Publications by authors named "Ntuthuko R Mkhize"

The study investigated the sperm motility and morphometry of pre-freeze and post-thaw boar epididymal semen cooled at increasing holding times at 18 °C. A total of 50 testes of heterogeneous boars were collected (5 testes/day) from the local abattoir and transported to the laboratory at 5 °C within 30 min after slaughter. Semen was retrieved from the caudal part of the epididymis using the slicing float-up method, diluted with Beltsville Thawing Solution extender, pooled in a 50 mL centrifuge tube/5 testes/day, and cooled at 18 °C.

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This study aimed to compare the morphometry, morphology, and maturation capacity of cattle oocytes subjected to vitrification using different vitrification and maturation media. In Experiment 1, a total of 900 oocytes were divided into three groups: (1) matured before vitrification, (2) non-vitrified, and (3) vitrified as immature oocytes using the straw vitrification method. Morphometric parameters, including oocyte diameter, ooplasm, zona pellucida width (ZPW), granulosa cell width (GRSW), and zona pellucida-granulosa cell width (ZP GRSW), were measured (µm) before and after cryopreservation.

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Intraspecific variation in adaptation to herbivory has been studied in juvenile (sapling) and adult (reproductive) stages of woody species in African savannas, but has not been studied at the early seedling stage. We hypothesized that, among species commonly occurring in African savannas, spinescence increases and growth rate decreases after herbivory, but these responses would be expressed most strongly in populations with slower growing seedlings. Seedlings of , , and were grown from seeds of different populations within the Southeastern Coastal Hinterland geomorphic province of South Africa.

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Changing climates threaten crop growth and fodder yields in dryland farming. This study assessed two radish genotypes (LINE 2, ENDURANCE) under three water regimes (W1 = well-watered, W2 = moderate stress, W3 = severe stress) and two leaf harvesting options over two seasons (2021/22 and 2022/23). Key findings revealed that water regime significantly (P < 0.

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Increasing densities of woody plants, known as woody plant encroachment, is a phenomenon affecting savannas and grasslands in many parts of the world. Yet, these ecosystems sustain a significant proportion of the human population through the provision of ecosystem services, such as forage for livestock and wildlife production. While low to medium altitude rangelands are encroached by many species of woody plants, high altitude rangelands in southern Africa show increasing densities of Leucosidea sericea, a woody shrub or small to medium-sized tree.

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Fodder radish is widely used as a livestock supplement, however, the nutritional value of fodder radish under different water conditions remains insufficiently understood. This study aimed to assess the chemical components and ruminal dry matter degradability of two fodder radish genotypes (Endurance and Line 2) subjected to three irrigation regimes: well-watered (W1), moderate water stress (W2), and severe water stress (W3). The analysis revealed statistically significant effects of the main factors on the chemical composition and estimates of fodder radish leaves and tubers, particularly in terms of Crude Protein (CP) and Ether Extract (EE) across genotypes.

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Along with the woody plant expansion that is predicted to continue at the expense of the grassy layer is the increasing societal demand for animal protein and livestock products. Unless concerted efforts by land users, ecologists, and animal scientists are made to increase the utilization of trees and shrubs as forage, it will be impossible to meet future demand for meat and meat products. We conducted two short-term pen experiments to determine the effects of (1) supplementation with polyethylene glycol (PEG-a polymer purported to bind and neutralize the negative effects of tannins), a high-protein source (soybean meal), and a high-energy source (yellow maize grain) and (2) diet mixing (single-species vs.

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Mechanical and chemical methods are widely used to control woody plant encroachment in many African countries. However, very little is known about the effectiveness of these control methods among woody species of different ages. We conducted a field experiment to determine the effects of different tree removal treatments (10%, 20%, 50%, 75% and 100%) and herbicide application (Picloram; 6 mL L) on the resprouting ability and vigour of 12 woody plant species.

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Herbivory plays a fundamental role in determining the structure of savannas. The impacts of small and medium-sized mammalian herbivores on trees in savannas remain poorly understood because most research attention focuses on large herbivores such as elephants whose destructive effects on trees can be pervasive at landscape scales. On the other hand, feeding activities of generalist herbivores such as Cape porcupines on woody plants can lead to tree mortality.

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Although condensed tannins (CTs) are known to reduce forage intake by mammalian herbivores in controlled experiments, few studies have tested these effects in the field. Thus the role of CTs on foraging ecology of free-ranging herbivores is inadequately understood. To investigate the effects of CTs under natural savanna conditions, we pre-dosed groups of goats with polyethylene glycol (PEG, a CT-neutralising chemical), CT powder or water before observing their foraging behaviour.

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