Theses and Dissertations (Agriculture, Animal Health and Human Ecology)
https://hdl.handle.net/10500/2728
2024-03-28T14:29:46ZMetabolomic analysis of GM and non-GM maize and its preference by cattle
https://hdl.handle.net/10500/30693
Metabolomic analysis of GM and non-GM maize and its preference by cattle
Payne, Joseph
GM organisms have started to infiltrate South Africa's agricultural landscape, altering how
farmers deal with weeds and insects. Adopted from the United States of America, it is a
technology that the commercial farming sector cannot do without anymore and the uptake
was enormous in the last 10 years. The technology involves altering the DNA of an
organism to provide a specific benefit using genetic engineering techniques.
But all new technologies and inventions bring the responsibility of stewardship and
accountability with it, and it is impossible to predict all possible outcomes of such an
invention to every possible scenario in terms of environmental stewardship. The question
and occurrence of cattle and wild animals seemingly choosing non-GM containing maize
plants have raised the question whether this is really the case of the presence of the GM or
maybe it is just due to the differences in plant genetic makeup. Quicker deterioration of
short, seasoned cultivars opposed to the longer seasoned cultivar that is known to be more
resistant to diseases and plant pathogens, might therefore not be as easily affected by mainly
pathogens and stay much tastier for longer.
This study used beef cattle of the Drakensberger indigenous breed to determine the taste
preference with the use of a trial that is planted with the different types of maize cultivars
that includes GM and non-GM maize and short and longer seasoned cultivars. The trial was
performed on a commercial farm near Standerton, Mpumalanga in the high rainfall area of
South Africa. The results clearly indicated that cattle could not differentiate the GM maize
from the non-GM maize, but that they preferred the longer season cultivar.
The chemical profiles of different materials, including those made from GM and non-GM,
were analyzed using NMR spectroscopy and OPLS-DA and pre-processing techniques. The
results of the metabolomic study revealed that the former had slightly different
metabolomics profiles than the latter. The differences were mainly concentrated in the
aliphatic and sugar regions. On the other hand, the long and short-season GM had similar
metabolomic profiles.
The study therefore clearly indicates that cattle could not differentiate GM from non-GM
material on taste and that any material can be provided to cattle. The slight difference in the
metabolomics profiles however raise a concern for differential metabolomic pathways and
should be investigated further.
2023-01-01T00:00:00ZThe effect of environmental factors on the metabolomic profile and the biological activities of Helichrysum aureonitens
https://hdl.handle.net/10500/30687
The effect of environmental factors on the metabolomic profile and the biological activities of Helichrysum aureonitens
Adeosun, Wilson Bamise
The use of plants for medicinal purposes precedes human written history. Accounts from many
archaeological sources agree that the Sumerians were the first to compile plants’ lists according
to their herbal remedy potentials over 5, 000 years ago. The World Health Organisation (WHO)
estimated that about 80% of the world population rely on herbal medicine as their primary
source of healthcare. There is a heightened public interest in the use of plant sources as natural
therapies in both developed and developing countries in the last decade, leading to a surge in
the availability of herbal remedies in pharmaceutical stores and supermarkets.
The Helichrysum genus comprises flowering plants which are aromatic perennial shrubs
belonging to the sunflower family. There are an estimated 600 species spread across Africa,
Europe, Australasia, and Eurasia with almost half of the species found in South Africa.
Helichrysum aureonitens is an important medicinal plant used for the treatment of many
infections especially in the KwaZulu-Natal and Eastern Cape provinces.
Previous studies on H. aureonitens have established antimicrobial activities against Gram positive bacteria (especially Bacillus species) and antiviral activity against viruses such as
herpes simplex virus type 1 (HSV-1), coxsackie B virus type 1 (Cox B1), adenovirus type 31
(Ad31) and reovirus. Many phenolic compounds linked to the plants’ activities include
chlorophenol, 4-chloro-2-(hepta-1,3,5-triyn-1-yl)-phenol, galangin (3,5,7 trihydroxyflavone)
and chlorogenic acids among others have been identified from the shoot and leaves of H.
aureonitens.
Many studies have established the influence of environmental factors on plants’ secondary metabolites. Only a few studies however exist on the influence of seasonal variation or different
growing locations with dissimilar climates on the chemical profile and antimicrobial activities
of any plant species from the Helichrysum genus. This study therefore focused on determining
the effect that change in seasons and locality with different climate has on the chemical profile
of H. aureonitens and how the shift in metabolites is linked to the plants’ bioactivity. The
antibacterial, antifungal, and antiviral activities of H. aureonitens extracts from different
collection sites were evaluated against certain pathogens. The Gram-negative bacterium
Proteus vulgaris and Gram-positive bacterium Bacillus subtilis were used for the study. The
extracts’ activities were also tested against five pathogenic fungal species including Aspergillus
flavus, Aspergillus nomius, Cladosporium cladosporioides, Fusarium oxysporum and
Penicillum halotolerans. Lastly, the extracts were evaluated against the human virus, herpes simplex virus
type 1 (HSV-1) to determine the antiviral activity.
Plant samples were collected during the spring (October) and autumn (May) seasons at
Wakefield farms, Midlands in KwaZulu-Natal (wetter location with lower temperature) and
Telperion farm in Mpumalanga (drier location with higher temperature) regions of South
Africa. Collections were made in both wet and dry sites selected at each of the two localities.
Temperature and rainfall data were also collected for Cedara and Witbank between August
2017 and June 2018 representing the closest stations of South African Weather Services to the
two collection locations.
Hydroalcoholic extracts (30:70) of most H. aureonitens plants collected from both
geographical locations and seasons showed good activities against the gram-negative
bacterium P. vulgaris with Minimum Inhibitory Concentration (MIC) ranging between 62.5-
125 µg/mL. Activities of extracts collected from spring however showed better activities than
the autumn harvests. No activity was however recorded against the gram-positive bacterium B.
subtilis.
Acetone extracts of H. aureonitens showed strong antifungal properties against four of the five
fungal species tested. No activity was recorded against A. nomius by any of the extracts. All
the other fungal species were however significantly inhibited by varied extract concentrations
of H. aureonitens with MIC values between 0.39 – 3.125 µg/mL. The observed activities were
specific to individual species. Generally, plant samples harvested from Telperion (drier
location) had better activity against A. flavus, C. cladosporioides, F. oxysporum, and P.
halotolerans compared to Wakefield (wet location). With the exception of F. oxysporum, rainfall had an inconsequential impact on the antifungal properties of the plant against the other
tested species.
A cytopathic effect (CPE) reduction approach was used to evaluate the anti-HSV activity of
the twenty-six samples of H. aureonitens leaves and stems extracts. Cytotoxicity evaluation of
the extracts was carried out using MTT assay prior to antiviral determination. It was observed
that seventeen (mostly spring collections) of the twenty-six extracts examined were found to
have considerable anti-HSV activity, as measured by a reduction in tissue culture infectious
dose (TCID50) of less than 105.
Through the application of multivariate statistical analysis using a Nuclear Magnetic
Resonance spectrometer (NMR), 1H-NMR spectra of H. aureonitens leaf extracts were
generated to compare samples collected in different seasons and locations as well as wet and
dry sites. It was observed that changes in season played a significant role in the production of
aromatics with the largest concentration found in the spring season and wet sites across both
locations. Comparatively, the aromatics level is also favoured in the wetter geographical
location which is Wakefield farm. Caffeoylquinic acids (CQA) which is the main Chlorogenic
acids reported in nature are a class of compounds reported to be abundant in the Helichrysum
genus. Ultra-Performance Liquid Chromatography Quadrupole Time of Flight Spectroscopy
(UPLC-qTOF-MS), was used as an analytical platform to determine the identity of three
derivatives of CQA and their isomers-monocaffeoylquinic acids (MCQA), dicaffeoylquinic
acid (DCQA) and tricaffeoylquinic acid (TCQA) in the chemical profile of H. aureonitens. The
DCQA derivative was the most abundant, with higher concentrations of all its isomers in both
locations and seasons.
The study highlights the impact of seasonal variation and different geographical locations on
the chemical profile and antimicrobial properties of H. aureonitens.
2022-09-01T00:00:00ZEvaluation of the contribution of Ilima-Letsema Programme to food security and poverty alleviation in Midvaal Local Municipality of Gauteng Province, South Africa
https://hdl.handle.net/10500/30685
Evaluation of the contribution of Ilima-Letsema Programme to food security and poverty alleviation in Midvaal Local Municipality of Gauteng Province, South Africa
Nkgudi, Tshidi Mokgadi
In 2008, the South African government introduced the Ilima-Letsema Programme (ILP) to create sustainable agricultural activities and improve the food security of farming communities. The impact this programme has had at the grassroots level has, however, not been thoroughly investigated. The purpose of this study was to evaluate the contribution of this programme to food security and poverty alleviation in the Midvaal Local Municipality of Gauteng, in South Africa. The objectives were to determine the socio-demographic characteristics of the beneficiaries; the impact of the programme on agricultural production; what factors influenced that impact; the food security status of the beneficiaries (with reference to availability, access and stability); and the contribution of the programme to net income, poverty alleviation and job creation. To this end, the study employed a quantitative research approach and survey design. Data were collected from 196 beneficiaries of the ILP through face-to-face interviews using a structured survey questionnaire. SPSS v. 24 was used to analyse the quantitative data. Descriptive statistics (mean, standard deviation and standard error of mean) ordered logistic regression, binomial test and Wilcoxon signed ranks test were applied. The socio-demographic results revealed that more males (53.6%) than females benefited from the ILP, with 60.7 per cent aged 51 years and above. About 43.4 per cent owned the land they farmed on, with an average farm/plot size of 4.4 ha. The respondents’ average annual income was R47 513.59, with 75 per cent relying on income earned from farming to sustain their livelihoods. The ILP was found to contribute significantly to the agricultural production (crop and livestock) of the beneficiaries, with only farming experience having a positive and significant (p < 0.05) impact. As regards the contribution of the programme to food security, the food availability of 55.6 per cent of the respondents improved, with 76.5 per cent reportedly producing food throughout the year, after receiving support. In addition, 52 per cent had access to food, and 54.5 per cent had the necessary farming experience to continue producing food, resulting in food stability. The results of the Wilcoxon signed rank test indicated that the ILP played a significant role in uplifting the beneficiaries from the upper-bound poverty line, creating job opportunities and improving income. Although the study was conducted at the local level, the findings showed that the programme improved the livelihoods of the farmers. For that reason, it was recommended that government increase the budget allocation for the programme and make it more inclusive, to enable most farming communities to benefit from it.
2019-01-01T00:00:00ZAn investigation on the role of food gardens to food security and community development in Thulamela Municipality
https://hdl.handle.net/10500/30649
An investigation on the role of food gardens to food security and community development in Thulamela Municipality
Kwinda, Pfanani Charlotte
This study was conducted in the Thulamela Municipality, Vhembe District of Limpopo Province, South
Africa. The study area is characterised by poverty-stricken rural households. A high proportion of
households relied on agriculture to supplement food for their families. The main objective of the study was
to investigate the role and contribution of food gardens to food security and community development. Prior
studies elsewhere and experiences of developing countries recognised the positive impacts of food gardens
in providing food security, household economic welfare and rural development. A longitudinal study was
undertaken to collect data from a sample of 383 households and 82 focus groups individuals selected
through purposive and snowball sampling. Qualitative and quantitative research methods were used to
collect data using interview questionnaires, observation checklists, a 24-hour food recall, a food frequency
questionnaire, and a focus-group checklist. Data were gathered on socio-demographics; the role and
contribution of food gardens to food security, household income and community development; challenges to
food gardening and strategies for sustainable year-round availability of food. The Statistical Package for
Social Science Version 23.0 was used to analyse quantitative data while the content of qualitative data was
analysed to develop themes. Inferential statistics was done to determine the significance of the findings
through correlation testing and regression analysis.
The findings revealed that 56% of food gardeners were men, with people of different age groups,
educational background, training and experiences in food gardening. Almost all (99.7%) participants had
food gardens, which allowed them access to food for consumption and selling. Food gardens enabled
households to spend less money on food. Income earned by selling garden produces helped to buy
uncultivated food stuff and other basic necessities. Different kinds of garden produces were available in
different seasons, which allowed households to access food throughout the year. Indigenous vegetables were
also utilised. Food gardens played a major role and contributed significantly to food security and community
development. Moreover, food gardens promoted avenues for job creation, self-employment and self reliance. Challenges to food gardening were addressed to ensure a sustainable year-round supply of food.
The study provided a framework for understanding the relationship between food gardening and food
security.; Ngudo iyi yo itwa kha Masipala wa Thulamela, Tshiṱirikini tsha Vhembe kha Vundu ḽa Limpopo, Afrika
Tshipembe. Sia ḽa ngudo ḽo ṱalulwa nga miṱa ya mahayani i re na vhushai. Tshipiḓa tshihulwane tsha miṱa
tsho ḓisendeka nga zwa vhulimi u tikedza zwiḽiwa zwa miṱa yavho. Tshipikwa tshihulwane tsha ngudo ho
vha u ṱoḓisisa mushumo na u dzhenelela ha ngade dza miroho kha tsireledzo ya zwiḽiwa na mveledziso ya
tshitshavha. Ngudo dzo rangelaho idzi huṅwe na tshenzhemo dza mashango ane a khou bvelela dzo dzhiela
nṱha masiandaitwa mavhuya a ngade dza zwiḽiwa kha u ṋekedza tsireledzo ya zwiḽiwa, mutakalo wa
ikonomi ya muṱa na mveledziso ya vhupo ha mahayani. Ngudo buḓa dzo itwa u itela u kuvhanganya data u
bva kha miṱa ya 383 na zwigwada zwo sedzwaho zwa vhathu vha 82 vho nangiwaho nga kha
tsumbonanguludzwa dzi re na ndivho na u vhudzisa vhaṅwe vhathu vha re kha ṱhoḓisiso. Ngona dza
ṱhoḓisiso khwaḽithethivi na khwanthithethivi dzo shumiswa u kuvhanganya data nga u shumisa
mbudzisombekanywa dza inthaviwu, mutevhe wa mbudziso dza mbono, u elelwa zwiḽiwa zwo liwaho kha
awara dza 24, mbudzisombekanywa dza misi yoṱhe dza nga ha zwiḽiwa, na mutevhe wa tsedzuluso wa
tshigwada tsho sedzwaho. Data yo kuvhanganywa kha demogirafi ya matshilisano, mushumo na u
dzhenelela ha ngade dza zwiḽiwa kha tsireledzo ya zwiḽiwa, mbuelo ya miṱa na mveledziso ya tshitshavha;
khaedu dza ngade dza zwiḽiwa na zwiṱirathedzhi zwa u wana zwiḽiwa ṅwaha woṱhe zwi sa nyeṱhi.
Tshiputelo tsha mbalombalo tsha Saintsi dza Matshilisano Vesheni ya vhu 23.0 yo shumiswa u saukanya
data ya khwanthithethivi, ngeno zwire ngomu zwa data ya khwaḽithethivi zwo saukanywa u bveledza thero.
Mbalombalo khumbulelwa yo itwa u itela u vhona ndeme ya mawanwa nga kha u linga u elana na
musaukanyo wa khumela murahu.
Mawanwa o dzumbulula uri 56% ya vhoradzingade dza zwiḽiwa vho vha vhe vhanna, hu na vhathu vha
vhukale ho fhambanaho, vhubvo ha pfunzo, vhugudisi na tshenzhemo kha ngade dza zwiḽiwa. Vhadzheneli
vhane vha ita mbaloguṱe (99.7%) vho vha vhe na dzingade dza zwiḽiwa dzine dza vha konisa u swikelela
zwiḽiwa u itela u ḽa na u rengisa. Ngade dza zwiḽiwa dzo konisa miṱa u shumisa tshelede ṱhukhu kha
zwiḽiwa. Mbuelo yo wanalaho nga u rengisa zwibveledzwa zwa ngadeni yo thusa u renga zwiḽiwa zwine
zwa sa tou limiwa na zwiṅwe zwithu zwa ndeme. Tshaka dzo fhambanaho dza zwibveledzwa zwa ngadeni
dzo vha dzi hone nga khalaṅwaha dzo fhambanaho, zwe zwa konisa miṱa u swikelela zwiḽiwa ṅwaha woṱhe.
Miroho ya vhongwaniwapo na yone yo shumiswa. Ngade dza zwiḽiwa dzo shuma mushumo muhulwane na
u dzhenelela zwihulwane kha tsireledzo ya zwiḽiwa na mveledziso ya tshitshavha. Zwiṅwe hafhu, ngade dza
zwiḽiwa dzo bveledza nḓila dza u sika mishumo, u ḓishuma na u ḓisendeka nga iwe muṋe. Khaedu dza
ngade dza zwiḽiwa dzo tandululwa u itela u khwaṱhisedza nḓisedzo ya zwiḽiwa i sa nyeṱhi ṅwaha woṱhe.
Ngudo dzo ṋekedza muhangarambo wa u pfesesa vhushaka vhukati ha u ita ngade dza zwiḽiwa na tsireledzo
ya zwiḽiwa
2023-07-01T00:00:00Z