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Effect of Peganum harmala (wild rue) extract on experimental ovine malignant theileriosis: Pathological and parasitological findings Полный текст
2008
Derakhshanfar, A.(Shahid Bahonar University of Kerman School of Veterinary Medicine Department of Pathobiology) | Mirzaei, M.(Shahid Bahonar University of Kerman School of Veterinary Medicine Department of Pathobiology)
Malignant theileriosis of sheep is a highly fatal, acute or subacute disease is caused by the tick-borne protozoan parasite, Theileria hirci. In this investigation ten healthy male lambs aged 5-6 months were randomly divided into two groups, A and B and were kept in isolated tick-proof pens. They were treated for internal and external parasite before commencement of the experiment. The lambs were experimentally infected with T. hirci by placing ticks Hyalomma anatolicum anatolicum infected with T. hirci on them. The ticks used in this survey had originally been isolated from sheep and colonies of them were established in an insectarium. Before and after infection rectal temperatures and clinical signs of the lambs were recorded, blood and prescapular lymph node smears were prepared and examined to determine the extent of the parasitaemia, and blood samples were analyzed to evaluate their haemoglobin (Hb) and packed cell volume (PCV) rates. Three days after the commencement of a febrile reaction and appearance of the schizonts in the lymph node smears, treatment of the lambs in Group A with an extract containing the alkaloids of Peganum harmala (wild rue) was commenced. Group B lambs were kept untreated controls. Before treatment there were no significant differences in the rectal temperature, parasitaemia rate, and the Hb and PCV values between animals in the two groups but after treatment significant differences in these values was detected (P < 0.05). After treatment, the clinical signs and parasites in the lymph node smears of the animals in Group A disappeared and they all animals recovered. These parameters in the animals of Group B progressed until their death. Pathological studies showed the characteristic lesions of theileriosis in lambs in Group B, but not in Group A. The results indicate a therapeutic effect of the alkaloids of P. harmala for treatment of ovine malignant theileriosis.
Показать больше [+] Меньше [-]Production trials involving use of the FAMACHA© system for haemonchosis in sheep: Preliminary results Полный текст
2008
van Wyk, J.A.
In three trials conducted on two separate farms the production of sheep treated for naturally acquired haemonchosis using the FAMACHA© system of targeted selective treatment (TST) (i.e. to treat only those animals unable to manage unaided in the face of heavy Haemonchus challenge) was compared to that of suppressively drenched sheep in the same flock. As expected by the research team who developed and evaluated the FAMACHA© system, TST did result in some loss in production. However, despite high levels of worm challenge in two of the trials and the fact that the comparison was with suppressive drenching which is not sustainable, the total effect was relatively small in relation to the important advantage of using the TST as regards reduced selection for anthelmintic resistance (AR). Concerning the sustainability of worm control, it is concluded that the development of drug resistance to anthelmintics leaves sheep and goat farmers in South Africa no choice but to use methods of TST such as FAMACHA©. The FAMACHA© system can also be a useful clinical aid for early on-farm detection of AR by farmers; the degree of improvement in the colour of the ocular mucous membrane from pale to red in individually drenched anaemic animals over a period of 7-14 days can give a good indication of the efficacy of the compound(s) used.
Показать больше [+] Меньше [-]Bovine intestinal cellular responses following primary and challenge infections with Calicophoron microbothrium metacercariae Полный текст
2008
Mavenyengwa, M.(University of Zimbabwe Department of Paraclinical Veterinary Studies Faculty of Veterinary Science) | Mukaratirwa, S.(University of KwaZulu-Natal School of Biological and Conservation Sciences) | Obwolo, M.(University of Zimbabwe Department of Paraclinical Veterinary Studies Faculty of Veterinary Science) | Monrad, J.(Danish Centre for Experimental Parasitology)
This study was carried out to establish whether cattle can develop resistance to re-infection by Calicophoron microbothrium by assessing the response of intestinal mucosal globule leukocytes, eosinophils, mast cells and basophils, and the establishment of the parasite in the host. A total of 24 1-year-old Tuli steers were randomly divided into four groups of six animals each and infected with C. microbothrium metacercariae. On the first day of the study, animals in Groups I and II were immunized with 5 000 metacercariae and then challenged with 15 000 metacercariae on Day 150 post-immunization. Animals in Group III were immunized with 15 000 metacercariae at the same time that Groups I and II animals were challenged to act as a positive control group. Animals in Group IV were left uninfected and acted as a negative control group. Three animals from each group were slaughtered on Day 28 post-challenge and the remainder were slaughtered on Day 42 post-challenge. The established amphistomes were recovered and histopathological and cytological examinations were done on the jejunum, duodenum, abomasum and the rumen. The establishment rates of the challenge infection in the immunized and challenged groups were lower and ranged from 0 to 0.2 % as compared to 6 %> from naive animals infected as positive controls. Animals immunized and then challenged with C. microbothrium had significantly higher eosinophil, mast cell and globule leukocytes counts in the intestinal mucosa (P < 0.05) as compared to those of the control group. The study indicates that cattle can develop resistance to C. microbothrium re-infection and that eosinophils and mast cells may be important cells in the rejection of the parasite.
Показать больше [+] Меньше [-]Can osteophagia provide giraffes with phosphorus and calcium? Полный текст
2008
Bredin, I.P.(Faculty of Veterinary Science Veterinary Wildlife Unit) | Skinner, J.D.(Faculty of Veterinary Science Veterinary Wildlife Unit) | Mitchell, G.(Faculty of Veterinary Science Veterinary Wildlife Unit ,University of Wyoming Department of Zoology and Physiology)
The daily requirement for calcium and phosphorus by giraffes to sustain the growth and maintenance of their skeletons is large. The source of sufficient calcium is browse. The source of necessary phosphorus is obscure, but it could be osteophagia, a frequently observed behaviour in giraffes. We have assessed whether bone ingested as a result of osteophagia can be digested in the rumen. Bone samples from cancellous (cervical vertebrae) and dense bones (metacarpal shaft) were immersed in the rumens of five sheep, for a period of up to 30 days, and the effect compared to immersion in distilled water and in artificial saliva for 30 days. Distilled water had no effect on the bones. Dense bone samples were softened by exposure to the saliva and rumen fluid, but did not lose either calcium or phosphorus. In saliva and rumen fluid the cancellous bone samples also softened, and their mass and volume decreased as a result of exposure to saliva, but in neither fluid did they lose significant amounts of calcium and phosphorus. We conclude that although saliva and rumen fluid can soften ingested bones, there is an insignificant digestion of bones in the rumen.
Показать больше [+] Меньше [-]Evaluation of different adjuvants for foot-and-mouth disease vaccine containing all the SAT serotypes Полный текст
2008
Cloete, M.(Onderstepoort Veterinary Institute) | Dungu, B.(Onderstepoort Veterinary Institute ,Onderstepoort Biological Products) | Van Staden, L.I.(Onderstepoort Veterinary Institute) | Ismail-Cassim, N.(Onderstepoort Veterinary Institute) | Vosloo, W.(Onderstepoort Veterinary Institute)
Foot-and-mouth disease (FMD) is an economically important disease of cloven-hoofed animals that is primarily controlled by vaccination of susceptible animals and movement restrictions for animals and animal-derived products in South Africa. Vaccination using aluminium hydroxide gel-saponin (AS) adjuvanted vaccines containing the South African Territories (SAT) serotypes has been shown to be effective both in ensuring that disease does not spread from the endemic to the free zone and in controlling outbreaks in the free zone. Various vaccine formulations containing antigens derived from the SAT serotypes were tested in cattle that were challenged 1 year later. Both the AS and ISA 206B vaccines adjuvanted with saponin protected cattle against virulent virus challenge. The oil-based ISA 206B-adjuvanted vaccine with and without stimulators was evaluated in a field trial and both elicited antibody responses that lasted for 1 year. Furthermore, the ISA 206 adjuvanted FMD vaccine protected groups of cattle against homologous virus challenge at very low payloads, while pigs vaccinated with an emergency ISA 206B-based FMD vaccine containing the SAT 1 vaccine strains were protected against the heterologous SAT 1 outbreak strain.
Показать больше [+] Меньше [-]The financial cost implications of the highly pathogenic notifiable avian influenza H5N1 in Nigeria Полный текст
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 [-]The prevalence and distribution of Argas walkerae (Acari: Argasidae) in the eastern region of the Eastern Cape Province, South Africa Полный текст
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 [-]2-Phenoxyethanol as anaesthetic in removing and relocating 102 species of fishes representing 30 families from Sea World to uShaka Marine World, South Africa Полный текст
2008
Vaughan, D.B.(Two Oceans Aquarium Dock Road Victoria and Alfred Waterfront) | Penning, M.R.(South African Association for Marine Biological Research uShaka Marine World) | Christison, K.W.(University of the Western Cape Department of Biodiversity and Conservation Biology)
2-Phenoxyethanol was used as an anaesthetic to translocate 102 species of fishes representing 30 families from the Sea World aquarium on Durban's beachfront to uShaka Marine World. Most fishes responded well to a final anaesthetic concentration of 0,150 mí/í and there were no mortalities.
Показать больше [+] Меньше [-]The helminth community of Helmeted Guineafowls, Numida meleagris (Linnaeus, 1758), in the north of Limpopo Province, South Africa Полный текст
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 [-]Cardiotoxic effects of pavetamine extracted from Pavetta harborii in the rat Полный текст
2008
Hay, L.(University of Limpopo Department of Physiology) | Schultz, R.A.(Onderstepoort Veterinary Institute Section of Toxicology) | Schutte, P.J.(University of Limpopo Department of Physiology)
Previous studies have shown that crude extracts from Pavetta harborii as well as dried plant material have cardiotoxic effects on rats and sheep that can lead to heart failure. The active component has since been isolated and identified. This substance has been named pavetamine. The aim of this study was to determine whether pavetamine has cardiotoxic effects similar to those seen in previous reports, when administered to rats intraperitoneally. Sprague Dawley rats received two doses, initially 4 mg/kg and then 3 mg/kg pavetamine respectively and were monitored for 35 days before cardiodynamic parameters were measured by inserting a fluid-filled catheter into the left ventricle via the right carotid artery. These values were compared to those of control rats that had received only saline. Pavetamine significantly reduced systolic function and body mass in the treated rats, which indicates that it has the potential to induce heart failure in this animal model.
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