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1.
S. Flasse C. Walker H. Biggs P. Stephenson P. Hutchinson 《Preventive veterinary medicine》1998,33(1-4):31-38
The Directorate of Veterinary Services of the Ministry of Agriculture, Water and Rural Development of Namibia issues warnings to farmers in the south of the country about the likelihood of infestation of small-stock by the nasal bot fly, Oestrus ovis. Farmers can then treat their stock at the most appropriate time. The O. ovis puparia develop at shallow depths in the soil and the timing of emergence is directly dependent on climatic conditions, specifically the number of degree-days above a particular threshold soil temperature. Based on temperature measurements from only a few stations scattered throughout the country, the veterinary department warnings lack precision in space and time. This paper presents an attempt to support the programme of warnings with accumulated temperature information from Meteosat satellite images, in order to strengthen predictions of the time of emergence in specific places, and to improve the precision and reliability of warnings given to farmers. 相似文献
2.
Umberto MOLINI Vimanuka MUTJAVIKUA Mari de VILLIERS Lourens de VILLIERS Alaster SAMKANGE Lauren M. COETZEE Siegfried KHAISEB Giovanni CATTOLI William G. DUNDON 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2022,84(5):707
Samples from eleven birds (chicken, dove and peacock) with symptoms of fowlpox, caused by the avipoxvirus (APV), were collected in seven different areas of the Windhoek district, Namibia between April and October 2021. A fragment of the 4b core protein and the DNA polymerase gene of APV were amplified by PCR from the DNA of the samples and sequenced. Phylogenetic analysis revealed that the viruses present in the chickens all belonged to clade A1 while the viruses in the doves and peacock were from subclade A3.1. This is the first report of subclade A3.1 avipoxvirus in peacock. In addition, all of the samples obtained from chickens were shown by PCR to be positive for the integration of reticuloendotheliosis virus while those from the doves and peacocks were negative. This study is the first characterization of avipoxvirus in Namibia and provides additional information on the presence of avipoxvirus in southern Africa. 相似文献
3.
Anthony R Palmer Igshaan Samuels Clement Cupido Andiswa Finca W Fransiska Kangombe Isa AM Yunusa 《African Journal of Range and Forage Science》2016,33(1):43-51
Following a field campaign to determine the species composition, canopy cover, aboveground annual production and leaf area index (LAI) of the semi-arid savanna of north-western Namibia, we present a production model that can be used by graziers to determine the livestock carrying capacity. The model predicts the annual aboveground net primary production (ANPP) from regression equations of canopy cover by annual production fraction for plant functional classes. We tested the output of the model against another fully independent net primary production (NPP) model, namely the MODIS NPP product. The mean MODIS NPP for the 29 sites was 343 ± 22?kg dry matter (DM) ha?1 y?1 as opposed to 285 ± 142?kg DM ha?1 y?1 for the fAP model that used the regression method (p < 0.01). As a proof of concept, these landscape-scale ANPP values are used to calculate a recommended livestock carrying capacity for the Ehirovipuka Communal Conservancy, a 1 980 km2 communal area with both wildlife and livestock populations. In addition, we also provide details of a field method for predicting landscape-scale LAI from line transect data. This approach can be used to ground reference the LAI values generated from the MODIS LAI product. 相似文献
4.
介绍了纳米比亚淡水养殖的基本现状,分析了存在的不足,并结合纳米比亚的基本国情和国际渔业环境,提出了纳米比亚淡水养殖发展的基本思路。既是纳米比亚渔业工作者的参考,也是我国对纳米比亚水产业有合作意向者的工作指南。 相似文献
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6.
H. C. Biggs E. McClain G. L. Muller M. Anthonissen K. M. Hare 《Preventive veterinary medicine》1998,33(1-4):267-282
A model was developed for predicting outbreaks of Oestrus ovis throughout the main sheep farming areas of Namibia. Pupal developmental periods were studied, concomitant air and soil temperatures enabling degree-day calculations to be made for prediction of adult fly strike. Monitoring of larval infection established seasonal incidence of O. ovis infestation and acted as verification of predictions. The establishment of relevant isothermal maps for Namibia made possible extrapolation from the several study sites to the entire sheep farming area. Retrospective and actual predictions of the important first peak after winter were considered accurate enough to recommend timing of control measures. No evidence of overwintering of first stage instars was found, the strategy used instead being extended pupation. Adult fly energy reserves were determined. 相似文献
7.
A computer system for collection of animal disease and related data was set up by the Directorate of Veterinary Services in 1985, and data are available from 1986 up to the present. The nationwide system consists of detailed disease and herd health data from field veterinarians, disease and related data (such as grazing and animal condition, vaccinations and farmer treatments) from animal health inspectors, laboratory results and investigations, and abattoir data. More recently, a socio-economic component has also been added. Considerable care has been taken to link related information. In addition, all data are geographically linked through a placename co-ordinate and attribute file, and a crude but effective automated map presentation system exists. The standard objectives of an information system (which were not historically met), namely, to facilitate the collection of complete, accurate, timely and relevant data which are easily accessible and processible, and in this way provide a better basis for management decision-making as well as for specific studies and queries, were strived for. The system has proved particularly valuable in terms of automation of routine reports and in answering ad hoc queries. It is underutilised with regard to epidemiological studies, but we feel that it holds great potential. 相似文献
8.
Anthony P Russell 《African Zoology》2013,48(2):393-408
The genus Rhoplropella Hewitt, 1937 is shown to be a junior synonym of Phelsuma Gray, 1825 and the genera Phelsuma and Rhoplropus Peters, 1869 are compared. It is pointed out that Phelsuma ocettata shows a great deal of convergence with Rhoplropus but that both of these forms exhibit their own distinctive derived character combinations. The distribution pattern of Phelsuma on the main-land of Africa and on Madagascar is reviewed inthe light of current theories of biogeography and past continental relationships. It is suggested that the distribution of Phelsuma may represent a track which is also occupied by other reptilian genera. 相似文献
9.
The relation between fuelwood use and fuelwood quality and quantity was studied in two northern Namibian rural communities with different levels of fuelwood availability. Household surveys were conducted and fuelwood quality was assessed through laboratory studies. The study found differences in fuelwood use and adaptation of liveli-hoods to fuelwood availability. Where there was an abundance of quality fuelwood, the community chose fuelwood intuitively in accordance with the optimum physical properties and in a sustainable way. A fuelwood shortage, however, was found to impact negatively on work and social practices and fuelwood was collected through destructive harvesting practices, such as the cutting of green branches, and without consideration for optimum timber properties, such as tree age and calorific value. 相似文献
10.
Debate among scientists about ecological dynamics and appropriate management of semi‐arid rangelands has led to a challenge of received wisdoms of range management and pastoral development in dryland Africa. In our study, we investigated impacts of grazing on grass composition around permanent water points along a pipeline and around a traditional hand‐dug well in an important grazing area in central northern Namibia. Grass species abundance and selected environmental variables sampled along transects radiating out from these water points were analysed using Canonical Correspondence Analysis (CCA). Significant grazing‐induced changes, manifested by palatable perennial grasses being replaced by less palatable annual grasses, were identified around water points along the pipeline. There annual grasses Schmidtia kalihariensis and Aristida stipioides dominate the vegetation as far as 5 km from the water points. No significant grazing‐induced changes in grass composition were observed around the hand‐dug well. Private ownership leading to stronger control of access to traditional wells compared to the open access water points along the pipeline seems to be a key factor preventing overutilisation of grazing resources around the former. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献