1991 Onderstepoort Journal of Veterinary Research, Volume 58, 1991

Permanent URI for this collectionhttp://hdl.handle.net/2263/32327

Contentes Pages: Onderstepoort Journal of Veterinary Research, Vol ??, 19??

CONTENTS

*Volume 58: Number 1*

Laboratory confirmation of African horsesickness in the Western Cape : application of a F(ab')₂-based indirect ELISA	Du Plessis, DH, Van Wyngaardt, W, Gerdes, GH & Opperman, E	1

The use of a membrane feeding technique to determine the infection rate of Culicoides imicola (Diptera : Ceratopogonidae) for 2 bluetongue virus serotypes in South Africa	Venter, GJ, Pajor, ITP, Nevill, EM & Hill, E	5

Parasites of South African wildlife. VI. Helminths of blue duikers, Cephalophus monticola, in Natal	Boomker, JDF, Booyse, DG & Keep, ME	11

Parasites of South African wildlife. VII. Helminths of suni, Neotragus moschatus, in Natal	Boomker, JDF, Booyse, DG & Braack, LEO	15

The antibiotic sensitivity patterns of Bacillus anthracis isolated from the Kruger National Park	Odendaal, MW, Pieterson, PM, De Vos, V & Botha, AD	17

The biochemical, morphological and virulence profiles of Bacillus anthracis isolated in the Kruger National Park	Odendaal, MW, Pieterson, PM, De Vos, V & Botha, AD	21

Drag-sampling of free-living ixodid ticks in the Kruger National Park	Spickett, AM, Horak, IG, Braack, LEO & Van Ark, H	27

Copper toxicity in ruminants: air pollution as a possible cause	Gummow, B, Botha, CJ, Basson, AT & Bastianello, SS	33

A reduction in the duration of infection with Trichomonas foetus following vaccination in heifers and the failure to demonstrate a curative effect in infected bulls	Herr, S, Ribeiro, LMM, Claassen, E & Myburgh, JG	41

Photosensitivity in South Africa. VI. The experimental induction of geeldikkop in sheep with crude steroidal saponins from Tribulus terrestris	Kellerman, TS, Erasmus, GL, Coetzer, JAW, Brown, JMM & Maartens, BP	47

Research communication:

Reproductive parameters in free-ranging female black rhinoceroses (Diceros bicornis) in Zimbabwe	Kock, N, Morton, D & Kock, M	55


*Volume 58: Number 2*

Health status of salmonids in river systems in Natal. I. Collection of fish and parasitological examination	Bragg, RR	59

Health status of salmonids in river systems in Natal. II. Isolation and identification of viruses	Bragg, RR	63

Health status of salmonids in river systems in Natal. III. Isolation and identification of bacteria	Bragg, RR	67

The effect of tick infestation on the productivity of cows of three breeds of cattle	Scholtz, MM, Spickett, AM, Lombard, PE & Enslin, CB	71

A gas-chromatographic headspace method for the determination of acetone in bovine milk, blood and urine	Winterbach, HEK & Apps, PJ	75

A review of the ixodid ticks (Acari, Ixodidae) occurring in Southern Africa	Walker, JB	81

Research communications:

Prevalence of ruminant pestivirus infections in Namibia	Depner, K, Hubschle, OJB & Liess, B	107

A serological comparison of complement fixation reactions using Brucella abortus and B. melitensis antigens in B. abortus infected cattle	Herr, S, Brett, OL, Ribeiro, LMM & Lawrence, JV	111


*Volume 58: Number 3*

Parasites of domestic and wild animals in South Africa. XXV. Ixodid ticks on sheep in the north-eastern Orange Free State and in the eastern Cape Provinces	Horak, IG, Williams, EJ & Van Schalkwyk, PC	115

Parasites of domestic and wild animals in South Africa. XXVI. The mosaic of ixodid tick infestations on birds and mammals in the Mountain Zebra National Park	Horak, IG, Fourie, LJ, Novellie, PA & Williams, EJ	125

Parasites of domestic and wild animals in South Africa. XXVII. Ticks on helmeted guineafowls in the eastern Cape Province and eastern Transvaal Lowveld	Horak, IG, Spickett, AM, Braack, LEO & Williams, EJ	137

The prevalence of blood parasites in helmeted guineafowls, Numida meleagris, in the Kruger National Park	Earle, RA, Horak, IG, Huchzermeyer, FW, Bennett, GF, Braack, LEO & Penzhorn, BL	145

Overberg research projects. X. Faecal egg counts in the interpretation of nematode worm burdens in sheep	Reinecke, RK & Groeneveld, HT	149

Afrotropical Culicoides: C. (Avaritia) miombo sp. nov., a widespread species closely allied to C. (A.) imicola Kieffer, 1913 (Diptera: Ceratopogonidae)	Meiswinkel, R	155

T cell-mediated immunity to Cowdria ruminantium in mice: the protective role of Lyt-2+ T cells	Du Plessis, JL, Berche, P & Van Gas, L	171

The relative resistance of six cattle breeds to the tick Boophilus decoloratus in South Africa	Rechav, Y & Kostrzewski, MW	181

Ultrastructural morphology of Cowdria ruminantium in midgut epithelial cells of adult Amblyomma hebraeum female ticks	Hart, A, Kocan, KM, Bezuidenhout, JD & Prozesky, L	187

Parasites of South African wildlife. VIII. Helminth and arthropod parasites of warthogs, Phacochoerus aethiopicus, in the eastern Transvaal	Boomker, JDF, Horak, IG, Booyse, DG & Meyer, S	195

Parasites of South African wildlife. IX. Helminths of kudu Tragelaphus strepsiceros, in the eastern Cape Province	Boomker, JDF, Horak, IG & Knight, MM	203

Parasites of South African wildlife. X. Helminths of red duikers, Cephalophus natalensis, in Natal	Boomker, JDF, Horak, IG & Flamand, JRB	205

The pathology of Cestrum laevigatum (Schlechtd) poisoning in cattle	Van der Lugt, JJ, Nel, PW & Kitching, JP	211

Sweating sickness : relative curative effect of hyperimmune serum and a precipitated immuno-globulin suspension and immunoblot identification of proposed immunodominant tick salivary gland proteins	Spickett, AM, Burger, DB, Crause, JC, Roux, EM & Neitz, AWH	223


*Volume 58: Number 4*

The tick-borne rickettsia Cowdria ruminantium has a chlamydia-like development cycle	Jongejan, F, Zandbergen, TA, Van de Wiel, PA, De Groot, M & Uilenberg, G	227

Treatment of Cyprinus carpio L. and Clarias gariepinus (Burchell) embryos with formalin and malachite green : effect of concentration and length of treatment on their survival	Theron, J, Prinsloo, JF & Schoonbee, HJ	239

Investigations into the effects of concentration and duration of exposure to formalin and malachite green on the survival of the larvae and juveniles of the common carp Cyprinus carpio L. and the sharptooth catfish Clarias gariepinus (Burchell)	Theron, J, Prinsloo, JF & Schoonbee, HJ	245

Parasites of domestic and wild animals in South Africa XXVIII. Helminths and arthropod parasites of Angora goats and kids in Valley Bushveld	Horak, IG, Knight, MM & Williams, EJ	253

Parasites of domestic and wild animals in South Africa. XXIX. Ixodid ticks on hares in the Cape Province and on hares and red rock rabbits in the Orange Free State	Horak, IG & Fourie, LJ	261

Parasites of South African wildlife. XI. Description of a new race of Cooperia rotundispiculum Gibbons & Khalil, 1980	Boomker, J	271

Parasites of South African wildlife. XII. Helminths of nyala, Tragelaphus angasii, in Natal	Boomker, JDF, Horak, IG & Flamand, JRB	275

Ixodid ticks and lice infesting red duikers and bushpigs in north-eastern Natal	Horak, IG, Boomker, JDF & Flamand, JRB	281

Overberg research projects. XI. First stage larval reduction test to assess, anthelmintic efficacy ante mortem in sheep	Reinecke, RK, Lourens, M & Petersen, B	285

Cardiomyopathy of ruminants induced by the litter of poultry fed on rations containing the ionophore antibiotic, maduramicin. 1. Epidemiology, clinical signs and clinical pathology	Fourie, N, Bastianello, SS, Prozesky, L, Nel, PW & Kellerman, TS	291

Perinatal mortality in lambs of ewes exposed to cultures of Diplodia maydis (=Stenocarpella maydis) during gestation	Kellerman, TS, Prozesky, L, Schultz, RA, Rabie, CJ, Van Ark, H, Maartens, BP & Lubben, A	297

Research communications:

Isolation and identification of adenovirus 127, the causative agent of egg drop syndrome (EDS) from commercial laying hens in South Africa	Bragg, RR, Allwright, DM & Coetzee, L	309

Spread in South Africa of the Oriental latrine fly Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae), an introduced species closely resembling Chrysomya bezziana Villeneuve	Braack, LEO	311

Author index		313

Subject index		320

Browse

Now showing 1 - 20 of 48

Subject index
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Unknown; Verwoerd, Daniel Wynand
Author Index
(Pretoria : Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Verwoerd, Daniel Wynand
Parasites of domestic and wild animals in South Africa. XXV. Ixodid ticks on sheep in the north-eastern Orange Free State and in the eastern Cape Province
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Williams, E.J.; Van Schalkwyk, P.C.; Verwoerd, Daniel Wynand; Horak, Ivan Gerard
The tick burdens of 115 Merino sheep, slaughtered over a period of 15 consecutive months on a farm in the north-eastern Orange Free State, were determined. A total of 7 ixodid and 1 argasid tick species were recovered and the seasonal abundances of Boophilus decoloratus, Hyalomma marginatum rufipes, Margaropus winthemi and Rhipicephalus evertsi evertsi were determined. One hundred and forty-nine Merino sheep were slaughtered over periods varying from 10 to 25 months on 3 farms in Eastern Province Thornveld in the eastern Cape Province and their tick burdens determined. Fourteen ixodid tick species were recovered from these animals and the seasonal abundances of Amblyomma marmoreum, B. decoloratus, Haemaphysalis silacea, R. evertsi evertsi and Rhipicephalus nitens were ascertained. On a farm in Valley Bushveld in the Eastern Cape Province, 2 Dorper sheep were slaughtered each month for a period of 24 consecutive months. These 48 sheep harboured 10 ixodid tick species and the seasonal abundances of A. marmoreum, H. silacea, Rhipicephalus appendiculatus and Rhipicephalus glabroscutatum were determined. A total of 17 ixodid tick species, of which 12 had reached the adult stage, where recovered from the sheep on the 5 farms.
Spread in South Africa of the Oriental latrine fly Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae), an introduced species closely resembling Chrysomya bezziana Villeneuve
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Verwoerd, Daniel Wynand; Braack, L.E.O.
Chrysomya megacephala, also known as the Oriental latrine fly, is indigenous to south-east Asia. During the 1970's it successfully invaded Africa and South America, and more recently during the 1980's also established itself in the United States of America. Although the first specimens from South Arica were collected from the south-western Cape Province in 1978, no published data appears to exist on its subsequent spread or status in southern Africa. During May 1991 a specimen of C. megacephala was incidentally captured near Beaufort West, Cape Province, South Africa, which prompted re-examination of blow-flies captured in the Kruger National Park during 1984. In this way it was found that C. megacephala was already well established in the south-eastern Transvaal by mid-1984. Adult C. megacephala can easily be confused with C. bezziana and medical/veterinary entomologists and veterinarians should take note of the existence of this species and the fact that it is probably widespread throughout southern Africa at this state.
Perinatal mortality in lambs of ewes exposed to cultures of Diplodia maydis (= Stenocarpella maydis) during gestation
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Kellerman, T. Stephanus; Schultz, R.A. (Rowena Anitra); Rabie, C.J.; Van Ark, H.; Maartens, B.P.; Lubben, Annelie; Verwoerd, Daniel Wynand; Prozesky, Leon
During 1987 when cob rot was rife, perinatal losses were reported in flocks and herds that had been exposed to diplodiosis. The affected lambs or calves were either stillborn or died soon after birth. Dosing trials at the Onderstepoort Veterinary Research Institute involving 82 ewes revealed that 66% of the offspring of dams exposed to cultures of Diplodia maydis (= Stenocarpella maydis) in the second trimester of pregnancy and 87% of lambs of ewes exposed in the third trimester were born dead or died soon afterwards. A status spongiosus similar to that of the field cases was present in the white matter of the brains of all the affected lambs. The lambs of ewes that had shown nervous signs and those of ewes that had not shown such signs were equally affected. The experiments also clearly demonstrated that foetuses were much more susceptible to diplodiosis than the adults, e.g. in the third trimester 87% of the lambs were affected compared to only 44% of the dams. No perinatal mortalities were recorded in the group exposed to the culture in the first trimester. Ewes developed significant resistance to intoxication after initial exposure to the culture and both the length of gestation and birth mass of the affected lambs were less than those of their untreated counterparts.
Investigations into the effects of concentration and duration of exposure to formalin and malachite green on the survival of the larvae and juveniles of the common carp Cyprinus carpio L. and the sharptooth catfish Clarias gariepinus (Burchell)
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Theron, J.; Prinsloo, J.F.; Schoonbee, H.J.; Verwoerd, Daniel Wynand
Prophylactic dip treatments using formalin and malachite green were applied to 4-day old larvae and 12- and 20-day old juveniles of the European common carp, Cyprinus carpio and the African sharptooth catfish, Clarias gariepinus. Treatments consisted of 100mg/l malachite green for exposure periods of 10, 30 or 90s and 200mg/l formalin, administered for 30, 60 or 90 min. Larvae and juveniles of C. gariepinus could be treated with 100mg/l malachite green for 10s, or with 200mg/l formalin for 30min, with minimum mortalities. Both chemicals affected the survival of the C. gariepinus juveniles, especially the 90 min exposure to formalin. Juveniles of both species were extremely sensitive to 100mg/l malachite green concentrations.
Treatment of Cyprinus carpio L. and Clarias gariepinus (Burchell) embryos with formalin and malachite green : effect of concentration and length of treatment on their survival
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Theron, J.; Prinsloo, J.F.; Schoonbee, H.J.; Verwoerd, Daniel Wynand
Malachite green and formalin were investigated as prophylactic dip treatments for developing embryos of Cyprinus carpio and Clarias gariepinus. Based on the findings, recommendations are made on the respective concentrations to be used and exposure periods to be followed for both formalin and malachite green for both fish species.
The tick-borne rickettsia Cowdria ruminantium has a Chlamydia-like developmental cycle
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Zandbergen, Thijs A.; Van de Wiel, Paul A.; De Groot, Mia; Uilenberg, Gerrit; Verwoerd, Daniel Wynand; Jongejan, Frans
The development of the tick-borne rickettsial pathogen Cowdria ruminantium (S stock) was studied in bovine umbilical endothelial (BUE) cell cultures and in goat choroid plexus, by light- and electron microscopy. Cowdria divided by binary fission within intracytoplasmic vacuoles resulting in large colonies of reticulate bodies. After three to four days in culture, reticulate bodies developed into smaller intermediate bodies characterized by an electron-dense core. Shortly before disruption of the host cells, intermediate bodies condensed further into electron-dense elementary bodies, which were released into the culture medium. Elementary bodies invade other endothelial cells thus initiating a new infectious cycle which lasts between 5 and 6 days. In the infected goat choroid plexus similar reticulate and intermediate bodies were identified within vacuoles of capillary endothelial cells. However, extracellular elementary bodies were not detected. Another stock of Cowdria (W) showed an identical developmental cycle as that of the S stock. The W isolate was also pathogenic for mice, making it possible to test the infectivity of reticulate and elementary bodies in these animals. Reticulate bodies appeared to be less infective than elementary bodies. The developmental cycle of Cowdria resembles the cycle known to occur in Chlamydia. Moreover, Cowdria has other similarities with Chlamydia. It has a Gram-negative envelope, it does not store iodine-stainable carbohydrates and may lack peptidoglycan as does Chlamydia. It is concluded, that Cowdria and Chlamydia are to a certain extent related, confirming a recent report that both organisms have certain antigenic determinants in common. Since Cowdria is also related to Ehrlichia it may well be that Cowdria takes an intermediate position between Chlamydia and Ehrlichia. The phylogenetic relationship between Cowdria and Chlamydia and also with Ehrlichia should be further elucidated by molecular analysis using 16S ribosomal DNA sequences.
Sweating sickness : relative curative effect of hyperimmune serum and a precipitated immunoglobulin suspension and immunoblot identifiation of proposed immunodominant tick salivary gland proteins
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Spickett, Arthur M.; Burger, D.B.; Crause, J.C.; Roux, Elizabeth M.; Verwoerd, Daniel Wynand; Neitz, Albert Walter Herman
Although of low morbidity, sweating sickness is readily induced in calves by infestation with positive Hyalomma truncatum adult ticks. This epitheliotrophic disease has no specific cure except by the administration of hyperimmune serum obtained from animals which have recovered and are subsequently immune to the disease. Treatment with hyperimmune serum, however, has associated problems of donor availability, possible serum contamination and i.v. administration of a relatively large volume. This paper compares the treatment and cure of sweating sickness using unrefined hyperimmune serum and that of an experimental suspension. The latter proved relatively inefficient probably due to a low concentration of effective immunoglobulins. Immunoblot analyses of the sera of affected animals, using tick salivary glands as antigen during the course of the trial revealed 4 tick salivary gland proteins with molecular masses of between 27-33 kDa. These are proposed as being associated with sweating sickness immunodominance.
Parasites of South African wildlife. X. Helminths of red duikers, Cephalophus natalensis, in Natal
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Flamand, J.R.B.; Verwoerd, Daniel Wynand; Boomker, Jacob Diederik Frederik; Horak, Ivan Gerard
The helminths of the following red duikers, Cephalophus natalensis, were examined: 24 from 3 game reserves in Natal and 1 that had originated from Charters Creek, Natal, shortly before it died in the National Zoological Gardens, Pretoria. The 21 animals from Charters Creek harboured 16 nematode species, a nematode genus, 2 cestode species and paramphistomes. The 2 red duiker from Fanies Island harboured 4 nematode species, 3 nematode genera and 1 cestode species, while the single red duiker from Ndumu was infected with 3 nematode species. The antelope from the National Zoological Gardens, Pretoria, harboured 2 nematode species, 1 nematode genus and 1 cestode species. A race of Cooperia rotundispiculum was the most abundant nematode in duikers from all the reserves. Hyostrongylus rubidus is a new parasite record in South Africa and in red duikers, and was present in 80% of the antelope. Although primarily a parasite of swine, Hyostrongylus rubidus should be regarded as a definitive parasite of these antelope.
Parasites of South African wildlife. VIII. Helminth and arthropod parasites of warthogs, Phacochoerus aethiopicus, in the eastern Transvaal
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Meyer, Santa; Verwoerd, Daniel Wynand; Boomker, Jacob Diederik Frederik; Horak, Ivan Gerard; Booyse, Dirk G.
Helminth and arthropod parasites were collected from 41 warthogs, Phacochoerus aethiopicus, in the Hoedspruit Nature Reserve, eastern Transvaal. This reserve consists of a military base, which is a restricted area and is surrounded by a reserve, which is open to the public. Eleven nematode species, 1 or 2 cestode species and the larvae of 2 cestode species were recovered from the animals in the reserve, and 8 nematode species and 1 or 2 cestode species were recovered from those in the military base. Oesophagostomum spp. were generally most abundant in warthogs in the reserve during the cooler months of the year, while Probstmayria vivipara also occurred in peak numbers during the cooler months, with an additional peak in October and November 1988 in warthogs in the reserve and the base, respectively. No pattern of seasonal abundance could be determined for the other helminth species. The warthogs also harboured 8 ixodid and 1 argasid tick species, 3 flea species and 1 louse species. Adult and immature Haematopinus phacochoeri were most numerous during August and September, and the largest numbers of adult Rhipicephalus simus were present from December to April.
Overberg Research Projects. XI. First stage larval reduction test to assess anthelmintic efficacy ante mortem in sheep
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Reinecke, R.K.; Lourens, M.; Petersen, B.; Verwoerd, Daniel Wynand
Two field trials, one with suckling Merino ewe lambs and the other with yearling Dohne Merino rams, are described. In these the anthelmintic efficacy of febantel (a benzimidazole), ivermectin, levamisole and morantel are compared, using the first stage larval reduction test. The mean natural log (+ 1 for zero values) of the post treatment larval counts of the treated groups was compared with that of the untreated controls and the percentage reduction used to assess anthelmintic efficacy. Febantel was only 87,4% effective against Teladorsagia in suckling lambs but the other anthelmintics were more than 99% effective against this genus. Efficacy against Haemonchus and Trichostrongylus ranged from 93,2%-100% for all 4 compounds. In the rams all compounds were 100% effective against Trichostrongylus, with the exception of morantel which was only 87,5% effective. None of the compounds were effective against Teladorsagia, particularly morantel, animals treated with which having more larvae than the controls. The interpretation of anthelmintic efficacy; the advantages of the first stage larval reduction test, compared with the faecal egg count reduction test; and the importance of incubating cultures at 30°C for 24 h, in order to harvest first stage larvae, are discussed.
Ixodid ticks and lice infesting red duikers and bushpigs in north-eastern Natal
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Flamand, J.R.B.; Verwoerd, Daniel Wynand; Horak, Ivan Gerard; Boomker, Jacob Diederik Frederik
Eighteen red duikers, Cephalophus natalensis, from the Charters Creek Nature Reserve and 2 from Fanies Island Nature Reserve were processed for arthropod parasite recovery. They harboured 8 species of ixodid ticks and 2 lice species. All were infested With Haemaphysalis parmata and the nymphs of Rhipicephalus muehlensi. Two bushpigs, Potamochoerus porcus, from the Ndumu Nature Reserve, 5 from the Eastern Shores Nature Reserve and 1 from Cape Vidal were examined for ectoparasites. They were infested with 8 ixodid tick species, of which Rhipicephalus maculatus was the most abundant, and with 1 louse species.
Parasites of South African wildlife. XI. Description of a new race of Cooperia rotundispiculum Gibbons and Khalil, 1980
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Boomker, Jacob; Verwoerd, Daniel Wynand
During surveys of the helminths of South African wildlife, a Cooperia sp. that closely resembles Cooperia rotundispiculum Gibbons & Khalil, 1980, was recovered from several antelope species. This nematode has spicules 0,140-0,248mm long and has 18-20 longitudinal cuticular ridges, whereas typical C. rotundispiculum has spicules 0,179-226 mm long and has 14 ridges. In view of the few differences between the 2 helminths, the Cooperia sp. is described here as a race of C. rotundispiculum.
Parasites of South African wildlife XII. Helminths of nyala, Tragelaphus angasii, in Natal
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Flamand, J.R.B.; Verwoerd, Daniel Wynand; Boomker, Jacob Diederik Frederik; Horak, Ivan Gerard
The helminths of 77 nyala, Tragelaphus angasii, from 4 game reserves in Natal, were collected, counted and identified. Ten nematode species and 4 nematode genera, a trematode species and paramphistomes, and 2 cestode genera were recovered from the antelope. Of these, a Cooperia rotundispiculum race, Gaigeria pachyscelis, a Gongylonema sp., Haemonchus vegliai, Impalaia tuberculata, an Oesophagostomum sp., a Setaria sp., Trichostrongylus deflexus, Trichostrongylus falculatus, the larval stage of a Taenia sp., a Thysaniezia sp. and Schistosoma mattheei are new parasite records for this host. Individual nematode helminth burdens varied from 3 to 13 493 and the total mean nematode burden was 700. The mean burdens of nyala from Mkuzi were the largest and those from animals from the Umfolozi Game Reserve and the False Bay Park the smallest. Ostertagia harrisi was the most prevalent nematode, and it was also the most numerous in nyala from Umfolozi, Mkuzi and False Bay. A race of Cooperia rotundispiculum was the most numerous in nyala from Ndumu. No clear-cut trends in the seasonal abundance could be discerned for any of the worm species recovered in this study.
Parasites of South African wildlife. IX. Helminths of kudu, Tragelaphus strepsiceros, in the eastern Cape Province
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Knight, M.M.; Verwoerd, Daniel Wynand; Boomker, Jacob Diederik Frederik; Horak, Ivan Gerard
The helminths of 25 kudu, Tragelaphus strepsiceros, from 3 localities in the eastern Cape Province were collected, counted and identified. The majority of kudu harboured no worms, and the burdens of those infected were small. A race of Cooperia rotundispiculum, a Dictyocaulus sp., a Haemonchus sp., Nematodirus helvetianus and Ostertagia ostertagi were recovered. Two parasites, Nematodirus helvetianus and Ostertagia ostertagi can be added to the list of helminth parasites of kudu in South Africa.
Isolation and identification of Adenovirus 127, the causative agent of egg drop syndrome (EDS), from commercial laying hens in South Africa
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Bragg, R.R. (Robert Richard); Allwright, D.M.; Coetzee, L.; Verwoerd, Daniel Wynand
A drop in egg production associated with loss of pigment and soft-shelled eggs was experienced on a farm in the Western Cape. Investigations revealed high levels of antibodies against adenovirus 127, the causative agent of egg drop syndrome (EDS) in chickens which were not vaccinated against EDS. A cytopathic agent was subsequently isolated in chicken embryo liver cell cultures and identified as EDS virus by haemagglutination inhibition and neutralization tests.
Cardiomyopathy of ruminants induced by the litter of poultry fed on rations containing the ionophore antibiotic, maduramicin. 1. Epidemiology, clinical signs and clinical pathology
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Fourie, Niel; Bastianello, Stella S.; Nel, P.W.; Kellerman, T. Stephanus; Verwoerd, Daniel Wynand; Prozesky, Leon
The epidemiological, clinical and clinical pathological findings in 20 cattle and 4 sheep from 15 outbreaks of poultry litter toxicity in South Africa over the past 6 years are documented. In 6 outbreaks, the litter emanated from batteries where maduramicin had been incorporated into rations of broilers. According to circumstantial evidence the litter involved in the 9 other outbreaks was also derived from broilers which had been fed on rations containing an ionophore. The litter was fed ad libitum to the affected stock or constituted 30-80% by volume of their rations. The principal sign manifested was sudden mortality of up to 70% of the herd or flock, usually within 20-40 days of commencement of feeding of poultry litter. A few cattle developed signs of congestive heart failure, and stiffness was commonly seen in sheep. In a dosing trial with poultry litter involving 1 steer and 6 sheep, the steer and a sheep died suddenly and a second sheep was destroyed in extremis. Tachycardia and/or cardiac arrythmia were recorded in 5 sheep, and the activity of aspartate transaminase (AST) and/or lactate dehydrogenase (LD) in the sera of 4 was elevated. Since the cardiac lesions in field cases were similar to those of ionophore poisoning and broiler rations containing maduramicin was a common factor in several outbreaks, toxic litter from some of these outbreaks were tested for the presence of this compound. Analysis by high performance liquid chromatography of litter from 2 specimens of outbreaks revealed that they contained 2,5ppm and 6,1ppm maduramicin. Sheep in a trial fed rations incorporating c 2,5ppm and 5ppm maduramicin, developed clinical signs and lesions consistent with those of the field cases.
Ultrastructural morphology of Cowdria ruminantium in midgut epithelial cells of adult Amblyomma hebraeum female ticks
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Hart, Alet; Kocan, Katherine M.; Bezuidenhout, J. Dürr; Verwoerd, Daniel Wynand; Prozesky, Leon
Amblyomma hebraeum male and female ticks, experimentally infected as larvae with the Ball 3 stock of Cowdria ruminantium, were fed on a heartwater susceptible sheep. The initial attachment of the males was required as a pre-requisite for female attachment. Reticulate bodies were the predominant morphologic form of Cowdria observed in gut epithelial cells after 1-3 days of feeding. Single intermediate bodies and no elementary bodies were observed. Organisms were found within a membrane-bound vacuole and each organism had a double-unit membrane. Infrequently colonies contained homogeneous electron-dense inclusions. Groups of Cowdria organisms within a haemocyte suggested a possible dissemination of organisms from the gut to various other tissues by haemocytes.
The relative resistance of six cattle breeds to the tick Boophilus decoloratus in South Africa
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991) Rechav, Y.; Kostrzewski, M.W.; Verwoerd, Daniel Wynand
Adult females of the tick Boophilus decoloratus were removed from 6 breeds of cattle on 2 farms in the Northern Transvaal. Highest numbers of female ticks were collected from Simmentaler, followed by Santa Gertrudis, Bonsmara, Afrikaner, Brahman and Nguni. Resistance levels of each breed to B. decoloratus was positively correlated with the amount of Bos indicus genes in the breed, with the exception of Nguni, which is a sanga type but not pure B. indicus.

Browse

Recent Submissions