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The financial cost implications of the highly pathogenic notifiable avian influenza H5N1 in Nigeria
2008
Fasina, F.O.(National Veterinary Research Institute Viral Research Department ,University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Sirdar, M.M.(Military Cooperative Corporation) | Bisschop, S.P.R.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies)
Nigeria and several other nations have recently been affected by outbreaks of the Asian H5N1 strain of highly pathogenic notifiable avian influenza (HPNAI) virus, which affects the pou sts associated with the current avian influenza outbreaks. The evaluation used epidemiological data, production figures and other input parameters to determine the final costs. An infection involving 10 % of the commercial bird population will cost Nigeria about $245 million and a worse scenario may lead to a loss of around $700 million. The results urge governments to invest more in measures aimed at the effective prevention of HPNAI and to consider the huge economic losses associated with the disease. Finally, an inter-disciplinary approach to managing and controlling HPNAI outbreaks is encouraged.
Показать больше [+] Меньше [-]Field experiences with early pregnancy diagnosis by progesterone-based ELISA in sows
2008
Boma, M.H. | Bilkei, G.
In four Kenyan pig breeding units the pregnancy diagnosis of sows has been carried out in two groups: Group 1 (n = 1911): the sows were transrectaly pregnancy tested between Days 17-22 post-mating by ultrasound. Sows testing non-pregnant immediately received one dose of 400 IU pregnant mare serum gonadotropin (PMSG) (equine chorion gonadotropin, eCG) and 200 IU human chorion gonadotropin (hCG). On showing signs of oestrous, the animals were subsequently artificially inseminated (AI). Group 2 (n = 1923): sows were pregnancy tested by serum progesterone (P4)-based enzyme-linked immunosorbent assay (ELISA) on Day 17 post-breeding. P4 concentrations were categorized as positive (> 5 ng/ml) or negative (< 5 ng/ml). Sows testing nonpregnant immediately received one dose of 400 IU PMSG and 200 IU hCG by injection, and were subsequently artificially inseminated. The following parameters were evaluated: sows diagnosed non-pregnant, days from first post-weaning insemination until the sows were inseminated at their first return to oestrus; farrowing rate and total piglets born and number of live-born piglets in litters. The percentage of sows diagnosed non-pregnant in the two groups, as well as the totals of born piglets and of live-born piglets in litters did not differ significantly between the two groups. The number of days from the first post-weaning mating until the sows were artificially inseminated at their first return to oestrus and the administration of eCG and hCG was shorter (P < 0.01) and farrowing rate was higher (P < 0.01) in the ELISA-tested sows.
Показать больше [+] Меньше [-]An immunohistochemical study of ovarian innervation in the emu (Dromaius novaehollandiae)
2008
Madekurozwa, M-C.(University of Pretoria Faculty of Veterinary Science Department of Anatomy and Physiology)
The present study investigated the distribution of nerves in the ovary of the emu. The neuronal markers, protein gene product 9.5, neurofilament protein and neuron specific enolase demonstrated the constituents of the extrinsic and intrinsic ovarian neural systems. The extrinsic neural system was composed of ganglia in the ovarian stalk, as well as nerve bundles, which were distributed throughout the ovary. Isolated neuronal cell bodies, in the medulla and cortex, formed the intrinsic neural system. An interesting finding of the study was the presence of nerve bundles, circumscribed by lymphocytes, in the ovarian stalk. The findings of the study indicate that the distribution of nerve fibres and neuronal cell bodies in the emu ovary is similar, but not identical to that of the domestic fowl and ostrich.
Показать больше [+] Меньше [-]Prevalence of bovine trypanosomosis in Central Mozambique from 2002 to 2005
2008
Specht, E.J.K.(Laboratório Regional de Veterinária)
The study is the result of analyzing 16 895 blood smears of cattle collected at 180 sites in the provinces of Manica, Sofala, Zambézia and Tete in Mozambique. Of the blood smears 73.9 % were from Manica, 11.8 % from Tete, 8.5 % from Sofala and 5.8 % from Zambézia; 75.6 % of these were collected from smallholder cattle. Infections with trypanosomes were highest in smallholder cattle from Sofala Province with 36.8 % of the 872 blood smears examined positive for trypanosomes, and lowest in cattle of commercial farmers in Manica Province with only 6.2 % of 2 252 blood smears being positive. Trypanosoma congolense was the predominant species, followed by Trypanosoma vivax and Trypanosoma brucei sensu lato. Trypanosoma brucei, which also infects humans, was more frequent in the districts of Buzi, Mutarara and Morrumbala with 15.1 %, 10.5 % and 9.8 % of all examined cattle in 2005 being infected with it, respectively. The results show a significant increase in the infection rate with trypanosomes compared with results obtained in previous years by the Regional Veterinary Laboratory in Manica Province and by the Regional Tsetse and Trypanosomiasis Control Programme in Zambézia, Tete and Sofala provinces.
Показать больше [+] Меньше [-]The prevalence and distribution of Argas walkerae (Acari: Argasidae) in the eastern region of the Eastern Cape Province, South Africa
2008
Nyangiwe, N.(Döhne Agricultural Development Institute ,University of Pretoria, Faculty of Veterinary Science Department of Veterinary Tropical Diseases) | Gummow, B.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Horak, I.G.(University of the Free State Department of Zoology and Entomology ,University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases,ARC-Onderstepoort Veterinary Institute Division of Parasitology)
The prevalence and geographic distribution of the fowl tampan, Argas walkerae Kaiser & Hoogstraal, 1969 was determined in the eastern region of the Eastern Cape Province, South Africa by inspecting two fowl houses in the vicinity of each of 72 randomly selected communal cattle dip-tanks. Tampans were collected from 102 (70.8 %) of the 144 fowl houses in the neighbourhood of 57 (79.2 %) of the 72 selected dip-tanks, and the localities of the collections were mapped. Argas walkerae was present in fowl houses from the warm coastal regions of the Indian Ocean in the south to the cold and mountainous Drakensberg in the north-east of the Province. Taking into account the probable sensitivity of the sampling method, it is estimated that A. walkerae is likely to be present in fowl houses belonging to between 74 and 84 % of communities making use of cattle dip-tanks in the eastern region of the Eastern Cape Province, and that when it is present, between 64 and 75 %> of fowl houses will be infested. The geographic distribution of A. walkerae seemed to be more strongly associated with the presence of fowls and fowl houses containing raw or processed wood in their structure than with climate.
Показать больше [+] Меньше [-]Detection of Anaplasma antibodies in wildlife and domestic species in wildlife-livestock interface areas of Kenya by major surface protein 5 competitive inhibition enzyme-linked immunosorbent assay
2008
Ngeranwa, J.J.N.(Kenya Agricultural Research Institute ,University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases) | Shompole, S.P.(Kenya Agricultural Research Institute) | Venter, E.H.(Kenya Agricultural Research Institute) | Wambugu, A.(Kenya Agricultural Research Institute) | Crafford, J.E.(University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases) | Penzhorn, B.L.(University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases)
The seroprevalence of Anaplasma antibodies in wildlife (eland, blue wildebeest, kongoni, impala, Thomson's gazelle, Grant's gazelle, giraffe and plains zebra) and domestic animal (cattle, sheep and goat) populations was studied in wildlife/livestock interface areas of Kenya. Serum samples were analyzed by competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA), using a recombinant antigen (MSP-5) from Anaplasma marginale surface membrane. A monoclonal antibody, FC-16, was used as the primary antibody, while anti-mouse conjugated to horseradish peroxidase was used as the secondary antibody. The results indicate a high seroprevalence in both wildlife and livestock populations, in contrast to earlier reports from Kenya, which indicated a low seroprevalence. The differences are attributed to the accurate analytical method used (CI-ELISA), as compared with agglutination techniques, clinical signs and microscopy employed by the earlier workers.
Показать больше [+] Меньше [-]Evaluation of biochemical and ultrasonographic measurements as indicators of undernutrition in cattle
2008
Strydom, S.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Agenäs, S.(Swedish University of Agricultural Sciences Department of Animal Nutrition and Management Kungsangen Research Centre) | Heath, M.F.(University of Cambridge Department of Veterinary Medicine) | Phillips, C.J.C.(University of Queensland School of Veterinary Science Centre for Animal Welfare and Ethics) | Rautenbach, G.H.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Thompson, P.N.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies)
Body condition scoring (BCS) gives an indication of the nutritional status of an animal and it is thus an invaluable management tool in domestic livestock systems. It is, however, subjective. This study aimed at identifying biochemical indicators which could be objectively used as an indicator of undernutrition in ruminants. Blood samples were collected from 50 cattle with BCS < 1 and from 50 cattle with BCS > 2.5, using a 0-5 scale, and analysed for albumin, urea, creatinine, fructosamine, beta-hydroxybutyrate, non-esterified fatty acids, total serum protein and haematocrit. Rumpfat and ribfat thickness and marbling relative index were determined ultrasonographically in 15 of the low BCS group and 13 of the high BCS group. The laboratory measure with the best predictive ability for severe undernutrition was albumin, which correctly classified 94 % of cattle, using a cut-off of 31.5 g/l. In contrast to a previous study, our study did not find the fructosamine:albumin ratio to be an accurate test to indicate undernutrition in cattle. Ultrasonic measurement of subcutaneous rumpfat and ribfat proved to reliably predict undernutrition, but may, however be impractical for routine use under most field conditions.
Показать больше [+] Меньше [-]Cercariae developing in Lymnaea natalensis Krauss, 1848 collected in the vicinity of Pretoria, Gauteng Province, South Africa
2008
Moema, E.B.E.(University of Limpopo Department of Biology) | King, P.H.(University of Limpopo Department of Biology) | Baker, C.(University of Limpopo Electron Microscope Unit)
Freshwater snails are known to serve as first intermediate hosts for various parasitic diseases such as schistosomosis and fasciolosis. Snails were collected on several occasions in the proximity of Pretoria, South Africa and their cercarial sheddings were studied. This article describes three different types of cercariae shed by the freshwater snail, Lymnaea natalensis, viz. a fork-tailed cercaria of a Trichobilharzia sp., an avian parasite belonging to the family Schistosomatidae, an echinostomatid cercaria of the family Echinostomatidae, also avian parasites and a xiphidiocercaria of the family Plagiorchiidae which parasitise avians and amphibians. The morphology of these cercariae was studied by light and scanning electron microscopy.
Показать больше [+] Меньше [-]The helminth community of Helmeted Guineafowls, Numida meleagris (Linnaeus, 1758), in the north of Limpopo Province, South Africa
2008
Junker, K.(University of Pretoria Department of Veterinary Tropical Diseases) | Debusho, L.(University of Pretoria Department of Statistics) | Boomker, J.(University of Pretoria Department of Veterinary Tropical Diseases)
The helminths of 15 Helmeted Guineafowls were collected in the north of Limpopo Province, South Africa. A total of 11 cestode, ten nematode and a single acanthocephalan species were present. Species richness ranged from 8 to 16 species per host, and nine core and nine secondary species accounted for 40.9 % of the component parasite community. The remaining 18.2 % comprised satellite species. Core species represented 91 % of all the worms present. Individual intensities ranged from 66 to 2 724 per host and overdispersion was pronounced. There were no significant differences regarding the abundance and species richness between male and female hosts. The number of component species and overall abundance did not differ significantly between juvenile and adult hosts, but Cyrnea parroti was significantly more abundant, and the prevalence of Hadjelia truncata was higher in young birds than in adults. In contrast, Gongylonema congolense and Porogynia paronai were absent in juveniles, but had a prevalence of 60 % and 70 %, respectively, in adults. Pairwise Spearman's rank correlation yielded one positive and 10 negative significant species correlations. A single trematode, Dicrocoelium macrostomum, was collected from five of nine guineafowls, but was not included in the helminth community study.
Показать больше [+] Меньше [-]Molecular characterization of SAT-2 foot-and-mouth disease virus isolates obtained from cattle during a four-month period in 2001 in Limpopo Province, South Africa
2008
Phologane, B.S.(Agricultural Research Council Onderstepoort Veterinary Institute Exotic Diseases Division,Tshwane University of Technology Department of Biomedical Science) | Dwarka, R.M.(Agricultural Research Council Onderstepoort Veterinary Institute Exotic Diseases Division) | Haydon, D.T.(University of Glasgow Division of Environmental and Evolutionary Biology) | Gerber, L.J.(Tshwane University of Technology Department of Biomedical Science) | Vosloo, W.(Agricultural Research Council Onderstepoort Veterinary Institute Exotic Diseases Division,University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases)
Foot-and-mouth disease (FMD) is an acute, highly contagious viral infection of domestic and wild cloven-hoofed animals. The virus is a single-stranded RNA virus that has a high rate of nucleotide mutation and amino acid substitution. In southern Africa the South African Territories (SAT) 1-3 serotypes of FMD virus are maintained by large numbers of African buffaloes (Syncerus caffer), which provide a potential source of infection for domestic livestock and wild animals. During February 2001, an outbreak of SAT-2 was recorded in cattle in the FMD control zone of South Africa, adjacent to the Kruger National Park (KNP). They had not been vaccinated against the disease since they form the buffer between the vaccination and free zones but in the face of the outbreak, they were vaccinated as part of the control measures to contain the disease. The virus was, however, isolated from some of them on several occasions up to May 2001. These isolates were characterized to determine the rate of genetic change in the main antigenic determinant, the 1D/2A gene. Nucleotide substitutions at 12 different sites were identified of which five led to amino acid changes. Three of these occurred in known antigenic sites, viz. the GH-loop and C-terminal part of the protein, and two of these have previously been shown to be subject to positive selection. Likelihood models indicated that the ratio of non-synonymous to synonymous changes among the outbreak sequences recovered from cattle was four times higher than among comparable sequences isolated from wildlife, suggesting that the virus may be under greater selective pressure during rapid transmission events.
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