Browsing by Author "van der Horst, Gerhard"
Now showing items 1-9 of 9
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Accurate automated quantitative imaging of tortoise erythrocytes using the NIS image analysis system
Walton, S.; Hofmeyr, Margaretha D.; van der Horst, Gerhard (Taylor & Francis, 2013)The standard method for assessing blood cell characteristics using an ocular micrometer is time-consuming and limited. We used the Nikon NIS Elements imaging software and May-Grünwald-Giemsa staining to determine whether ... -
CASA in invertebrates
van der Horst, Gerhard; Bennett, Monique; Bishop, John D. D. (CSIRO Publishing, 2018)Sperm movement has been described in several phyla of invertebrates. Yet, sperm motility has only been quantified using computer-aided sperm analysis (CASA-Mot) in externally fertilising species (broadcast spawners) of ... -
Effects of GnRH vaccination in wild and captive African Elephant bulls (Loxodonta africana) on reproductive organs and semen quality
Lueders, Imke; Young, Debbie; Maree, Liana; van der Horst, Gerhard; Luther, Ilse (Public Library of Science, 2017)OBJECTIVES: Although the African elephant (Loxodonta africana) is classified as endangered by the International Union for Conservation of Nature (IUCN), in some isolated habitats in southern Africa, contraception is of ... -
Morphometric and structural analysis of Florida manateespermatozoa
Cowart, Jonathan R.; Collins, Danielle M.; van der Horst, Gerhard (Wiley, 2022)Sperm characteristics, such as sperm morphology and sperm morphometry areimportant in assessing sperm quality. This is especially important for the man-agement and conservation of endangered and exotic species, like the ... -
A new fluorescent method to determine honey bee sperm motility parameters with computer-aided sperm analysis
Murray, Janice Faith; van der Horst, Gerhard; Allsopp, Mike (Taylor and Francis Ltd., 2023)Honey bees are a keystone species, playing an important role in the food cycle. Improving honey bee reproduction will aid in the replacement of lost colonies. Fertility potential and reproductive health are dependent on ... -
Progesterone, myo-inositol, dopamine and prolactin present in follicular fluid have differential effects on sperm motility subpopulations
Keyser, Shannen; van der Horst, Gerhard; Maree, Liana (MDPI, 2021)Considering the challenges surrounding causative factors in male infertility, rather than relying on standard semen analysis, the assessment of sperm subpopulations and functional characteristics essential for fertilization ... -
Quantification and identification of sperm subpopulations using computer-aided sperm analysis and species-specific cut-off values for swimming speed
Maree, Liana; van der Horst, Gerhard (Taylor & Francis, 2013)Motility is an essential characteristic of all fl agellated spermatozoa and assessment of this parameter is one criterion for most semen or sperm evaluations. Computer-aided sperm analysis (CASA) can be used to measure ... -
Quantitative sperm characteristics of Tankwa goats with special reference to hyperactivated motility
Ngcauzele, Asanele; van der Horst, Gerhard; Kotze, A (South African Society for Animal Science, 2020)Computer-assisted semen analysis (CASA) is an automated and objective method of evaluating structural (e.g. morphology) and functional sperm parameters (e.g. motility and hyperactivation). Sperm hyperactivation is essential ... -
Status of sperm functionality assessment in wildlife species: From fish to primates
van der Horst, Gerhard (2021-05)(1) Background: in order to propagate wildlife species (covering the whole spectrum from species suitable for aquaculture to endangered species), it is important to have a good understanding of the quality of their sperm, ...