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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Reproductive performance of cows in sweet and sour veld types under communal production systems in the Eastern Cape Province of South Africa

Nqeno, Noluvuyo January 2008 (has links)
The objective of the study was to evaluate cow reproductive performance in the sweetveld and sourveld communal grazing areas of the Eastern Cape Province, South Africa. In the first experiment, farmer perceptions were obtained using participatory rural appraisals. Farmers ranked lack of fences, tick-borne diseases, poor animal condition during winter and poor breeding practices, respectively as major constraints limiting cattle production in the Eastern Cape. Cattle, sheep and goats, in that order, were ranked as the most important livestock species and were mainly kept for meat, cash and ceremonies, respectively. The non-descript cattle breed was the most common breed found in the smallholder areas. Most farmers preferred Nguni breed because of its adaptive attributes. In the second experiment, structured questionnaires were administered, between June and August 2006, to a total of 551 farmers from 10 communities of the Eastern Cape. There was a significant association (P<0.05) between the use of pregnancy diagnoses and community. About 87 and 77 % of the interviewed farmers did not respond on the extent of pregnancy and calving rates in their herds. A higher proportion of farmers from Hekele (51%) and from Upper Mnxe (45.3%) communities reported low number of bulls as a major constraint to cow reproductive performance. Body condition and ovarian activity were measured in the sweet and sour veld types. Body condition score of animals was measured from March iii 2007 until January 2008 and ovarian activity of cows was performed by a veterinarian through rectal palpation in June, August and October 2007 and January 2008. From March to July, there was a marked decline in body condition on both veld types. In the sweetveld, body condition improved from September until January, whereas in the sourveld the improvement in body condition started in October. The cows in both veld types conceived throughout the year. Most cows in the sweetveld were cycling in January and August (P<0.05) whereas in the sourveld there was no distinct period when the animals were cycling. Overall, there were no differences in the proportion of cows that were cycling between the sour and sweet veldts (P>0.05). There were more cows cycling in sourveld in October than in the sweetveld. Reproductive performance of cows in communal areas could, therefore, be determined by levels and quality of nutrition. Keywords: Participatory rural appraisals; Structured questionnaires; Farmer participation; Farmer perceptions; Body condition scoring; Ovarian activity; Pregnancy diagnoses.
12

Assessment of veld utilisation practices and veld condition in the Little Karoo

Cupido, Clement F. 03 1900 (has links)
Thesis (MScConsEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2005. / The veld condition in the Little Karoo is in various states of degradation and grazing by domestic livestock is considered as the major anthropogenic force that changed the landscape. This region with its extremely rich plant species diversity and endemics, has supported small livestock for at least 2 000 years, and since colonization (250 years ago) been intensively used for the production of a variety of livestock. Ostrich production developed as the major source of income for this region. The first part of this study investigates the current veld management practices employed by livestock farmers in the Little Karoo region. Recommended veld management practices considered in this study are grazing rotation, moderate stocking rate control, moderate veld utilisation, separation of ecotopes, veld rehabilitation, controlling declared weeds and alien vegetation and regular assessment of veld condition. One hundred randomly selected farmers were personally interviewed by means of a structured questionnaire. Questions were grouped into the following categories: (a) demography of farmers, (b) ostrich farming, (c) perceptions and knowledge of farmers on farming practices, (d) grazing rotation, (e) stocking rate, (f) veld utilisation and veld assessment, (g) separation of ecotopes, (h) veld rehabilitation, (i) control of alien vegetation and (j) farmers’ knowledge on legislation. This was used to obtain information on the Little Karoo farming community, sizes of farms and camps, types of farming enterprises and on adoption of recommended veld management practices in the region. The main findings from this section are that relatively small farming units with few camps, poor separation of ecotopes and a low estimated grazing capacity, limit extensive livestock farming within the region. Perceptions of farmers on veld condition, grazing rotation, stocking rate, separation of ecotopes are fairly optimistic. As a result grazing capacities are overestimated and overstocking occurs within this region. The current stocking rate in ostrich camps (67.7% overstocked) and mammalian livestock camps (55.1% overstocked) is evidence that farmers overstock to compensate for these limiting factors in order to make a living from the land. The majority of farmers are well aware of the Articles in the Conservation of Agricultural Resources Act of 1983, which are applicable to veld management. Only more that 50% comply with this legislation by rehabilitating veld and 80% of them control invasive alien species on their farm. In the second part, veld assessments were done in randomly selected veld camps, using the multi-criterion, semi-subjective Quick Rangeland Health Assessment (QRHA) Method. Veld condition was significantly poorer closer to water or feeding points due to the piosphere effect caused by livestock. Veld condition in the Little Karoo can be related to altitude, vegetation types and land use. Therefore, the lowlying Little Succulent Karoo vegetation type is in a poorer condition compared to Spekboom Succulent Thicket and South and South-west Coast Renosterveld. Ostrich production on plains in the Little Succulent Karoo vegetation type is the main cause for the degradation of this vegetation type. It would seem as if historically high stocking rates cannot be ignored in explaining the current veld condition. A positive correlation between veld condition and the diversity of plant species (species density) were found, which highlights the importance of good veld management practices in sustainable agriculture. The third part tested whether all indicators in the QRHA method are equally sensitive and whether there is a positive correlation between the QRHA method and the Grazing Index Method. A significant positive linear correlation was found between the two methods. Cover was the least sensitive indicator of rangeland condition, and livestock induced disturbances (which include the indicators grazing intensity, disturbance indicators, soil health and species richness) were the most sensitive for Karoo veld assessment. A major benefit of the QRHA method is heuristic; therefore this method may have value in agricultural extension work.
13

A comparison of standard scientific methods and pastoralists’ perceptions of vegetation responses to livestock exclusion in Namaqualand, South Africa

Snyman, Dirk 03 1900 (has links)
Thesis (MSc (Conservation Ecology and Entomology))--University of Stellenbosch, 2010. / ENGLISH SUMMARY: Protected areas do not always achieve the desired level of biodiversity conservation, while often reducing the welfare of indigenous communities by reducing availability of land for subsistence. Traditional agricultural landscapes are significant biodiversity refugia and can contribute meaningfully to conservation. Rangelands comprise one-third to one-half of the world’s terrestrial surface, providing livelihoods for around 220 million people, usually in a communal subsistence system. Colonial practices impinged on traditional land-use practices with far-reaching social and environmental impacts. This has resulted in management based on assumptions regarding vegetation dynamics and traditional lifestyles that are increasingly shown to be inaccurate. A comparison of a vegetation survey based on conventional scientific methods and a survey of the perceptions of pastoralists was undertaken to highlight differences and similarities between the two knowledge systems with the hope of providing guidelines for more sustainable land-use practices in the communal rangelands of Namaqualand, South Africa. Vegetation responses to removal of grazing pressure revealed complex interactions that do not correspond with the prevailing management paradigm. Rather than a predictive relationship between livestock and vegetation, environmental factors play a large role in determining plant composition, abundance and cover. Pastoralists’ perceptions reflected this complexity in rangeland resource dynamics. The impact of livestock on rangeland resource dynamics was perceived by herders to be secondary to a range of environmental and climatic factors. Both sets of results were at odds with the theories that currently govern management in this system. Studies in rangeland systems must take the complexity of the subject into account. Research into such socio-ecological systems must take a multiplicity of factors – social, environmental, economic, political and other – into account. Implications for management are that it is inappropriate to adhere strictly to the conventional, conservative strategies that are prescribed by conservation and agricultural authorities. Rather, a more flexible, opportunistic grazing strategy would allow the persistence of traditional subsistence livelihoods without serious negative consequences for biodiversity conservation. / AFRIKAANSR OPSOMMING: Die instelling van beskermde gebiede lewer nie altyd die gewenste vlak van biodiversiteitsbewaring, terwyl die welvaart van plaaslike gemeenskappe dikwels daaronder ly deur die afname in grond beskikbaar vir bestaanspraktyke. Tradisionele landboulandskappe is beduidende biodiversiteitshawens wat ‘n belangrike bydrae tot bewaring kan maak. Weivelde bevat ‘n derde tot ‘n helfte van die wêreld se landsoppervlakte en ondersteun rondom 220 miljoen mense, gewoonlik binne ‘n gemeenskaplike bestaansstelsel. Kolonialisasie het inbraak gemaak op tradisionele bestuurspraktyke, met verrykende sosialeen omgewingsimpakte. Dit het gelei tot bestuurspraktyke gebaseer op standpunte oor plantegroeidinamika en traditionele lewenswyses wat toenemend verkeerd bywys word. ‘n Vergelyking van ‘n plantegroei opname gebaseer op konvensionele wetenskaplike metodes en ‘n opname van die standpunte van veewagters is onderneem om die verskille en ooreenkomstes tussen die twee kennisstelsels uiteen te lê met die hoop om riglyne vir meer volhoubare bestuurspraktyke in die meentgronde van Namakwaland, Suid-Afrika te verskaf. Plantegroei reaksies tot die verwydering van weidingsdruk wys op komplekse interaksies wat nie ooreenstem met die heersende bestuursparadigma. Eerder as ‘n voorspelbare verwantskap tussen vee en plantegroei, omgewingsfaktore speel ‘n groot rol in die bepaling van plantgemeenskapsamestelling, -getalle en grondbedekking. Die veewagters se standpunte het hierdie kompleksiteit in plantegroeidinamika weerspiëel. Die impak van vee op die weiveldhulpbron is deur veewagters as sekondêr beskou teenoor ‘n reeks omgewings- en klimaatsfaktore. Beide stel resultate is in teenstelling met die teoriëe wat tans bestuur in hierdie stelsel bepaal. Studies in weiveldstelsels moet die kompleksiteit daarvan in ag neem. Navorsing oor hierdie sosio-ekologiese stelsels moet ‘n verskeidenheid faktore – sosiale-, omgewings-, ekonomiese-, politiese- en ander – in ag neem. Implikasies vir bestuur is dat dit onvanpas is om te volhard met konvensionele, konservatiewe strategiëe voorgeskryf deur bewarings- en landboukundige gesagte. ‘n Meer aanpasbare, voordeelnemende weidingsstrategie sal die voortbestaan van traditionele bestaanslewenspraktyke toelaat sonder ernstige negatiewe nagevolge vir biodiversiteitsbewaring.
14

Ecological characterisation and effects of fire and grazing on Cyrtanthus nutans (R.A.Dyer) in North-Western Kwazulu-Natal, South Africa

Ruddle, Lynne Michelle 05 1900 (has links)
Cyrtanthus nutans (RA Dyer) is a KwaZulu-Natal Province near-endemic species, classified as vulnerable in South Africa (IUCN Red Data categories). Literature references suggest that no recent ecological research has been conducted on Cyrtanthus nutans. Last assessed in 2007, the current study determined the demographics and the abiotic and biotic factors that influenced the distribution and range of Cyrtanthus nutans. Key determinants influencing the autecology, distribution and population dynamics of Cyrtanthus nutans were investigated. Anthropological factors influencing the decline of populations were addressed. Two investigations were undertaken for the current study on Cyrtanthus nutans in Dundee in North-western KwaZulu-Natal, South Africa namely a survey to determine the population dynamics and autecology of the species and the effect key determinants have on the recruitment and survival. Sites of occurrence and the ecological and anthropological factors that influence the existence of plants were documented. Experimental plots were conducted to determine the influence of climatological factors, fire and defoliation on the emergence and survival of Cyrtanthus nutans plants. A preference was found for soils with high nitrogen and organic carbon, low phosphorus and acidity levels situated on slopes of < 10% on mid to lower terrain slopes within an altitude range of between 1 100 and 1 300 m (a.m.s.l.) in the Sour Sandveld and Moist Tall Grassveld Bioresource Groups. The influence that climatological factors, fire and defoliation had on the emergence and seed recruitment of Cyrtanthus nutans were determined through a small plot experiment in the Dundee area. Mean relative humidity (%) and mean rainfall two weeks before emergence in conjunction with treatments were highly significant (P<0.001). Burning treatments B (fire inclusion and defoliation inclusion) and BC (fire inclusion and defoliation exclusion) were more highly significant on the emergence of Cyrtanthus nutans plants than any other treatments. ii | P a g e Increasing fragmentation of thriving populations of Cyrtanthus nutans populations is occurring through landuse change, mismanagement of veld and non-compliance of legislation. Continued monitoring and awareness is essential in the survival of this species. / Environmental Sciences / M. Sc. (Environmental Sciences)
15

Some performance characteristics of wooled sheep in the sweet and sourveld communal rangelands of Eastern Cape Province, South Africa

Mvinjelwa, Sivuyile Alex January 2013 (has links)
The objective of the study was to determine sheep growth performance, fleece weights and wool quality characteristics in the sweet and sourveld communal rangelands of the Eastern Cape Province of South Africa. Data were obtained in 80 ewes aged two to three years, selected in four ecologically different communities. Two communities (Roxeni and Tyabane) were in a sweetveld area and the other two communities (Luzi I and Luzi II) were in a sourveld area. The ewes from Tyabane were nondescript, whereas ewes from Roxeni, Luzi I and Luzi II were crossbred between Merinos and non-descript sheep. Selected ewes were monitored for live weight, body condition scoring and fleece weight during shearing. Wool samples were collected from each ewe and were analysed for fibre diameter, comfort factor, clean yield, wool crimps, staple length, staple strength and the Position of break. Sheep from Roxeni were heavier (P <0.05) (39.9 ± 1.1kg) than sheep from Tyabane (29.8 ± 1.1kg). Sheep from Tyabane had the lightest (P <0.05) fleece weight (1.0 ± 1.1kg) and sheep from Roxeni had the heaviest (3.1 ± 1.1kg). There were no significant differences (P ≥0.05) between body condition scores of sheep in Roxeni and the Luzi communities. The live weights of the two-year old ewes were similar (P ≥0.05) to the three-year old ewes’ live weight. However, the three year old ewes had higher (P <0.05) body condition scores than the two year old ewes. Two year old ewes also had lower (P <0.05) fleece weight than the three years old ewes. Wool from Roxeni, Luzi I and Luzi II had lower fibre diameter (P <0.05) than wool from Tyabane. Roxeni sheep had the highest clean yield (P <0.05) of wool, followed by Luzi I and Luzi II; Tyabane had lowest clean yield percentage of wool. Wool from sheep grazing on sweetveld had a higher (P <0.05) clean yield percentage (74.3 ± 0.7%) than those grazing on sourveld (71.7 ± 0.7%). There were higher staple mid-breaks (69.5 ± 5.2) and lower base-breaks (30.5 ± 5.2) in sweetveld (P <0.05) than in sourveld, 7.5 ± 5.2 and 92.5 ± 5.2 for mid-breaks and lower base-breaks, respectively. It was concluded that sheep raised in the sweetveld and bred with purebred Merino rams had higher performance than the ones reared in the sourveld. The young upgraded ewes had a higher wool quality than the older ewes raised on communal rangelands.
16

Using nutritional quality of forage and faeces for predicting sustainable livestock and game stocking rates at Pniel Estates in Northern Cape, South Africa

Mbatha, Khanyisile R. 03 1900 (has links)
Thesis (PhD)--University of Stellenbosch, 2010. / The aim of the study was to assess the importance of spatial and temporal variation in diet quality and abundance for determining sustainable stocking rates on commercial, communal and game ranches in a semi-arid savanna, with the ultimate goal of avoiding land degradation in the long term, to provide sustainable livelihoods in rangelands and to make policy that will help in managing the available natural resources in the rangelands. Thus, firstly the effects of grazing, fire, nitrogen and water availability on nutritional quality of grass in semi-arid savanna was assessed. Secondly, spatial and temporal variation in plant quantity and quality among management (commercial, communal and game) types and habitat types (open savanna, rocky, shrubby and pans) and stocking rates in different management types were determined. Thirdly, the quality and quantity of variation inside and outside herbivore exclosures among commercial, communal and game management and habitat types in the semi arid savanna were estimated. Fourthly, faecal profiling was used to assess the effects of different management types on diet quality in semi-arid savanna. Lastly, policy based on the results of the present study was formulated.
17

Sheep production practices, flock dynamics, body condition and weight variation in two ecologically different resource-poor communal farming systems

Mapiliyao, Luke January 2010 (has links)
The objective of this study was to determine sheep production practices, constraints, flock dynamics, body condition and weight variation in two ecologically different resource-poor communal farming systems of the Eastern Cape Province of South Africa. Mean sheep flock sizes per household were not significantly different between the two ecologically different areas (villages); Gaga (19.0±3.10) and Sompondo (18.3±3.10). Shortage of feed, disease and parasite were reported the most important constraints across the two villages. In both villages, sheep housing was poorly constructed using acacia brushwoods. Fewer farmers owned rams: the rams to ewes ratio for the two villages were 1:20, 1:19 for Gaga and Sompondo, respectively. The low ram: ewe ratios reported suggest that inbreeding might have been reducing productivity of their flocks. There was also uncontrolled breeding due to undefined and mating seasons. Gall sickness, heart water and footrot caused most of the sheep mortalities. Dohne Merinos were the common genotypes in the two villages. Total entrances for each flock were higher (p < 0.05) in hot-dry season and hot-wet season than in other seasons. Most of the entrances were lambs and were born in hot-dry season (September) and cool-dry season (June) for larger flocks (10.90 ± 3.02) and for small flocks (3.65 ± 3.02). High lamb mortalities were experienced in the post-rainy (April) and hot-wet (December) season. There was a significant interaction between season and flock size. Most of the sales occurred in the hot-wet season. Ecological area had significant effect on sheep production potential (p < 0.05) in both flock classes. The average sheep production efficiency (SPE) value for Gaga and Sompondo were 0.50 ± 0.116 and 0.50 ± 0.096 respectively. The SPE for large flock was higher (p < 0.05) by season and flock size. Large flocks had a higher (p < 0.05) SPE values and the SPE ranged from 1.11 ± 0.193 in April, a post-rainy season month to 1.55 ± 0.193 in December, a hot-wet season month. Lamb mortalities constituted the greater part of outflows. High lamb mortalities occurred in hot-wet (December), hot-dry (September) and post-rainy (April) seasons. There was a significant interaction between season and age of sheep on body weight of sheep. Highest (p < 0.05) body weights were recorded in the post-rainy and autumn season in both lambs and ewes. It is therefore very important to come up with affordable interventions which take into play ecological differences of the areas for improved nutritional status of sheep in communal areas which will lead to improved sheep productivity and the poor-resourced farmer human nutritional and livelihood.
18

Cattle production on communal rangelands of South Africa and the potential of acacia karroo in improving Nguni beef production

Mapiye, Cletos January 2009 (has links)
No description available.

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