from a chicken from a live bird market in the Mbeya region of Tanzania. Complete genome characterization of the isolate identified it as a member of subgenotype Vd. This is the first complete genome sequence of this subgenotype.

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&ndash, 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 &ge, 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.

Aim: To determine the carriage and antimicrobial resistance of Thermophilic Campylobacter species in the gastrointestinal tracts of farm and laboratory animals in Morogoro, Tanzania Materials and Methods: Faecal samples were collected from farm (n=244) and laboratory (n=466) animals and were subjected to the Cape Town protocol for isolation of Campylobacter. Isolates were preliminarily identified based on potassium hydroxide string and hippurate hydrolysis tests. Polymerase chain reaction (PCR) was employed for confirmation of isolates. Antimicrobial resistance testing was done using disc diffusion method. Results: Of the laboratory animals 26.7% of guinea pigs (n=30) and 1.2% of rats (n=242) were colonized with Campylobacter. Four isolates from guinea pigs were Campylobacter jejuni and the other four were C. coli. From rats, two isolates were C. jejuni and one was C. coli. In farm animals thermophilic Campylobacter were detected from 31.6% of sheep (n=57) and 60% horses (n=5). Of the isolates 12 (57%) were C. jejuni (10 from sheep and 2 from horses) and the remaining were C. coli (8 from sheep and 1 from a horse). The isolates were frequently resistant to erythromycin, norfloxacin, colistin sulphate and nalidixic acid; whereas low levels of resistance were observed for ciprofloxacin and gentamicin. Conclusion: Our study reveals carriage of antimicrobial resistant thermophilic Campylobacter in the intestines of the study animals. This highlights possibilities in involvement of these animals in the epidemiology of Campylobacter infections. Thus, there is a need to consider these animal species when planning control measures for this zoonotic bacterium.

The perception of risks of exposure to avian influenza and other poultry diseases among adults in Tanzania is influenced by their previous experiences, beliefs, and values, which can stand in the way of learning new approaches. We tested a novel disease risk communication approach centered on elementary school pupils, involving their teachers and parents. Age-appropriate training modules were developed and taught to teachers who then taught their pupils through extracurricular activities. The pupils practiced what they learned through club projects and subsequently transmitted what they learned to their parents. In 2009 we developed a poultry health and production curriculum as part of efforts to prevent and control poultry diseases, including avian influenza, in Tanzania. The curriculum developed for veterinarians and veterinary paraprofessionals was adapted for use with elementary school children and translated into Kiswahili. Twenty teachers from 10 primary schools in Mzumbe ward, Morogoro, were trained by poultry veterinary extension experts on teaching the curriculum to standard 5 pupils (ages 11-12 yr). Pupils and teachers practiced the curriculum in four demonstration chicken coops established on the grounds of the Changarawe, Lubungo, Masanze, and Mzumbe primary schools. By October 2011, at the conclusion of the funded project, a total of 202 girls and 193 boys had been trained. Additionally, 34 adults from surrounding villages made official learning tours to the schools and received training from their children and teachers involved in the projects. With at least 75% of the 395 pupils coming from different households, it can be safely assumed that over 250 households have heard about poultry disease risks and how to manage poultry to prevent those risks.

A study was conducted to evaluate the disease resistance potential in 105 chickens of six indigenous local chicken ecotypes in Tanzania by orally challenging 1-week-old chicks with 2.5 x 10(8) colony-forming units of virulent S. Gallinarum. For 14 days post infection, clinical signs, necropsy findings, antibody titres, packed cell volume, leukocyte population count, and viable bacterial cell counts in the liver and spleen were recorded. Clinical signs were recorded daily but other parameters were recorded on the day of infection, then on days 3, 6, 10 and 14 after infection. Clinical signs of fowl typhoid were evident in chickens from day 3 post infection and disappeared by day 9 post infection. Pathological lesions on sacrificed birds included enlargement of the liver and spleen with foci of necrosis on the liver, spleen and myocardium. The mean viable bacterial cell counts in the liver and spleen varied between ecotypes, although the differences were not statistically significant. There were significant differences in the leukocyte population in the peripheral blood, with one ecotype (Morogoro-medium) showing a consistent and significantly higher heterophil count compared with other ecotypes. It was concluded that there is a selectable resistance potential to S. Gallinarum among the local chicken ecotypes in Tanzania that may be attributable to non-specific host immune responses. Further studies are suggested.

The study aimed to evaluate the genetic diversity of Tanzanian chicken populations through phylogenetic relationship, and to trace the history of Tanzanian indigenous chickens. Five ecotypes of Tanzanian local chickens (Ching’wekwe, Kuchi, Morogoro-medium, Pemba and Unguja) from eight regions were studied. Diversity was assessed based on morphological measurements and 29 microsatellite markers recommended by ISAG/FAO advisory group on animal genetic diversity. A principal component analysis (PCA) of morphological measures distinguished individuals most by body sizes and body weight. Morogoro Medium, Pemba and Unguja were grouped together, while Ching'wekwe stood out because of their disproportionate short shanks and ulna bones . Kuchi formed an independent group owing to their comparably long body sizes. Microsatellite analysis revealed three clusters of Tanzanian chicken populations. These clusters encompassed i) Morogoro-medium and Ching’wekwe from Eastern and Central Zones ii) Unguja and Pemba from Zanzibar Islands and iii) Kuchi from Lake Zone regions, which formed an independent cluster. Sequence polymorphism of D-loop region was analysed to disclose the likely maternal origin of Tanzanian chickens. According to reference mtDNA haplotypes, the Tanzanian chickens that were sampled encompass two haplogroups of different genealogical origin. From haplotype network analysis, Tanzanian chickens probably originated on the Indian subcontinent and in Southeast Asia. The majority of Kuchi chickens clustered in a single haplogroup, which was previously found in Shamo game birds sampled from Shikoku Island of Japan in the Kōchi Prefecture. Analysis of phenotypic and molecular data, as well as the linguistic similarity of the breed names, suggests a recent introduction of the Kuchi breed to Tanzania. Keywords: Tanzanian indigenous chickens, genetic diversity, microsatellites, mitochondrial DNA

The implementation of strategies to detect, prevent, and control highly pathogenic avian influenza (HPAI) in developing countries presents several challenges, one of which is the presence of other diseases in poultry populations. Training workshops in developing countries using the Avian Flu School have revealed that in areas with heavy Newcastle disease burdens, smallholder poultry keepers do not recognize HPAI as an immediate threat. We have developed a strategy to address the more proximal needs and priorities of communities with free-ranging poultry flocks as a means to create value in poultry, and thus to improve disease detection and prevention overall. To this end, we have created the Poultry Health and Well-Being for Development project, which trains graduate veterinarians and paraprofessionals in poultry disease diagnosis, control, and treatment. These trainees then serve their local communities to improve poultry health and to implement disease detection and management programs.

A study was carried out to confirm and identify sources and elucidate factors associated with the introduction of Peste des Petits Ruminants (PPR) in southern Tanzania. This study was conducted in Tandahimba and Newala districts of Mtwara region following suspected outbreak of PPR in the area. Qualitative data were collected using semi-structured questionnaires and in-depth interviews of key informants who included goat and sheep owners with suspected cases of PPR and animal health service providers as well as local administrative authority. Additionally, 216 serum samples and 28 swabs were collected for serological and virological laboratory disease confirmation. The results show that PPR was first introduced in Likuna village of Newala district in February 2009 through newly purchased goats from the Pugu livestock market located about 700 km in the outskirts of Dar es Salaam city. Factors which contributed to spread of PPR included communal grazing and the cheap prices of sick animals bought by livestock keepers for slaughtering in other villages. Laboratory findings confirmed presence of PPR in the area by RT-PCR and serological analysis revealed that seroprevalence was 31%. These findings have confirmed, for the first time, introduction of PPR in southern Tanzania. The presence of PPR poses high risk of southward spread of the disease to other southern African countries in the SADC region thus calling for concerted and collaborative efforts in prevention and control of the disease to avoid losses. Further elaborate studies on the spread, prevalence and risk factors associated with the disease should urgently be investigated.

Background Small-scale poultry production has the potential to increase animal-source food consumption, improve household income, and reduce food insecurity. Objective To assess the impact of a chicken Newcastle disease vaccination program on consumption of chicken and eggs among women and children, income, and food insecurity in rural Tanzanian households. Methods Comparisons were made between house-holds from three project villages, which participated in a Newcastle disease vaccination program for chickens, and three control villages, which did not participate. Household interviews were done with mothers from a random sample in March 2008 (237 households) and March 2009 (261 households). Results After the first year of vaccinations (three rounds), project households kept significantly more chickens and tended to be more food secure than control households. Mothers from project households ate significantly more eggs than their counterparts in control households. A similar trend was observed among children. In 2009, fewer chickens were vaccinated in the project villages than in 2008, and more chickens were independently vaccinated in the control villages. This corresponded with an increase in ownership of chickens, a reduction in food insecurity, and improved consumption of eggs in control villages, whereas chicken ownership and egg consumption decreased and food insecurity remained relatively stable in project villages. We saw no differences between project and control villages in income earned from chicken and egg sales. Conclusions Our findings suggest that an increase in chicken Newcastle disease vaccination can lead to an increase in ownership of chickens and egg consumption and may also have an effect on reducing household food insecurity.

In- vitro studies on the efficacy of crude extracts of Aloe secundiflora on Candida albicans was conducted. Five mature leaves of Aloe secundiflora were collected and the crude extract was prepared, then autoclaved. The extract was then tested on Candida albicans grown on solid media. The results from these studies revealed complete inhibition of Candida albicans growth caused by Aloe secundiflora crude extract on solid media. The findings from this study suggest that the crude extract of Aloe secundiflora can inhibit the growth of Candida albicans. Further studies are required to establish the in-vivo activity of the crude extract, the active ingredient, dosage and safety of Aloe secundiflora, before recommending for clinical use.

In-vitro studies on the efficacy of crude extracts of Aloe secundiflora on Candida albicans was conducted. Five mature leaves of Aloe secundiflora were collected and the crude extract was prepared, then autoclaved. The extract was then tested on Candida albicans grown on solid media. The results from these studies revealed complete inhibition of Candida albicans growth caused by Aloe secundiflora crude extract on solid media. The findings from this study suggest that the crude extract of Aloe secundiflora can inhibit the growth of Candida albicans. Further studies are required to establish the in-vivo activity of the crude extract, the active ingredient, dosage and safety of Aloe secundiflora, before recommending for clinical use.

A social strategy was tested for implementing Newcastle disease (ND) vaccination and biosecurity improvements among free-ranging chicken at village level in Tanzania. In addition to training the local poultry vaccinators, data recorders and poultry-keepers, the strategy involved training and empowering leaders at the district, ward and village level. The trainings covered poultry health, management, and marketing of village chickens, with an emphasis on ND vaccination and improving biosecurity against avian influenza (AI), The study sites included villages in one ward in each of three each three districts (Iringa, Mtwara-Mikindani, and Mvomero) of mainland Tanzania. Ninety-six local leaders at district level and 101 leaders at ward levels were trained. In addition, 196 farmers (households) were trained, as well as 86 vaccinators and 26 data recorders. Data recorders were also trained as poultry first aid workers. ND vaccination was conducted by the vaccinators, supervised by their local leaders with technical assistance from veterinarians. A total of 158,343 village chickens were vaccinated in three rounds of vaccination three months apart. The training and empowerment of local leaders and local implementers was the key element for success as it fostered the feeling of local ownership of the program and prevented conflicts with other development activities within the villages. We conclude that most animal health programs will increase their odds of success by involving local leaders and by addressing the current challenges facing the farmers. Further assessment on the usefulness of this approach is needed.