grace manyelo

Prof. grace manyelo

University of Limpopo

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 September 2020 in Antibiotics
Verified
Journal Article
Open access
PDF file
Letlhogonolo SelalediLetlhogonolo Selaledi
Letlhogonolo Selaledi
Zahra HassanZahra Hassan
Zahra Hassan
GMgrace manyelo
grace manyelo
MMMonnye Mabelebele
Monnye Mabelebele
Over the years the growth and health of food-producing animals have been enhanced by the use of antibiotics. These have helped reduce on-farm mortalities, lower incidences of diseases and more importantly improve productivity. Generally, the utilization of antibiotics in feed has been reevaluated since bacterial pathogens have established and shared a variety of antibiotic resistance mechanisms that can easily be spread within microbial communities. Multiple countries have introduced bans or severe restrictions on the non-therapeutic use of antibiotics. This has therefore warranted the urgent need for alternatives. Africa is facing its own challenges as it has been reported to be one of the continents with the highest number of foodborne diseases with approximately 91 million related diseases and 137,000 death per annum. Stakeholder and policy direction has been put in place to curb this escalation; however, the problem persists. The use of alternatives has been recommended and some successfully used in other countries as well as Africa, including pro- and prebiotics and phytochemicals. This then leads to the core aim of this review which is to (1) determine the extent to which antimicrobial-resistant pathogens have affected Africa, (2) assess the current measures put in place by Africa to reduces antimicrobial resistance and finally (3) explore the alternative use of antibiotics in poultry production. Improved sanitary conditions and farm biosecurity are important alternatives that could be adopted by farmers instead of depending on antibiotic drugs for disease control and prevention.

30 November 2020 in Animals
Verified
Journal Article
Open access
PDF file
GMgrace manyelo
grace manyelo
Letlhogonolo SelalediLetlhogonolo Selaledi
Letlhogonolo Selaledi
Zahra HassanZahra Hassan
Zahra Hassan
MMMonnye Mabelebele
Monnye Mabelebele
There has been a research gap in the genetic, physiological, and nutritional aspects of indigenous chickens of Africa over the past decade. These chickens are known to be economically, socially, and culturally important to the people of Africa, especially those from marginalised communities. Although they are associated with poor productivity in terms of the number of eggs laid, most consumers prefer their flavoursome meat. Several local chickens have been classified into breeds or ecotypes, but many remain unidentified and are facing extinction. To prevent this, the Food and Agriculture Organization has launched an indigenous poultry conservation programme. In addition, the Agricultural Research Council in South Africa has established a programme to protect four local chicken breeds. The purpose of this review is to provide a detailed understanding of the description, uses and conservation methods of local chicken breeds of Africa. Several studies have been conducted on the nutritional requirements of local chickens, but the results were inconclusive and contradictory. This review concludes that local chickens play a significant role in improving livelihoods, and strategies to preserve and sustain them must be intensified.

14 October 2020 in Molecules
Verified
Journal Article
Open access
PDF file
Zahra HassanZahra Hassan
Zahra Hassan
GMgrace manyelo
grace manyelo
Letlhogonolo SelalediLetlhogonolo Selaledi
Letlhogonolo Selaledi
MMMonnye Mabelebele
Monnye Mabelebele
Over recent years, the monogastric animal industry has witnessed an increase in feed prices due to several factors, and this trend is likely to continue. The hike in feed prices is mostly due to extreme competition over commonly used conventional ingredients. For this trend to be subdued, alternative ingredients of both plant and animal origin need to be sourced. These types of ingredients are investigated with the aim of substituting all or some of the conventional compounds. However, alternative ingredients often have a double-edged sword effect, in that they can supply animals with the necessary nutrients although they contain antinutritional factors such as tannins. Tannins are complex secondary metabolites commonly present in the plant kingdom, known to bind with protein and make it unavailable; however, recently they have been proven to have the potential to replace conventional ingredients, in addition to their health benefits, particularly the control of zoonotic pathogens such as Salmonella. Thus, the purpose of this review is to (1) classify the types of tannins present in alternative feed ingredients, and (2) outline the effects and benefits of tannins in monogastric animals. Several processing methods have been reported to reduce tannins in diets for monogastric animals; furthermore, these need to be cost-effective. It can thus be concluded that the level of inclusion of tannins in diets will depend on the type of ingredient and the animal species.

11 May 2021 in Insects
Verified
Journal Article
Open access
PDF file
Letlhogonolo SelalediLetlhogonolo Selaledi
Letlhogonolo Selaledi
Zahra HassanZahra Hassan
Zahra Hassan
GMgrace manyelo
grace manyelo
MMMonnye Mabelebele
Monnye Mabelebele
Edible insects can be produced sustainably, with less environmental impact than other forms of livestock. Globally, over 2000 edible insect species have been reported and are regarded as a great source of nutrition, both as food and feed. Over the years, rural people have used indigenous knowledge to either store or process such insects. However, such valuable knowledge, if not properly recorded and documented, can easily be lost. Thus, there is a need to strike a balance between the use of indigenous and scientific knowledge to produce and process these delicacies. In addition, such indigenous knowledge is vital for preserving biodiversity, since insects are good indicators of climate change as it influences their development, reproduction, and survival. Therefore, successful and sustainable solutions may lie in bringing back indigenous knowledge systems.

26 August 2020 in Animals
Verified
Journal Article
Open access
PDF file
GMgrace manyelo
grace manyelo
NSNthabiseng Sebola
Nthabiseng Sebola
ERElsabe van Rensburg
Elsabe van Rensburg
MMMonnye Mabelebele
Monnye Mabelebele
This review presents, discusses, and provides a comprehensive understanding of the potential use of amaranth as feed for monogastric animals. Amaranth is an ancient nutritious crop that has been cultivated for multiple purposes. In America, Asia, and Africa, the leaves of amaranth species are used as vegetables. The change in climatic conditions globally has resulted in shortages of rainfall, unpredictable weather, and lack of inputs such as fertilizer. This has led to scarcity of protein sources in the market and instability in prices which makes it necessary to consider alternative ingredients in poultry, pigs, fish, and rabbits feed formulation. Amaranth is rich in fiber, proteins, vitamins, minerals, and phenolic compounds which have some health benefits in animals and can be used to improve productivity. It also contains anti-nutritional factors which can be reduced by several processing methods. Moreover, its use in monogastric nutrition is useful because amaranth has shown to improve monogastric productivity without having any adverse effect on animals’ productivity. Thus, from this review, it can be concluded that amaranth leaves and grains can be used successfully in monogastric animals though different processing methods which might need to be employed in order to reduce anti-nutritional factors before use in animals.

18 September 2020 in Molecules
Verified
Journal Article
Open access
PDF file
GMgrace manyelo
grace manyelo
NSNthabiseng Sebola
Nthabiseng Sebola
Zahra HassanZahra Hassan
Zahra Hassan
MMMonnye Mabelebele
Monnye Mabelebele
Phenolic compounds that are present in amaranth crops have gained a lot of interest from researchers due to their health benefits potential. Therefore, the aim of this study was to investigate phenolic compounds present in different plant parts of Amaranthuscruentus using liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry. Moreover, data were analyzed by one-way analysis of variance of the statistical analysis software, whereas commercial statistical package version 4.02 was used for principal component analysis. A total of 21 phenolic compounds were detected and eight were not identified. Caffeoylsaccharic acid isomer, coumaoryl saccharic acid, tryptophan, feruloyl-d-saccharic acid isomer a, b, and c, caffeoyl isocitrate, quercetin 3-O-rhamnosyl-rhamnosyl-glucoside, feruloyl isocitrate, hyperoside, kaempferol rutinoside, and alkaloid compounds were mostly detected in tender and mature leaves. Generally, rutin content was higher (p < 0.05) in most vegetative parts of the amaranth plant, thus, late maturity leaves, tender leaves, and mature leaves, respectively. Lower quantities of rutin were observed in tender grains, flowers, and mature grains. It can be concluded that amaranth contains phenolic compounds, predominantly in the vegetative parts, which makes it to be a promising source of phenolic compounds beneficial to human health.