Current discourse regarding the use and management of natural resources in the drylands of sub-Saharan Africa is inspired by three issues: 1) the growing emphasis on strengthening 'community-based' management of natural resources as a means of combining resource conservation with improvements in livelihoods; 2) continuing debate concerning the replacement of communal forms of land management with systems of private tenure; 3) and the widespread assumption of environmental 'degradation' and 'desertification' caused by the land-use practices of African livestock farmers. The way these areas of debate are interpreted affects policy and development intervention relating to the management and conservation of dryland natural resources. In relation to these issues, this thesis has two primary aims: 1) to analyse patterns and determinants of natural resource-use and management by Khoe-speaking Damara farmers in and north-west Namibia; 2) to assess the ecological implications of this resource-use in the context of the unpredictable variations in primary productivity characteristic of dryland environments. A combination of quantitative and qualitative anthropological and ecological techniques are employed to meet these objectives. The use of gathered non-timber products for food and medicine was monitored in 7 repeat-surveys over an 18 month period for a sample of 45 households comprising 2017 individual 'diet-days'. Statistical analysis suggests that food resources are consumed when abundant rather than as dry season supplements, that wealth is a poor predictor of gathered resource-use and that the use of natural resources is remarkably resilient given the disruptive effects of land alienation during this century. The utilisation of timber for fuel and building-poles was quantified at the household level and compansons with equivalent data from rural societies in more humid environments suggests conservative use of these resources. Qualitative data emphasise the continuing relevance of culturally-informed management practice relating to the use of natural resources. With regard to the second research objective, woody and herbaceous vegetation datasets were compiled, the former comprising 2760 plant individuals in a stratified sample of 75 transects and the latter consisting of 48 qradrats, half fenced to exclude livestock, in which herbaceous vegetation was monitored over two growing seasons. A number of standard ecological variables, including patterns in community floristics, diversity, cover and population structure, were used to explore the prediction that concentrations of people and livestock cause measurable impacts on vegetation around settlements. Statistical analysis suggests that effects of settlement are extremely localised and are within the range of variability shown by these measures over larger spatial scales, and that between-year variability in herbaceous vegetation dominates that measured both between- and within-sites. The research results indicate that current understanding of local resource-use practices in northwest Namibia is constrained by two conceptual influences: 1) a misleading colonial ethnography which continues to inform debate and interventions regarding the use and management of natural resources, operating to deny the present-day validity of local ecological knowledge and practice; 2) a temperate-zone ecology which focuses on density-dependent interactions between the biotic components of ecosystems, and plays-down the role of unpredictable abiotic factors, particularly rainfall, in driving a continuing dynamic of non-equilibrium variability in arid environments.

This study formed part of the collaborative IDEAL (Infectious Diseases of East African Livestock) project, which focused on the sedentary mixed crop-livestock smallholding system in Western Kenya. This was a longitudinal study where calves were recruited at birth and followed at 5-weekly intervals until 51 weeks of age. The main aim was to investigate the total disease burden of cattle in the study area for the first year of life. The main objectives of the study concerned anaemia as a syndrome in the calves. Anaemia can provisionally be diagnosed based on clinical signs, but a confirmatory diagnosis is based on measuring of red blood cell parameters, such as packed cell volume (PCV), red cell counts (RCC) or haemoglobin (HGB). The FAMACHA / Thesis (PhD)--University of Pretoria, 2012. / Veterinary Tropical Diseases / unrestricted

Near infrared reflectance spectroscopy (NIRS) and geostatistical techniques were used to predict diet quality of sub-Saharan African (SSA) livestock, and to create cokriged estimated diet quality maps for cattle across a landscape. Rations of native vegetation were stall-fed to cattle (Bos indicus), sheep (Ovis aries), and goats (Capra hircus) to generate diet-fecal pair data. Trials were conducted in Ethiopia, Kenya, Uganda, Tanzania, and Ghana. Historical data from Ethiopia, Nigeria, and Niger were included. Diet samples were analyzed for crude protein (CP%), and digestible organic matter (DOM%), while feces were scanned for NIR spectra. NIRS equations were developed from data using modified partial least square (MPLS) regression. Coefficients of determination (R2) of CP for cattle, sheep, and goats were 0.92, 0.95, and 0.97, with corresponding standard errors of calibration (SEC) being 0.90, 0.79, and 0.80, respectively. Standard errors of cross validation (SECV) for CP were 1.12%, 1.08%, and 1.03% for cattle, sheep, and goats, respectively. R2 and SEC values for DOM were 0.88, 0.94, 0.94 and 2.82%, 1.68%, and 2.65%, for cattle, sheep, and goats, respectively. Corresponding SECV values for DOM were 3.26%, 2.07%, and 3.30%, respectively. The statistics reported were within the acceptable limits for NIRS calibrations. The results indicate that dietary CP and DOM of free-ranging SSA livestock can be predicted with the same precision as that of conventional wet chemistry methods. The cattle equation was used to predict cattle fecal samples collected, from February to August 2000, from selected households located within the northern Ghana savanna. The predicted CP% and DOM% were used with Normalized Differential Vegetation Index (NDVI) data, and cokriging technique to create diet quality maps for March and July 2000 for the northern Ghana savanna. Cross validation results indicated a moderate capability of cokriging to estimate predicted CP% for March (r2 = 0.687, SEp = 1.736) and July (r2 = 0.513, SEp = 1.558). Cokriged-estimated DOM value for July was above average (r2 = 0.584, SEp = 3.611), while March DOM% estimation was rather poor (r2 = 0.132, SEp = 3.891). The techniques of cokriging and creation of diet quality maps were moderately successful in this study.

Near infrared reflectance spectroscopy (NIRS) and geostatistical techniques were used to predict diet quality of sub-Saharan African (SSA) livestock, and to create cokriged estimated diet quality maps for cattle across a landscape. Rations of native vegetation were stall-fed to cattle (Bos indicus), sheep (Ovis aries), and goats (Capra hircus) to generate diet-fecal pair data. Trials were conducted in Ethiopia, Kenya, Uganda, Tanzania, and Ghana. Historical data from Ethiopia, Nigeria, and Niger were included. Diet samples were analyzed for crude protein (CP%), and digestible organic matter (DOM%), while feces were scanned for NIR spectra. NIRS equations were developed from data using modified partial least square (MPLS) regression. Coefficients of determination (R2) of CP for cattle, sheep, and goats were 0.92, 0.95, and 0.97, with corresponding standard errors of calibration (SEC) being 0.90, 0.79, and 0.80, respectively. Standard errors of cross validation (SECV) for CP were 1.12%, 1.08%, and 1.03% for cattle, sheep, and goats, respectively. R2 and SEC values for DOM were 0.88, 0.94, 0.94 and 2.82%, 1.68%, and 2.65%, for cattle, sheep, and goats, respectively. Corresponding SECV values for DOM were 3.26%, 2.07%, and 3.30%, respectively. The statistics reported were within the acceptable limits for NIRS calibrations. The results indicate that dietary CP and DOM of free-ranging SSA livestock can be predicted with the same precision as that of conventional wet chemistry methods. The cattle equation was used to predict cattle fecal samples collected, from February to August 2000, from selected households located within the northern Ghana savanna. The predicted CP% and DOM% were used with Normalized Differential Vegetation Index (NDVI) data, and cokriging technique to create diet quality maps for March and July 2000 for the northern Ghana savanna. Cross validation results indicated a moderate capability of cokriging to estimate predicted CP% for March (r2 = 0.687, SEp = 1.736) and July (r2 = 0.513, SEp = 1.558). Cokriged-estimated DOM value for July was above average (r2 = 0.584, SEp = 3.611), while March DOM% estimation was rather poor (r2 = 0.132, SEp = 3.891). The techniques of cokriging and creation of diet quality maps were moderately successful in this study.