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Tree farming investments and implications to carbon storage in Bukoba district, Tanzania
No full textMSc. Ecosystem Sciences and ManagementThe current contribution of farm trees in solving wood related
problems and income generation to smallholders in developing
countries is unquestionable. However, the factors influencing
households‟ decisions to invest in tree planting and the amount of
carbon stored in agroforestry systems in many areas remain to be
site and time specific and not clearly understood. The study aimed at
assessing the factors influencing household decisions to invest in
tree planting and implications to soil organic carbon storage in
Bukoba district, Tanzania.
A total of 80 households (40 with and 40 without woodlots) were
randomly selected in four villages and questionnaires were applied
for data collection. Data were analysed through descriptive statistics
and binary logit regression. In the other hand, random sampling
technique was used to select 32 homegarden and 32 woodlot farms.
In farm sampling plots of 5m x 5m were established and two soil
samples per plot were extracted, one from a depth 0-15cm and
another from 15-30cm. A total of 128 composite soil samples were
collected for laboratory analysis. The Walkley – Black procedures for
Soil sample analysis was applied.
The study‟s results showed that household land size, the age of the
household head, accessibility to loan and credit services, availability
of land not suitable for crop production, and education level of the
household head, significantly (P<0.05) influenced households‟
decisions to invest in tree planting. Sex of the household head,
market availability, land ownership and risk perception had no
influence (P<0.05) on the decisions of the household to invest in
woodlot farming. Furthermore, the results revealed that woodlots
significantly (P<0.5) stored higher soil organic carbon content (125.2
ton/ha) compared to the homegarden agroforestry (96.8 ton/ha) in
general. The knowledge created in this study is essential for policy makers
and implementers to come out with appropriate agricultural
approaches, which will have multi impacts economically, socially and
environmentally
Assessing the influence of climate variability and land cover change on water resources in the Wami river catchment, Tanzania
No full textJournal of Environmental Earth SciencesUnderstanding the trend, extent, and effect of climate variability and land cover change are globally important for monitor-
ing river catchments water resources. Due to the majority of river catchment from developing countries such as Tanzania
experiencing insufficient time series data, the long-term ERA5-Land (1960–2021) reanalysis was used to assess the influence
of climate variability and land cover change on water resource in the Wami river catchment. The Mann–Kendal–Sneyer test
revealed a change that reflects the effect of land cover change on runoff in 1992, hence the mean annual runoff, precipitation,
and actual evapotranspiration decreased by 19%, 9.7%, and 8.9%, respectively, while potential evapotranspiration increased
by 5% after the change. Budyko decomposition and climate elasticity methods illustrated that variability change caused a
notable contribution to the reduction of Wami River runoff. Hydrological sensitivity analysis revealed that variability of
climate is a primary factor that reduced runoff with a contribution of 69%, while land cover change is 31%, this illustrates
runoff in the Wami river catchment is more vulnerable to climate variability than land cover change by considering that
most of the catchment are classified as arid or semi-arid. Thus, our study emphasizes the importance embracing climate
adaptation strategies, particularly a nature-based solution (NbS), to ensure the sustainability of water resources within the
Wami river catchment
Mechanisms of gestational diabetes mellitus using rat model
No full textPhD ThesisGestational diabetes mellitus (GDM) is a form of
hyperglycemia due to carbohydrate intolerance that begins
during pregnancy. This may be due to insulin resistance or
impairment of insulin secretion during pregnancy.
Knowledge on the pathophysiology of GDM is important for
its management. Thus, the main objective of the current
study was to explore the mechanisms of GDM development
due to high fat diet (HFD) or heat stress (HST) in a rat model.
Specifically, the study was done to evaluate the role of
differential adipose tissue (AT) expansion, influence of
oxidative stress (OS) and to determine the role of placental
cytokine (tumour necrosis factor-alpha (TNF-α) and
interleukin-6 (IL-6)) in the development of GDM.
The study used Wistar rats as experimental animals. Rats of
8 - 10 weeks old were used and experiments were
conducted at the Small Animal Research Unit (SARU),
College of Veterinary Medicine and Biomedical Science
(CVMBS), Sokoine University of Agriculture (SUA),
Morogoro, Tanzania. Samples were analysed in research
laboratories in the Departments of Physiology, Biochemistry
and Pharmacology and Veterinary Anatomy and Pathology.
This thesis is divided into three chapters. Chapter one is on
introduction and literature review. It includes a general
introduction, animal models for GDM, factors governing the
development of GDM, establishing GDM models,
histopathology of pancreas during GDM, placenta and GDM,
objectives of the study, and organization of the thesis.
Chapter two comprises three manuscripts describing the
research findings. The first manuscript describes the
contribution of HFD to the development of GDM. The second
manuscript is on evaluation of how OS due to HST
predisposes rats to GDM. Findings on assessment of theiv
role of placental cytokines (TNF-α and IL-6) in the
development of GDM are presented and discussed in the
third manuscript. Lastly, general discussion, conclusion and
recommendations of the study are provided in chapter three.
Work described in the first manuscript evaluated contribution
of HFD in differential AT expansion and subsequent
development of GDM in Wistar rats. Pregnant and non-
pregnant rats were given streptozotocin (STZ) by a single
intraperitoneal injection or HFD throughout the experiment.
The animals were sacrificed by a combination of ketamine
50 mg/kg and xylazine 5 mg/kg on days 1, 8, 15, and 21 of
the experiment. Blood, AT (both visceral (VAT) and
subcutaneous (SAT)) and pancreas were collected and
analysed. In this study, STZ-treated animals had a
significant increase (p<0.05) in serum glucose and a
decrease in insulin, without changes in the size of
adipocytes. The levels of both serum glucose and insulin
were significantly high in HFD-fed animals (p<0.05); being
higher in pregnant (p<0.05) than non-pregnant rats. The
increase in glucose and insulin levels was associated with
an increase in the size (hypertrophy) than the number
(hyperplasia) of adipocytes. The increase in adipocytes was
higher in VAT and corresponded to insulin resistance and
GDM development than in SAT. Histologically, β-cells were
decreased in number and deformed in STZ groups while
maintained in HFD groups in both pregnant and non-
pregnant animals. This study concluded that intake of HFD
during pregnancy leads to AT expansion, which is one of the
risk factors for the hyperglycemia and development of GDM.
This study demonstrates in the second manuscript the
association between HST and GDM. Pregnant and non-
pregnant Wistar rats were maintained at 41 - 42°C for 21
days. On days 1, 8, 15 and 21 the animals were humanely
sacrificed by a combination of ketamine 50 mg/kg andv
xylazine 5 mg/kg. Blood samples were collected from the
heart for glucose, insulin, malondialdehyde (MDA) and
glutathione peroxidase (GPx) analyses. Pancreatic tissues
were fixed in neutral buffered formalin, and processed for
histopathology. The findings demonstrated that, in pregnant
rats, HST induced a significant increase in glucose in
conjunction with a drop in insulin levels than non-pregnant
rats (p<0.05). In addition, heat treatment was accompanied
by an increase in MDA and a drop in GPx levels. Histological
examinations of the pancreas revealed damaged β-cells
from day 15 and a reduction in the number of β-cells by day
21 of the experiment in pregnant rats. These results suggest
that HST raises the levels of OS in pregnant rats more than
in non-pregnant rats and increases the chances of GDM as
it is associated with β-cell defects in the pancreas.
Findings on serum concentration and placental production of
TNF-α and IL-6 of HFD-given rats during pregnancy and
their correlation with the development of GDM are presented
and discussed in the third manuscript. Pregnant and non-
pregnant rats were given STZ single IP injection or HFD
throughout the experiment. On days 1, 8, 15 and 21, the
animals were humanely sacrificed by a combination of
ketamine 50 mg/kg and xylazine 5 mg/kg. Blood samples
were collected from the heart for glucose, insulin, TNF-α and
IL-6 analyses. Placenta samples were dissected, fixed in
neutral
buffered
formalin,
and
processed
for
histopathological and immunohistochemical analyses for
TNF-α and IL-6. The levels of serum glucose and insulin
were significantly high in HFD-fed animals (p<0.05); being
higher in pregnant (p<0.05) than non-pregnant rats. The
increase in glucose and insulin levels was associated with
an increase in serum levels of TNF-α and IL-6; which were
higher in HFD pregnant than non-pregnant animals on day
21 of the experiment. Histologically, placenta tissues of STZ-
treated animals were severely congested with blood vesselsvi
on days 15 and 21 compared with those from HFD-fed rats
which had low congestion on day 21. In both pregnant and
non-pregnant rats, immunostaining intensity for TNF-α and
IL-6 was high in HFD and STZ-treated animals on day 15
and 21. The findings of this study show that intake of HFD
during pregnancy leads to an increase in the levels of IL-6
and TNF-α in the placenta towards the end of gestation
resulting in insulin resistance and hyperglycemia that may
predispose to GDM.
Therefore, Intake of HFD during pregnancy causes AT
expansion as well as increase in the levels of placental
cytokines (TNF-α and IL-6) resulting in insulin resistance and
hyperglycemia, which are risk factors for GDM development.
In addition, exposing rats to HST during pregnancy raises
the levels of OS which is associated with β-cell defects
hence increasing the chances for GDM.African Centre of Excellence for
Rodent Pest Management and Biosensor Technology
Development (ACEII-IRPM&BTD) projec
Assessment of functionality in monitoring and evaluation systems of selected agricultural non-governmental organizations in Morogoro Municipality, Tanzania
No full textMA. DissertationMonitoring and evaluation (M&E) systems have evolved over time as
important tools that can enhance the management of programmes
and thus facilitate measurement of progress on project
implementation. This has raised interest among researchers who
have noted the importance to assess M&E system so as enhance
the efficiency of the systems. The study aims to assess functionality
of the selected agricultural NGOs’ M&E systems to determine the
functionality of key M&E components and the challenges of the M&E
system in its current status. The study adopted case study research
design and data were collected through desk reviews and interviews
with M&E technical officers guided by a checklist of items.
Quantitative data were analyzed using descriptive and inferential
statistics whereas qualitative data were analyzed using content
analysis. Generally, the enabling environment and data and
information management well functioned respectively at 88.9% and
91.1%. Specifically, the functionality differed and ranged from 76.7%
to 100% from one NGO to another. However, the Kruskal Wallis H
Test showed no significant difference at a 5% level of significance
among the NGOs. Therefore, the selected agricultural M&E system
NGOs well functioned but needed improvement to strengthen some
indicators. The study concludes that the M&E system of agricultural
NGOs was functioning well with minimal improvements. Challenges
were revealed in human capacity, communication and advocacy
plan, databases and data dissemination. The assessment of
agricultural NGOs revealed that there are improvements needed for
the M&E system to be sustainable. These include a more systematic
and long-term approach to develop M&E systems, staff training in
M&E principles and practices, stronger supervision, feedback loops,
and technical assistance and an information system that links
program-specific sub-system
Sources and knowledge of smallholder farmers in agricultural information in Mvomero district, Tanzania: where does misinformation originate?
No full textJournal Articlehis study examined the access to sources and knowledge of smallholder farmers
in agricultural information in Mvomero District, Tanzania, and identified the origin of
misinformation among these farmers. The study employed a mixed-methods approach, including
a survey of 192 smallholder farmers and interviews with agricultural extension officers and key
informants. The study adopted a cross-sectional research design involving both qualitative and
quantitative research methods through key informant interviews and questionnaires respectively.
Descriptive statistics results indicated that more than half of the respondents (70%) were poorly
accessing the reliable agricultural information. Furthermore, more than three quarters of the
respondents (96%) had high level of knowledge on agricultural misinformation but still, they
could not well access reliable agricultural information. Likewise, more than half of respondents
(74.5%) accessed agricultural information through farmers – farmers while half of respondents
(50%) accessed agricultural information through other sources such as radio, television, mobile
phones, smartphones, and extension officers, and this may be a problem in accessing the reliable
agricultural information. Additionally, the study revealed that misinformation among smallholder
farmers originates from various sources, including fellow farmers, traditional beliefs, and
inadequate agricultural extension services. The study recommends interventions to improve
smallholder farmers' access to agricultural information, including expanding communication
channels and improving agricultural extension services, to mitigate the spread of misinformation
Value chain analysis of medicinal plants in Liwale District, Tanzania
No full textDissertationMedicinal plants as non-timber forest products have been playing a
crucial role in the health care sector. The acceptance of herbal
products by the developed world has to a large extent fuelled the
current demand for medicinal plants and it is expected to grow even
further with time in terms of herbal supplements and remedies.
However, the medicinal plants business in Tanzania has faced and
continues to face a significant number of regulatory and institutional
challenges. Also, most of the research activities on medicinal plants
value chain development have paid more attention to food crops and
food security with few focused on the development of a friendly
business environment for medicinal plants. This study examined the
value chain analysis of medicinal plants in the Liwale district,
Tanzania. A cross-sectional study design was adopted. The sample
size was 100 medicinal plant value chain actors, where a 5%
sampling intensity was used in each village under study. Quantitative
data was obtained; descriptive and binary logistic regression
analyses were used with the aid of SPSS software. Qualitative data
was obtained from key informant interviews and focused group
discussions. Later the data was analyzed using content analysis. The
study found that there was a lack of awareness (82.4%) and low
compliance with the business environment (83.2%). The study also
found that a large number of herbal clinics and traditional healers
lacked training for improving their business skills (85%). Most of the
herbal clinics and traditional healers had access to financial services,
especially mobile money, but few tend to use such services (79%).
Furthermore, the study found out through the Binary logistic
regression results that only three actors/collectors, middlemen
(transporters and processors), herbal clinics, and traditional healers
were found to exist along the value chain of medicinal plants.
Additionally, it was concluded that the actors' profits differ, with
herbal clinics and traditional dealers benefiting (1,500,000 Tshs)
more than other actors along the value chain. Finally, it can be said
that the medicinal plant industry has been impacted by several factors, with the capital issue being the most frequent among the
respondents, indicating that it was the main issue affecting the
majority of actors in the value chain for medicinal plants. The study
recommends that the government should implement policies that
prioritize product quality by investing in capacity-building skills and
innovations to make the business more lucrative. Financial
institutions should also work closely with herbal clinics and medicinal
plant dealers to assist them financially. Training in the medicinal
plants business is thus recommended to assist them in lowering
operational costs. Different responsible organizations and authorities
should provide more education to enhance awareness of the rules
and regulations to herbal clinics and other traditional healers for
enhancing revenue collection and also ensuring the safety of users
of the medicinal plants
Community ecology of rodents in a natural and agricultural landscape- in Western Serengeti, Tanzania
No full textDissertationRodents are beneficial ecologically as they act as food for other
organisims including humans. However, about 17% of rodent species
are problematic since they transmit zoonotic diseases, damage
properties and depredate crops. Various strategies have been
designed worldwide to control them but have proven futile due to limited
knowledge on the animals’ biology, behaviour and ecology. This
knowledge is essential for preparing integrated rodent conservation and
management strategies. Also, no one single strategy can effectively
be used to manage rodents in every part of the world, hence rodent
ecological studies in as many local areas as possible are needed.
Therefore, two ecological studies were carried out to generate
information that would contribute to the formulation of effective
strategies. The first study aimed to determine: i) spatio-temporal
community structure (species composition, age and sex structure), ii)
spatio-temporal population dynamics and breeding patterns and iii)
influence of ecological factors (vegetation attributes, soil characteristics
and seasonality) on abundance of
a dominant rodent species
M.natalensis. The second study aimed at investigating the dietary
patterns of the dominant rodent species. These are the first detailed
ecological studies in our study area.
The first study was conducted within Kijereshi Game Reserve and the
surrounding Nyamikoma village in the western Serengeti using Capture-
Mark-Recapture (CMR) technique from April 2020 to March 2022.
Sherman live traps were used to trap rodents on a 3 consecutive night’s
basis every month for twenty four months. Trapping was done in nine
70 x 70 m2 permanent grids in the wooded grassland habitat within
Kijereshi Game Reserve, and in fallow land and maize crop fields within
Nyamikoma village land. One year data collected from from 2020 April to March 2021 were used
to investigate spatio-temporal community structure of rodents in the
three habitats whereby 1,075 individuals were captured. They
comprised eight 8 rodent species and one shrew species. Mastomys
natalensis (76.6%) was the most whereas Acomys wilsoni (02%)
occurred the least abundant species across habitats and the
insectivorous animal was Crocidura cf. flavescens (11.1%). Species
richness was highest in the wooded grassland and least in maize crop
fields, probably due to mono-cultivation nature in the maize crop fields.
Fallow land had a higher diversity (1.05) while maize fields had the
lowest (0.35), suggesting presence of heterogeneity in fallow land
habitats as compared to maize crop fields. A statistical difference in
number of adults, subadults and juveniles was detected between
habitats (F2, 102 = 3.09, P=0.05), and a marginally significant
difference between seasons (F1, 102 = 3.743, p = 0.06). There were
more Juveniles in the maize crop fields than in the wooded grassland
habitat probably due to availability of food resources that favour their
reproduction. On the other hand, there was a significant difference
between numbers of females and males of M. natalensis captured
across dry and wet seasons (F1, 64 = 8.311, p = 0.005) and the three
habitats (F2, 64 = 6.9, p = 0.004). The study suggests that small scale
comparisons of the community structures of small mammals between
habitats can provide knowledge that is needed for conservation and
control of small mammal species.
A two year period data on population dynamics and breeding patterns
of M.natalensis revealed that, its abundance varied significantly across
habitats ( Chi-squared = 8.922, df = 2, p-value = 0.012) and between
seasons (W = 982.5, p-value<0.001). Females bred continuously
throughout all seasons and there was no significant difference in the
number of actively breeding females across habitats (Chi-squared =
3.52, df = 2, p-value = 0.172) and between seasons (W = 584, p-value = 0.472) probably due to presence of seeds/grains especially in maize
crop fields throughout the year. However, in most cases breeding
started to increase immediately after long rains in March/April except in
the wooded grassland where there was a lag. Numerically, the M.
natalensis abundance was higher in maize crop fields as compared to
other habitats, but densities dropped similarly in all habitats during wet
season. Nevertheless, the reasons for this is not yet clear as
substantial food resources are available especially in the maize crop
fields resulting from maize crops harvest of the second cropping
season. Although, analysis of data on several selected ecological
correlates, indicated that the latter have influence on the abundance of
M.natalensis. For example, its abundance was significantly higher
during the dry season and in farmlands than in wet season and
protected areas (χ2= 79.393, df = 2, p < 0.001). Also, the abundance
significantly associated positively with farmlands (p = 0.023) and sandy-
clay-loam soils (p = 0.007). Hence, control of the animals might be
effected between the months of November and January when densities
are low and farmers should maximize maize production during this
period which falls in their minor cropping. Also, soil type issue should
be taken into consideration during farm site selection.
The second study was conducted in the same study site as the first one,
to investigate on the dietary patterns of M.natelensis, whereby, kill traps
(Victor kill trap (1.0 x 20.3 x 30.1 cm, Animal Trap Co., Lititz Pennal)
baited with peanut butter mixed with maize bran/flour were used in
three grids of 70 x 70 m2. About 111 captured specimens were
dissected, their stomachs removed and labelled, then preserved in
containers (20 ml, glass bottle, HiSupplier_.com) containing 70%
ethanol. The analysis of stomach contents was carried out by evenly
spreading each stomach contents in a Petridish and categorised using a
binocular dissecting microscope under 25 x and 50 x magnification, into
various food categories. Overall, vegetative plant materials (41%) andinvertebrates (39.1%) dominated. During the wet season, invertebrates
dominated in the wooded grassland, followed by fallow land and maize
crop fields. On the other hand, seeds/grains were more eaten in maize
crop fields than in other habitat types. Also, in the dry season,
vegetative plant materials dominated the animal’s diet in maize crop
fields suggesting that this rodent is an opprtunistice feeder
Agronomic performance of local and improved rice (Oryza Sativa l.) cultivars under weed pressure in Malinyi District, Morogoro, Tanzania
No full textDissertationWeeds significantly reduce the quantity and quality of the
rice harvest and raise the cost of production. More than half
of the world's population relies primarily on rice (Oryza
sativa L.), which accounts for more than 20% of all calories
consumed.
African continent is the third-most rice
producer, after Asia and America. After maize, rice is
Tanzania's second-most significant food and commercial
crop, where the principal rice-producing regions are
Morogoro, Mbeya, Rukwa, Tabora, Shinyanga and
Mwanza. Rice is the primary crop planted in Malinyi
District, Morogoro region, followed by maize. Local rice
cultivars comprise more than 95% of the cultivated land
area, while improved rice varieties occupy less than 5%.
Compared to the national average yield of 2.5 t/ha, the rice
productivity in Malinyi district is low at an average of 1.5
t/ha caused by both abiotic and biotic factors, including
weeds as a key barrier. Farmers do weeding up to four
times per season. Weedscan result in losses of up to 48 to
100%. In Tanzania, little is known about the cultivars of rice
used by farmers to combat weeds in terms of their
competitive ability and critical period for weed
competition.Thus experiment was conducted at Malinyi
district from January to July 2021 in which the main
objective of the study was to boost the productivity of a few
farmer-preferred rice cultivars in Malinyi district, Morongo,
Tanzania, through weed-competitive cultivars and effective
weeding regime.Specific objectives of the study were (i)
assess weed diversity and abundance in rice growing
areas in Malinyi District, Morogoro and (ii) identify weed-
competitive rice cultivars under natural weed pressure in
Malinyi District, Morogoro. For specific objective 1; Survey was conducted in 70 rice
fields, each 0.4ha to identify weeds. Systematic quadrat
sampling technique in diagonal pattern used. Ten samples
from each field by using 1m2 quadrat were recorded.
Weeds in each field were identified, counted by species
and the data were used to calculate frequency, uniformity,
density, abundance of each species. Weed species
diversity in each village was measure by Shannon weinner
and Simpson indices while similarity of floristic composition
between pairs of villages was obtained by Sorensen index.
For objective 2, the experiment was laid out in Randomized
Complete Block Design (RCBD) with 20 treatment
combinations replicated three times. Factor A contained
four rice cultivars and factor B had five weeding regimes as
treatments. Subplots had 9 m2. Space between replications
was 1 meter. An alley of 0.5 m separated subplots and 1m
separated main plots and 1.5 m border space. Sowing
Space was 25 cm by 20 cm for inter and intra row. Four
rice cultivars were randomly assigned with five weeding
regimes. Data were collected for crop and weed plant
growth and yield parameters. Summed dominance ratio
and relative yield loss were computed by formulae. Two-
way mode of analysis of varience usedin data analysis and
Turkey's honest and least significance difference test at 5%
level used in mean separation.
The present survey identified 35 weed species from 13
families; 19 were annual, 16 perennial; 15 grassy, 3 sedges
and 17 broad leaved weeds. This study revealed high
relative abundance in grass weeds; Paspalum
scrobiculatum (36.7%), sedges; Fimbristylis miliacea
(26.0%) and broad leaved; Ageratum conyzoides (22.5%)
The results indicated Paspalum scrobiculatum was more
dominant than other weeds. Number of weed species count
in villages ranged from 15 to 29 species. Shannon Wienner
and Simpson index had the highest values (2.68, 1.95) and lowest value (0.92, 0.79), respectively; Indicating there is
medium weed species diversity due to uneven distribution.
Similarity index between pairs of villages ranged from 50%
which low to 89% which is high. Results revealed, out of six
weed species, Paspalum scrobiculatum with summed
dominant ratio (43.60), indicated that had greater
contribution in competition. The results had statistical
significance differences (p<.001) in relative yield loss
ranging from 39.54% to 63.84%, Karimata cultivar with
lowest value, demonstrated high tolerance to weeds while
SARO 5 with high value had less tolerance. At least two
weeding had positive effect (p <.001) on rice grain yield in
all cultivar tested. Correlation between weed drymater and
grain yield had significant negative relationship (p<.001, R2
= 0.2691).
This study revealed that Paspalum scrobiculatum,
Fimbristylis miliacea and Ageratum conyzoides were the
most prevalent and abundant grass, sedge and broadleaf
groups, respectively. This may be they are highly adapted
to the environment which favors reproduction and survival.
These weeds need special attention to reduce their
populations. This study also concludes that weed species
in Malinyi district were moderately diverse and most similar
between villages. The study concluded that Karimata
contained weed competitiveness and high yield. Weedingat
15 and 45 DAE had no statistical significance difference of
grain yield with weeding more than two.
This study recommends; regular survey is needed to
identify possible problematic weed and weed population
shifts, sequential cropping system proposed to rice farmers
in order to minimize weed pressure, furtherresearch toward
new or enhanced weed control measures, evaluation of
karimata weed competitive ability and control methods of
Paspalum scrobiculatum and Ischaemum rugosum weed species, and farmers are adviced do weeding at 15 and 45
DAE, as the optimal weeding
Virulence attributes and antimicrobial profile of pasteurella multocida isolated from pneumonic goats in Northern Tanzania
No full textDissertationPneumonic pasteurellosis, stemming from Pasteurella multocida,
poses a significant economic threat to small-scale goat farmers in
northern Tanzania. This study aimed to assess the prevalence of
antimicrobial resistance and virulence genes within Pasteurella
multocida isolates collected from goats displaying clinical symptoms
of the disease. A total of 200 nasal swab samples were obtained from
goats exhibiting signs of pneumonic pasteurellosis. In the laboratory,
these samples underwent culture on blood agar enriched with 5%
horse blood at 37°C and 5% carbon dioxide for 24-48 hours. Isolates
displaying characteristics resembling Pasteurella multocida were
subjected to gram staining and biochemical tests, including indole,
oxidase, and catalase. Among the presumptive Pasteurella multocida
isolates, 10 were initially identified, later confirmed using specific
molecular primers, Pm0762 and Pm1231, with only five isolates
ultimately confirming the presence of either or both genes. The
confirmed isolates were then subjected to susceptibility testing
against ten antibiotics. Additionally, screening for the presence of
virulence genes, including ptfhA, ptfA, fimA, exbD, and exbB, was
conducted. Moreover, antimicrobial resistance genes (sul1, sul2,
blaTEM, aac(3)-1, tetA, and acrA) were investigated. Out of the 200
analyzed nasal swab samples, Pasteurella multocida was isolated in
only 2.5%. This seemingly low prevalence may be attributed to the
larger sample size utilized in this study compared to prior
investigations or the influence of geographic and environmental
factors. Serogrouping revealed that 20% of the isolates belonged to
serogroup A, while a substantial 80% defied classification, posing
challenges for surveillance and control efforts. Further analysis
uncovered the presence of virulence genes crucial for iron acquisition
(exbD found in 100% of isolates) and adhesion (ptfA in 60%), pivotal
for bacterial survival and respiratory tract infection. However, despite
their significance, all isolates exhibited resistance to a broad
spectrum of antimicrobials, including commonly used drugs such as
ampicillin, amoxicillin and erythromycin. Resistance extended to
cephalosporins (cefotaxime), sulfamethoxazole/trimethoprim, and
even macrolides. This widespread resistance underscores the need
for judicious antibiotic use in veterinary medicine to curb the emergence of multidrug-resistant strains. Notably, susceptibility was
retained against gentamicin and ciprofloxacin, suggesting potential
alternative treatment options. Nevertheless, the prevalence of
multidrug resistance across all isolates (100%) emphasizes the
urgency for innovative strategies to combat pneumonic pasteurellosis.
Additionally, the identification of antimicrobial resistance genes like
blaTEM and sul1 in some isolates further accentuates the evolving
threat of resistance. Moreover, the prevalence of untypable strains
underscores the necessity for further research to understand their
implications and devise alternative typing methodologies for effective
control. In summary, this study reveals a concerning landscape of
antimicrobial resistance and virulence in Pasteurella multocida among
goats in northern Tanzania. Addressing challenges such as low
isolation rates, untypable strains, and widespread resistance
necessitates a multifaceted approach involving prudent antibiotic use,
exploration of novel treatment modalities and diagnostics, and
collaboration among public health authorities, veterinarians, and
livestock producers. Only through concerted efforts can we effectively
combat pneumonic pasteurellosis and safeguard the health and
livelihoods of small-scale goat farmers in the region.Sua Research Institute
(SUARIS) for providing financial support through the grants awarded
to Dr. Mzula
Effects of spacing on growth,yield and wood properties of Tectona grandis at Longuza forest plantation, Tanzania
No full textMSc DissertationIn forest management, understanding the influence of spacing on
tree growth is crucial, as it goes hand in hand with stand growth as
well as yield at the final harvest. Also, spacing, especially narrow
spacing, has been used to control the stem quality of trees, as it
influences the stem straightness as well as the branching behaviour.
On the other hand, tree growth, particularly radial growth, means an
increase in wood materials such as cell wall substances, latewood,
and earlywood. Those wood materials influence the physical and
mechanical properties of wood. Behind those influences, an
understanding of the influence of spacing on the final harvest is
required to decide on appropriate spacing to economize the value of
the final harvest. However, information on the spacing influence on
growth, yield, and wood properties of Tectona grandis at an older
age in Tanzania is limited. Thus, this study is intended to evaluate
the influence of spacing on the growth, yield, and wood properties of
24-year-old Tectona grandis at Longuza Forest plantation, Tanzania.
Data were collected from a spacing trial with a randomized complete
block design with three treatments, namely 2 x 2 m, 3 x 3 m, and 4 x
4 m, replicated three times. For growth and stem quality, all trees'
diameter at breast height (dbh), height, and stem quality were
evaluated. Then, dbh data were used to obtain basal area (Ba),
volume, and the mean annual increment (MAI). Furthermore, three
trees from each spacing were sampled for physical and mechanical
properties.
The basic density (BD) was determined using
over-dry weight and green volume, while the heartwood (HW)
percentage was calculated using the cross-sectional area of the HW
and disk underbark. Moreover, all mechanical properties were tested
using a Monsanto tensiometer machine. An analysis of variance
(ANOVA) was used to evaluate the influence of spacing. Then,
Tukey’s Honest Significant Difference test (p = 0.05) was used for
multiple comparisons of means. Results revealed that at the older
age of 24 years, spacing did not statistically influence all growth and
yield parameters studied. A 4 x 4 m spacing produced trees with
higher dbh and height, while higher Ba, volume, and MAI values
were observed at 3 x 3 m. Stem quality was statistically different in
some spacings, where only 2 x 2 m differed statistically from 4 x 4
m. All physical and mechanical properties evaluated were not
statistically influenced by spacing except CLST to grain, whereby the
spacings of 2 x 2 m and 3 x 3 m had significantly higher values than
a spacing of 4 x 4 m. In conclusion, results showed that despite the
growth and yield parameters not being statistically influenced by
spacing, a spacing of 3 x 3 m could ensure a higher yield compared
to other spacings. Also, it produces trees with high stem quality,
similar to closer spacing, without affecting both physical and
mechanical properties. This is because the values of those
properties appear to have slight differences among the spacings.
Keywords: Tectona grandis, Spacing, Volume, Stem quality, Basic
density, Heartwood percentageForest Services Agency (TFS