Despite a wide distribution through Africa, the genus Alcelaphus has been little studied. The aim of the work described here was the study of a population of Coke's hartebeest in the Athi Plains of Kenya, which included the Nairobi National Park. It was designed to complement existing information on the species' behaviour and to examine the interactions between the hartebeest and their food supply. The approach, both in the field and subsequently, is also described in Ch.1. In Ch.2 I describe the methods which are referred to frequently through later chapters. These include the field methods of counting and ageing hartebeest, the location of study areas and the sampling of vegetation, the measurement of rainfall and the collection of specimen animals. The organisation of the resulting data and their analysis are described. Descriptions of the Athi Plains are few. Their geology and topography are outlined in Ch.3, while Ch.4 concerns their climate, with the emphasis on rainfall as the most important seasonal parameter. The vegetation of the Nairobi Park and the rest of the plains is then described (Ch.6) at the level of the vegetation zones for the whole plains (1850 km²) and of vegetation types for the study areas. The Nairobi Park is shown to have a very varied vegetation despite its small size (114 km²). In Ch.6 the sizes and distributions of the populations of hartebeest and other numerous herbivores are described from aerial censuses over the plains and ground counts in the park. This establishes that the density of hartebeest in the park is 6.6 times that of the plains. The latter population also contains significantly fewer adult females and young above the age of 1 month. The hartebeest in the plains show very minor population movements compared to either wildebeest or zebra, and exchange with the park population is infrequent. Using information theory methods, Ch.7 serves to define the niche of the hartebeest in relation to those of other herbivore species, and to compare the structure of the communities of the two areas. The herbivore community of the plains also includes cattle, sheep and goats. The results of this ground-work confirm the sedentary existence of the hartebeest population, but show it to occupy a relatively wide variety of vegetation zones through the year, occupying many vegetation types and tolerating a broad range of grass standing crops. Compared to other species, the hartebeest shows a very marked seasonal occupation of vegetation types in the park, but this is not apparent in the plains. The same methods are extended to measure the similarity between species' distributions, and the cases of high overlaps are examined using published information on the feeding habits and diets of the species. Considerable ecological separation can be inferred between all species- pairs except between hartebeest and zebra in the park in the dry season, and between hartebeest and cattle in the plains in the wet season. The distributions of the latter pair in the dry season, also, suggest their ecological equivalence. In Ch.8, starting Part II, I describe the hartebeest's diet and its seasonal changes from the analysis of rumen contents. The hartebeest grazes exclusively. Its diet is described in terms of its content of grass parts, rather than grass species, amongst which Themeda triandra is shown by various sources to be predominant. The effects of the differential digestion of these parts in the rumen are reversed by applying a correction factor based on specific gravity (Appendix 12) to obtain the diet proportions. In the wet season the proportion of leaf in the diet is higher than in the sward, while the less nutritious stem is under-represented. When the leaf in the sward has been depleted in the dry season, the hartebeest no longer exercise any dietary selection. Comparison of these results with those published for zebra show that the parts taken by the 2 species are very different in proportion, and I conclude that this would result in their ecological separation even when feeding together. On the other hand, comtemporary evidence on cattle diets, also from the Athi Plains, shows them to be taking the same diet as the hartebeest, and evidence is presented that Themeda is also frequently eaten by cattle. Their coincident distributions are parallelled by similarities in their rumen morphology and bacteriology, with both classified as the only "bulk roughage grazers" in the Athi Plains community. The method developed for the correction of grass part proportions in the rumen to those in the diet allows the daily dry matter intake to be calculated from the weight of dry matter in the rumen (Ch.9). Intake varied between 26 and 87 g/kg.W^.73.day in the dry and wet seasons respectively, through the effect of the water content of the food on its specific gravity and subsequent behaviour in the rumen. The calculated variation in intake with the succulence and quality of the food is consistent with experimental observations on the factors controlling the intake of coarse feeds by domestic ruminants. The calculated intakes are similar to those of 42 and 34 g/kg.W^.73.day of an experimental hartebeest and sheep, respectively. A regression method for predicting the hartebeest's intake under field conditions from the faecal nitrogen content is developed. In Ch.10 the dry matter intake is converted into the intakes of protein and energy, and the gain to the hartebeest of selective feeding is calculated. Selection appears capable of increasing the digestible crude protein intake by 50%. The calculated intakes are compared with maintenance standards for domestic ruminants and are shown to have fallen below the maintenance levels in the dry season of September 1972. Calculation of the intakes uses information from a feeding trial with hartebeest and sheep, whose intakes were also measured. The experimental hartebeest's metabolisable energy intake was 51.5 kcal/kg.W^.73.day, which was considerably lower than the measured metabolic heat production of 116.1 kcal/kg.W^.73.day of another tame animal. The metabolisable energy intake of the sheep of 45.1 kcal/kg.W^.73.day suggests that the lower metabolic rate may be more correct, and further supporting evidence is presented. Chapter 11 is the first of 3 chapters in which the hartebeest's energy expenditure is considered. The daily activity patterns are described from day and night observations in the wet and dry seasons. Little seasonal variation in the regime of 3 feeding periods at nearly equal intervals through 24 hours was apparent. The total times spent feeding was 2 hours shorter at 8.6 h/24h in the dry season than the wet. About half of this reduction was made up by an increase in the time spent walking, associated with the need to visit water sources in the dry season. Further observations showed that males drank every 3 days, females every 2 days. The energy cost of this activity was almost the same in both seasons at 52% greater than the basal metabolic energy expenditure. The use of energy for growth and the deposition of body reserves is considered in Ch.12. The shot animals showed that full adult body weight is not reached until the fourth year, after which weight appears to decline immediately. Using a photographic method the external condition of territorial males was shown to depend on the rainfall over the previous 4 months. Non-territorial males were always in significantly better condition. The shot hartebeest were characterised by very small kidney fat reserves which showed no seasonal variation. Marrow fat varied seasonally, as did the weight of a selected muscle, representing the protein reserves of the body. The latter also changed through age, parallelling the changes in total body weight.

Thesis (PhD (Food Sc))--Stellenbosch University, 2011. / ENGLISH ABSTRACT: The wildlife industry in Namibia has shown tremendous growth over the past decades and is currently the only extensive production system in Namibia that is expanding. Harvesting game for the purpose of meat production is a viable option since there is a worldwide demand for healthy and high quality proteins. The main objective of the dissertation was to investigate selected parameters required to develop a sustainable Namibian game meat industry. The major species suitable for commercial harvesting operations are springbok (Antidorcas marsupialis – Zimmerman, 1780), gemsbok (Oryx gazella – Linnaeus, 1785), kudu (Tragelaphus strepsiceros – Pallas, 1766), mountain zebra (Equus zebra hartmannae – Linnaeus, 1758) and red hartebeest (Alcelaphus buselaphus caama – Pallas, 1766). Eland (Tragelaphus oryx – Pallas, 1766) could be considered as a suitable species, although the numbers of animals that can be harvested during an operation are limited. This study demonstrated that gender influenced live weight of springbok, kudu and red hartebeest. Gender also influenced carcass weights for springbok, gemsbok, kudu and red hartebeest, but not for eland, while dressing percentage did not differ between gender for springbok, gemsbok, kudu and red hartebeest. Although there were some statistical differences in the chemical composition of the various muscles from the different species (Mm. biceps femoris, infraspinatus, longissimus dorsi, semimembranosus, semitendinosus and supraspinatus), it is doubtful whether consumers would be able to distinguish between these. Discriminant analysis could not differentiate among the different muscle groups for springbok and gemsbok. A differentiation was, however, revealed among the various muscles for red hartebeest. During the investigation on the influence of season and gender on the carcass yields and meat quality characteristics of kudu and red hartebeest, dressing percentage was affected by season, but not by gender. Muscle colour differed significantly between seasons. Results from this study showed that male eland contained more saturated fatty acids than females, but no gender differences were observed for polyunsaturated fatty acids. Hides of gemsbok, kudu and red hartebeest contributed 6 – 7% of live weight, while the skin of springbok contributed 4 – 5% of live weight. Comparisons of offal items among species showed significant differences for all offal items, except for intestines. Retail cuts showed significant species difference for rump, topside, silverside and sinews. No significant species differences were observed for thick flank and bolo. Significant gender differences were observed for silverside. No interactions between species and gender were found for the different retail cuts from gemsbok and kudu. Microbiological counts of game meat, chilled for 6 weeks and frozen for 12 months, respectively, were found to be within acceptable limits as prescribed by the South African retail market. Differences in physico-chemical and microbiological properties were observed among salami from different game species. The springbok salami was found to be microbiologically unstable. The main characteristics observed while tasting the salami from springbok, gemsbok, kudu and zebra were a distinctive smoky, salty, pepper and salami flavour combined with a smoky, salami aroma. Game flavour did not feature as strong during the sensory analyses. Sustainable utilization of game for commercial meat production has the potential to increase earnings to beneficiaries in the wildlife sector. Results from this study contributed knowledge which can be utilized to develop the Namibian game meat industry. / AFRIKAANSE OPSOMMING: Die wildsbedryf in Namibië het die afgelope dekades buitengewone groei getoon en is huidiglik die enigste ekstensiewe produksie-sisteem wat in Namibië uitbrei. Die oes van wild is ʼn voordelige opsie, aangesien daar wêreldwyd ʼn aanvraag is na gesonde en hoë kwaliteit proteïene. Die hoofdoelwit van hierdie dissertasie was die loods van ʼn ondersoek na geselekteerde aspekte wat benodig word om die Namibiese wildsvleisbedryf te ontwikkel. Die belangrikste spesies geïdentifiseer as geskik vir kommersiële oes, is springbok (Antidorcas marsupialis – Zimmerman, 1780), gemsbok (Oryx gazella – Linnaeus, 1785), koedoe (Tragelaphus strepsiceros – Pallas, 1766), berg sebra (Equus zebra hartmannae – Linnaeus, 1758) en rooihartbees (Alcelaphus buselaphus caama – Pallas, 1766). Eland (Tragelaphus oryx – Pallas, 1766) is ook ʼn geskikte spesies, maar die hoeveelhede wat op een slag geoes kan word, is beperk. Hierdie studie het gedemonstreer dat geslag ʼn invloed op die lewendige gewig van springbok, koedoe en rooihartbees het. Geslag het ook ʼn invloed gehad op karkasgewigte van springbok, gemsbok, koedoe en rooihartbees, maar geen invloed op die karkasgewig van eland nie, terwyl uitslagpersentasie geensins geslagsverskille getoon het vir springbok, gemsbok, koedoe of rooihartbees nie. Nieteenstaande statistiese verskille in die chemiese samestelling van die verskillende spiere van die onderskeie spesies (Mm. biceps femoris, infraspinatus, longissimus dorsi, semimembranosus, semitendinosus en supraspinatus), is dit te betwyfel of verbruikers ʼn onderskeid sal kan tref tussen die spiere. Diskriminant-analise kon nie verskille uitwys tussen die verskillende groepe spiere van springbok en gemsbok nie. Verskille was egter te bespeur tussen verskillende spiere van die rooihartbees. Gedurende hierdie ondersoek is die invloed van seisoen en geslag op die karkasopbrengs en vleiskwaliteit van koedoe en rooihartbees ondersoek. Uitslagpersentasie is beïnvloed deur seisoen, maar nie deur geslag nie. Kleur het betekenisvol verskil tussen seisoene. Resultate van die studie het getoon dat elandbulle meer versadigde vetsure het as koeie, maar dat geen verskille vir geslag gevind is vir poli-onversadigde vetsure nie. Gemsbok-, koedoe - en rooihartbeesvelle het 6 – 7% bygedra tot die lewendige gewig, terwyl die vel van die springbok 4 – 5% bygedra het. Vergelykings van afvalopbrengs tussen spesies het verskille uitgewys ten opsigte van al die items, behalwe die ingewande. Kleinhandelsnitte het betekenisvolle verskille getoon vir die kruis, binneboud, dy en senings. Geen betekenisvolle spesies verskille is opgemerk vir die diklies en bolo nie. Die dy het betekenisvolle verskille tussen geslagte getoon. Geen interaksie tussen spesies en geslag is opgemerk vir die verskillende kleinhandelsnitte van gemsbok en koedoe nie. Mikrobiologiese tellings vir wildsvleis, verkoel vir 6 weke en gevries vir 12 maande, onderskeidelik, het voldoen aan die aanvaarbare vlakke soos voorgeskryf deur die Suid-Afrikaanse kleinhandelsmark. Verskille in fisiese, chemiese en mikrobiologiese kwaliteite was opgemerk vir die salami van die verskillende spesies. Springbok salami was mikrobiologies onstabiel. Die belangrikste karaktereienskappe bemerk tydens die proe van die salami vervaardig van springbok-, gemsbok- , koedoe - en sebravleis, was ʼn oorheersende rook-, sout-, peper- en salamigeur, gekombineer met ʼn rook- en salami aroma. Wildsvleisgeur het nie sterk na vore gekom tydens die sensoriese analise, nie. Die volhoubare gebruik van wild vir kommersiële vleisproduksie het die potensiaal om inkomste vir belangegroepe in die wildsektor te verhoog. Resultate van hierdie studie het kennis uitgebrei wat gebruik kan word om die wildsvleisindustrie in Namibië te ontwikkel.

Thesis (MSc Consumer Science)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Please see fulltext for abstract / AFRIKAANSE OPSOMMING: Sien asb volteks vir opsomming