1990 Onderstepoort Journal of Veterinary Research, Volume 57, 1990

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

CONTENTS

*Volume 57: Number 1*

Cryopreservation of some common nematodes of ruminants for up to 11,3 years	Van Wyk, JA, Gerber, HM & Alves, RMR	1

Resistance of Brahman and Simmentaler cattle to Southern African ticks	Rechav, Y, Dauth, J & Els, DA	7

An immunohistochemical study of various peptide-containing endocrine cells and neurones at the equine ileocaecal junction	Kotze, SH & Van Aswegen, G	13

Scanning electron and light microscopy of the mucosa of the equine ileocaecal junction	Soley, JT & Kotze, SH	19

Udder health implications of premature bovine mammary regression. I. Clinical, subclinical and reducing-sugar changes in milk during 168 hours of suspended milking in mid-lactation	Giesecke, WH, Korybut-Woroniecki, PA & Kowalski, ZE	25

A light microscopic and immunocytochemical study of the gastro-intestinal tract of the ostrich (Struthio camelus L.)	Bezuidenhout, AJ & Van Aswegen, G	37

Udder health implications of premature bovine mammary regression. II. Collateral intramammary reactions in quarters milked normally during 168-hour milk stasis in opposite quarters	Giesecke, WH, Korybut-Woroniecki, PA & Kowalski, ZE	49

Two new species of ticks from southern Africa whose adults parasitize the feet of ungulates : Rhipicephalus lounsburyi n. sp. and Rhipicephalus neumanni n. sp. (Ixodoidea, Ixodidae)	Walker, JB	57

Heat stress in dairy cattle and other livestock under southern African conditions. I. Temperature-humidity index mean values during the four main seasons	Du Preez, JH, Giesecke, WH & Hattingh, PJ	77

Epidemiology of wildebeest-derived malignant catarrhal fever in South Africa : inability to transfer the disease with an African face fly Musca xanthomelas (Diptera: Muscidae)	Barnard, BJH, Bengis, RG & Voges, SF	89

The prehatch period and larval survival of Boophilus decoloratus (Koch, 1844) (Acarina: Ixodidae) under natural conditions in the Transvaal, South Africa	Spickett, AM & Heyne, H	95

The transovarial transmission of Babesia caballi by Hyalomma truncatum	De Waal, DT	99

Mycobacterium fortuitum isolated from three species of fish in South Africa	Bragg, RR, Huchzermeyer, HFAK & Hanisch, MAM	101


*Volume 57: Number 2*

Evaluation of the efficacy of anthelmintics against parafilariosis in cattle	Van Wyk, JA, Groeneveld, HT & Carmichael, IH	103

Pyridoxine (a vitamin B6) and its derivative pyridoxal as treatment for Albizia versicolor poisoning in guinea-pigs	Gummow, B & Erasmus, GL	109

Fitting the Gompertz function to dose-response data of larval tick populations	Spickett, AM & Van Ark, H	115

A field strain of Trichostrongylus colubriformis resistant to levamisole and morantel in South Africa	Van Wyk, JA, Bath, GF, Gerber, HM & Alves, RMR	119

On sampling tick populations : the problem of overdispersion	Petney, TN, Van Ark, H & Spickett, AM	123

Research communications:

The use of sensitivity discs in the identification of Campylobacter species	Ribeiro, LMM, Herr, S, Pefanis, SM & Gous, AGS	129

Effects of microclimatic variables on the availability and movement of third-stage larvae of Ostertagia ostertagi on herbage	Krecek, RC, Murrell, KD & Douglass, LW	133

Host cellular components adhering to the tegument of schistosomes from cattle, buffalo, hippopotamus and lechwe	Kruger, FJ & Wolmarans, CT	137

Feeding habits and flight-range of blow-flies (Chrysomyia spp.) in relation to anthrax transmission in the Kruger National Park, South Afnca	Braack, LEO & De Vos, V	141

The isolation and serology of Brucella melitensis in a flock of goats in central RSA	Ribeiro, LMM, Herr, S, Chaparro, F & Van der Vyver, FH	143


*Volume 57: Number 3*

The freeze-drying of Cowdria ruminantium	Du Plessis, JL, Van Gas, L, Labuschagne, FJ & Wijma, S	145

Concurrent babesiosis and ehrlichiosis in the dog : blood smear examination supplemented by the indirect fluorescent antibody test, using Cowdria ruminantium as antigen	Du Plessis, JL, Fourie, N, Nel, PW & Evezard, DN	151

A comparison of haemodynamic and vasoconstrictory responses in sheep with a toxic fraction from Pachystigma pygmaeum and with the plant material	Van Der Walt, JJ, Van Rooyen, JM & Lotter, AP	157

The detection and isolation of a paralysis toxin present in Argas (Persicargas) walkerae	Neitz, AWH, Viljoen, GJ, Van Wyngaardt, S, Gothe, R, Visser, L & Bezuidenhout, JD	163

Parasites of South African wildlife. V. A description of the males of Oesophagostomum mocambiquei Ortlepp, 1964 from warthogs, Phacochoerus aethiopicus (Pallas, 1766)	Boomker, JDF	169

Salmonella isolated from feeds and feed ingredients during the period 1982-1988 : animal and public health implications	Durand, AM, Giesecke, WH, Barnard, M-L, Van der Walt, ML & Steyn, HC	175

Heat stress in dairy cattle under southern African conditions. II. Identification of areas of potential heat stress during summer by means of observed true and predicted temperature-humidity index values	Du Preez, JH, Giesecke, WH, Hattingh, PJ & Eisenberg, BE	183

A survey of annoyance of livestock by Simulium chutteri Lewis along the Orange River, South Africa (Diptera: Simuliidae)	Jordaan, LC & Van Ark, H	189

Research communications:

The use of filter paper discs impregnated with thionin acetate, basic fuchsin and thionin blue in the identification of Brucella species	Ribeiro, LMM & Herr, S	197

Epizootology of wildebeest-derived malignant catarrhal fever : possible transmission among cows and their calves in the north-western Transvaal	Barnard, BJH	201

An attempt to improve the immunization of sheep against heartwater by using different combinations of 3 stocks of Cowdria ruminantium	Du Plessis, JL, Potgieter, FT & Van Gas, L	205

An efficient medium for the isolation of Trichomonas foetus	Ribeiro, LMM	209


*Volume 57: Number 4*

An experimental Schistosoma mattheei infection in man	Wolmarans, CT, De Kock, KN & Van der Walt, MPK	211

Identification of the antigenic proteins of Cowdria ruminantium	Neitz, AWH, Rossouw, M, De Waal, DT, Du Plessis, JL, Van Gas, L & Brett, S	215

The toxic effects on cardiac myocytes of tyledoside F, a cumulative neurotoxic cardiac glycoside isolated from Tylecodon grandiflorus	Van Rooyen, JM & Van der Walt, JJ	223

The isolation and transmission of an unidentified Babesia sp. to cattle by Hyalomma truncatum Koch 1844	De Waal, DT, Potgieter, FT, Combrink, MP & Mason, TE	229

Increased pathogenicity of an Ehrlichia-like agent after passage through Amblyomma hebraeum : a preliminary report	Du Plessis, JL	233

Failure of an Actinomyces pyogenes vaccine to protect sheep against an intravenous challenge	Hunter, P, Van der Lugt, JJ & Gouws, JJ	239

Heat stress in dairy cattle and other livestock under southern African conditions. III. Monthly temperature-humidity index• mean values and their significance in the performance of dairy cattle	Du Preez, JH, Hattingh, PJ, Giesecke, WH & Eisenberg, BE	243

The pathology of experimental Lasiospermum bipinnatum (Thunb.) Druce (Asteraceae) poisoning in sheep. I. Hepatic lesions	Williams, MC	249

The pathology of experimental Lasiospermum bipinnatum (Thunb.) Druce (Asteraceae) poisoning in sheep. II. Pulmonary and miscellaneous lesions	Williams, MC	263

Leukoencephalomalacia in two horses induced by oral dosing of fumonisin B1	Coetzer, JAW, Kellerman, TS, Marasas, WFO, Thiel, PG, Gelderblom, WCA & Cawood, M	269

Research communications:

Overberg Research Project. IX. First stage larvae per gram (L1p.g.) of faeces : an efficient method of diagnosing nematode parasites of sheep ante mortem	Reinecke, RK	277

Serological reactions to Leptospira species in buffalo (Syncerus caffer) from the Kruger National Park	Myburgh, JG, Bengis, RG, Bester, CJJ & Chaparro, F	281

An attempt to establish an inbred line of mice genetically resistant to Cowdria ruminantium	Du Plessis, JL, Meyer, EHH & Van Gas, L	283

Author index		287

Subject index		293

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Now showing 1 - 20 of 50

Fitting the Gompertz function to dose-response data of larval tick populations
(Published by the Government Printer, Pretoria., 1990) Spickett, Arthur M.; Van Ark, H.; Verwoerd, Daniel Wynand
Samples of 6, 1st generation larval populations of Boophilus decoloratus, originating from field collected females, were subjected to increasing doses of the organophosphate acaricide, Dioxathion. The dose-response relationship for 3 populations showed random heterogeneity, where systematic deviations from the linear probit lines were observed for the other 3 populations. Logistic and Gompertz regressions were also fitted for all 6 populations. Probit regressions fitted best for 2 populations exhibiting heterogeneous responses. The logistic regression fitted best for 1 population with heterogeneous responses and 1 population with systematic deviating responses. The Gompertz regression fitted best for the 2 remaining populations exhibiting systematic deviating responses. The Gompertz function may be useful in describing the dose-response relationship obtained for certain acaricidal toxicity tests.
Pyridoxine (a vitamin B6) and its derivative pyridoxal as treatment for Albizia versicolor poisoning in guinea-pigs
(Published by the Government Printer, Pretoria., 1990) Erasmus, G.L.; Verwoerd, Daniel Wynand; Gummow, Bruce
In the course of three experiments it was established that all the toxic effects of a lethal dose of Albizia versicolor pods (> 4,5g/kg) in guinea-pigs could be countered by concurrent subcutaneous injection of pyridoxine (10mg/kg). This treatment was also successful once severe symptoms had set in. Pyridoxal, on the other hand, was found to be ineffective as a therapeutic agent. The fact that pyridoxal does not counter the action of the toxin indicates an atypical site of action by the toxin as regards the normal pathways which require vitamin B6 as a co-factor.
Evaluation of the efficacy of anthelmintics against parafilariosis in cattle
(Published by the Government Printer, Pretoria., 1990) Carmichael, I.H.; Verwoerd, Daniel Wynand; Groeneveld, Hendrik T.; Van Wyk, Jan Aucamp
Parafilariosis was first described in South Africa in 1964, thereafter being discovered at numerous localities in the country. When it became obvious that Parafilaria bovicola, for which no treatment was known, caused considerable economic losses, trials involving a series of compounds were conducted to identify candidate remedies. This paper describes an anthelmintic test for evaluating the efficacy of compounds for registration for field use. Recovery of Parafilaria worms is impractical for anthelmintic testing, and consequently the lesion sizes of treated and control groups of cattle are compared statistically, using appropriate statistical tests. The seasonal incidence of mature worm infection in cattle in South Africa is such that trials should commence after June and be completed before the end of January, allowing a lapse of 70 days between treatment and slaughter for resolution of the lesions. The presently available parafilaricidal compounds while of value for treating slaughter stock, when used alone will probably not be effective for control of infection in the field.
Heat stress in dairy cattle and other livestock under southern African conditions. III. Monthly temperature-humidity index· mean values and their significance in the performance of dairy cattle
(Published by the Government Printer, Pretoria., 1990) Du Preez, J.H.; Hattingh, P.J.; Giesecke, W.H.; Eisenberg, B.E.; Verwoerd, Daniel Wynand
Temperature-humidity index (THI) values applicable to South Africa and Namibia have been established during this investigation for each month of the year by means of computerized modelling and mapping techniques. The data indicate that each year heat stress risk areas (HSRA's) expand from August to January and retract from February to July. The THI values classified according to the Livestock Weather Safety Index (LWSI) for lactating dairy cattle (LDC), suggest that, especially during November to March there is the risk of moderate to advanced heat stress in most South African dairy cows. This has important implications for their general health, udder health, production and reproduction. Careful planning of facilities and highly adaptable herd management are required to protect dairy cattle from heat stress.
Identification of the antigenic proteins of Cowdria ruminantium
(Published by the Government Printer, Pretoria., 1990) Rossouw, Mirinda; De Waal, D.T.; Du Plessis, J.L.; Van Gas, Letitia; Brett, Susan; Verwoerd, Daniel Wynand; Neitz, Albert Walter Herman
Immunoblotting of Cowdria ruminantium proteins with sheep or bovine antiserum identified 2 antigenically conserved proteins, one being an immunodominant 31 kDa and the other a minor 27 kDa protein. These proteins are present in the electrophoretic profiles of the Welgevonden, Ball 3 and Kwanyanga stocks and are recognized by sheep antiserum to the Welgevonden, Ball 3, Kwanyanga, Mali, Comoro, Breed, Germishuys, Kümm and Mara stocks and by bovine antiserum to the Welgevonden stock of C. ruminantium. The stocks did not reveal identical or unique antigenic properties which could explain differences in pathogenicity and cross-immunity observed amongst the various stocks of C. ruminantium.
Failure of an Actinomyces pyogenes vaccine to protect sheep against an intravenous challenge
(Published by the Government Printer, Pretoria., 1990) Hunter, Pamela; Van der Lugt, Jaco J.; Gouws, J.J.; Verwoerd, Daniel Wynand
The immunity conferred by an A. pyogenes bacterin-toxoid was evaluated in sheep, using an intravenous challenge system. Three sheep were vaccinated and 3 served as controls. The vaccinated sheep were not protected against pyogenic conditions. High antitoxin levels were induced by vaccination but could not be associated with protection against infection. Antibacterial antibody levels elicited with initial vaccination dropped progressively with the 2nd and 3rd vaccinations. Nevertheless, these antibodies did not seem to be necessary for protection against A. pyogenes conditions.
Subject index
(Published by the Government Printer, Pretoria., 1990) Unknown; Verwoerd, Daniel Wynand
Author index
(Pretoria : Government Printer, 1990) Verwoerd, Daniel Wynand
Increased pathogenicity of an Ehrlichia-like agent after passage through Amblyomma hebraeum : a preliminary report
(Published by the Government Printer, Pretoria., 1990) Du Plessis, J.L.; Verwoerd, Daniel Wynand
After being passaged through 3 generations of Amblyomma hebraeum, an Ehrlichia-like agent isolated from an adult Hyalomma truncatum female became more pathogenic and elicited a disease in sheep indistinguishable from heartwater. Cross-immunity between this agent and several stocks of Cowdria ruminantium and high levels of antibody elicited by the agent against 2 stocks of C. ruminantium in the indirect fluorescent antibody test, confirmed its close relationship to Cowdria.
The isolation and transmission of an unidentified Babesia sp. to cattle by Hyalomma truncatum Koch 1844
(Published by the Government Printer, Pretoria., 1990) De Waal, D.T.; Potgieter, F.T.; Combrink, M.P.; Mason, T.E.; Verwoerd, Daniel Wynand
An unidentified Babesia sp. which causes a mild disease in cattle was isolated in a splenectomized ox that received pooled blood from field cattle. That this organism is pleomorphic and resembles Babesia occultans makes it difficult to differentiate between these organisms microscopically. Initially, it was suspected that this Babesia could be B. occultans. Several attempts to transmit this parasite transovarially with Hyalomma marginatum rufipes, the vector of B. occultans, failed. Continued efforts to identify possible vectors, using Boophilus microplus, Rhipicephalus evertsi evertsi and Rhipicephalus appendiculatus, all failed. The only tick thus far identified that could have transmitted the infection transovarially in the adult stage was the two-host tick Hyalomma truncatum.
The toxic effects on cardiac myocytes of tyledoside F, a cumulative neurotoxic cardiac glycoside isolated from Tylecodon grandiflorus
(Published by the Government Printer, Pretoria., 1990) Van Rooyen, J.M.; Van der Walt, J.J.; Verwoerd, Daniel Wynand
To investigate the cardiac cellular effects of tyledoside F, a cumulative neurotoxic bufadienolide and ouabain, a non-cumulative cardenolide, the whole-cell clamp method was used to measure the Na-K pump current after the Na-K pump had been activated by high intracellular Na²⁺. The toxic effects of tyledoside F and ouabain on cardiac myocytes were also investigated by observing the effect of the Ca²⁺ overload on the viability of myocytes during a period of 75 min. From the results it is clear that there are similarities in the direct effects of tyledoside F and ouabain on the Na-K pump. It was found that ouabain inhibited the Na-K pump current more than that of tyledoside F. With regard to Ca²⁺ overload, there are differences in their mode of production of Ca²⁺ overload because cinnarizine protects the myocytes against ouabain-induced Ca²⁺ overload but not against tyledoside-induced Ca²⁺ overload. This study shows that with the whole-cell clamp technique tyledoside F inhibited the Na-K pump in a manner similar to inhibition of the pump by ouabain. Viability studies with myocytes indicated that tyledoside F also has other effects which are different from these of ouabain.
An attempt to establish an inbred line of mice genetically resistant to Cowdria ruminantium
(Published by the Government Printer, Pretoria., 1990) Du Plessis, J.L.; Meyer, E.H.H.; Van Gas, L.; Verwoerd, Daniel Wynand
An attempt to establish an inbred line of mice resistant to Cowdria ruminantium failed. First generation couples were constituted from those mice out of 100 males and 100 females that had survived infection with the Kümm stock of C. ruminantium and that were serologically negative to the indirect fluorescent antibody test. An attempt to establish 10 separate inbred lines by constituting next generation brother and sister matings from predominantly seronegative survivor mice from the preceding generation, was unsuccessful because too few mice survived the challenge. The percentage seronegative survivors increased to 94% over the first 6 generations, but then declined sharply during the next.
Serological reactions to Leptospira species in buffalo (Syncerus caffer) from the Kruger National Park
(Published by the Government Printer, Pretoria., 1990) Bengis, Roy G.; Bester, C.J.J.; Chaparro, F.; Verwoerd, Daniel Wynand; Myburgh, Jan G.
Four hundred and six serum samples from buffalo (Syncerus caffer) were tested for leptospirosis, using the microscopic agglutination test. Seven buffaloes (1,7%) reacted positive and 27 (6,6%) inconclusive. Reactions against L. tarassovi and L. hardjo were the most prevalent.
Overberg Research Project. IX. First stage larvae per gram (L₁p.g.) of faeces : an efficient method of diagnosing nematode parasites of sheep ante mortem
(Published by the Government Printer, Pretoria., 1990) Reinecke, R.K.; Verwoerd, Daniel Wynand
Nematode eggs were collected by mixing the faeces with a sugar solution, filling a flat-sided medicine bottle (100 ml), and allowing eggs to float and adhere to the upper surface for 30 min. After discarding the faeces, eggs hatched within 24 h at 20-30⁰C. Each genus was counted in a counting chamber and the L₁p.g. estimated. The morphology of L₁ of Haemonchus, Teladorsagia, Trichostrongylus, Oesophagostomum and Strongyloides is briefly described.
Leukoencephalomalacia in two horses induced by oral dosing of fumonisin B₁
(Published by the Government Printer, Pretoria., 1990) Kellerman, T. Stephanus; Marasas, Walter F.O. (Walter Friedrich Otto); Thiel, P.G.; Gelderblom, W.C.A.; Cawood, M.; Verwoerd, Daniel Wynand; Coetzer, Jacobus A.W.
Leukoencephalomalacia (LEM) was induced by the oral administration of fumonisin B₁ (FB₁) to 2 horses: a filly received 59,5mg/kg of a 50% preparation of FB₁ administered in 21 doses of 1,25-4mg/kg over 33 days; a colt, 44,3mg/kg of 95% pure FB₁ in 20 doses of 1-4 mg/kg in 29 days. Both animals developed nervous signs such as apathy, changes in temperament, inco-ordination, walking into objects, and one showed paralysis of the lips and tongue. Characteristic lesions of LEM were present in the brains. These trials proved conclusively that FB₁ can induce LEM in horses.
Epizootology of wildebeest-derived malignant catarrhal fever : possible transmission among cows and their calves in the north-western Transvaal
(Published by the Government Printer, Pretoria., 1990) Barnard, B.J.H.; Verwoerd, Daniel Wynand
The investigation involved 52 cases of wildebeest-derived malignant catarrhal fever in 1986 and 1989 in a herd of cattle kept in camps adjacent to a game farm harbouring a herd of approximately 330 blue wildebeest (Connochaetes taurinus). In the outbreaks, 34 cows and 18 calves died as result of the disease. The exceptionally high incidence of the disease in both cows and their calves, the low incidence in calves of unaffected cows, the relatively short period between the death of cows and their calves as well as the occurrence of the disease in 2 calves born after their mothers had been moved away from wildebeest, are indicative of transmission among cows and calves. The death of at least 6 calves within 6 weeks of birth is ascribed to intra-uterine infection while some calves that survived longer may have acquired the infection from other cattle or from wildebeest.
A survey of annoyance of livestock by Simulium chutteri Lewis along the Orange River, South Africa (Diptera: Simuliidae)
(Published by the Government Printer, Pretoria., 1990) Jordaan, Leonora C.; Van Ark, H.; Verwoerd, Daniel Wynand
A survey by means of questionnaires was conducted along the Orange River to determine the extent of blackfly annoyance to livestock during 1984-1988. Severe annoyance reached peaks during September-November and increased over the years. Annoyance levels decreased with distance from the river with occasional severe annoyance as far away as 76 km. Annoyance levels increased with distance downstream from the P. K. le Roux dam to Augrabies (750 km). Greater water releases for increased irrigation and electricity generation may be an important reason for the higher annoyance levels. Present day high and increasing irrigation water requirements and the great length of the river probably render control by water level fluctuations impractical. Loss of condition of especially small livestock is the main consequence of annoyance by female blackflies. Decreased percentage lambing and occasional deaths were also reported.
On sampling tick populations : the problem of overdispersion
(Published by the Government Printer, Pretoria., 1990) Petney, T.N.; Van Ark, H.; Spickett, Arthur M.; Verwoerd, Daniel Wynand
Data collected on both free-living and parasitic tick populations are likely to be overdispersed. The use of means from few replicate samples of overdispersed data as quantitative estimators of tick population density is in turn likely to lead to inaccurate interpretations which may be scientifically misleading. In this paper ways of estimating overdispersion are listed and suggestions for the use of correct statistical tests for handling overdispersed data are given.
An attempt to improve the immunization of sheep against heartwater by using different combinations of 3 stocks of Cowdria ruminantium
(Published by the Government Printer, Pretoria., 1990) Du Plessis, J.L.; Potgieter, F.T.; Van Gas, L.; Verwoerd, Daniel Wynand
Neither sheep immune to the Ball 3, the Kwanyanga or the Mara stocks of Cowdria ruminantium nor those immunized with combinations of these 3 stocks were protected against challenge with the Mali stock. Against challenge with the Welgevonden stock, however, immunization with each of the 3 combinations and with single stocks effected a protective immunity.
The freeze-drying of Cowdria ruminantium
(Published by the Government Printer, Pretoria., 1990) Du Plessis, J.L.; Van Gas, L.; Labuschagne, F.J.; Wijma, S.; Verwoerd, Daniel Wynand
Lyophilized tissues of mice and blood of sheep, infected with either the Kumm, the Welgevonden or the Ball 3 stock of Cowdria ruminantium, remain infective to mice and sheep after storage at 4ºC for 90 days. Freeze-dried tissues stored at -18 ºC and -28 ºC are still infective after 6 months and 2 years respectively.

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