Tshimangadzo Lucky Nedambale

Tshwane University of Technology | tut · Department of Animal Sciences

Ram fertility is not defined by a single trait. Quantifiable physical parameters that are correlated to fertilization capacity of sperm are required to advise farmers on ram selection activities. The objective was to investigate the relationship between body measurements and sperm traits of Bapedi rams conserved in situ and ex situ. Before semen co...

The purpose of this study was to evaluate how ascorbic acid with dietary flaxseed oil affects the quality and fertility of cryopreserved ram sperm in South African indigenous rams. Treatment diets were supplemented 60 days before semen collection to afford proper spermatogenesis, adaptation to the feed formulated and fed throughout the study. Semen...

The study aims to compare different concentrations (0, 2.5, 5, 7.5 and 10 mM) of antioxidants, Dithiothreitol (DTT) and Glutathione (GSH), on sperm parameters following the freeze-thawing of semen from large white boars. Three large white boars were selected for semen collection and the collected semen was sent to the lab for analysis. Following di...

South Africa is home to numerous indigenous and locally developed sheep (Nguni Pedi, Zulu, and Namaqua Afrikaner, Afrino, Africander, Bezuidenhout Africander, Damara, Dorper, Döhne Merino, Meat Master, South African Merino, South African Mutton Merino, Van Rooy, and Dorper), goat (SA veld, Tankwa, Imbuzi, Bantu, Boer, and Savanna) and cattle (Afrig...

Traditionally, egg yolk is a protective agent that is used to freeze semen in various species. However, the addition of egg yolk in extender risks the introduction of disease. Therefore, an alternative cryoprotective agent should be found to preserve ram semen. The aim of this study was to evaluate the effect of phosphatidylcholine (PC) as a protec...

The domestic pig breeds are in danger of extinction whereas the erosion of their gene pool is a serious concern because they significantly contribute to the rich biodiversity. Overall aim of this study was to determine the protocol for preserving the semen of the Windsnyer boars for conservation. A total of 18 ejaculates (6 replications/boar) were...

The purpose of this study was to determine the seasonal variations in semen quality, testosterone levels, and scrotal size, following dietary flaxseed oil and ascorbic acid in South African indigenous rams. A total of 22 South African indigenous rams were randomly distributed into five treatment diets from June 2021 to May 2022 (12 months). To allo...

The purpose of this study was to examine the effects of quail egg yolk extenders in the cryopreservation of cockerel semen. Ten Venda cockerels were chosen randomly and semen was collected twice a week with a two-day rest period using an abdominal massage technique. Immediately following semen collection, semen samples were evaluated for microscopi...

The study was conducted to compare differences in vitro maturation media and their effect on subsequent in vitro embryo production. The study procedures were approved by the agricultural research council animal ethics committee (Ref no: APAEC 2020/05) and the Tshwane university of technology animal research ethics committee (Ref no: AREC 2021/08/00...

The current study aimed to evaluate the effects of the dietary inclusion of flaxseed oil and ascorbic acid on the reproductive performance of South African indigenous sheep (Ovis aries). Twenty-two matured South African indigenous rams (eight BaPedi, nine Zulu, and five Namaqua Afrikaner; age of 6 years and body weight of 64.4 ± 1.6 kg) were random...

The study aimed to determine the efficacy of different semen extenders and in vitro storage periods on the Windsnyer boar sperm quality equilibrated at 18°C. Ejaculates (n=18) from three Windsnyer boars of known fertility were evaluated for macroscopic traits, pooled, and then allocated for extension in Beltsville Thawing Solution (BTS) and Kobidil...

Cryopreservation is the most practical approach for the long-term storage of sperm in boars. However, the freezing and thawing processes result in compromised sperm function and in vitro fertilization (IVF) success. The study aimed to evaluate the fertilizing ability of frozen-thawed semen on matured porcine oocytes following IVF. Semen was collect...

Oestrous synchronization and artificial insemination (AI) are two advanced reproductive technologies that dairy and beef cattle productions are increasingly using to enhance their herds' reproductive performance. However, oestrus synchronization can be influenced by many intrinsic and extrinsic factors. Therefore, the objectives of this study were...

Boar sperm is associated with the post-thawed sperm quality reduction due to the low cholesterol and high polyunsaturated fatty acid contents in their sperm plasma membrane (Li J, 2017, Cryobiology, 80, 119-125). The objective of the study was to investigate the efficacy of the cryoprotectants combination at different concentrations on the Windsnye...

South African indigenous breeds’ population is decreasing at a time when their genetic material is mandatory due to the rising climate change and global warming. South African indigenous sheep breeds include Namaqua Afrikaner, Zulu, BaPedi, and Damara sheep. These breeds are the most preferred breeds by rural farmers in South Africa due to their ad...

The objectives of this study were to evaluate the properties of sperm motility and morphology under induced oxidative stress, compare the antioxidant capacity of dithiothreitol (DTT) and glutathione (GSH) following the cryopreservation of Large White boar semen, investigate the ability of cryopreserved Large White boar semen to fertilize the mature...

The aim of the study was to compare the effect of age and live body weight on the oestrus response, duration, pregnancy rate and lambing rate among South African indigenous sheep breeds (Zulu sheep = 36, Bapedi sheep = 26, Damara sheep = 10 and Namaqua Afrikaner sheep = 9). Control Intravaginal Drug Release Dispensers (CIDR's) were inserted into th...

The present study aimed to evaluate the effect of different freezing methods (slow freezing and liquid nitrogen vapour) and thawing temperatures (5, 18, 37, and 40°C) on post-thawed sperm motility and morphology of Windsnyer boar semen. Total of 18 ejaculates (6 replication/boar) were collected from three Windsnyer boars of proven fertility with th...

In response to the conservation of threatened livestock species, different strategies to improve semen quality have been developed. However, spermatozoa remain sensitive to cryopreservation damages especially that of avian species, thus limiting the use of reproductive biotechnologies such as artificial insemination in the conservation programs. Im...

This study address historical legacy of South Africa that has dual economies resembling low and high income beef sectors. Low-income herds are farmed mainly under communal village or land reform farms. The study focused on providing assisted reproductive technologies (ARTs) to the low-income sector including finding challenges to its implementation...

The purpose of the present work was to determine the response in growth performance and spermatozoa characteristics of Windsnyer boars supplemented with progressive levels of α-tocopherol. Twenty Windsnyer boars aged 12 weeks with an average body weight of 19.5 ± 2.67 kg were used. Each boar was housed individually in a 1.54 × 0.8 m pen in environm...

The objectives of the study were to evaluate the effect of two extenders (Triladyl® and Bioxcell®) and the removal of seminal plasma on indigenous buck’s semen. Semen was collected from six indigenous bucks using an electro-ejaculator. Raw semen was pooled and randomly allocated into six groups as follows: (i) Raw non-washed, (ii) Raw washed, (iii)...

The study investigated the influence of Assisted Hatching (AH) techniques (mechanical, chemical, enzymatic thinning and laser) and two in vitro culture media (Ham’s F10 and TCM-199) on hatching rate of mice embryos (blastocyststage) following 24 hours of culture. The C57BL/6-black (n=30) and BALB/cwhite (n=30) mouse breeds were raised until maturit...

The present study aimed to evaluate an oestrous synchronization protocol and oestrus response before AI in cows from an organised communal production system. A total of 74 cows Bos indicus (Brahman) and Bos taurus/indicus hybrid (Nguni) type from different communal farmers were screened based on: age (3 to 8 years), body condition score of ≥3 (1–5...

The invitro embryo production technique is one of the assisted reproduction technologies that has the potential in speeding up genetic improvement in cattle. The developmental competence of invitro-matured oocytes is influenced by several factors during invitro maturation (IVM), such as maturation environment, oocyte quality, type of media, and add...

The invitro maturation (IVM) rate of pig oocytes is a critical step for subsequent invitro embryo production. The objective of the present study was to compare different IVM media (NCSU 23, NCSU 37, TCM-199, pFF, BO-IVM commercial, and Bovine IVM) on polar body extrusion in pig oocytes following 44h of maturation duration. Ovaries from sows were co...

Climate change represents a major stressful environmental condition that compromises the reproductive efficiency of animals. The temperature affects various components of the maturation processes in cattle oocytes, this includes disruptions of oocyte development and maturation. Therefore, the study aimed to compare the effects of different incubati...

In poultry industry, chick viability is a crucial factor determining profitability from fertilized egg to placement at the farm. However, decreases in fertility and hatchability have been observed. Recently, there has been renewed interest in the use of silver nanoparticles (Ag-NPs) due to their antimicrobial properties and growth-promoting ability...

Traditionally, egg yolk is a protective agent that is used to freeze semen in various species. However, the addition of egg yolk in extender risks the introduction of disease. Therefore, an alternative cryoprotective agent should be found to preserve ram semen. The aim of this study was to evaluate the effect of phosphatidylcholine (PC) as a protec...

This study was conducted to assess genetic variation in Bapedi sheep using 14 microsatellite markers. Blood samples were collected from 174 unrelated Bapedi sheep on six farms in various districts of Limpopo and from the Agricultural Research Council Animal Production Institute (ARC-API) in Gauteng. Genotypes from other South African indigenous she...

The study was conducted to evaluate the seasonal variations in semen parameters of Zulu rams preserved at 10°C for 72 h. The study site was the Agricultural Research Council (ARC) Irene, during the breeding season and the non-breeding season. Zulu rams (n = 6, age = 3 years and average weight = 35 kg ±2.29) were used in this study. Semen was collec...

A study was designed to assess factors affecting response to oestrus synchronization, conception and calving rate of communal cows following timed artificial insemination (AI) in Limpopo province, South Africa. A total of 140 cows were selected from communal villages based on; body condition score (BCS) of 2 and above (1-5 scale), not pregnant (exc...

Bapedi is a fat-tailed, hardy, and disease-tolerant breed of sheep that is indigenous to South Africa. The Bapedi sheep breed is facing genetic degradation due to nonselective cross-breeding and irregular mating; therefore, breeding strategies for urgent conservation of Bapedi sheep are crucial. The aim of the present study was to investigate the r...

Cryoprotectant (CPA) toxicity has been recognised as a critical barrier to further advancement of cattle oocytes. Furthermore, CPA at high concentration might be toxic to oocytes, leading to osmotic shock and cell death (Arav et al. 1993). Selection of quality oocytes among a heterogeneous pool is mostly done subjectively. The use of Brilliant Cres...

Context Indigenous cattle breeds represent an important genetic resource for livelihood of communal-area inhabitants. Indigenous breeds have the ability to withstand harsh climatic conditions, can adapt genetically to poor-quality forages and are resistant to parasites and diseases. These unique traits possessed by indigenous breeds are under threa...

The processes of semen cryopreservation and thawing affect sperm membrane integrity and motility and increases morphological defects as well as DNA damage. The most influential cause of this is oxidative stress. When endogenous antioxidant capacity of seminal plasma is reduced during the freeze-thawing process, plant extracts exhibiting strong anti...

The aim of this study was to characterise and compare phenotypic characteristics of South African unimproved indigenous and Tankwa goats. Phenotypic characteristics of 44 South African unimproved indigenous and 41 Tankwa goats were assessed. The qualitative characteristics were assessed through visual appraisal. Quantitative characteristics such as...

The study was designed to determine the impact of magnesium (Mg2+) on bovine embryo development. We found that two commercially available sources of bovine serum albumin (BSA) and fetal bovine serum (FBS) contained different amounts of Mg2+ residue: 4 ppm in ICPbio BSA, 114 ppm in Sigma BSA, and 44 ppm in FBS. When CR1 was used as basal medium, PVA...

Egg yolk has been reported to have a beneficial effect on sperm quality following cryopreservation, and this led to its widespread use in semen extenders. However, egg yolk contains substances that inhibit respiration of sperm cells and diminish their motility rate. Moreover, it also contains low-density lipoproteins (LDL) that have a protective ef...

In vitro embryo production in pigs remains a challenging obstacle, given the high rate of polyspermy following in vitro fertilization. Improving the efficiency of successful in vitro maturation, which leads to sequential in vitro fertilization and culture, augments the need for modern biotechnologies in pig farming systems, and subsequently conserv...

The aim of the study was to characterize and compare seminal plasma constituents of unimproved indigenous and Tankwa goats. In this study, unimproved indigenous (11) and Tankwa (11) goats were used. Their average age was 3 ± 0.8 years and average bodyweights were 35.5 ± 2.1 kg and 59.8 ± 1.9 kg, respectively. Semen samples were collected with an el...

This study aimed to assess the perception of cattle farmers regarding the challenges affecting implementation and adoption of Assisted Reproductive Technologies (ARTs) such as oestrous synchronisation and artificial insemination under communal and emerging farming systems in South Africa. The study was conducted in Limpopo, Mpumalanga and KwaZulu-N...

The study aimed to determine the effect of assisted reproductive technologies on cow productivity. The study was conducted with organized cattle farmers under communal and emerging farming systems from three provinces, namely; Limpopo, Mpumalanga and KwaZulu-Natal. Cow parameters evaluated were breed type, body frame size, parity, age, body conditi...

The objective of the study was to determine pre-weaning performance of piglets born following artificial insemination (AI) at smallholder farms of Gauteng province. Data from 496 piglets originating from 73 multiparous crossbred sows were used in the study. Litter size, number of piglets born alive, number of piglets weaned, birth and weaning weigh...

In South Africa, assisted reproductive technologies (ART) such as oestrus synchronization and AI in cattle have traditionally been applied in commercial production systems but not communal production systems because of several challenges such as infrastructure and cost. The study was designed to assess factors affecting response to oestrus synchron...

Subjective semen evaluation using standard optical microscopy is the most common practice. Semen parameters routinely assessed are volume, concentration, progressive motility, and morphology. However, computer-aided sperm analysis (CASA) represents an objective evaluation, sperm assessment that are reproducible and reliable. Such semen parameters h...