1980 Onderstepoort Journal of Veterinary Research, Volume 47, 1980

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CONTENTS

*Volume 47: Number 1*

A survey of the mosquito and Culicoides faunas at two localities in the Karoo region of South Africa with some observations on Bionomics	Jupp, PG, McIntosh, BM & Nevill, EM	1

The temperature preferences of the motile stages of Stomoxys calcitrans Linnaeus (Diptera : muscidae)	Sutherland, B	7

Aetiology of Jaagsiekte : experimental transmission to lambs by means of cultured cells and cell homogenates	Verwoerd, DW, Tustin, RC & De Villiers, E-M	13

Experimental infection of warthog (Phacochoerus Aethiopicus) with African swine fever virus	Thomson, GR, Gainaru, MD & Van Dellen, AF	19

A description of the immature stages of Kirkioestrus minutus (Rodhain & Bequaert, 1915) (Diptera : oestridae), and the life cycle and seasonal prevalence of this fly in blue wildebeest	Horak, IG, De Vos, V & Boomker, JDF	23

Studies on neonatal calf diarrhoea caused by rotavirus : transmission of the disease and attempted vaccination of colostrum-deprived calves	Theodoridis, A, Prozesky, L & Els, HJ	31

Studies on Haemonchus contortus. III. Titration of Trichostrongylus axei and expulsion of H. contortus	Reinecke, RK, Bruckner, C & De Villiers, IL	35

Research communications:

Antibody to porcine parvovirus in warthog (Phacochoerus aethiopicus)	Thomson, GR & Peenze, I	45

Cerebral mycosis in a dog caused by Cladosporium trichoides Emmons 1952	Newsholme, SJ & Tyrer, MJ	47


*Volume 47: Number 2*

A critical evaluation of the role played by the red-billed oxpecker Buphagus erythrorhynchus in the biological control of ticks	Bezuidenhout, JD & Stutterheim, CJ	51

The control of bacterial contamination in carcass meal with propionic acid	Van Staden, JJ, Van der Made, HN & Jordaan, E	77

Physiological age determination in female Stomoxys calcitrans Linnaeus (Diptera : muscidae)	Sutherland, B	83

Turkey Meningoencephalitis in South Africa	Barnard, BJH, Buys, SB, Du Preez, JH, Greyling, SP & Venter, HJ	89

The haemocytology and histology of the haemopoietic organs of South African freshwater fish. II. Erythrocytes and thrombocytes of Clarias gariepinus and Sarotherodon mossambicus	Boomker, JDF	95

The aetiology of ram epididymitis	Jansen, BC	101

Presence of Herpesvirus ovis DNA sequences in cellular DNA from sheep lungs affected with Jaagsiekte (pulmonary adenomatosis)	De Villiers, E-M & Verwoerd, DW	109

A haemagglutination and haemagglutination inhibition test for bluetongue virus	Van Der Walt, NT	113

Research communications:

Occurrence of Taenia solium in a Cape fur seal (Arctocephalus Pusillus)	De Graaf, AS & Shaughnessy, PD	119

Tissue culture studies on a suspected lysosomal storage disease in Abyssinian cats	Lange, AL	121


*Volume 47: Number 3*

Survival and development of larvae of the common nematodes of ruminants after long-term cryopreservation and investigation of different routes of infestation	Van Wyk, JA & Gerber, HM	129

A field strain of Haemonchus contortus showing slight resistance to rafoxanide	Van Wyk, JA & Gerber, HM	137

Benzimidazole-resistant Haemonchus contortus - the effect of cryopreservation on the resistance of successive generations	Van Wyk, JA & Gerber, HM	143

A technique for the recovery of nematodes from ruminants by migration from gastro-intestinal ingesta gelled in agar : large scale application	Van Wyk, JA & Gerber, HM	147

Studies on the physiopathology of chronic obstructive pulmonary disease in horses. I. Clinical signs	Littlejohn, A & Bowles, F	159

The use of faecal analyses to estimate the phosphorus intake by grazing sheep. I. The use of pool instead of individual samples	Belonje, PC & Van den Berg, A	163

The use of faecal analyses to estimate the phosphorus intake by grazing sheep. II. The repeatability of the technique and the influence of varying the phosphorus intake	Belonje, PC & Van den Berg, A	169

Glucose turnover, tolerance and insulin response in wethers, ewes and pregnant ewes in the fed and fasted state	Vanderwalt, JG, Procos, J & Labuschagne, FJ	173

Plasma progesterone in cattle. I. Development and validity of the assay	Terblanche, HM & Labuschagne, JM	179

Studies on the physiopathology of chronic obstructive pulmonary disease in the horse. II. Right heart haemodynamics	Littlejohn, A	187


*Volume 47: Number 4*

Studies on the physiopathology of chronic obstructive pulmonary disease in the horse. III. The intrathoracic pressure	Littlejohn, A & Bowles, F	193

Determination of the physicochemical and microbiological quality of carcass, bone and blood meal	Van Der Made, HN, Van Staden, JJ, Du Toit, J de V, Jordaan, E, Barrett, EL & Coetzee, JD	197

Laboratory studies on the biology of Simulium nigritarse Coquillett and Simulium adersi Pomeroy (Diptera : simuliidae)	Begemann, GJ	203

Lack of cross-immunity among Pasteurella multocida Type A strains	Cameron, CM, Pienaar, L & Vermeulen, ASM	213

Wesselsbron disease : Virological and serological studies in experimentally infected sheep and goats	Theodoridis, A & Coetzer, JAW	221

Photosensitivity in South Africa. II. The experimental production of the ovine hepatogenous photosensitivity disease geeldikkop (Tribulosis ovis) by the simultaneous ingestion of Tribulus terrestris plants and cultures of Pithomyces chartarum containing the mycotoxin sporidesmin	Kellerman, TS, Van der Westhuizen, GCA, Coetzer, JAW, Roux, C, Marasas, WFO, Minne, JA, Bath, GF & Basson, PA	231

The pathology of bacterial infection of the genitalia in rams	Jansen, BC	263

Lesions resulting from inoculation of porcine foetuses with porcine parvovirus	Prozesky, L, Thomson, GR, Gainaru, MD, Herr, S & Kritzinger, LJ	269

Aetiology of jaagsiekte : Transmission by means of subcellular fractions and evidence for the involvement of a retrovirus	Verwoerd, DW, Williamson, A-L & De Villiers, E-M	275

Research communications:

A surgical technique for the experimental reproduction of epididymitis in rams	Jansen, BC	281

Isolation of anaplasma marginale from Rhipicephalus simus males	Potgieter, FT & Van Rensburg, L	285

Effective immunization of lambs against enterotoxaemia	Cameron, CM	287

Author index		291

Subject index		295

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Now showing 1 - 20 of 43

Effective immunization of lambs against enterotoxaemia
(Pretoria : The Government Printer, 1980) Cameron, Colin McKenzie; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
In contrast to adult sheep, 2- to 3-month-old lambs do not respond well to a single injection of Clostridium perfringens Type D oil adjuvant epsilon toxoid. This unresponsiveness can be overcome, however, by administering 2 injections of oil adjuvant vaccine or one injection of oil adjuvant followed 4 weeks later by an injection of alum-precipitated toxoid. The latter procedure evokes protective antitoxin levels which persist for 8 months, and a booster injection of alum-precipitated toxoid given at this stage results in an immunity which lasts for at least 1 year.
Aetiology of Jaagsiekte : transmission by means of subcellular fractions and evidence for the involvement of a retrovirus
(Pretoria : The Government Printer, 1980) Verwoerd, Daniel Wynand; De Villiers, Ethel-Michele; Tustin, R.C.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
Jaagsiekte (ovine pulmonary adenomatosis) was transmitted to new-born lambs by inoculation of the microsomal fraction of a cytoplasmic extract of cultured tumour cells or tumour tissue. Various treatments of the biologically active fraction were carried out to differentiate between various classes of possible aetiological agents. The results obtained suggested the involvement of a membraneassociated RNA containing virus. Reverse transcriptase activity dependent on Mg++ was subsequently demonstrated in these extracts and in lung exudate, and was shown to be associated with particles banding at a density of 1 , 175 in sucrose gradients. These characteristics, as well as the appearance of the particles in the electron microscope, are similar to those reported for Type B and Type D retroviruses. Serial transmissions of jaagsiekte over a number of years, using cytoplasmic extracts and purified virus, strongly suggest that this virus is the aetiologic agent of jaagsiekte.
Subject index
(Pretoria : The Government Printer, 1980) Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
Lesions resulting from inoculation of porcine foetuses with porcine parvovirus
(Pretoria : The Government Printer, 1980) Prozesky, Leon; Thomson, G.R. (Gavin); Gainaru, M.D.; Herr, S.; Kritzinger, L.J.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
In utero inoculation of 15 sows at various stages of gestation with a local strain of porcine parvovirus (PPV) resulted in resorption, abortion or the birth of weak, dead, or mummified foetuses. Histopathological lesions observed in foetuses of sows slaughtered at various post-inoculation intervals consisted of a perivascular inflammatory reaction primarily observed in the brain and kidneys. The presence and extent of the inflammatory reaction were dependent upon the age of the foetus at the time of infection. In the sow a perivascular inflammatory reaction was found in the endometrium, while the larger blood-vessel walls were infiltrated by lymphocytes, and it is suggested that these vascular lesions may contribute to the reproductive failures associated with PPV.
Author index
(Pretoria : Government Printer, 1980) Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
The pathology of bacterial infection of the genitalia in rams
(Pretoria : The Government Printer, 1980) Jansen, B.C.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
Details are given of the macroscopic and histopathological changes brought about by infection of the genitalia of rams by bacteria other than Brucella ovis. Lesions of the vesiculae seminales and ampullae are described which, in addition to the clinically evident lesions of the testes and epididymices, could be an important reason for impaired fertility. The name "bacterial infection of the genitalia", abbreviated to BIG, is suggested as a more appropriate designation for this condition than "ram epididymitis" .
Isolation of Anaplasma marginale from Rhipicephalus simus males
(Pretoria : The Government Printer, 1980) Potgieter, F.T.; Van Rensburg, L.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
Approximately 100 adult Rhipicephalus simus from a batch known to be infected with Anaplasma marginale were used to infest an ox. Fifty male ticks were manually removed from the animal's ears 9 days after infestation. These ticks were triturated and a stabilate was prepared which was injected intravenously into 2 susceptible oxen. Both these animals became infected with A. marginale. The prepatent periods following inoculation of the tick suspensions before and after freezing in liquid nitrogen were 16 and 17 days respectively.
Photosensitivity in South Africa. II. The experimental production of the ovine hepatogenous photosensitivity disease geeldikkop (Tribulosis ovis) by the simultaneous ingestion of Tribulus terrestris plants and cultures of Pithomyces chartarum containing the mycotoxin sporidesmin
(Pretoria : The Government Printer, 1980) Kellerman, T. Stephanus; Van der Westhuizen, G.C.A.; Coetzer, Jacobus A.W.; Roux, Cecilia; Marasas, Walter F.O. (Walter Friedrich Otto); Minne, J.A.; Basson, P.A.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.; Bath, Gareth F.
The mycoflora of toxic pastures were surveyed during a number of outbreaks of ovine hepatogenous photosensitivity in South Africa. Pure cultures of several isolates were dosed to sheep, but only those of Pithomyces chartarum and Myrothecium verrucaria proved to be toxic. Photosensitization was induced in sheep by dosing them with cultures of a P. chartarum isolate (GAIO) obtained from Tribulus terrestris plants collected during an outbreak of geeldikkop in the Karoo. Thus for the first time a mechanism whereby T. terrestris plants can contribute to the causation of ovine hepatogenous photosensitivity was demonstrated. When cultures of GA10 equivalent to approximately 0, 75-4,0 mg/kg sporidesmin were dosed at Onderstepoort Veterinary Research Institute to Highveld and Karoo sheep on a diet of lucerne, facial eczema was produced. Dosing the same cultures at levels equivalent to c. 1,0 mg/kg of sporidesmin in the Karoo resulted in lesions characteristic of both facial eczema and geeldikkop. Typical hepatic lesions of geeldikkop could be elicited by dosing GAIO at levels equivalent to c. 0,25- 0,7 mg/kg of sporidesmin to Karoo sheep grazing on predominantly T. terrestris pastures in the Karoo. In the latter experiment geeldikkop was induced in the sheep on T. terrestris pastures, while those receiving identical doses on veld with little T. terrestris developed facial aczema. Geeldikkop, therefore, can be brought about by the ingestion of T. terrestris plants together with toxic cultures of P. chartarum. The plant appears not only to act as a vehicle for ingestion of spores, but also to interact with sporidesmin to induce lesions typical of geeldikkop, whereas sporidesmin alone results in facial eczema. Indications are that it can enhance the ability of sporidesmin to cause photosensitivity or, possibly, vice versa. The histopathological findings of these experiments are described in detail.
A surgical technique for the experimental reproduction of epididymitis in rams
(Pretoria : The Government Printer, 1980) Jansen, B.C.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
A surgical technique is described for introducing a bacterial culture into the vas deferens of a ram close to the epididymis in such a manner that the infective material spreads to the lumen of the ductus epididymidis.
Wesselsbron disease : virological and serological studies in experimentally infected sheep and goats
(Pretoria : The Government Printer, 1980) Theodoridis, A.; Coetzer, Jacobus A.W.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
Adult sheep and goats and new-born lambs and kids were experimentally infected with a Wesselsbron disease virus. The viraemia in lambs commenced approximately 27 h after infection and lasted on the average for 50 h. A febrile reaction, which was mostly biphasic, commenced several hours after the viraemia and outlasted it by 50 h. The viraemia in adult animals began about 50 h after infection and lasted for 30 h. The fever usually commenced several hours after the viraemia and, as in 3 cases out of 4 in lambs, it outlasted the viraemia by at least 30 h. The virus could be reisolated in mice from every tissue examined in lambs,although it has previously been shown that pathological lesions are restricted to the liver and lymphatic tissues.
Lack of cross-immunity among Pasteurella multocida Type A strains
(Pretoria : The Government Printer, 1980) Cameron, Colin McKenzie; Pienaar, Lorraine; Vermeulen, Aletta S.M.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
Active and passive protection studies in mice using sheep antisera revealed that the immunological relationship among Pasteurella multocida Type A strains could not be correlated with their serological relationship as determined by a haemagglutination or an agglutination test. Furthermore, strains possessing similar phenol extractable antigens or heat stable antigens did not provide complete cross-protection. The conclusion was reached that immunity to P. multocida Type A strains is induced by an antigen which is strain specific and not detectable by existing serological typing systems. The immunological relationship of strains can therefore not be predicted on the basis of their serological characteristics.
Tissue culture studies on a suspected lysosomal storage disease in Abyssinian cats
(Pretoria : The Government Printer, 1980) Lange, A. Lucia; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
Cell cultures prepared from the spleen and mesenteric lymph nodes of affected kittens were subjected to histochemical and ultrastructural studies. Macrophages in the cultures contained lipid in the cytoplasm and the ultrastructural studies revealed lysosomes containing lamellae similar in appearance to phospholipids.
Studies on the physiopathology of chronic obstructive pulmonary disease in the horse. II. Right heart haemodynamics
(Pretoria : The Government Printer, 1980) Littlejohn, A.; Bowles, Felicity; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
Pressure curves obtained by cardiac catheterization of the pulmonary artery, right ventricle and right atrium of 9 horses and ponies with chronic obstructive pulmonary disease (COPD) were compared with those similarly recorded from 6 clinically normal control subjects. The mean pulmonary peak systolic, pulmonary minimum diastolic and ventricular peak systolic pressures of the COPD subjects were significantly higher (P< 0,01) than the corresponding mean pressures of the clinically normal control subjects. The mean pressures calculated from pressure curves obtained from 8 Thoroughbreds in training did not differ significantly from those of the clinically normal subjects not in training.
Plasma progesterone in cattle. I. Development and validity of the assay
(Published by the Government Printer, Pretoria., 1980) Terblanche, H.M.; Labuschagne, J.M.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Terb; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
The development of a practical competitive protein-binding assay for plasma progesterone in cattle is described. With an intra-assay coefficient of variation of 5,46% and an interassay coefficient of variation of 14,25%, the method is sufficiently accurate and sensitive for practical purposes, and for use in routines and surveys. The statistical level of sensitivity was found to be in the region of 0,25 ng/mℓ. based on the confidence limits of zero dose and 0,25 ng/mℓ, with the practical sensitivity level at 0,50 ng/mℓ. Method and reagent blanks were found to be negligible. The specificity of the assay is based entirely on the partial specificity of the petroleum ether used for the extraction of progesterone (87,5% extraction, n=141).
Glucose turnover, tolerance and insulin response in wethers, ewes and pregnant ewes in the fed and fasted state
(Published by the Government Printer, Pretoria., 1980) Procos, J.; Labuschagne, F.J.; Van der Walt, J.G.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
Glucose turnover parameters were obtained in fed and fasted wethers, ewes and pregnant ewes in their 2nd and 3rd trimesters, using a jugular bolus injection of D-glucose-2-³H. Fasting significantly (P<0,05) reduced glucose turnover (c. 40%) in both the wether and the non-pregnant ewe. A somewhat larger difference (c. 54%) between the fed and fasted ewes was found in their 3rd trimester of pregnancy due to an increase when fed (c. 29% higher turnover than in the non-pregnant ewe) rather than a decrease when fasted, since there was no statistical difference (P< 0, 1) between glucose turnover values of pregnant or non-pregnant fasted ewes. Glucose tolerance was estimated from an intrajugular glucose load (1 g/kg⁰'⁷⁵ body mass) in these 3 groups of sheep under both fed and fasted conditions, and the resulting insulin response was followed for 4 h after the injection. Fasting reduced the plasma clearance rate of glucose by c. 63% in both the wether and the nonpregnant ewe while the reduction was somewhat smaller (c. 51%) during the 2nd trimester of pregnancy. Only the pregnant ewe group showed a corresponding reduction in the resulting insulin response of 46% which was similar in magnitude to the diminished clearance, indicating that factors other than insulin are responsible for the reduced glucose clearance associated with fasting in the weather and non-pregnant ewe. Despite similar baseline plasma glucose values the glucose load appeared to distribute in a space that was significantly less than that found in all 3 groups of fed sheep when trace amounts were injected.
Laboratory studies on the biology of Simulium nigritarse Coquillett and Simulium adersi Pomeroy (Diptera : simuliidae)
(Published by the Government Printer, Pretoria., 1980) Begemann, G.J.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
The eggs of both Simulium nigritarse and S. adersi took up to 13 days to hatch in water at a temperature of 25 °C. The larvae of S. nigritarse required a minimum of 20 days and those of S.adersi a minimum of 17 days to pupate when reared in water at 20± 1 °C. No difference between the sexes was observed in the time taken by the larvae of either species to complete their life cycle. The duration of the pupal stage of S. nigritarse ranged from a minimum of 47 hours at 25 °C to a maximum of 569 hours (23,7 days) at 6 °C. An ambient temperature of 30± 1°C was lethal for both the larvae and the pupae of S. nigritarse. Eclosion of S. nigritarse reaches a peak after sunrise, then the rate declines towards sunset. A mean of 76% of the flies were found to hatch during the day. The time of eclosion of both males and females was similar. Pupation of S. nigritarse could take place at a water-depth of 2m and was common at a depth of 1,1 m. In still water no negative geotropism could be detected in the behaviour of S. nigritarse larvae and they were positively phototropic. In agitated water larvae did not respond to a light gradient ranging from 5 to 1100 lux. Adult larvae became negatively phototropic before the onset of pupation, which took place in dark, fast-flowing water. S. nigritarse can overwinter in both the larval and the pupal stages.
Occurrence of Taenia solium in a Cape fur seal (Arctocephalus pusillus)
(Published by the Government Printer, Pretoria., 1980) De Graaf, A .S.; Shaughnessy, P. D.; McCully, R.M.; Verster, Anna J.M.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
The larval stage of Taenia solium was recovered from the brain, skeletal muscles, heart, lungs and liver of a Cape fur seal collected near Cape Town. This is apparently the second record of the larval stage of this cestode in a marine mammal.
The use of faecal analyses to estimate the phosphorus intake by grazing sheep. II. The repeatability of the technique and the influence of varying the phosphorus intake
(Published by the Government Printer, Pretoria., 1980) Belonje, P.C.; Van den Berg, A.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Steyn, P.J.J.
Analyses of rectal faeces of sheep for phosphorus, calcium and magnesium may be useful to indicate the mineral status of the herbage being consumed. A number of sheep should be used for each pasture, but this would entail a large number of individual analyses. In this experiment it was shown that a pool analysis of faeces did not differ significantly (P < 0,01) from the arithmetic mean of the individual samples (20). In 13 replications this was true for phosphorus, calcium and magnesium, whether the sheep were non-pregnant, non-lactating, pregnant, or lactating. From the results it was estimated that 3 faecal pellets from at least 30 sheep should be used to make the pool. Blood was also taken on 11 occasions for pool and individual (20) analyses. No significant difference was found for plasma inorganic phosphate, magnesium and total protein, but on 3 occasions there was a significant difference (P< 0,01) for plasma calcium.
Determination of the physicochemical and microbiological quality of carcass, bone and blood meal
(Published by the Government Printer, Pretoria., 1980) Van Der Made, H.N.; Van Staden, J.J.; Du Toit, J. de V.; Jordaan, E.; Barrett, E.L.; Coetzee, J.D.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
The pH value and the moisture, fat and protein content of abattoir by products which are commercially available in the Republic of South Africa were examined, and the total bacterial count and the extent of Salmonella, Escherichia coli, Bacillus, yeast and fungus contamination were determined. The extremes and reasonably attainable quality standards were deduced from the highest frequency and mean values of these figures. The total bacterial count was not statistically predictable from variables such as pH, moisture, protein and fat, but was found to be related to the combined effect of all 4 independent variables.
A haemagglutination and a haemagglutination inhibition test for bluetongue virus
(Published by the Government Printer, Pretoria., 1980) Van der Walt, N. T.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.; Steyn, P.J.J.
Haemagglutination of bluetongue virus (BTV) was demonstrated for the first time by making use of a purified preparation of the virus. The reaction was found to be independent of variations in the pH, temperature, buffer system and origin of the erythrocytes used in the test. A haemagglutination inhibition test, subsequently developed, was demonstrated to be serotype specific. The storage of the virus for indefinite periods was facilitated by lyophilization of BTV in the presence of a low concentration of sucrose.

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