1995 Onderstepoort Journal of Veterinary Research, Volume 62, 1995

Permanent URI for this collectionhttp://hdl.handle.net/2263/19070

Contents Pages: Onderstepoort Journal of Veterinary Research, Vol 62, 1995

CONTENTS

*Volume 62: Number 1*

Paired-ion extraction and high-performance liquid chromatographic determination of diminazene in cattle plasma: a modified method	Gummow, B, Du Preez, JL & Swan, GE	1

Cardiomyopathy of ruminants induced by the litter of poultry fed on rations containing the ionophore antibiotic, maduramicin. II. Macropathology and histopathology	Bastianello, SS, Fourie, N, Prozesky, L, Nel, PW & Kellermann, TS	5

Reactions to heartwater vaccination in crossbred Zebu cattle	Lawrence, JA, Malika, J, Whiteland, AP & Kafuwa, PT	19

A rapid method to determine bacterial contamination on hatching eggs. 2. Correlation of the optical-density measurements after incubation to bacterial counts on hatching eggs	Pienaar, ACE, Coetzee, L & Bragg, RR	25

A rapid method to determine bacterial contamination on hatching eggs. 3. Use of commercial DNA probe kits for detection of specific pathogens after six hours of incubation	Pienaar, ACE, Coetzee, L & Bragg, RR	35

Canine ehrlichiosis in Egypt: sero-epidemiological survey	Botros, BAM, Elmolla, MS, Salib, AW, Calamaio, CA, Dasch, GA & Arthur, RR	41

Mycoplasma-associated polyarthritis in farmed crocodiles (Crocodylus niloticus) in Zimbabwe	Mohan, K, Foggin, CM, Muvavarirwa, P, Honywill, J & Pawandiwa, A	45

A survey of the Culicoides (Diptera: Ceratopogonidae) of the Umlalazi Nature Reserve in Zululand, South Africa, with notes on two species biting man	Nevill, H & Nevill, EM	51

Research communications:

Evaluation of some reproductive parameters in the indigenous boar of Zimbabwe	Akingbemi, BT & Makinde, MO	59

Cryopreservation of sheathed third-stage larvae of Gaigeria pachyscelis (Sandveld hookworm)	Titoy, GAP & Schwan, EV	63

Short communication:

The prevalence of intestinal Salmonella infection in horses submitted for necropsy	Van Rensburg, IBJ, Jardine, JE, Carstens, JH & Van der Walt, ML	65

Book review:

Ectoparasites of animals and control methods - OIE		69

Guide for authors		71


*Volume 62: Number 2*

Isolation of the toxin responsible for gousiekte, a plant-induced cardiomyopathy of ruminants in southern Africa	Fourie, N, Erasmus, GL, Schultz, RA & Prozesky, L	77

Rhipicephalus interventus sp. nov. (Acari: Ixodidae), a new tick species closely related to Rhipicephalus tricuspis Donitz, 1906 and Rhipicephalus lunulatus Neumann, 1907, from East and Central Africa	Walker, JB, Pegram, PG & Keirans, JE	89

An outbreak of encephalomyocarditis-virus infection in free-ranging African elephants in the Kruger National Park	Grobler, DG, Raath, JP, Braack, LEO, Keet, DF, Gerdes, GH, Barnard, BJH, Kriek, NPJ, Jardine, J & Swanepoel, R	97

Monitoring experimental Alcelaphine Herpesvirus-1 infection in cattle by nucleic-acid hybridization and PCR	Michel, AL, Buchholz, GS & Van der Lugt, JJ	109

Microclimatic effect on vertical migration of Haemonchus contortus and Haemonchus placei third-stage larvae on irrigated Kikuyu pasture	Krecek, RC, Hartman, R, Groeneveld, HT & Thorne, A	117

Parasites of domestic and wild animals in South Africa. XXXIII. Ixodid ticks on scrub hares in the north-eastern regions of Northern and Eastern Transvaal and of KwaZulu-Natal	Horak, IG, Spickett, AM, Braack, LEO, Penzhorn, BL, Bagnall, RJ & Uys, AC	123

Fleas, lice and mites on scrub hares ( Lepus saxatilis) in Northern and Eastern Transvaal and in KwaZulu-Natal, South Africa	Louw, JP, Horak, IG, Horak, ML & Braack, LEO	133

Research communications:

In vitro cultivation of a Babesia sp. from cattle in South Africa	Zweygarth, E, Van Niekerk, C, Just, MC & De Waal, DT	139

The diagnosis of Wesselsbron disease in a new-born lamb by immunohistochemical staining of viral antigen	Van der Lugt, JJ, Coetzer, JAW, Smit, MME & Cilliers, C	143

Detection of Brucella abortus antigens by immunoperoxidase histochemical staining of lochia smears	Alberts, JN & Erasmus, JA	147


*Volume 62: Number 3*

Pentastomid parasites of the family Sebekidae Fain, 1961 in West African dwarf crocodiles Osteolaemus tetraspis Cope, 1851 from the Congo, with a description of Alofia parva n. sp	Riley, J & Huchzermeyer, FW	151

In vivo effects of a novel calcium antagonist (R56865) against induced epoxyscillirosidin and tulp poisoning in sheep	Swan, GE, Schultz, RA, Kellerman, TS, Mulders, MSG, Maartens, BP & Van der Walt, JJ	163

The use of preserved colostrum for rearing replacement dairy calves: calf performance, economics and on-farm practicability in Kenya	Karioki, DI, Gitau, GK & Munyua, SJM	167

Parasites of domestic and wild animals in South Africa. XXXIV. Arthropod parasites of nyalas in north-eastern KwaZulu-Natal	Horak, IG, Boomker, J & Flamand, JRB	171

Causes of calf mortality in Kabete area of Kenya	Mulei, CM, Gitau, GK & Mbuthia, PG	181

Characterization of mucus glycoproteins in the intestinal mucosa of the African elephant (Loxodonta africana) following lectin histochemistry	Coetzee, HL, Kotze, SH & Lourens, N	187

Sperm-storage tubules in the vagina of the ostrich (Struthio camelus)	Bezuidenhout, AJ, Soley, JT, Groenewald, HB & Burger, WP	193

The role of Hyalomma ticks in foot infestations and temporary lameness of sheep in a semi-arid region of South Africa	Kok, DJ & Fourie, LJ	201

Research communications:

The prevalence of neosporosis in aborted bovine foetuses submitted to the Allerton Regional Veterinary Laboratory	Jardine, JE & Last, RD	207

Attachment preferences of Hyalomma truncatum and Hyalomma marginatum rufipes ticks (Acari: Ixodidae) on two sheep breeds	Fourie, LJ & Kok, DJ	211

An improved technique for the cryopreservation of Gaigeria pachyscelis (Sandveld hookworm)	Titoy, GAP	215


*Volume 62: Number 4*

Detection of bluetongue virus and African horsesickness virus in co-infected cell cultures with NS1 gene probes	Venter, EH, Huismans, H & Dijk, Van AA	217

The distribution of Pasteurella haemolytica serotypes among cattle, sheep and goats in South Africa and their association with disease	Odendaal, MW & Henton, MM	223

The use of sucrose-acetone-extracted Rift Valley fever virus antigen derived from cell culture in an indirect enzyme-linked immunosorbent assay and haemagglutination-inhibition test	Paweska, JT, Barnard, BJH & Williams, R	227

The effect(s) of carbaryl-treated seed on body maintenance and survival of the multi-mammate mouse, Mastomys natalensis (sensu lato)	Neluvhalani, MJ, Ferreira, SM & Van Aarde, RJ	235

Detection of bovine-virus-diarrhoea-virus antibodies in cattle with an enzyme-linked immunosorbent assay	Muvavarirwa, P, Mudenge, D, Moyo, D & Javangwe, S	241

The skull and mandible of the African elephant (Loxodonta africana)	Van der Merwe, NJ, Bezuidenhout, AJ & Seegers, CD	245

Effects of transformation on the hemagglutinins of Haemophilus paragallinarum	Bragg, RR, Purdan, G, Coetzee, L & Verschoor, JA	261

Epidemiology of African horsesickness: antibodies in free-living elephants (Loxodonta africana) and their response to experimental infection	Barnard, BJH, Bengis, RG, Keet, DF & Dekker, EH	271

Immunohistochemical identification of Cowdria ruminantium in formalin-fixed tissue sections from mice, sheep, cattle and goats	Jardine, JE, Vogel, SW, Kleef, Mv & Van der Lugt, JJ	277

Serological prevalence of leptospiral antibodies in pigs in South Africa	Potts, AD, Lotter, C & Robinson, JTR	281

Author index		285

Subject index		295

Browse

Now showing 1 - 20 of 47

The diagnosis of Wesselsbron disease in a new-born lamb by immunohistochemical staining of viral antigen
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Van der Lugt, Jaco J.; Cilliers, C.; Smit, Marie M.E.; Verwoerd, Daniel Wynand; Coetzer, Jacobus A.W.
Wesselsbron disease (WSL) was diagnosed in a 2-d-old lamb on a farm in the north-eastern Free State Province where a few abortions and neonatal deaths occurred in sheep in April 1994. The liver of the lamb was slightly swollen and orange-brown and, microscopically, it revealed single or small groups of necrotic hepatocytes that were randomly scattered throughout the lobules. Other histopathologic hepatic lesions included the presence of acidophilic bodies, intranuclear inclusion bodies in a few hepatocytes, neutrophils in the parenchyma, mild Kupffer-cell and bile-ductular proliferation and infiltration of mixed inflammatory cells in the portal tracts. Immunohistochemical staining of sections of formalin-fixed specimens of the liver with polyclonal antibody against WSL virus revealed positive staining in acidophilic bodies, cytoplasmic fragments of necrotic liver cells, the cytoplasm of degenerated hepatocytes and, rarely, in intranuclear inclusions. Positive staining was also obtained in liver sections from two newborn lambs experimentally infected with WSL virus. The results of this investigation showed that the immunohistochemical staining of sections of formalin-fixed liver can be used to confirm the diagnosis of WSL in new-born lambs.
Epidemiology of African horsesickness: antibodies in free-living elephants (Loxodonta africana) and their response to experimental infection
(Pretoria : Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Barnard, B.J.H.; Bengis, Roy G.; Keet, D.F.; Dekker, E.H.; Verwoerd, Daniel Wynand
The presence of low levels of group- and type-specific antibodies against African horsesickness virus in the serum of some free-living elephants was reconfirmed. Experimental infection resulted in conflicting results. No detectable viraemia nor virus could be demonstrated in the organs of the six elephant calves and none of them mounted significant levels of neutralizing antibodies against the virus. On the other hand, all calves showed a slight rise in ELISA titres. This rise, however, was modest when compared with the rise in experimentally infected zebra. The presence of low levels of group- and type-specific antibodies in the serum of some free-living elephants is judged to be the result of natural hyperimmunization due to frequent exposure to infected biting insects. Elephants should therefore, despite the presence of low levels of antibodies, be regarded as poorly susceptible and unlikely to be a source of African horsesickness virus.
Author index
(Pretoria : Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Verwoerd, Daniel Wynand
The use of sucrose-acetone-extracted Rift Valley fever virus antigen derived from cell culture in an indirect enzyme-linked immunosorbent assay and haemagglutination-inhibition test
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Barnard, B.J.H.; Williams, R.; Verwoerd, Daniel Wynand; Paweska, Janusz Tadeusz
A sucrose-acetone-extracted, Madin-Darby-bovine-kidney (MDBK)-derived Rift Valley fever virus (RVFV) antigen was tested both in an indirect ELISA and a haemagglutination-inhibition test for its ability to detect serum antibodies to RVFV. Optimal conditions for antigen concentration, serum and conjugate dilutions for the ELISA were established by checkerboard titration. The specificity and sensitivity of ELISA were determined by the use of paired pre- and post-vaccination sheep-serum samples. Compared with the virus neutralization test, the overall ELISA specificity and sensitivity were 97,4 and 97,3 %, respectively. There was a 100% correlation between the results obtained in haemagglutination-inhibition tests with a RVFV sucrose-acetone-extracted antigen derived from hamster liver, and from MDBK cells. A total of 10 582 field-serum samples (84 cattle, 3 659 sheep, 6 839 goats) collected in 1994-1995 from animals of unknown vaccination status in different regions of South Africa were tested with ELISA for antibodies against RVFV. There were no seropositive cattle, 0,16% seropositive sheep and 0,12% seropositive goats. This study demonstrates the potential diagnostic application of cell-culture-derived, sucrose-acetone-extracted RVFV antigen in an indirect ELISA and HI test.
The distribution of Pasteurella haemolytica serotypes among cattle, sheep and goats in South Africa and their association with disease
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Odendaal, M.W.; Henton, Marijke M.; Verwoerd, Daniel Wynand
Over an 8-year period (September 1986 to March 1994), a total of 497 organ specimens from sheep and goats and 96 from cattle, were received for the isolation of Pasteurella haemolytica. They were collected in seven geographical areas in South Africa (as it existed before the April 1994 elections). These areas include the eastern Cape, Transvaal (new name: Gauteng), Namibia, Orange Free State (new name: Free State), Natal (new name: KwaZulu-Natal), western Cape and the northern Cape. This investigation does not represent the statistical incidence of the organism from each region, only the distribution of serotypes isolated from organ specimens submitted from diseased animals in these regions. Pasteurella haemolytica serotype 6 was the most prevalent type isolated from sheep and goats, but was followed closely by types 9 and 2. From cattle, P. haemolytica serotype 1 comprised 39% of the isolates. In sheep and goats, the majority of serotypes were associated with pneumonia, followed by gangrenous mastitis ("blue udder") and septicaemia. The situation in cattle was similar regarding the incidence of pneumonia followed by septicaemia. Up to 33% of the isolates from cattle and sheep specimens were non-typeable.
Subject index
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Anonymous; Verwoerd, Daniel Wynand
An improved technique for the cryopreservation of Gaigeria pachyscelis (Sandveld hookworm)
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Titoy, G.A.P.; Verwoerd, Daniel Wynand
A technique for the cryopreservation of third-stage larvae of Gaigeria pachyscelis is described. It consists of incubating sheathed infective larvae at 37°C in 40% (v/v) ethylene glycol for 7 min, followed by 2 min at 0°C in 82,8% (v/v) cryoprotectant mixture, prior to transferring the larvae to liquid nitrogen. The survival rate obtained with this technique is consistently high: 69,1% as assessed by motility.
Monitoring experimental Alcelaphine Herpesvirus-1 infection in cattle by nucleic-acid hybridization and PCR
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Buchholz, G.S.; Van der Lugt, Jaco J.; Verwoerd, Daniel Wynand; Michel, Anita Luise
The DNA probe SW15 derived from the laboratory-attenuated Alcelaphine Herpesvirus-1 (AHV-1) strain WC11 as well as from the polymerase chain-reaction test (Hsu, Shih, Castro & Zee 1990), was used to detect viral DNA of malignant catarrhal fever (MCF) in six experimentally infected cattle. Heparinized blood samples were collected and tested at least three times a week over a period of up to 142 d. Results of hybridization and PCR tests were compared with the results of clinical examinations, and on various occasions with those of viral isolation and serum-neutralization assays as well as with those of pathology. Three animals developed clinical signs and lesions typical of MCF, while the other three animals remained clinically healthy. All cattle seroconverted, and viral nucleic acid was detected by DNA hybridization and PCR at various intervals during the observation period. Virus isolation was successful in two of the clinical cases and all cattle seroconverted. Storage of blood samples at 4°C for up to 10 d did not influence the hybridization and DNA-amplification results.
Microclimatic effect on vertical migration of Haemonchus contortus and Haemonchus placei third-stage larvae on irrigated Kikuyu pasture
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Krecek, R.C.; Hartman, R.; Thorne, A.; Verwoerd, Daniel Wynand; Groeneveld, Hendrik T.
The influence of microclimate on numbers of third-stage larvae of Haemonchus contortus and Haemonchus placei in four strata of irrigated Kikuyu pasture was assessed. On 36 different, interspersed days three replicates of pasture samples were collected on three occasions per day from 1990-1992 for larval recovery and the log₁₀ mean counts of the larvae recovered were analysed by use of ANOVA models. Because the ground-surface area from which herbage was collected was standardized, estimated larval counts for the different strata could be compared; this was not possible in our previous studies. For H. contortus, the estimated larval counts in the four strata were predicted by microclimatic air temperature, relative humidity and soil moisture, with the coefficient-of-determination (R²) values ranging from 0,15-0,35. Of these, air temperature had the greatest effect. The same three predictors, together with illumination and wind speed, featured for H. placei, with R² values of 0,19-0,52. With the exception of wind speed and illumination, which (for H. placei) had the opposite effect, all the microclimatic parameters listed, predicted an increase in numbers of larvae from a lower to an upper strata.
An outbreak of encephalomyocarditis-virus infection in free-ranging African elephants in the Kruger National Park
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Grobler, D.G.; Raath, J.P.; Keet, D.F.; Gerdes, Gertruida Hermanna; Barnard, B.J.H.; Kriek, N.P.J.; Jardine, J.; Swanepoel, R.; Verwoerd, Daniel Wynand; Braack, L.E.O.
A cluster of four deaths in late December 1993, marked the onset of an outbreak of disease of African elephants (Loxodonta africana) in the Kruger National Park (KNP) in South Africa, which has an estimated population of 7 500 elephants. Mortalities peaked in January 1994, with 32 deaths, and then declined steadily to reach pre-outbreak levels by September, but sporadic losses continued until November. During the outbreak altogether 64 elephants died, of which 53 (83%) were adult bulls. Archival records revealed that, in addition to the usual losses from known causes such as poaching and intraspecific fighting, sporadic deaths from unexplained causes had, in fact, occurred in widely scattered locations from at least 1987 onwards, and from that time until the perceived outbreak of disease there had been 48 such deaths involving 33 (69%) adult bulls. Carcases had frequently become decomposed or had been scavenged by the time they were found, but seven of eight elephants examined early in 1994 had lesions of cardiac failure suggestive of encephalomyocarditis (EMC)-virus infection, and the virus was isolated from the heart muscles of three fresh carcases. The results of tests for neutralizing antibody on 362 elephant sera collected for unrelated purposes from 1984 onwards and kept frozen, indicated that the virus had been present in the KNP since at least 1987. Antibody prevalences of 62 of 116 (53 %), 18 of 139 (13%) and seven of 33 (21 %) were found in elephants in three different regions of the KNP in 1993 and 1994. Studies had been conducted on myomorph rodents in the KNP for unrelated purposes since 1984, and trapping attempts were increased during the perceived outbreak of disease in elephants. There was a striking temporal correlation between the occurrence of a population explosion (as evidenced by markedly increased catch rates per trap-night) and a surge in prevalence of antibody to EMC virus in rodents, and the occurrence of the outbreak of disease in elephants.
Rhipicephalus interventus sp. nov. (Acari: Ixodidae), a new tick species closely related to Rhipicephalus tricuspis Dönitz, 1906 and Rhipicephalus lunulatus Neumann, 1907, from East and Central Africa
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Walker, Jane B.; Keirans, J.E.; Pegram, R.G.; Verwoerd, Daniel Wynand
Descriptions of the adults of this new species are given, together with information on its hosts and distribution. Previously it was referred to briefly by Walker, Keirans, Pegram & Clifford (1988), who noted that in many respects it is intermediate in appearance between R. tricuspis and R. lunulatus.
Isolation of the toxin responsible for gousiekte, a plant-induced cardiomyopathy of ruminants in southern Africa
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Fourie, Niel; Erasmus, G.L.; Schultz, R.A. (Rowena Anitra); Verwoerd, Daniel Wynand; Prozesky, Leon
Gousiekte was induced in sheep and goats by the oral and intravenous (i/v) administration of methanolic and ethanolic precipitates of aqueous extracts of Pavetta harborii. Further purification of the toxic principle was carried out by dialysis and ion-exchange chromatography. The toxin was eluted from the cation-exchange resin with 1 mol/l of ammonium acetate and finally purified on Sephadex G-10 and silica gel. Spots on thin-layer chromatographic plates (TLC) were visualized with ninhydrin. Gousiekte was induced with the pure toxin after i/v administration in goats. The yield of pure toxin was about 10 mg/kg of dried leaves. A compound, indistinguishable from the above on TLC, was also isolated from the gousiekte-inducing plants Pavetta schumanniana, Fadogia homblei and Pachystigma pygmaeum.
The skull and mandible of the African elephant (Loxodonta africana)
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Van der Merwe, N.J.; Bezuidenhout, A.J. (Abraham Johannes), 1942-; Seegers, Christine D.; Verwoerd, Daniel Wynand
In the present study the bones of the skull, excluding the hyoid apparatus, are described. All the bones are aerated by sinuses. In the occipital bone the squamous part is aerated from the sinus of the parietal bone, the lateral part is aerated from the tympanic bulla and the basal part from the sinus of the basisphenoid bone. Condylar foramens and hypoglossal canals are absent. A small interparietal bone is present at birth. At an early age it fuses with the surrounding cranial bones. The squamous part of the temporal bone lies sagittally in young animals, but moves progressively to a transverse plane as the animals age. A foramen lacerum is represented by jugular and oval foramens and the carotid canal. The body of the basisphenoid bone is excavated by the massive maxillary tuberosity. The latter extends to the oval foramen and contains the developing molar teeth. The ethmoturbinate, nasal and lacrimal bones are exceptionally small. In old bulls the palatine processes of the incisive bones and their sinuses are gradually displaced by the palatine processes of the maxillae. The incisive part of the mandible does not carry any teeth and both lateral and medial mental foramina are present.
Guide for authors
(Pretoria : Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Verwoerd, Daniel Wynand
Fleas, lice and mites on scrub hares (Lepus saxatilis) in Northern and Eastern Transvaal and in KwaZulu-Natal, South Africa
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Louw, J.P.; Horak, M. Louise; Verwoerd, Daniel Wynand; Horak, Ivan Gerard; Braack, L.E.O.
Fleas, lice and mites were collected from 24 and 120 scrub hares at Pafuri and Skukuza, Northern and Eastern Transvaal, respectively, in the Kruger National Park, and from 34 scrub hares in the Hluhluwe region, north-eastern KwaZulu-Natal. Ctenocephalides felis damarensis, the only flea recovered, reached peak burdens on the hares at each locality during late winter or spring. Juvenile hares harboured significantly fewer fleas than did adult animals. The lice Haemodipsus lyriocephalus and Haemodipsus setoni were collected from hares at each locality, with H. setoni generally being the most abundant. Listrophorus leporicolus was found on hares at Skukuza and Hluhluwe, and mites of the genus Cheyletiella were collected from hares at Skukuza.
Immunohistochemical identification of Cowdria ruminantium in formalin-fixed tissue sections from mice, sheep, cattle and goats
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Jardine, J.E.; Vogel, S.W.; Van der Lugt, Jaco J.; Verwoerd, Daniel Wynand; Van Kleef, Mirinda
An immunohistochemical staining technique in which a monospecific serum was used against the major antigenic protein-1 (MAP-1) of Cowdria ruminantium, was evaluated for the detection of C. ruminantium in formalin-fixed tissues of experimentally infected mice and field cases of heartwater in sheep, cattle and goats. Mice were infected with the mouse-pathogenic stocks: Mara, Kwanyanga, Welgevonden, Nonile, Vosloo, Kümm, Mali and Omatjenne. In all these cases and in the naturally infected cattle, sheep and goats, Cowdria colonies were identified as clearly-defined, brown-staining rickettsial colonies within the cytoplasm of endothelial cells. No positive staining was observed in the control group. This technique was shown to be reliable for detecting infection with C. ruminantium in the formalin-fixed tissues of mice and domestic ruminants.
Detection of bovine-virus-diarrhoea-virus antibodies in cattle with an enzyme-linked immunosorbent assay
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Muvavarirwa, P.; Mudenge, D.; Moyo, Doreen Zandile; Javangwe, S.; Verwoerd, Daniel Wynand
The serum-neutralization (SN) and the indirect-immunofluorescence (IIF) assays have invariably been used for detecting antibodies against bovine virus diarrhoea virus (BVDV) in cattle sera. An enzyme-linked immunosorbent assay (ELISA) was applied which has a sensitivity comparable with the SN and IIF in detecting antibody to BVDV. A total of 472 bovine sera were assayed and a high prevalence of 79,2% was recorded. Positive correlations between the ELISA and the SN were found when certain sera were assayed, implying that the former test could then be used for routine diagnosis of BVDV.
The effect(s) of carbaryl-treated seed on body maintenance and survival of the multi-mammate mouse, Mastomys natalensis (sensu lato)
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Neluvhalani, M.J.; Ferreira, Sam M.; Verwoerd, Daniel Wynand; Van Aarde, Rudi J.
Maintenance, expressed as change in daily body mass, and survival rates of Mastomys natalensis (sensu lato) were recorded from May to September 1994 in laboratory feeding trials, to investigate the short-term effects of a carbaryl insecticide on these variables. Individuals were subjected to seeds treated with carbaryl insecticide in three different treatments (5, 10 and 20 g of carbaryl/kg of seeds). Carbaryl did not have short-term adverse effects on growth and survival of this species when the seeds were kept in the laboratory and when they were exposed to environmental conditions between measurements. This suggests that the ingestion of carbaryl-treated seeds is not the cause of the decline in density of M. natalensis on rehabilitating coastal dune forests at Richards Bay.
Effects of transformation on the hemagglutinins of Haemophilus paragallinarum
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Bragg, Robert Richard; Purdan, G.; Coetzee, L.; Verwoerd, Daniel Wynand; Verschoor, Jan Adrianus
Strain 0083 and two field isolates of H. paragallinarum were previously converted into NAD-independent organisms by the use of crude DNA extractions from naturally occurring NAD-independent H. paragallinarumisolates. Two of these transformed isolates [0083(T) and A745(T)] were used as DNA donors in another transformation experiment in which another field isolate (M85) was used as the DNA recipient. Transformation was confirmed by lack of NAD requirement for growth, by carbohydrate fermentation patterns and by a comparison of the monoclonal antibody patterns of the isolates before and after transformation. Previously, antigenic differences were observed when DNA from an NAD-independent isolate was introduced into strain 0083. Antigenic differences were also seen in the transformed M85 organisms prepared in this work, and these differences were dependent on the antigenic patterns of the DNA donors. It was established by haemagglutination (HA) and haemagglutination inhibition (HI) that the hemagglutinins of 0083, A745/92 and M85 were not affected by transformation. The use of strains transformed to NAD independence for vaccine production appears to be a valid approach, as the transformation appears not to affect the hemagglutinins of the transformed organisms. The major advantage would be the alleviation of the requirement for chicken serum or NAD in the bacterial growth medium used for infectious-coryza-vaccine production.
Parasites of domestic and wild animals in South Africa. XXXIII. Ixodid ticks on scrub hares in the north-eastern regions of Northern and Eastern Transvaal and of KwaZulu-Natal
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995) Spickett, Arthur M.; Bagnall, R.J.; Uys, A.C. (André Charles); Verwoerd, Daniel Wynand; Horak, Ivan Gerard; Braack, L.E.O.; Penzhorn, Barend Louis
Ixodid ticks were collected from scrub hares (Lepus saxatilis) at three localities. Nine tick species were recovered from 24 hares examined at Pafuri, Kruger National Park, Northern Transvaal. The most abundant and prevalent species were Hyalomma truncatum, Rhipicephalus kochi and a Rhipicephalus species (near R. pravus). Twelve tick species were collected from 120 scrub hares examined around Skukuza, Kruger National Park, Eastern Transvaal. The immature stages of Hyalomma truncatum were most abundant and those of Amblyomma hebraeum most prevalent on the hares. No haematozoa were found on blood smears made from these hares. Thirty-four scrub hares on mixed cattle and game farms near Hluhluwe, north-eastern KwaZulu-Natal harboured 12 tick species. The most abundant and prevalent of these were the immature stages of Rhipicephalus muehlensi. Piroplasms, tentatively identified as Babesia leporis, were present on blood smears of eight of these hares. The host status of scrub hares for 18 ixodid tick species or subspecies found in South Africa is tabulated.

Browse

Recent Submissions