Thesis (Ph.D.)(Botany)--University of Pretoria, 2007. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.

Thesis (MSc.)(Botany)--University of Pretoria, 2007. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.

Thesis (MSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The purpose of this study was to describe the nature of springbok (Antidorcas marsupialis) muscle and the changes that take place in the longissimus thoracis et lumborum (LTL) and biceps femoris (BF) muscles post-mortem (PM); thereby providing recommendations for the handling of the meat. Springbok muscle contained 64 - 78% type IIX fibres, suggesting that it is considerably more glycolytic than bovine muscle. In males the BF contained more type I and fewer type IIA fibres than the LTL and it appeared that female springbok contained a greater proportion of type IIX fibres than males. The cross-sectional areas (CSA’s) of the fibres were low but within the range reported for domestic species. There was an increase in the CSA with the glycolytic capacity of the fibres in males (I < IIA < IIAX < IIX) but no difference between fibre-types in females. Springbok muscle cooled rapidly and acidified slowly relative to recommended set points for domestic species, with this being most evident in the female LTL. Differences in cathepsin and calpain activity between the genders and muscles were evident, with the higher calpain activity in the BF and male springbok likely a reflection of the fibre-type composition of these samples. The cathepsin BL activity increased PM, possibly due to the degradation of the lysosomal membranes. Calpain and calpastatin activity declined PM, with correlations (r = -0.64; p < 0.01) between the pH decline rate and the change in calpastatin activity indicating that more rapid acidification results in a greater decrease in calpastatin activity. No further improvement in the Warner Bratzler shear force (WBSF) of springbok LTL or BF took place from five to 21 days of ageing. The cathepsin activity increased during the ageing period, with the high activity in the absence of a decline in WBSF suggesting that the cathepsins did not contribute to tenderization. The calpain and calpastatin activity declined to negligible levels by five days PM, suggesting that they were activated in situ and were involved in tenderization. Higher WBSF values were found for the BF throughout the ageing period. Springbok LTL increased in sensorial tenderness and sustained juiciness and decreased in residue from three to eight days PM; however ageing to 28 days increased a number of undesirable aroma and flavour attributes and decreased beef-like aroma. This was most likely due to oxidative and proteolytic changes. The WBSF was low for all ageing periods, with no significant change being found. Gender did not have a large influence on the sensory quality of the meat. The results of this study indicate that springbok meat tenderizes rapidly PM, with ageing periods of five to eight days being recommended to avoid detrimental flavour changes. The chilling rate appears to have a greater effect on the meat than any differences in the fibre-type composition, with the temperature and pH declines PM indicating a risk of cold-shortening. However the WBSF values found question the necessity of specialized handling techniques being used. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die aard van springbokvleis en die veranderinge wat plaasvind na dood in die Longissimus thoracis et lumborum (LTL) en biceps femoris (BF) spiere te omskryf. Sodoende word voorstelle vir die korrekte hantering van springbok vleis voorsien. Die springbokspiere bevat 64 - 77% tipe IIX vesels wat aandui dat dit aansienlik meer glikolities van aard is in vergelyking met die van bees. In die manlike diere het die BF meer tipe I en minder tipe IIA vesels gehad as die LTL. Daarmee saam het die vroulike springbokke ‘n hoër hoeveelheid tipe IIX vesels gehad as die manlike. Die opeervlakte van die springbok vesels was klein, maar steeds binne die omvang van wat gemeld is vir gedomestiseerde diere. Tesame met ‘n toename in die glikolities kapasiteit was daar ‘n toename in die vesel oppervlakte van die manlike diere (I < IIA < IIAX < IIX), maar geen verskil is egter gevind vir die vroulike diere. Die springbok spiere het snel verkoel en redelik stadig versuur, relatief tot die van gedomestiseerde spesies. Dit was die mees voor die hand liggend in die vroulike LTL spier. Verskille in die katepsien en kalpaïen aktiwiteit tussen die geslagte was duidelik en die hoër kalpaïen aktiwiteit in die BF van die manlike diere is waarskynlik as gevolg van die samestelling van die veseltipes. Die katepsien BL aktiwiteit het toegeneem na-dood wat moontlik te wyte is aan die afbraak van die lisosomale membrane. Kalpaïen en kalpastatien aktiwiteit het verlaag na-dood en korrelasies (r = -0.64; p < 0.01) tussen die tempo van die pH daling en die verandering in die kalpastatien aktiwiteit het aangedui dat ‘n snel versuring lui tot ‘n groter afname in kalpastatien aktiwiteit. Daar was geen verbetering in die instrumentele sagtheid van die springbok LTL of BF vanaf vyf dae veroudering tot en met 21 dae. Die katepsien aktiwiteit het toegeneem tydens die verouderings tydperk. As gevolg van die hoë aktiwiteit tesame met die afwesigheid van ‘n afname in instrumentele sagtheid wil dit voorkom of die katepsiene geen bydrae gelewer het tot versagting. Beide die kalpaïen en kalpastatien aktiwiteit het weglaatbaar afgeneem teen vyf dae van veroudering wat aandui dat hierdie ensieme moontlik geaktiveer is in-situ en daarom betrokke was by versagting. Die BF spier het hoër instrumentele taaiheid waardes getoon reg deur die verouderings tydperk. Die springbok LTL het ‘n toename in sensoriese sagtheid en verlangde sappigheid tesame met ‘n afname in residu getoon vanaf drie tot ag dae veroudering. Die veroudering tot en met 28 dae het egter verskeie ongewensde aroma en geur eienskappe na vore gebring. Die paneel het ook ‘n afname in die bees aroma opgetel. Die voorkoms van hierdie ongewensde sensoriese eienskappe is heel waarskynlik as gevolg van oksidatiewe en proteolitiese veranderinge tydens veroudering. Die instrumentele sagtheid was redelik laag reg oor die verouderingstydperk en geen beduidende verskille is gevind. Geslag het geen verskil gehad op die sensoriese kwaliteit van die vleis nie. In geheel toon die resultate van hierdie studie dat springbokvleis snel verouder. Die aanbevole verouderingstydperk is tussen vyf en agt dae om sodoende nadelige aroma en geur veranderinge te vermy. Dit wil blyk of die verkoelingstempo ‘n groter invloed op die vleis het as enige verskil in die samestelling van die vesel tipes. Die temperatuur en pH dalings na-dood dui wel op die risiko van kouekrimping maar die resultate rondom die instrumentele sagtheid bevraagteken wel die noodsaaklikheid van gespesialiseerde hanteringstegnieke.

Thesis (MScAgric)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Regardless of the extensive game eradication during most of the previous century, the game farming industry in South Africa has shown dynamic growth over the past few decades. Currently the approximately 8 000 game farms have a total income of more than R850 million per annum. Although there are various game species included in these farming enterprises, three of the most important species for commercial farming and meat marketing are springbok iAntidorcas marsupialisï, blesbok (Damaliscus dorcas phillipsiï and impala (Aepyceros melampus). Since nutrition is a key factor in the productivity of animals, any information on this subject is essential for the successful management of a game farm. However, apart from the general lack in applied research on game animals (due to the different approaches by biologists and agricultural researchers), there is also only limited information available on the nutritional requirements of game species or any of the aspects affected by nutrition. In order to address the above shortcomings in game animal nutrition, two separate studies were conducted. The purpose of the first study was to determine the physical body component and nitrogen (N) distribution in the springbok, blesbok and impala. The chemical composition of the three-rib cut was also compared with that of the carcass. Amino acid requirements for growth of the three game species were investigated in the second study according to the ideal protein concept. The essential amino acid (EAA) profile of the whole empty body of the three game species was compared with the EAA profile of the duodenal digesta in order to detect any imbalances for optimal growth. The same animals were used in both studies, namely eight of each of the three game species. Characterization of the physical body composition revealed that the dressing percentages (% of body weight; % of empty body weight) for the three game species were: springbok (57.1 ± 2.4 %; 64.0 ± 2.5 %), blesbok (50.2 ± 2.1 %; 62.8 ± 1.4 %) and impala (57.4 ± 2.2 %; 65.6 ± 2.0 %). The proportional distribution ofN between the carcass, external offal and internal offal was also determined. The mean carcass N concentration of the impala was higher (P<0.05) than that of the springbok and blesbok on a dry matter basis. According to the carcass chemical composition, the three game species seem to have a better potential for lean meat production (fat content of carcass 4.7-5.2 %) than domestic sheep (17-25 % fat). Male animals had a lower (P<0.05) fat and higher (P<0.05) moisture percentage in the carcass and threerib cut than the females. The fat correlation between the three-rib cut and the carcass on both an as-is and dry matter basis was significant across species and sexes. The protein content of the same cuts did, however, not yield a significant correlation on an as-is basis, and only the protein content of the springbok three-rib cut related (P<0.05) to that in the carcass on a dry matter basis. The second study concentrated on the nutritional requirements of springbok, blesbok and impala, and more specifically the EAA requirements. Differences (P<0.05) were found between the whole empty body EAA composition of the three game species. These differences were present whether protein quantity was included in the calculations (g AA/100 g crude protein) or not (expressed as % of lysine). The chemical scores indicated that the four most limiting amino acids (three for impala) in the duodenal digesta for whole empty body growth were: arginine, histidine, threonine and methionine (springbok); methionine, arginine, histidine and lysine (blesbok); and methionine, histidine and arginine (impala). Further disproportion of the amino acids in the duodenal digesta was present in excess levels of isoleucine (blesbok) and lysine, valine, leucine, threonine, isoleucine and phenylalanine (impala). The EAA:Lysine ratios of the whole empty body indicated a similar trend for the three game species. / AFRIKAANSE OPSOMMING: Die essensiële aminosuurbenodighede van springbok, blesbok en rooibok vir optimale groei: Ten spyte van die feit dat wild grootskaals uitgedun is gedurende die vorige eeu, het die wildboerdery-bedryf in Suid-Afrika oor die laaste paar dekades dinamiese groei getoon. Die totale inkomste van die ongeveer 8000 wildsplase beloop tans meer as R850 miljoen per jaar. Alhoewel daar verskeie wildspesies is wat by hierdie tipe boerdery ingesluit word, is die springbok (Antidorcas marsupialis), blesbok (Damaliscus dorcas phillipsi) en rooibok (Aepyceros melampus) van die belangrikste spesies vir kommersiële boerdery en vleisbemarking. Voeding IS 'n sleutelfaktor in die produktiwitieit van diere en daarom is emge inligting oor hierdie onderwerp noodsaaklik vir die suksesvolle bestuur van 'n wildsplaas. Afgesien van die algemene tekort aan toegepaste navorsing op wilde diere (as gevolg van die verskillende benaderings van bioloë en landboukundige navorsers), is daar ook slegs beperkte inligting beskikbaar oor die voedingsbehoeftes van wilde dierspesies of enige van die faktore wat deur voeding beïnvloed word. In 'n poging om bogenoemde tekortkominge in die voeding van wilde diere aan te spreek, is daar twee aparte studies uitgevoer. Die doel van die eerste studie was om die fisiese liggaamsamestelling en die stikstof (N) verspreiding in die springbok, blesbok en rooibok te bepaal. Die chemiese samestelling van die drie-ribsnit is ook met die van die karkas vergelyk. In die tweede studie is ondersoek ingestel na die aminosuurbehoeftes van die drie wildspesies deur van die ideale proteïen konsep gebruik te maak. Die bepaling van die essensiële aminosuurprofiel van die totale leë liggaam van die onderskeie drie wildspesies is bepaal en met die essensiële aminosuurprofiel van die duodenale-inhoud vergelyk, ten einde enige wanbalans vir optimale groei vas te stel. Dieselfde diere is in beide studies gebruik, naamlik ag springbokke, blesbokke en rooibokke. 'n Beskrywing van die fisiese liggaamsamestelling het aangetoon dat die uitslagpersentasies (% van liggaamsmassa; % van leë liggaamsmassa) van die drie wildspesies as volg was: springbok (57.1 ± 2.4 %; 64.0 ± 2.5 %), blesbok (50.2 ± 2.1 %; 62.8 ± 1.4 %) en rooibok (57.4 ± 2.2 %; 65.6 ± 2.0 %). Die proporsionele verspreiding van N in die karkas, uitwendige afval en inwendige afval is ook bepaal. Die gemiddelde N konsentrasie in die karkas van die rooibok was hoër (P<0.05) as die van die springbok en blesbok op 'n droë materiaal basis. Dit blyk vanaf die chemiese samestelling van die karkas dat die drie wildspesies 'n groter potensiaal het vir die produksie van maer vleis (vet-inhoud van karkas 4.7-5.2 %) as skape (17-25 % vet). Manlike diere het 'n laer (P<0.05) vetpersentasie en 'n hoër (P<0.05) vogpersentasie in beide die karkas en die drie-ribsnit teenoor die vroulike diere gehad. 'n Betekenisvolle korrelasie is tussen die persentasie vet in die drie-ribsnit en die karkas van al drie wildspesies en vir beide geslagte gevind, op beide 'n nat en droë materiaal basis. Die proteïeninhoud van dieselfde snitte was egter nie op 'n nat basis betekenisvol gekorreleerd nie, en slegs die proteïen-inhoud van die springbok se drieribsnit het verband gehou (P<0.05) met die in die karkas op 'n droë materiaal basis. Die klem van die tweede studie was op die voedingsbehoeftes van springbok, blesbok en rooibok, en meer spesifiek die essensiële aminosuurbenodighede. Daar is verskille (P<0.05) tussen die totale leë liggaam essensiële aminosuursamestelling van die drie wildspesies gevind. Hierdie verskille was aanwesig afgesien daarvan of die hoeveelheid proteïen in berekening gebring is (g aminosure /100 g ruproteïen) of nie (uitgedruk as % van lisien). Volgens die chemiese tellings was die vier mees beperkende aminosure (drie vir rooibok) in die duodenale-inhoud vir totale leë liggaamsgroei as volg: arginien, histidien, treonien en metionien (springbok); metionien, arginien, histidien en lisien (blesbok); en metionien, histidien en arginien (rooibok). Verdere wanbalanse in die armnosure van die duodenale-inhoud was aanwesig in die oormaat isoleusien (blesbok) en lisien, valien, leusien, treonien, isoleusien en fenielalanien (rooibok). Die verhouding van die essensiële aminosure tot lisien van die totale leë liggaam het by al drie wildspesies dieselfde tendens getoon.

The first part of a novel submitted to the University of Canterbury to fulfil the requirements of the degree of Master of Fine Arts in Creative Writing.

This study is informed by the rising demand for power needs in South Africa and aims at understanding the geophysical and geochemical characteristics of the energy minerals in the Springbok Flats Basin and relating them to the prevailing geological and structural setting for improved exploration targeting. The Springbok Flats Basin is part of the Karoo sediments and host to uranium, coal and coal bed methane (CBM) resources. The lithology sections in the basin indicate presence of basaltic lavas at the top, underlain by mudrocks, siltstones, sandstones, conglomerates and diamictite, with interbedded coal beds occasionally. The coals are uraniferous and shale bounded and of lower Beaufort age at 250 Ma. The regional radiometric data identifies the regional extent of the Springbok Flats Basin as a basin with low total count values. This information is useful in exploration as it gives an idea of the limits of the area where to focus application for prospecting licenses. The reduced to pole of the total magnetic field, residuals and first vertical derivative maps clearly show the high magnetic susceptibility nature of the surrounding Bushveld rocks as compared to the low Karoo sediment susceptibility within the basin. There are distinct ring shaped picks within the basin possibly due to known Karoo dolerite sills in particular to the central south western part of the grid. The regional geochemical mapping program is a cost-effective way of providing an overview of the relative abundance levels, regional trends and anomalous patterns in the underlying lithological units. Background values of elements in soils over different lithological units and the identification of anomalous values relative to these elements can easily be identified. The geochemical results show an excellent correlation between soil chemistry and underlying geological formations. A few distinct gravity highs are clearly shown within the basin. Assuming the effect of the Letaba basalt to the gravity readings is uniform across the basin; these distinct anomalies could be due to Karoo dolerite sills as they coincide with areas of distinct high magnetic signature. A conceptual model was generated assuming that the Karoo sediments’ layering is uniform across the gravity profile but changes in the residual are due to an increased thickness of the sill supported by the gentle changes on the surface topography. Satellite imagery has got its challenges especially in areas of vegetation but it does provide a very useful tool in exploration. A number of spectral analysis techniques and band rations can be used to differentiate the areas underlain by the Letaba basalts, the Karoo sandstones/shale and Bushveld granites for mapping purposes. The priority focus will be on the shallower Karoo sediments because of the potential for cheaper mining. Exploration targeting needs to be guided by observed geochemical and geophysical characteristics in order to prioritize areas taking into account the presence of Karoo intrusives such as the dolerite sills that tend to devolatize the coal hence affecting the quality/rank. Structures and gravity signatures are very important in delineating areas with thick sediments that have a potential for CBM. The same understanding in targeting goes a long way in planning drill holes, resource modelling and pre-feasibility stages for mine planning. A high resolution airborne geophysical survey is recommended over the basin to better resolve structures. Geophysical borehole logging is recommended to be part of the exploration drilling programs in the Springbok Flats Basin in order to define the in-situ geophysical characteristics. Geophysical logging is useful in particular for the uranium reserves that cannot be delineated from the surface due to deep intersection.

Game farming developed in Namibia over the years as a result of constraints associated with livestock farming such as diseases and profitability. The development of this industry has brought livestock and game species into close contact. In the Karas Region, a major sheep producing area, sheep and springbok are reared together on commercial farms. The rearing of these species in close proximity may result in crosstransmission of zoonotic diseases such as brucellosis, enabling such diseases to enter the human population through meat and other livestock products. Game species may complicate the control of brucellosis by acting as reservoirs of infection after the disease has been controlled in sheep. Brucellosis due to B. melitensis has been reported in Namibia as a cause of reproductive failure in sheep. An outbreak of brucellosis occurred xvi in 2009 affecting sheep, goats and humans on a farm in the adjacent Hardap Region. Brucellosis outbreaks in sheep have the potential to disrupt Namibia’s foreign currency earning as the sheep industry contributes greatly to the economy of the country. This aim of the study was to estimate the prevalence of Brucella (B. melitensis, B. abortus, B. ovis).infections in sheep and springbok in the Karas Region and to find out if the outbreak of brucellosis which occurred in the Hardap Region in 2009 had spread to the Karas Region. Two experimental designs were used in this study. The first was a retrospective analysis of brucellosis testing results from 2008-2010 to indicate probable prevalence and to identify positive farms for follow-up sampling in sheep and springbok. Serological testing results of sera (n=22994) collected from 762 farms between 2008 and 2010 were analyzed and used to estimate apparent brucellosis prevalence. A total of 472 sheep sera and nine springbok sera were collected from eight farms that tested positive for Brucella antibodies between 2008 and 2010. The second part of the study was a prospective serological study in sheep and springbok reared together; sheep in the Tses and Berseba communal areas and in culled ewes at the regional abattoir. Sexually mature sheep and springbok were selected for the prospective serological study because they are more likely to show serological responses than younger animals. Prior to the serological study, eleven questionnaires were completed on the farms (n=11) that reared sheep and springbok together to gather information about farm management and risk factors for brucellosis. In the serological prevalence study, 332 sheep and 345 springbok sera were collected from the eleven commercial farms and 664 sheep sera were taken from the two communal areas. At the abattoir, 2302 sheep sera were collected from 40 farms in the region using the sample size for determining the absence or presence of disease. All sera were tested for Brucella (B. melitensis, B. abortus) antibodies using the RBT as a screening test and the CFT as a confirmatory test. B. ovis antibodies were tested for in sera from commercial farms only using the CFT test. Results from the retrospective study revealed an apparent sheep brucellosis prevalence of 0.14% (95% CI: 0.1%-0.2%) over the three years and an annual brucellosis prevalence of between 0.05% and 0.19%. At district level, apparent prevalence was between 0% and 0.49%. The prevalence of positive farms was between 0.72% and 1.82%. When apparent prevalence was adjusted for CFT sensitivity and specificity, the prevalence was zero in all cases, suggesting that the prevalence detected in this study may be due to false positive reactions. However, some of the positives serological reactions were from suspected brucellosis clinical cases which were also confirmed by the PCR test. At district level, brucellosis prevalence was shown to be rising in the Karasburg district and decreasing in the Keetmanshoop and Bethanie districts. However, statistical analysis of the data using Fisher’s exact test showed that the differences in brucellosis prevalence between districts was not significant, but that the differences in brucellosis prevalence between the three years was significant. All trace back sera collected in 2011 (using the sample sizes for proving disease freedom) from sheep (n=472) and springbok (n=9) on previously positive farms (n=8) identified by the retrospective study, tested negative for Brucella (B. melitensis, B. abortus, B. ovis) antibodies. The negative results provided strong evidence that brucellosis control measures implemented on the farms following the outbreak were effective and that these farms were now free of brucellosis. Results of questionnaire interviews showed that sheep and springbok were the main species on the farms and that the two species came into close proximity throughout the year especially at watering points in the summer. The interviews also revealed that the study population was naïve because farmers did not vaccinate sheep against brucellosis. All sera collected in the serological study on commercial farms (sheep and springbok), in the two communal areas (sheep) and at the abattoir (culled ewes) tested negative for Brucella antibodies (B. melitensis, B. abortus). The prevalence of B. ovis antibodies in rams on one farm was 10% (3/30). B. ovis antibodies were not detected in springbok. The role of springbok in the epidemiology of sheep brucellosis could not be inferred due to the negative results recorded in both species. Results of the retrospective and prospective serological studies confirmed that apparent brucellosis prevalence in sheep in the Karas Region was low. These results provided evidence that sheep and springbok reared together on the eleven commercial farms were not infected with Brucella. It was surprising that no positive reactors were found in sheep in the communal areas because the intermingling of sheep from different flocks enhances the spread of brucellosis. The absence of positive reactors at the abattoir confirms that the chances of contracting human brucellosis at the abattoir were low and confirms that the forty farms tested were free of Brucella infections. / Dissertation (MMedVet)--University of Pretoria, 2013. / Paraclinical Sciences / unrestricted

Springbok Antidorcas marsupialis ecology was examined on the South African side of the Kgalagadi Transfrontier Park in the Kalahari, with the use of public questionnaires and field forms. Statistically significant differences were found between data that were collected by public respondents and the researcher when using the same questionnaire. Questionnaires are useful for gathering large amounts of data, but should be carefully structured to ensure the quality of the data. Feeding was the most common activity of springbok and the frequency thereof varied during the day and between seasons. Environmental conditions and seasonal changes affected the feeding behaviour of springbok in the southwestern Kalahari. Springbok fed in direct sunlight in the mornings and moved into the shade during the afternoon. More time was spent feeding in the shade during the warmer months than during the colder months, especially under northerly to northeasterly wind directions. Herd sizes were found to increase during the cold-dry season and decreased during the hot-wet season. Springbok and blue wildebeest Connochaetes taurinus taurinus displayed niche separation by competition avoidance. Springbok utilized natural licks. Night-time observations of springbok were made during different seasons and habitats on the South African side of the Kgalagadi Transfrontier Park in 2003. Nocturnal feeding behaviour was described in the context of other similar studies. Feeding times were highlighted, yet the role and importance of nocturnal feeding remains unclear. The nutritional content of some southwestern Kalahari food plant species were determined. The nutrients in the sampled plants showed a wider fluctuation range than plants in other regions. Phosphorus levels in the Kalahari were found to be low in general and calcium levels were higher than in other regions. Browse species contained higher crude protein levels than grass species. The nutritional value of the plants was lowest during the cold-dry season and highest during the hot-dry one. The nutritional status of springbok in the southwestern Kalahari was assessed by using faecal profiling. The faecal nutritional status for springbok populations in different habitats and seasons was examined. Faecal nutrient levels confirmed springbok as mixed feeders with a diet composition that was between that of true browsers and grazers. Faecal concentrations of phosphorus and nitrogen were similar to that of springbok in other areas, but phosphorus intake was shown to be low, particularly during the cold-dry season. Phosphorus appears to be a limiting nutrient and may cause nutritional stress in springbok in the southwestern Kalahari during dry periods. / Dissertation (MSc (Botany))--University of Pretoria, 2007. / Plant Science / unrestricted

This first detailed description of the pathology of tuberculosis, caused by Mycobacterium tuberculosis in springbok is reported. The springbok were part of a semi free-ranging herd kept on the grounds of iThemba Laboratory for Accelerator Based Science (LABS) in the Kuils River district of the Western Cape Province, South Africa. Of the 33 animals sampled, two animals had tuberculosis lesions. Mycobacterium tuberculosis was isolated from these two animals, as well as an animal that did not show tuberculosis pathology. The index case was an adult ewe that was presented for necropsy in a severely weakened condition. The ewe showed advanced miliary tuberculosis with marked macroscopic lesions in the lungs, pleura and respiratory lymph nodes. Limited sampling was done but microscopic tuberculosis lesions were found in almost all the organs sampled, and acid-fast bacilli were generally numerous. Six healthy rams were culled nine months later and a pilot study indicated miliary tuberculosis lesions in one ram, which again were macroscopically most prominent in the lungs, pleura and respiratory lymph nodes. Macroscopic lesions were also noted in the sternal, iliac, prefemoral and retropharyngeal lymph nodes. Microscopy in this animal revealed lesions in the macroscopically affected organs as well as numerous other lymph nodes, and suspected lesions occurred in the testicle and colon. Acid-fast bacilli were scarce to moderate in affected organs. Because of the miliary nature of the lesions in both affected animals, the route of infection could not be established conclusively. The lesions in most affected organs of both animals resembled classical tuberculous granulomas, viz. central caseous necrosis, with various degrees of calcification, surrounded by various numbers macrophages, epithelioid cells, multinucleated giant cells and lymphoplasmacells, and mild to moderate fibrous encapsulation. Necrotic lesions in the spleen, liver and kidney of the ewe were more disseminate and coagulative. A main study conducted on healthy culled animals 19 months after the pilot study failed to find any animal with tuberculosis lesions in the group of 25 sampled. These animals were all negative for mycobacteria via mycobacterial culture. The Interferon-gamma (INFg) assay was performed on all the animals of the pilot and main study but failed to identify the culture-positive animals and showed one false-positive reaction. / Dissertation (MMedVet (Pathology))--University of Pretoria, 2007. / Paraclinical Sciences / unrestricted

Habitat selection may be considered a behavioural consequence of an individual actively selecting where it lives or passively persisting in a certain habitat. There are a variety of approaches to assessing habitat selection, including relating densities to predefined habitats and the characteristics of these habitats, measuring the behaviour of animals within predefined habitats in order to assess the relative benefits to the animal and comparing these between habitats, and using optimality theory to allow the animal to provide measures of its preference for particular habitats or patches. Each approach provides different perspectives on an animal’s choice and use of habitat, with some approaches working more effectively with certain species or habitats than others. There have, however, been no attempts to apply all these approaches to a single species at a single site. The objective of this study was therefore to apply the three above-mentioned approaches to assess habitat use and quality to a single species, the springbok (Antidorcas marsupialis) at the Augrabies Falls National Park (AFNP), on the northern bank of the Orange River, in order to provide the basis for further work on comparing and integrating these approaches. The relative abundance of springbok in Augrabies Falls National park was used to develop a habitat suitability model for the park, and thus determine the habitat variables that influenced habitat suitability. Isodar analysis revealed information on the mechanisms underlying habitat preference. Behavioural models were developed to improve our understanding of how springbok behaviour changes in relation to the habitat, and incorporated the variables identified in the habitat suitability model. The different spatial and temporal scales influencing springbok habitat selection were determined using optimal foraging theory and giving-up densities. Springbok preferred open habitats providing high food quality. Springbok behaviour was related to the foraging and predation risk characteristics of the habitat, and springbok varied their temporal and spatial utilisation so as to minimise their risk of predation and maximise their food intake. The habitat suitability model, behaviour models and giving-up densities were compared for ease of use and applicability. Using giving-up densities to reveal habitat suitability had greater applicability and was both efficient and objective.