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Helminth parasites of Natal long-fingered bats, Miniopterus natalensis (Chiroptera: Miniopteridae), in South Africa Полный текст
2008
Junker, K.(University of Pretoria Department of Veterinary Tropical Diseases) | Bain, O.(Muséum National d'Histoire Naturelle, Parasitologie comparée et Modèles expérimentaux) | Boomker, J.(University of Pretoria Department of Veterinary Tropical Diseases)
The helminth community infecting Miniopterus natalensis was studied at two localities, the De Hoop Nature Reserve (DHNR) (n = 57), Western Cape Province and Pretoria (n = 12), Gauteng Province, South Africa. Hosts from the DHNR had formed part of an earlier, unrelated study and were all pregnant females. A single hymenolepidid cestode species, the nematodes Molinostrongylus ornatus and Litomosa chiropterorum together with nematodes of the subfamily Capillariinae were present at both study sites, while a single digenean, Allassogonoporus sp., was only found in hosts from the DHNR. The prevalence of helminth infections was high at both localities, 68.4 % in the DHNR and 77.7 % in Pretoria, whereas the mean intensity of infection was low at the DHNR (3.76 ± 3.15), but higher in Pretoria (10.4 ± 9.9). Molinostrongylus ornatus and, to a lesser extent L. chiropterorum, were the main contributors to the higher intensities in Pretoria. The species richness ranged from 0 to 4 at both localities.
Показать больше [+] Меньше [-]Characterization of pigeon paramyxoviruses (Newcastle disease virus) isolated in South Africa from 2001 to 2006 Полный текст
2008
Abolnik, C.(ARC-Onderstepoort Veterinary Institute) | Gerdes, G.H.(ARC-Onderstepoort Veterinary Institute) | Kitching, J.(Stellenbosch Provincial Veterinary Laboratory) | Swanepoel, S.(Deltammune Laboratorie) | Romito, M.(ARC-Onderstepoort Veterinary Institute) | Bisschop, S.P.R.(University of Pretoria Poultry Reference Laboratory)
Pigeon paramyxovirus type 1 (PPMV-1), a variant of Newcastle disease virus that primarily affects doves and pigeons has been isolated in South Africa since the mid-1980s. Phylogenetic evidence indicates that pigeon paramyxovirus type 1 viruses were introduced into South Africa on multiple occasions, based on the presence of two separate lineages, 4bi and 4bii, that have been circulating in Europe and the Far East since the early 1990s. During 2006, a PPMV-1 virus was isolated from an African ground hornbill (Bucorvus leadbeateri) which became acutely infected with PPMV-1 and died, probably after scavenging off infected dove carcasses in the region, since a closely-related PPMV-1 strain was also isolated from doves collected nearby. The hornbill isolate had ICPI and MDT values characteristic of PPMV-1 strains. The threat of PPMV-1 to poultry production and biodiversity in southern Africa highlights the importance of monitoring the spread of this strain.
Показать больше [+] Меньше [-]Studies on effects of lactose on experimental Trypanosoma vivax infection in Zebu cattle. 1. Plasma kinetics of intravenously administered lactose at onset of infection and pathology Полный текст
2008
Fatihu, M.Y.(Ahmadu Bello University Department of Veterinary Pathology and Microbiology) | Adamu, S.(Ahmadu Bello University Department of Veterinary Pathology and Microbiology) | Umar, I.A.(Ahmadu Bello University Department of Biochemistry) | Ibrahim, N.D.G.(Ahmadu Bello University Department of Veterinary Pathology and Microbiology) | Eduvie, L.O.(Ahmadu Bello University National Animal Production Research Institute) | Esievo, K.A.N.(Ahmadu Bello University Department of Veterinary Pathology and Microbiology)
Lactose in normal saline was administered intravenously to a group of Zebu cattle infected with Trypanosoma vivax to determine the blood plasma kinetics at onset of an experimental infection and its ability to protect tissues against damage as part of preliminary studies to determine its suitability for use in the treatment of trypanosomosis. Significantly (P < 0.01) higher lactose concentrations were observed in the T. vivax-infected bulls at 30 min and 1 h (P < 0.05) post-infection (p.i.) and by 4 h p.i. the plasma lactose remained above the level prior to infusion, after which it fell slightly below the pre-infusion level in the uninfected group. Calculated pharmacokinetic parameters revealed delayed excretion of lactose in the T. w'vax-infected group soon after infection. The total body clearance (CI B) was significantly (P < 0.05) reduced. The biological half-life (t ½), elimination rate constant (k e) and apparent volume of distribution (Vd) were relatively decreased (P > 0.05) as a result of the T. vivax infection. Retention of lactose in the plasma was attributed to decreased plasma clearance. It is suggested that the presence of trypanosomes in circulation rather than organic lesions could have been responsible for the delay observed in the excretion of lactose. At 12 weeks p.i., when the experiment was terminated, the group infected and given lactose infusion (despite higher parasitaemia) had no gross or histopathological lesions in the brain, spleen, lymph nodes, heart, kidneys, liver and testes. However, the group infected but not infused with lactose were emaciated, had pale mucosae, watery blood, general muscular atrophy, serous atrophy of coronary fat and other adipose tissue, hepatomegaly, splenomegaly, swollen and oedematous lymph nodes, all of which are suggestive of trypanosomosis. Histopathological lesions included narrowing of Bowman's space and hypercellularity of glomerular tufts in the kidneys with the mean glomerular tuft nuclear indices (GTNs) in the group significantly higher (P< 0.01) than the mean GTNs of the lactose-infused and control bulls. Degenerative changes occurred in the myocardium, spleen, testes and epididymides. The tesicular and epididymal lesions are indicative of male reproductive dysfunction.
Показать больше [+] Меньше [-]Preliminary survey of ticks (Acari: Ixodidae) on cattle in Central Equatoria State, Southern Sudan Полный текст
2008
Salih, D.A.(Central Veterinary Research Laboratories) | Julla, I.I.(University of Bahr El Ghazal College of Veterinary Science) | Hassan, S.M.(University of Khartoum Faculty of Veterinary Medicine Department of Parasitology) | El Hussein, A.M.(Central Veterinary Research Laboratories) | Jongejan, F.(Utrecht University Faculty of Veterinary Medicine Department of Infectious Diseases and Immunology,University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases,)
In a preliminary survey conducted in 2005, the species composition and seasonality of ticks infesting cattle in Central Equatoria State, Southern Sudan was determined. Three locations were selected (Gumbo, Khor Rumla and Nyaing) and surveyed every 3 months. Two cattle herds in each of the three locations were visited four times during the study period. Total body collections of ticks were made from each of five cattle (Nilotic Zebu breed) kept in six different herds. Four tick genera and ten species were identified. The tick species identified were Amblyomma lepidum, Amblyomma variegatum, Boophilus annulatus, Boophilus decoloratus, Hyalomma marginatum rufipes, Hyalomma truncatum, Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi, Rhipicephalus praetextatus and Rhipicephalus sanguineus group. The highest number of ticks was collected in October during the rainy season. A finding of great significance was that R. appendiculatus, vector of East Coast fever, has now firmly established itself throughout the year with possible implications for cattle production in Central Equatoria State.
Показать больше [+] Меньше [-]An immunohistochemical study of ovarian innervation in the emu (Dromaius novaehollandiae) Полный текст
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 Полный текст
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 [-]Evaluation of biochemical and ultrasonographic measurements as indicators of undernutrition in cattle Полный текст
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 [-]Relative economic benefits of tactical anthelmintic treatment and urea-molasses block supplementation of Boer goats raised under extensive grazing conditions at Onderstepoort, Pretoria, South Africa Полный текст
2008
Vatta, A.F.(Onderstepoort Veterinary Institute ,University of KwaZulu-Natal) | Krecek, R.C.(University of Johannesburg) | Pearson, R.A.(University of Edinburgh Royal (Dick) School of Veterinary Studies Division of Veterinary Clinical Science (incorporating Centre for Tropical Veterinary Medicine)) | Smith, M.F.(Agricultural Research Council) | Stenson, M.O.(Onderstepoort Veterinary Institute) | Van Wijk, E.F.(Onderstepoort Veterinary Institute) | Harrison, L.J.S.(University of Edinburgh Royal (Dick) School of Veterinary Studies Division of Veterinary Clinical Science (incorporating Centre for Tropical Veterinary Medicine))
The potential economic benefits of combining tactical anthelmintic treatment for gastrointestinal nematodes and nutritional supplementation with urea-molasses blocks were examined in Boer goats raised under extensive grazing conditions in the summer rainfall area of South Africa. Eight groups of nine goats were monitored over a 12-month period from 1 October 2002 to 9 October 2003. Ad libitum nutritional supplementation with urea-molasses blocks was provided when the goats were housed at night, during the summer (wet season-December 2002 to February 2003), and/or the winter (dry season-June 2003 to August 2003). All the goats were treated symptomatically for Haemonchus contortus infection when deemed necessary by clinical examination of the conjunctiva for anaemia using the FAMACHA© system. Half the groups were tactically treated for gastrointestinal nematodes in mid-summer (28 January 2003). Under the symptomatic treatment, climatic and extensive grazing conditions encountered during the trial, feed supplementation in the winter dry season had the greatest economic benefit and is therefore recommended. Tactical anthelmintic treatment afforded no additional advantage, but the nematode challenge was low.
Показать больше [+] Меньше [-]Intramammary antibiotic withdrawal periods for dairy goats compared to those for dairy cattle Полный текст
2008
Petzer, I.M.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Donkin, E.F.(University of Pretoria Faculty of Natural and Agricultural Sciences Department of Animal and Wildlife Sciences) | Du Preez, E.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Karzis, J.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Van Der Schans, T.J.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Watermeyer, J.C.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Van Reenen, R.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies)
This study investigated the withdrawal periods (WP) of two intramammary antibiotics Cloxamast LC (Intervet SA) and Spectrazol Milking Cow (Schering-Plough Animal Health) in dairy goats and compared them to those recommended for use in cattle. The WP for Cloxamast LC, measured by the Thermo Resistant Inhibitory Substances (TRIS) test, was 60 h in composite samples, 56 h in udder half samples, and the dye was visible for up to 56 h. The WP was significantly shorter than the 72 h recommended WP for use in cattle. It was however significantly longer when the 24 h safety margin (48 h) was subtracted from the recommended WP for cattle. For Spectrazol Milking Cow the antibiotics could be detected by the TRIS test for 61 h in composite samples and 59 h in udder half samples. This did not differ significantly from the recommended 60 h WP for cattle. However, it was significantly longer than that recommended for use in cattle without the 24 h safety margin. There was no significant difference in WP between infected and non-infected udder halves, while there was a weak positive correlation between WP and stage of lactation (R² = 0.253). There was a moderate positive correlation (R² = 0.583) between the TRIS test and the presence of dye in milk in udder half samples and between WP in both udder half and composite milk samples (R² = 0.456). Weak to moderate positive correlations were present between milk yield and the WP in both udder half (R² = 0.414) and composite (R² = 0.262) milk samples. Significant differences (P < 0.001) were also observed between the milk yield of udder halves with and without palpable udder damage and between samples that tested TRIS positive and negative on both composite (P = 0.008) and udder half samples (P < 0.001). There was no significant difference between the milk yield of samples with or without dye. There was a significant difference in milk yield between infected and non-infected udder halves (P = 0.054) and a weak negative correlation between milk yield and stage of lactation (R² = -0.379).
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 Полный текст
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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