The present study was conducted on Ezemvelo Nature Reserve in the highveld grasslands of South Africa. The evidence for ecological separation between the black and blue wildebeest was investigated in an area with suboptimal habitat for both types of wildebeest. Habitat selection and separation of the black and blue wildebeest population were investigated at three main scales. A combination of logistic regression analysis, discriminant analysis and hypothesis testing techniques were used to determine whether habitat separation occurred between the black and blue wildebeest at the various scales. Seasonal, social group and weather influences on the habitat selection of both types of wildebeest were also investigated. Black and blue wildebeest showed resource partitioning in terms of habitat at the macro and mesoscales but not at the microscale. The preference for open areas by the black wildebeest and its more specialised territoriality were found to be the main driving factors contributing to the habitat separation of the two types of wildebeest. The population of black wildebeest was found to be decreasing while the blue wildebeest population was found to be increasing in the study area during the study period. Spatial overlap between the black and blue wildebeest was found to be low. Little evidence of interference interspecific competition between the black and blue wildebeest was found. It was, however, concluded that exploitative competition between the two types of wildebeest would be found in areas with low habitat heterogeneity. Ecological separation between the black and blue wildebeest was found to be incomplete. However, the coexistence of the black and blue wildebeest was deemed possible provided habitat heterogeneity in terms of the factors found to be important for habitat separation was high and population sizes were strictly monitored and actively controlled. Finally, a number of additional management recommendations for the black and blue wildebeest at Ezemvelo Nature Reserve and for other reserves confining both types of wildebeest together based on the results of this study were made. / Dissertation (MSc (Wildlife Management))--University of Pretoria, 2007. / Animal and Wildlife Sciences / MSc / unrestricted

Malignant catarrhal fever (MCF) is a mostly fatal lymphoproliferative disease in cattle, pigs, farmed deer, bison and a range of wild ungulates in zoos and game parks. The disease in domestic cattle is caused by either alcelaphine herpesvirus type 1 (AlHV–1) or ovine herpesvirus type 2 (OvHV–2). Both are members of the subfamily Gammaherpesvirinae. The major reservoir host of AlHV–1 is the blue wildebeest (Connochaetes taurinus), but it is generally accepted that the black wildebeest (Connochaetes gnou) is also a reservoir host. Sheep is the reservoir host for OvHV–2. These viruses are non-pathogenic in their natural hosts. No viral studies in the black wildebeest have been reported and as the carrier status of black wildebeest has not been documented, samples from 304 black wildebeest and 51 of their foetuses were collected for this purpose. Blood samples, including serum and blood collected in EDTA-coated collection tubes; cornea and spleen samples were collected from culled black wildebeest. Cornea and spleen samples were collected from foetuses during the culling operations. Blood samples, as above, were also collected from live animals during the capture of such animals. Tissue and EDTA-blood samples were tested by means of conventional and real-time polymerase chain reaction (PCR) assays for detection of a gammaherpesvirus similar or related to AlHV–1. Conventional PCR failed to produce any consistent results. Real-time PCR successfully amplified a region on the gene that codes for a transactivator protein, open reading frame (ORF) 50. Melting curves were generated to determine which samples were positive for a gammaherpesvirus. Only 15.8% of the animals tested positive with the real-time PCR assay. Ninety percent (90%) of the foetuses tested positive and suggests that, unlike sheep lambs, the virus is mainly transmitted in utero and soon after birth. Virus isolated from a black wildebeest calf of one week of age, was confirmed by electron microscopy and sequence analysis to be a gammaherpesvirus related to AlHV–1 and used as a positive control for the real-time PCR assays. Serum samples were tested by a direct competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA) for group specific malignant catarrhal fever virus antibody. All the serum samples that were tested of culled and live animals, tested positive with the CI-ELISA. This indicates a persistent infection and a carrier status. / Dissertation (MMedVet)--University of Pretoria, 2007. / Veterinary Tropical Diseases / MMedVet / unrestricted

Ph.D., Faculty of Science, University of the Witwatersrand, 2000

How so many species coexist while utilizing the same resources is both of ecological interest and important for the management of wildlife communities and parks. This thesis endeavours to understand how grazing herbivores co-exist, with special emphasis on understanding the mechanisms of competition and facilitation over temporal and spatial scales. I compared the dry season use of grasslands, grass species, grass height and grass greenness by white rhino and three other ungulate species, zebra, wildebeest, and impala. I was specifically interested in the extent to which white rhinos, with their capacity to graze both short and tall grass, either competed with or facilitated other grazers. In Chapter Two, I clarify the mechanisms of facilitation and competition in terms of temporal and spatial scales, and discuss why there is little evidence in the literature to support these mechanisms. I conclude that evidence for facilitation through stimulation of grass re-growth during the growing season appears stronger than that for increased resource access through removal of obstructing grass structures during the dormant season. Facilitation may benefit the nutritional gains obtained by certain species in the short term, but these benefits do not appear to be translated into the expected population consequences. In collaboration with co-author Norman Owen-Smith, we suggested this could be due to seasonal tradeoffs between facilitation and competition, as well as to restrictions on the spatial extent of trophic overlap. In Chapter 3 Norman Owen-Smith and I compared the grass height use in relation to body size. We expected that the grass height favoured would increase with the body size of the herbivore species, as suggested from past studies of resource partitioning among large mammalian herbivores. Instead we found that the largest of these species, white rhino, concentrated on the shortest grass, while the smallest species, impala, favoured grass heights intermediate between those grazed by wildebeest and zebra. Results suggest that the scaling of mouth width relative to body size, and hence metabolic demands, is the primary factor governing grass height selection, rather than body size alone. Hence grazing successions governed by body size differences may not be a typical feature of their ecology, contrary to past suggestions. Furthermore, there was considerable overlap in grass height grazed among these four species, indicating that niche separation by grass height is inadequate alone to explain their coexistence. More attention needs to be paid to other aspects such as the grass species selected and habitat structure favoured. Chapter Four compared the overlap in grassland use and grass species use, as well as grass height and grass greenness of swards utilized by the herbivores as the dry season advances. I show that all species prefer grazing lawns during times of abundance, and that zebra leave grazing lawns before other species, and wildebeest leave grazing lawns before white rhino and impala. This suggests zebra and wildebeest may be competitively excluded from grazing lawns through a reduction in grass height, by white rhino and impala, during the dry season. However, white rhino are also potentially the ‘supreme’ facilitator increasing the availability of nutritious grazing lawns, as well as increasing the quality of those lawns through grazing in the wet season. A better understanding of the trade-off between “habitat facilitation” and competitive exclusion by white rhino, allows us to better understand how grazing herbivores co-exist.

Wild animal capture has progressed over the years from trapping or physical capture, which was dangerous to both animal and man, to chemical immobilization. Opioids and butyrophenones are the most common classes of drugs used for ungulate immobilization; however newer drugs and drug combinations are commonly used in an attempt to reduce time to immobilization in wildlife. The enzyme hyaluronidase is often added to drug combinations in the belief that it reduces time to immobilization by improving drug absorption. The primary objective of this study was to ascertain if the addition of hyaluronidase to an etorphine and azaperone drug combination would be of value in reducing time to immobilization in blue wildebeest. The study also tried to ascertain if the added hyaluronidase enabled one to reduce the etorphine and azaperone doses required to immobilize blue wildebeest, without affecting time to immobilization. The study made use of a four-way cross-over study design, with four treatment groups, four sequences and four periods. The four treatment groups were etorphine and azaperone; etorphine, azaperone and 5000 international units (IU) hyaluronidase; etorphine, azaperone and 7500 IU hyaluronidase; and 75 % of the original etorphine dose, 75% of the original azaperone dose and 7500 IU hyaluronidase. Each animal was immobilized with each of the above four drug combinations randomly over an eight week period with a two week interval between each period. The times to first effect, first down and immobilization were recorded. The etorphine and azaperone treatment group was used as the control group. The difference in time to first effect between the control group and the etorphine, azaperone and 7500 IU hyaluronidase treatment group was statistically significant (95 seconds versus 67 seconds; p = 0.007). When compared to the time to immobilization in the control group (323 seconds) the time to immobilization in the etrophine, azaperone and 5000 IU hyaluronidase (228 seconds); etorphine, azaperone and 7500 IU hyaluronidase (210 seconds) and the low dose etorphine, low dose azaperone and 7500 IU hyaluronidase (268 seconds) groups were statistically significantly reduced (p=0.002, p=0.001 and p=0.045 respectively). It is therefore concluded that the addition of 5000 or 7500 IU hyaluronidase to an etorphine and azaperone combination significantly reduced the time to immobilization in blue wildebeest. The unexpected decrease in time to immobilization in the low dose etorphine, low dose azaperone and 7500 IU hyaluronidase treatment group requires further investigation. / Dissertation (MMedVet)--University of Pretoria, 2011. / Production Animal Studies / unrestricted

The aim of the study was to describe the helminth parasites of the common game species in the Limpopo Province, focusing on the northern and western parts where the climate is harsh and dry, with a large area considered to be semi-arid. In total 36 animals were examined which included ten impala, Aepyceros melampus, eight kudu, Tragelaphus strepsiceros, four blue wildebeest, Connochaetes taurinus, two black wildebeest, Connochaetes gnou, three gemsbok, Oryx gazelle, one nyala, Tragelaphus angasii, one bushbuck, Tragelaphus scriptus and one waterbuck, Kobus ellipsiprymnus, as well as six warthogs, Phacochoerus aethiopicus, and a single bushpig, Potamochoerus porcus. New host records for species include Trichostrongylus deflexus in the blue wildebeest, Agriostomum gorgonis in the black wildebeest, Stilesia globipunctata in the waterbuck, and Fasciola hepatica in the kudu. The only known zoonotic helminth recovered was one hydatid cyst of an Echinococcus sp. from the lungs of a warthog. The total burdens and species variation of the helminths in this study were all consistently low compared to other studies done in areas with higher rainfall. This has practical implications when animals are translocated to areas with higher rainfall and higher prevalence of helminths. / Dissertation (MSc)--University of Pretoria, 2008. / Veterinary Tropical Diseases / unrestricted

La trazodone est une drogue antagoniste et agoniste dose-dépendante de la sérotonine utilisée en médecine humaine et vétérinaire pour le traitement de troubles reliés à l’anxiété. Le trauma a été identifié comme la cause primaire de morbidité et de mortalité chez plusieurs espèces de ruminants sauvages et peut être exacerbé par le stress. Dans une étude récente chez la chèvre domestique, la trazodone a réduit les niveaux d’activité sans effets secondaires. La trazodone a le potentiel de réduire le stress et de permettre des captures et manipulations plus sécuritaires chez ces espèces. Les objectifs de cette étude étaient d’identifier une dose de trazodone résultant en une diminution du niveau d’activité chez une espèce de ruminant sauvage, le gnou bleu (Connochaetes taurinus), d’évaluer la sécurité de cette dose et ses effets sur les concentrations de cortisol sérique suivant une procédure vétérinaire de routine. Une étude pilote effectuée à l’aide d’éthogrammes a permis d’identifier une dose orale de 15 mg/kg comme étant efficace pour réduire les niveaux d’activité. Cette dose a mené à une augmentation de 111% du temps passé à dormir/se reposer (P = 0.0003) et de 41% du temps à être couché (P = 0.0016) et une diminution 64% du temps passé à bouger (P = 0.005) et de 65% du temps passé à être vigilant (P = 0.026). La concentration systémique de trazodone mesurée 2 heures suivant l’administration était de 95 ± 48 µg/L. Les concentrations de cortisol sérique durant une procédure de prise sanguine n’ont pas été significativement modifiées par l’administration de trazodone (P > 0.05). Le seul effet adverse noté avec la dose de 15 mg/kg était la baisse d’appétit, ce qui n’était pas présent avec la dose de 12 mg/kg évaluée lors du projet pilote. La trazodone apparaît sécuritaire et prometteuse pour la diminution de l’activité chez le gnou bleu et ainsi pour avoir des effets positifs sur leur bien-être et la sécurité des ruminants sauvages lors de procédures vétérinaires. / Trazodone is a dose-dependant serotonin antagonist and agonist used in human and veterinary medicine to treat anxiety-related conditions. Trauma has been identified as the leading cause of morbidity and mortality in several wild ruminant species and can be exacerbated by stress. In a recent study in domestic goats, trazodone reduced activity levels without adverse effects. Trazodone could allow for safer capture and handling in ruminant species. The objectives of the present study were to identify a dose of trazodone that decreases activity levels in captive blue wildebeest (Connochaetes taurinus), to evaluate its effects on serum cortisol levels following a routine veterinary procedure, and its safety. A pilot study using ethograms identified a 15 mg/kg oral dose of trazodone as effective to reduce activity levels. Over 6 hours, this dose resulted in a 111% increase in time spent sleeping/resting (P=0.0003), a 41% increase in time spent lying down (P=0.0016), a 64% reduction in time spent moving (P=0.005), and a 65% reduction in time spent being vigilant (P=0.026). Systemic absorption of trazodone was identified when plasma concentrations were measured after 2 hours (95 ± 48 µg/L). Serum cortisol levels during a routine venipuncture event were not significantly different following trazodone adminstration (P > 0.05). Mild hyporexia was the only adverse effect noted at 15 mg/kg and was absent at a 12 mg/kg dose. Trazodone appears safe and promising to decrease activity in the blue wildebeest and might thus have a positive effect on wild ruminant welfare and the safety of veterinary procedures.

No description available.

The treatment of tuberculosis (TB) is currently a challenge due to multi- and extensively drug resistant strains of Mycobacterium tuberculosis. Mycobacterium bovis and M. tuberculosis cause clinically indistinguishable tuberculosis in humans. Both M. bovis and M. tuberculosis have been isolated from humans and animals. Plant species contain antimicrobial compounds that may lead to new anti-TB drugs. To conduct in vitro antimycobacterial assays, it is important to include current clinical isolates as new strains of bacteria might be circulating under the ongoing climate change environment. The overall goal and objectives of this study were to isolate and characterize mycobacteria species from South Africa, to test some selected plant species of the Anacardiaceae family for antimycobacterial activity using some of the newly isolated and reference strains of mycobacteria followed by cytotoxicity evaluation of the most active plant species, and finally the isolation and characterization of at least one compound from the most active and least toxic plant. This study led to the discovery of a new isolate of Mycobacterium Avium Complex species from black wildebeest. Other non-tuberculous mycobacteria and M. bovis isolates were identified from other animal species. Five out of 15 plant species screened showed good activity against Mycobacterium species. Five antimycobacterial compounds were isolated from Searsia undulata, the most active plant species. Two out of the five compounds were identified, and one compound appears to be novel, but both compounds have been isolated for the first time from Searsia undulata. An incidental finding was the potential anticancer property of extracts of Searsia undulata. Recommended future activities include isolation and identification of more active compounds from Searsia undulata which were visible in bioautography analysis, as well as synergy evaluation of antimycobacterial activities of the different compounds with current anti-tubercular drugs. / Environmental Sciences / Ph. D. (Environmental Science)