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Start date: 2022Subject: search.filters.subject.Tanzania

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    Knowledge, Attitudes, and Practices of Smallholder Dairy Cattle Farmers in Tanzania: A Cross-Sectional Survey on Cattle Infertility
    (MDPI, Basel, Switzerland, 2025-10) Ngou A; Laven R; Parkinson T; Kashoma I; Donaghy D
    Infertility is one of the major farming constraints facing smallholder dairy cattle farming in Tanzania. Despite its impact, there is limited information on how farmers understand and manage it. The present study aimed to assess farmers’ knowledge, attitudes and practices related to dairy cattle infertility. A cross-sectional survey was conducted using a structured questionnaire involving 301 farmers across six major dairy-farming regions: Tanga, Arusha, Kilimanjaro, Mbeya, Morogoro and Njombe. Overall, 95% of respondents reported encountering infertility on their farms. Farmers were asked to identify signs of infertility from the list of 10 (8 correct and 2 distractors); the median score for correct identification was 7 (range 2–10). The most recognised sign was return to oestrus after insemination (94%). Most farmers correctly identified low milk yield and mastitis as not being signs of infertility. The main reported causes included poor nutrition/housing (93%), livestock diseases (89%), poor record keeping (85%), and poor oestrus detection (83%). Nearly all (98%) viewed infertility as a serious issue, predominantly naming repeat breeding (95%) and failure to produce a calf/year (90%). Management strategies included seeking veterinary services (94%), slaughter (69%), sell to other farmers (23%) and self-treatment (16%). Our findings highlight widespread awareness of infertility while pointing out gaps in management, which reinforces the need for improved farmer education and support services.
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    Improving the performance of Mpwapwa breed cows in Tanzania : a fertility management approach : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, School of Veterinary Science, Manawatu
    (Massey University, 2024-12-12) Kabuni, Kabuni Thomas
    Beef cattle farming is an important part of Tanzania’s economy being widespread throughout Tanzania. It is commonly practiced by small-scale farmers, often in conjunction with other agricultural and commercial activities. As part of the colonial government’s efforts to develop agriculture in Tanzania in the 1940’s, the Mpwapwa breed was developed, largely from Bos indicus stock, as a dual-purpose breed to provide better beef and milk production. The Mpwapwa TALIRI research centre, in the Dodoma region of Tanzania, maintains a nucleus herd of Mpwapwa cattle from which it has provided breeding stock and, prior to 1973, an artificial insemination (AI) program to farmers. These programs fell into abeyance during the post-colonial era. Critically, the AI service was discontinued until TALIRI Mpwapwa started to re-equip its facilities in 2018. The major limiter to re-establishing the AI service has been the high cost and poor availability of liquid nitrogen, which means that it is not feasible to develop a service that is dependent on cryopreserved semen. In the past globally, and in New Zealand currently, bovine AI services have been based upon chilled or ambient temperature (AT) diluents, so the feasibility of developing a new AI service for Mpwapwa cattle using ambient-temperature semen was investigated. Most of the use of AT diluents has been in temperate climates, so an important component of re-establishing the AI service was to determine whether AT diluents could sustain sperm viability at the high (>30oC) temperatures that pertain in Tanzania. The first step was to survey farmers who kept Mpwapwa cattle about their management and breeding practices using a cross-sectional survey. This was undertaken to determine whether they were interested in an AI program for their cattle and whether they thought it would be a useful method of breeding for their cattle. A survey was administered across 100 farmers in the Mpwapwa region. Median herd size was 7 (range 1-150) and median farm size was 12 acres (0.4-500), milk yields were generally under 5 L/cow/day and carcass weights were typically 112-142 kg. The Mpwapwa breed was regarded as better than other local breeds. Only 17 farmers had used AI, almost always after single-PGF2α synchronisation. However, 69 farmers who had not used AI were interested in doing so and 61 considered that AI was better than natural bull mating being aware of the significant of AI on livestock breeding. The conclusions from the survey were that an AI service would have to be tailored around small herds, probably with fixed-time AI (FTAI) after single-PGF2α synchronisation, and would have to offer farmers significant improvements in animal genetics and fertility and/or easier management of breeding than at the present. As the Mpwapwa bulls had never been evaluated to determine whether their semen was of adequate quality to use in an AI service, the next step was to undertake breeding soundness examination (BSE) of the bulls in the TALIRI Mpwapwa stud. The 53 heaviest bulls out of the total stud of 120 were subjected to a full BSE including semen examination (collection by electroejaculation). Scrotal circumference was similar in bulls that were 24-36 months old (mean: 27.1 cm, SD: 1.6 cm) and those that were >36 months old (mean: 27.8 cm, SD: 2.0 cm). Semen was successfully collected from 44 bulls. Mean ejaculate volume was 5.5 mL (SD: 2.7 mL). Only 4 bulls did not have ≥75% morphologically normal sperm. Mean ejaculate density was relatively low at 303 x106 sperm/mL (range: 57-966, SD: 258 x106 sperm/mL). Density was >400 x106/mL in 31 bulls, >700 x106/mL in 2 bulls and >800 x106/mL in 6 bulls. These 8 bulls were considered suitable for use in an AI program. The variation of semen quality was largely as expected for a breed that had not been subjected to any form of selection for breeding ability. Findings for these Mpwapwa breed bulls largely align with those of similar low body-weight breeds of B. indicus that are found in East Africa and South-East Asia, but are significantly less than would be expected from the improved indicus breeds of South America, Australia and southern Africa. DNA fragmentation was examined in the same 53 bulls, again, as the status of these hitherto unselected bulls was unknown. Most bulls had unfragmented sperm (mean: 94.7%, SD: 6.8, Mode: 100%), with only 5 bulls having <90% normal sperm. Fragmentation was therefore not sufficiently widespread in the bull stud to cause concern about their use in AI. The next step was to assess the survival of sperm at ambient temperatures. Ejaculates from 35 bulls were diluted 1:1 in Tris-egg yolk (TE), Optixcell and coconut water, loaded into 0.25 mL mini- straws and incubated in water baths at 20°C, 27°C and 33°C (Year 1) or 8°C, 17°C and 33°C (Year-2). Motility was evaluated using computer-assisted analysis after 6, 24, 48, 72 and 120 h. Sperm survival was related to temperature, such that survival at 8°C was better than at other temperatures. Survival in coconut water was poor, with limited survival even at 24 h. Mean survival at 72 h was <40% in both TE and Optixcell, but was >40% at 48 h except at 32oC. These results suggested that storage at <20oC for up to 48 h would give acceptable motility (i.e. ≥50%) for use in AI. Sperm from some (n=4) individual bulls survived, however, for up to 120 h at 8oC and from 2 bulls at 17oC. Semen from 3 bulls survived for 120 h at 32oC. These results showed that storage for 48 h at 17°C in TE or Optixcell was feasible for most bulls, and individuals could be identified whose semen survived longer and/or at higher temperatures for at least 72 h. Thus, maintaining semen at ambient temperatures of 32°C was difficult for >24 h, but was readily achievable in an AT diluent with a modest amount of cooling for 48 h. This survival would permit an AI service based on AT semen, provided inseminations could be performed soon after collection, or after a period of modest refrigeration. Finally, a proof-of-concept AI trial was undertaken, in which 303 cows were inseminated with cryopreserved or AT semen after a double-PGF2α synchronisation (to detected oestrus after PGF2α- 1 and by FTAI after PGF2α-2). Conception rates to AI were 62% to AT and 38% to cryopreserved semen (final pregnancy rates were 99% and 97% respectively after 12 weeks of bull mating). Whilst the trial was not undertaken to demonstrate that one method was superior to the other, it did demonstrate that FTAI with AT semen was at least as good as with cryopreserved semen. In terms of developing an AT AI service, this thesis has shown that it would likely be well-received by smallholder farmers, that there is a cohort of bulls which are of satisfactory breeding quality for use in AI, that their semen survives for long enough for AT semen to be the basis of an AI service, and that results to FTAI are at least as good as with cryopreserved semen. In summary, the protocol itself is cost-effective and, as such, it could be used within the Tanzanian beef cattle breeding programmes. Being simple to schedule should make it easily accessible and implementable by poor smallholder farmers in the Mpwapwa region and, hence more accessible than other expensive protocols with more hormones. Even compared to natural mating, the costs of AT AI are still cheaper, making it more affordable than the costs of buying and managing a high genetic merit Mpwapwa bull. Wider screening of bulls for those whose semen survives longer and/or at higher ambient temperatures would allow for the selection of bulls with the highest quality semen. Addition of a limited degree of refrigeration (maintaining semen at 15-20oC) would allow more flexibility to the AI collection/processing centre.
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    Population Structure and Antimicrobial Resistance in Campylobacter jejuni and C. coli Isolated from Humans with Diarrhea and from Poultry, East Africa.
    (Centers for Disease Control and Prevention, 2024-10) French NP; Thomas KM; Amani NB; Benschop J; Bigogo GM; Cleaveland S; Fayaz A; Hugho EA; Karimuribo ED; Kasagama E; Maganga R; Melubo ML; Midwinter AC; Mmbaga BT; Mosha VV; Mshana FI; Munyua P; Ochieng JB; Rogers L; Sindiyo E; Swai ES; Verani JR; Widdowson M-A; Wilkinson DA; Kazwala RR; Crump JA; Zadoks RN
    Campylobacteriosis and antimicrobial resistance (AMR) are global public health concerns. Africa is estimated to have the world's highest incidence of campylobacteriosis and a relatively high prevalence of AMR in Campylobacter spp. from humans and animals. Few studies have compared Campylobacter spp. isolated from humans and poultry in Africa using whole-genome sequencing and antimicrobial susceptibility testing. We explored the population structure and AMR of 178 Campylobacter isolates from East Africa, 81 from patients with diarrhea in Kenya and 97 from 56 poultry samples in Tanzania, collected during 2006-2017. Sequence type diversity was high in both poultry and human isolates, with some sequence types in common. The estimated prevalence of multidrug resistance, defined as resistance to >3 antimicrobial classes, was higher in poultry isolates (40.9%, 95% credible interval 23.6%-59.4%) than in human isolates (2.5%, 95% credible interval 0.3%-6.8%), underlining the importance of antimicrobial stewardship in livestock systems.
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    Spread of Nontyphoidal Salmonella in the Beef Supply Chain in Northern Tanzania: Sensitivity in a Probabilistic Model Integrating Microbiological Data and Data from Stakeholder Interviews
    (Wiley Periodicals LLC on behalf of Society for Risk Analysis, 2022-05) Zadoks RN; Barker GC; Benschop J; Allan KJ; Chaters G; Cleaveland S; Crump JA; Davis MA; Mmbaga BT; Prinsen G; Thomas KM; Waldman L; French NP
    East Africa is a hotspot for foodborne diseases, including infection by nontyphoidal Salmonella (NTS), a zoonotic pathogen that may originate from livestock. Urbanization and increased demand for animal protein drive intensification of livestock production and food processing, creating risks and opportunities for food safety. We built a probabilistic mathematical model, informed by prior beliefs and dedicated stakeholder interviews and microbiological research, to describe sources and prevalence of NTS along the beef supply chain in Moshi, Tanzania. The supply chain was conceptualized using a bow tie model, with terminal livestock markets as pinch point, and a forked pathway postmarket to compare traditional and emerging supply chains. NTS was detected in 36 (7.7%) of 467 samples throughout the supply chain. After combining prior belief and observational data, marginal estimates of true NTS prevalence were 4% in feces of cattle entering the beef supply and 20% in raw meat at butcheries. Based on our model and sensitivity analyses, true NTS prevalence was not significantly different between supply chains. Environmental contamination, associated with butchers and vendors, was estimated to be the most likely source of NTS in meat for human consumption. The model provides a framework for assessing the origin and propagation of NTS along meat supply chains. It can be used to inform decision making when economic factors cause changes in beef production and consumption, such as where to target interventions to reduce risks to consumers. Through sensitivity and value of information analyses, the model also helps to prioritize investment in additional research.
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    Detection and management of lameness in dairy cattle in New Zealand and Tanzania : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University Te Kunenga Ki Pūrehuroa, University of New Zealand, School of Veterinary Science, Manawatu
    (Massey University, 2022) Werema, Chacha Wambura
    Alongside mastitis and infertility, lameness is one of the key animal health challenges on dairy farms. Lameness is particularly challenging due to the complex nature of its aetiopathogenesis and its multiple risk factors. Early detection combined with effective treatment, management and prevention are integral approaches to reducing the impact of lameness on dairy farms, improving productivity, and enhancing animal health and welfare. This thesis focused on improving detection and improved management. Visual locomotion scoring (LS) is currently the most widely used system for detecting lameness worldwide but has attributes that limit its usefulness and application. The first part of this thesis presents three studies looking at alternatives to LS: infrared thermography (IRT) and in-parlour scoring (IPS). IRT was compared to LS in both New Zealand and Tanzania, while IPS was tested in New Zealand alone. Both IRT and IPS proved to be useful alternatives to LS, but further research on more farms across more countries is required before they can replace LS for lameness detection on dairy farms. The second part of the thesis evaluates the response to a three timepoint regime of prophylactic hoof trimming (dry-off, early lactation, and end of lactation) on; 1) lameness incidence and time from calving to increased locomotion score, and 2) the distance from the external claw sole surface to the distal phalanx (DDP), and how this relates to lameness risk. On the study farm, prophylactic hoof trimming did not decrease lameness incidence or time to clinical lameness (locomotion scores ≥2). However, it did increase the interval from calving to an observable change in gait (locomotion scores ≥1). In regard to DDP, the study showed that DDP was not affected by trimming and that changes in DDP did not affect the hazard of increased locomotion score, i.e. either locomotion scores ≥1 or locomotion scores ≥2. Keywords: lameness; locomotion scoring; infrared thermography; in-parlour scoring; prophylactic hoof trimming; dairy cattle; pasture-based system; tropical