1935 Onderstepoort Journal of Veterinary Science and Animal Industry, Volume 5, 1935

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

CONTENTS

*Volume 5: Number 1*

Section I: Protozoal Diseases

The transmission of Spirochaeta theileri to a blesbuck (Damaliscus albifrons)	Neitz, WO	7

Bovine anaplasmosis : the transmission of Anaplasma marginale to a black wildebeest (Conochaetes gnu)	Neitz, WO	9

Section II: Virus Diseases

The transmission of louping ill by ticks (Rhipicephalus appendiculatus)	Alexander, RA & Neitz, WO	15

The blesbuck (Damaliscus albifrons) and the black wildebeest (Conochaetes gnu) as carriers of heartwater	Neitz, WO	35

Section III: Parasitology

On some helminths from the "Nylghiae" Boselaphus tragocamelus (Pall) with observations on the parasitic larval stages of the stomach worm Ashworthius martinagliai sp. n.	Ortlepp, RJ	43

On the metacercaria and adult of Clinostomum van der horsti sp. n., a trematode parasite of fishes and herons	Ortlepp, RJ	51

Section IV: Bacteriology

The lethal dose of the toxins of some anaerobes for sheep	Mason, JH	61

The antigenic components of the toxins of Cl. botulinum types C and D	Mason, JH & Robinson, EM	65

Section V: Plant Studies and Poisonous Plants

Note upon the isolation of the toxic principle from a species of Dimorphotheca, probably Dimorphotheca fruticosa	Steyn, DG & Rimington, C	79

Chemical investigations of the "Gifblaar" Dichapetalum cymosum (Hook) Engl. I	Rimington, C	81

Hydrocyanic acid in grasses	Leemann, AC	97

Section VI: Toxicological Studies

The detection of strychnine in carcasses and corpses	Steyn, DG	139

Section VII: Mineral Metabolism and Nutrition

The effect of supplements of different forms of sulphur to the diet upon the wool of Merino sheep	Van Wyk, CM, Botha, ML & Bekker, JG	177

Studies in mineral metabolism. XXXIII. Iodine in the nutrition of sheep. Second report	Malan, AI, Du Toit, PJ & Groenewald, JW	189

A study of the mineral content and feeding value of natural pastures in the Union of South Africa. Third report	Du Toit, PJ, Malan, AI, Louw, JG, Holzapfel, CR & Roets, G	201

A study of the mineral content and feeding value of natural pastures in the Union of South Africa. IV. The influence of season and frequency of cutting on the yield, persistency and chemical composition of grass species	Du Toit, PJ, Louw, JG & Malan, AI	215

Section VIII: Surgery

The operation of splenectomy in horses, cattle, sheep, goats, pigs, dogs and some South African antelopes : a summary of the results of 98 splenectomies	Quinlan, J, De Kock, G & Marais, IP	273

Section IX: Animal Husbandry

Studies in native animal husbandry 12 : a Wankonde milk pail	Curson, HH	307

Crossbred lambs under Eastern Transvaal conditions	Van Rensburg, CT & Roux, LL	309

The seasonal influence on Merino wool production	Bosman, V	323

Section X: Poultry

The enzymic activity of egg-white. Its bearing on the problem of watery-whites	Van Manen, E & Rimington, C	329

Section XI: Miscellaneous

Anatomical studies no. 58 : Diprosopus tetrophthalmus in a bull calf	Green, WJB	347

Anatomical studies no. 59 : On a false masculine hermaphrodite in an avian hybrid	Viljoen, NF & De Bruin, JH	351


*Volume 5: Number 2*

Section I: Bacteriology

The bloedpens strain of Cl. welchii type B, Wilsdon. (The "Lamb dysentery bacillus")	Mason, JH	363

The production of immunity against Cl. welchii type B, Wilsdon. (The "Lamb dysentery bacillus")	Mason, JH	391

Section II: Parasitology

The chemotherapy of oesophagostomiasis in sheep. II	Monnig, HO	419

Section III: Poisonous Plants

The toxicity of pumpkin seed (Cucurbita pepo L.)	Steyn, DG	441

The occurrence of cyanogenetic glucosides in South African species of Acacia. II. Determination of the chemical constitution of acacipetalin. Its isolation from Acacia stolonifera, Burch	Rimington, C	445

Section IV: Toxicology

The toxicity of trypan blue	Steyn, DG	467

Section V: Mineral Metabolism and Nutrition

The carotene content of some South African feeds	Myburgh, SJ	475

Section VI: Physiology

Studies on the alimentary tract of the Merino sheep in South Africa. II. Investigations on the physiology of deglutition	Monnig, HO & Quin, JI	485

Studies on the alimentary tract of sheep in South Africa. III. The influence of bowel anastomosis on the general nutritional state of Merino sheep	Besselaar, HJ & Quin, JI	501

Section VII: Animal Husbandry

A freak Merino fleece	Bosman, V	517

Wool studies. I. The variation and interdependence of Merino fleece and fibre characteristics	Malan, AP, Van Wyk, CM & Botha, ML	519

Studies in native animal husbandry. 13. A note on the three parent stocks of African cattle	Curson, HH	531

Factors affecting the growth of range cattle in semi-arid regions	Schutte, DJ	535

Section VIII: Miscellaneous

Anatomical studies no. 60 : some comments on the hump of African cattle	Curson, HH & Bisschop, JHR	621

Author index		645

Subject index		647

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Now showing 1 - 20 of 39

The operation of splenectomy in horses, cattle, sheep, goats, pigs, dogs and some South African antelopes : a summary of the results of 98 splenectomies
(Pretoria : Government Printer, 1935) Quinlan, J.; De Kock, G.; Marais, I.P.; Du Toit, P.J.
De Kock and Quinlan published the results of their first series of experiments on splenectomised horses, cattle, sheep, and goats in 1926. Since then observations have been continued and extended to other species of domesticated animals as well as to wild antelopes. The results of the later splenectomies have been published mostly as isolated papers in various subsequent Reports of the Director of Veterinary Services. (De Kock and Quinlan, 1927; de Kock, 1929; du Toit, 1931; Neitz and du Toit, 1932.) HORSES. Of the four horses splenectomised three were immune ''carriers'' of Nuttallia equi and all three showed fatal relapses of Nuttalliosis in from 3 to 8 days after the operation. The fourth animal was a young foal, not a carrier of Nuttalliosis. It was kept under tick-free conditions for four months following the operation when it was killed by injections of haemolytic serum. CATTLE. Five animals were observed by de Kock and Quinlan (1926 report) and their findings may be summarised briefly as follows: (1) Relapses of Theileriosis (Theileria mutans), anaplasmosis, and piroplasmosis (P. bigeminum) occurred in immune "carriers" of these parasites. Piroplasmosis relapses were in these cases particularly severe. (2) These diseases in splenectomised animals assumed a chronic course particularly with regard to the blood changes. A total of 23 bovines were splenectomised of which 20 recovered from the operation. One animal died three days afterwards, and on post mortem no apparent cause of death could be established; one died as a result of haemorrhage and one from surgical shock. Some of the animals were used in East Coast fever transmission experiments and two animals which had recovered from East Coast fever were splenectomised in order to try and break down their immunity (du Toit, 1931). Removal of the spleen was found to have no effect on the course of this disease or on the immunity. Two bovines were splenectomised for further study of the blood changes in anaplasmosis. One animal, No. 4627, infected with the mild A. centrale strain, reacted so severely after splenectomy that it died as the result of the extensive blood changes. Two calves, Nos. 4658 and 4676, susceptible to anaplasmosis and piroplasmosis, were injected with blood from sheep showing Anaplasma ovis and then splenectomised to see whether the Anaplasma ovis would appear in the calves' blood, or whether the calves could become "carriers" of the disease. After the operation, however, both animals became accidentally infected with bovine piroplasmosis and anaplasmosis and sheep sub-inoculated from them showed no reaction. SHEEP. Fifty-four sheep have been splenectomised of which seven died as the direct result of the operation. In one of the latter, namely No. 8462, the attachments of the spleen were loosened and the splenic vessels ligated, but the organ itself left in situ. The most striking result of de Rock and Quinlan's observations on sheep was the discovery of the hitherto unsuspected presence of an anaplasma, A. ovis, and a Theileria, T. recondita (called Gonderia ovis by them) present in the blood of some South African sheep. Anaplasmosis of Sheep. The result of their observations can be briefly summarised as follows: (1) Non-splenectomised susceptible sheep can be infected by means of blood inoculation. The disease then runs a mild course with distinct anaemic changes and the appearance of parasites in the blood in large numbers, but no mortality. (2) In splenectomised "carriers" and splenectomised susceptible sheep the course is much more severe and protracted and there is a fairly high mortality. (3) The disease could not be transmitted to splenectomised or non-splenectomised bovines nor did these animals become carriers of the parasites. (4) Non-splenectomised goats could not be infected but in splenectomised goats parasites appeared in the blood with very slight anaemic changes, and such animals became carriers of the disease. Sheep, splenectomised and non-splenectomised, did not react to bovine anaplasmosis nor did they become carriers of the parasites. Theileriosis of Sheep. De Rock and Quinlan (1927) reported on the occurrence of Theileria (T. recondita, Gonderia ovis) in the blood of some splenectomised sheep. Transmission to non-splenectomised sheep and to bovines failed. The parasites did not produce any symptoms and appeared to be quite harmless. Histological Changes. De Rock (1929) reported on the appearance of haemo-lymphoid-like nodules in the liver of sheep, bovines and a goat killed three years after splenectomy. The nodules varied in size from ¼ in. to 1½ in. in diameter, were dark red in colour, and circumscribed. In some instances a distinct capsule could be recognised, and in others there was no demarcation between this foreign tissue and the liver substance. Lymphoid nodules could be recognised in some of these structures. The haemo-lymphoid-like nodules were not seen in the animals which died or were killed within the first two years following splenectomy. The first indications being found in a sheep which died 33 months after the spleen was removed. From the microscopic appearances de Kock concludes that this newly formed tissue resembles most closely that of haemolymph glands. GOATS. Before splenectomy the two animals were injected with blood from sheep showing anaplasma but no reaction followed nor could anaplasma be demonstrated. Splenectomy failed to produce a relapse as in the case of immune carriers. Subsequent to the operation, however, when reinjected the blood showed the presence of anaplasma with practically no anaemic changes. The histological changes which were found at autopsy on the one goat which died 8½ years later have been mentioned above. CANINES. Seven dogs were successfully splenectomised. One animal showed the presence of microfilaria in the blood three days later and continued to show these parasites until it died from other causes. In no case did piroplasma appear in the blood as the result of removal of the spleen. However, it was only assumed that the animals were carriers of Piroplasma canis as they had been exposed to tick infestation, but there can be no certainty with regard to this. Subsequently three of these dogs were injected with blood from a known carrier of the disease. One of them died from piroplasmosis and two recovered after treatment, but continued to show parasites for several weeks afterwards. Owing to the uncertainty with regard to the previous immunity it is not possible to draw definite conclusions on the effect of the removal of the spleen on canine piroplasmosis. The disease, however, appeared to affect the splenectomised dogs more severely than is experienced in clinical cases of the disease in normal dogs. One of the animals showed a severe haemoglobinuria. Miessner (1931) reports on a few cases of relapses of piroplasmosis following splenectomy in dogs. The experiment will be repeated with known carriers of Piroplasma canis. Four dogs were injected with the virus of African horsesickness after splenectomy but did not show any reaction to the disease. PORCINES. Four pigs were splenectomised and all made uneventful recoveries. No parasites appeared in the blood following the operation. Attempts were made to infect the splenectomised pigs with African horsesickness (two cases) and with ovine blue tongue (two cases) without success. ANTELOPES. Neitz and du Toit (1932) reported on a method of obtaining pure strains of Anaplasma marginale and centrale by transmission through antelopes. The antelopes were injected with blood from bovine carriers of Piroplasma bigeminum, Theileria mutans, and either Anaplasma marginale or A. centrale. In each case only the anaplasma appeared in the blood. These antelopes were then splenectomised in order to exclude the possibility of the other parasites from the donor's blood being present in a latent form. In the cases of the two that survived the operation only the anaplasma reappeared in the blood after splenectomy. Three blesbuck (Damaliscus albifrons) and one grey duiker (Sylvicapra grimmi grimmi L.) were operated on. One blesbuck died soon after the operation and the other two recovered. The duiker seemed to recover completely but interfered with the wound on the eighth day and died as a result. One of the blesbuck, No. 33606, was later injected with the virus of ovine blue tongue and although it showed no reaction it was found to be a carrier on subinoculation of susceptible sheep. Spirochaeta theileri could also be transmitted to the blesbuck. Heartwater. Finally the animal was injected with heartwater from a sheep and died 23 days later of this disease. Rickettsia could be demonstrated and susceptible sheep were infected from it.
Subject index
(Pretoria : Government Printer, 1935) Anonymous; Du Toit, P.J.
Author index
(Pretoria : Government Printer, 1935) Anonymous; Du Toit, P.J.
Anatomical studies no. 60 : some comments on the hump of African cattle
(Pretoria : Government Printer, 1935) Curson, H.H.; Bisschop, J.H.R.; Du Toit, P.J.
The result of this study suggests that humps may be classified: (a) According to situation – cervico-thoracic and thoracic. (b) According to structure – muscular and musculo-fatty. (c) According to function – traction (locomotion) and storage of reserve fat. It is interesting that some cattle have humps and others not. The similarity of the humps of the Afrikander and Sanga types, being cervico-thoracic and muscular is noteworthy in view of Epstein's theory that the latter is derived from the intermixture of the Longhorned Zebu and Hamitic Longhorn. The dissimilarity between the above humps and that of the Shorthorned Zebu is striking. As just stated little is known regarding the significance of the hump from an evolutionary point of view.
Factors affecting the growth of range cattle in semi-arid regions
(Pretoria : Government Printer, 1935) Schutte, D.J.; Du Toit, P.J.
Data are presented on the growth of range cattle over a period of four years in a semi-arid region of South Africa. A total of 176 half-bred animals of five different breeds are included in this study. The data consist of live weights taken at bi-monthly intervals of all animals, and linear body measurements taken at bi-monthly intervals for a period of 28 months for three different age groups. Growth in weight is strictly seasonal from weaning to maturity. These seasonal fluctuations are shown to be closely allied to monthly rainfall. The bulk of the annual precipitation occurs from November to February and the period of greatest relative growth in weight lags approximately three months behind the period of heaviest precipitation. The greatest increase in body weight occurs from January to March and the periods of smallest increase or greatest loss in weight occur from July to September. Body measurements are also influenced by seasonal changes but to a lesser extent than body weight. The following measurements are least affected: height at withers, height over hips, body length, depth of chest and depth of flank. The measurements markedly influenced by season of the year are length of pelvis, width at hooks, width at thurls, width of loin and width of chest. Significant differences between the sexes exist from birth, males being heavier than females. Sex differences in body measurements are not so marked, especially in the earlier age groups. When maturity is approached the steers exceed the heifers to a marked degree in all body measurements except those of the pelvic region. The breeds may be divided into two classes in respect to weight and size, Herefords and Sussex comprising one class and Aberdeen-Angus and Afrikander constituting another. The animals of the first class exceed those of the second class in weight and most body measurements. The Shorthorns occupy an intermediate position and the peculiar behaviour of this breed is discussed. The Afrikanders proved to have greater wither height and hip height than all other breeds. The relative importance of genetic and environmental factors on the growth of the animals is discussed. It is shown that the variance in height at withers in this population is approximately three-fourths genetic and one-fourth environmental in origin. In width at thurls and width at hooks more than 60 per cent of the variance is genetic. The variance in body length and live weight is accounted for equally by genetic and environmental factors. In all chest measurements the variance appear to be only slightly hereditary. It is shown that the factor of nutrition plays a very important role in the growth of range cattle under the conditions of this experiment. It is not possible to determine from this study whether permanent stunting results from inadequate nutrition but it is concluded that growth is retarded and maturity delayed.
Studies on the alimentary tract of the Merino sheep in South Africa. II. Investigations on the physiology of deglutition
(Pretoria : Government Printer, 1935) Monnig, H.O.; Quin, J.I.; Du Toit, P.J.
(1) A solution of copper sulphate stimulates reflex closure of the oesophageal groove in sheep so that drugs subsequently administered will pass into the abomasum. (2) Preliminary starvation has no favourable influence, unless the sheep are starved for such a long period that the ruminal contents become fluid, in which case the latter condition is favourable. Starvation is, however, contra-indicated for reasons which are discussed. (3) The method of administration and the position in which the animal is held are of no importance. (4) The reflex is established immediately after the stimulant touches the mucosa of the pharynx. (5) The groove remains closed for 15 seconds, sometimes longer, after stimulation. (6) Other conditions being favourable, the stimulus can definitely be produced by a 0.25 per cent. copper sulphate solution. Unfavourable factors are advanced age, poor condition and dryness of ruminal contents. It is shown that a 10 per cent. solution is necessary to overcome the counteracting effects of these adverse factors. (7) It has not been definitely proved whether acidity of the ruminal contents is an unfavourable condition, but there are indications that this is not the case. (8) Copper salts other than the sulphate produce the reflex, but it has not been definitely proved that the stimulus may not be due to astringency of the stimulant. (9) There are indications that the related metals zinc and silver may also produce the reflex. (10) Various drugs administered after the stimulant did not reverse the reflex. Small pills may be swallowed into the abomasum after stimulation but larger objects (small capsules) are not. (11) Preliminary tests indicate that a drug administered into the abomasum may reach the colon in about five hours and that it may be passed in the faeces from about the 15th hour. (12) Since the abomasal mucosa is very tender, care must be exercised in administering drugs in the way indicated.
The chemotherapy of oesophagostomiasis in sheep. II
(Pretoria : Government Printer, 1935) Monnig, H.O.; Du Toit, P.J.
1. Chemotherapy for oesophagostomiasis must be based on the administration of the remedy into the abomasum. At first a 1 per cent. copper sulphate solution was used for stimulation of the oesophageal reflex, then higher concentrations until finally satisfactory results were obtained with 2.5 c.c. of a 10 per cent. solution. 2. Preliminary tests were made with 15 different chemicals which had either previously given indications that they may be effective, or appeared, according to their chemical and physical properties, to be suitable. Of these copper arsenate and copper tartrate gave rather outstanding results. 3. Both these drugs were found to be dangerous in doses which would be large enough to effect a cure. An overdose of copper arsenate leads to arsenical poisoning while an overdose of copper tartrate leads to copper poisoning. 4. A mixture of the two drugs produced variable results which were found to be connected with the variable amount of acid in the abomasum. Since the drugs are relatively soluble in acid and alkaline media, high stomach acidity would cause solution and absorption of the drugs with consequent poisoning of the sheep and little or no effect against the parasites. Calcium hydroxide was found to be a suitable corrective and was incorporated in the mixture. Effective doses of this mixture were found to possess a suitable degree of safety even if treatment is repeated at relatively short intervals. 5. Taking into account all ages and conditions of sheep, the efficacy of one treatment, i.e. a dose on each of two successive days, is expected to reach at least 75 per cent. If only young sheep under 2 years of age are treated the efficacy will be considerably higher. 6. It has incidentally been observed that the mixture has a fair degree of efficacy against Haemonchus contortus and Moniezia expansa. 7. Measures for treatment and prevention of oesophagostomiasis by means of a suitable remedy under South African conditions are outlined.
The enzymic activity of egg-white. Its bearing on the problem of watery-whites
(Pretoria : Government Printer, 1935) Van Manen, E.; Rimington, C.; Du Toit, P.J.
1. The enzymic activity of solutions of thick and thin albumen from normal and watery-white eggs has been studied, using a micro-titration method determining peptide cleavage in terms of the increase in amino nitrogen. 2. Thick or thin albumen alone at pH values ranging from 5.5 to 8.5 suffer no autolysis at 37°, neither can any protein-splitting enzyme be detected at any pH by the addition of gelatin as substrate. 3. The work of Balls and Swenson is criticised on account of insufficient sensitivity of the method employed and the fact that it is such as would fail to distinguish between an increase in acid groups due to lipolytic and due to proteolytic activity. Moreover, the use of casein as a substrate is incapable of differentiating protease from ereptase activity. 4. The presence in egg white of at least two erepsin-like enzymes having different pH optima (approximately 5.5 and 7.0-8.0) has been demonstrated. Whether or not these enzymes play any part in the development of “watery-white” is uncertain but for reasons discussed it would seem unlikely. Some observations upon “watery-white” in eggs are recorded and the problem subjected to a short discussion.
A study of the mineral content and feeding value of natural pastures in the Union of South Africa. IV. The influence of season and frequency of cutting on the yield, persistency and chemical composition of grass species
(Pretoria : Government Printer, 1935) Du Toit, P.J.; Louw, J.G.; Malan, A.I.; Du Toit, P.J.
The investigation which has been dealt with in this paper is a continuation of earlier work carried out in 1932 on species of grasses grown on separate plots and exposed to the same climatic conditions while being subjected to the following system of cutting: A portion of each plot was cut at monthly intervals, another portion of the plot was cut at two-monthly intervals, a third portion at three-monthly intervals, and so on, up to twelve months, when a sample of twelve months’ growth was taken off each plot. The grass resulting from each cutting was weighed when air-dry and sampled for analytical purposes. The constituents determined were crude protein, crude fibre, phosphorus, calcium, potassium, magnesium, sodium, and chlorine, while the determination of soluble or silica-free ash was included towards the end of the investigation. Detailed data relating to all the cuts obtained from individual species from February, 1933, to February, 1934, are tabulated in an appendix. Average values for all the species combined have been chosen as a basis for discussion. (1) Grasses cut at monthly intervals are highest in percentage phosphorus and crude protein and lowest in percentage crude fibre. With decreased frequency of cutting the crude fibre content rises to a maximum at maturity, while the phosphorus and crude protein contents drop markedly to minima in the old mature herbage cut prior to the commencement of new growth in the following season. (2) The different frequencies of cutting do not appreciably influence the lime and magnesia contents of the herbage. (3) Pure species grown on the same soil and exposed to the same climatic conditions show appreciable differences in mineral and protein content when harvested after definite intervals, e.g. one month. (4) Fluctuations in the chemical composition of species cut at, say, monthly intervals during the growing season are indicated. These variations are attributed mainly to the stage of growth attained by the species and to the rainfall in so far as it influences the stage of growth. (5) Rainfall is the most important factor governing the yield from monthly cuts. (6) During dry seasons the phosphorus content of herbage cut at monthly intervals tends to be low. At the same time the percentage lime is high. The crude protein content does not appear to be adversely affected by drought. (7) The percentage of mineral constituents and crude protein are low and crude fibre high during seasons of plentiful rain. (8) Cutting at monthly intervals impairs the persistency of most species, Pennisetum ciliare and Cynodon dactylon being the only grasses not visibly affected by the severe treatment. (9) The highest yield of dry matter is obtained from pasture species by cutting at two-monthly intervals during the growing season. The evidence suggests that while the yield from fewer cuts or a single harvest may not be much smaller the herbage will definitely be of lower nutritive value. (10) The aggregate production of crude protein and phosphate is highest by cutting at two-monthly intervals. (11) The difference in nutritive value between herbage cut at monthly and two-monthly intervals becomes insignificant during seasons of dry weather conditions. (12) The date on which a system of cutting is initiated is found to exercise a determining influence on the productiveness of herbage plants in the course of the growing season. The production of dry matter seems to be depressed by a first cut during the period when active growth commences. (13) The practical suggestion which is a corollary to this investigation is that an attempt should be made to prevent natural pastures from growing undisturbed during the entire season if economic utilization of such pasture is to be made. Provided the effects of periodic cutting are at all comparable with grazing by animals this object appears to be attainable by following a system of management in which the pasture is grazed down at least once every two months during the active growing season depending, of course, on the prevailing climatic conditions and the botanical composition of the pasture.
A study of the mineral content and feeding value of natural pastures in the Union of South Africa. Third report
(Pretoria : Government Printer, 1935) Du Toit, P.J.; Malan, A.I.; Louw, J.G.; Holzapfel, C.R.; Roets, G.; Du Toit, P.J.
1. The third report of the series on the mineral content and feeding value of South African natural pastures is presented. 2. Both pasture and blood analysis confirm the earlier statement that practically all South African pastures are low in phosphorus for the greater part of the year. 3. Crude protein varies more or less directly as the phosphorus content of the pasture and is extraordinarily low during certain seasons of the year. 4. Generally, the sodium content of the samples is so low that it suggests an insufficiency of sodium for producing animals on pasturage. 5. The samples analysed were representative of the herbage in the areas of collection and not necessarily of the pasture actually eaten by stock as will be the case with all samples collected subsequently and to be reported on in due course.
Studies in mineral metabolism. XXXIII. Iodine in the nutrition of sheep. Second report
(Pretoria : Government Printer, 1935) Malan, A.I.; Du Toit, P.J.; Groenewald, J.W.; Du Toit, P.J.
1. Data are presented on the effect of KI in the feed of 40 merino ewes for a period of 30 months. 2. The quantities of KI given per sheep daily were 0.002 grm., 0.02 grm., 0.06 grm. in three groups respectively, while one group received no KI and acted as controls. 3. Observations were made on the food consumption, weight increase, wool production, reproduction and health of the animals for the full period of the experiment. Further, observations were made on the oestrus cycle of the ewes and no significant group differences were observed. 4. The animals were fed in individual feeding boxes except the hay, which was given ad lib. 5. It is concluded that neither the small dose nor the bigger quantities of KI fed had any visible effect on the weights, wool production and reproduction of the animals. 6. It is also pointed out that the ill effects ascribed to iodide feeding in the earlier work were apparently aggravated by another deficiency, the possibility of the existence of which was not considered in the earlier work, viz. vitamin A. 7. It is concluded that the addition of KI to sheep licks is unwarranted, may even produce visibly detrimental effects under conditions of drought, when a vitamin A shortage may exist, and is to be discouraged in practical farming unless there is reason for believing that an iodine deficiency exists. 8. Further work on the effects of iodine feeding under practical conditions, as for instance during severe droughts when apparently detrimental effects may be experienced, is being undertaken. The writers wish to acknowledge gratefully the assistance of Mr. A. P. Malan, Statistician, in dealing with the results given in the lambing charts.
The detection of strychnine in carcasses and corpses
(Pretoria : Government Printer, 1935) Steyn, D.G.; Du Toit, P.J.
(1) In order to express a definite opinion as to the presence or absence of strychnine in purified extracts of specimens of organs, etc., it is essential that the following tests be conducted: (a) taste test, (b) colour test, and (c) a biological test. Immature white mice are for various reasons more suited to the biological test than frogs, (Rana esculenta, Rana pipiens, Rana palustris, Rana aqualensis). It is definite that very unreliable and inaccurate results will be obtained if both the colour and biological tests for strychnine are not applied to extracts as a large number of chemical substances, including ptomaines, are known which yield positive results either with the colour test, or with the biological test for strychnine. Many of these substances also have a bitter taste. The greatest care should be exercised in expressing an opinion as to the presence of strychnine in decomposed carcasses and corpses. The author isolated a strychnine-like ptomaine(s) from a decomposed liver, which was known not to contain any strychnine. This ptomaine(s) had a bitter taste and gave a positive sulphuric acid-potassium bichromate test for strychnine. The results of taste, chemical and biological tests with unidentified and identified ptomaines are recorded. (2) If three weeks old white mice are used in the biological test at least 0.008 mgm. strychnine sulphate is required in order to produce recognisable strychnine spasms in a mouse weighing 10 to 12 gm. With 14 day old white mice weighing 5 to 6 gm. 0.004 mgm. strychnine sulphate is detectable. In order to achieve reliable results in the detection of strychnine in purified extracts of organs, etc., at least 0.011 mgm. strychnine sulphate should be present as approximately 0.007 mgm. is required for the Otto test and 0.004 mgm. For the biological test if this is conducted upon 14-day old white mice weighing from 5 to 6 gm. If three-weeks-old white mice are employed the least amount of strychnine detectable in extracts is 0.015 mgm. if both the Otto and biological tests are conducted. (3) The symptoms of strychnine poisoning in white mice and in the frog (Rana aqualensis) are described. (4) The taste test and chemical and biological tests for strychnine are discussed. (5) Factors responsible for the disappearance of strychnine from corpses and carcasses are discussed. Of four dogs killed with strychnine and exhumed ten weeks after death strychnine was detectable in three carcasses, whilst of four carcasses exhumed eighteen weeks after death only one was positive for strychnine. Eleven months after death eight carcasses of dogs killed with strychnine were exhumed and strychnine was detectable in only four of these. Subsequent exhumations of carcasses of dogs killed with strychnine and of control dogs are to be conducted. (6) Methods of extracting strychnine from carcasses and corpses and of purifying these extracts are discussed. (7) In fresh carcasses and corpses the most suitable organs for analysis for the presence of strychnine are liver, stomach, spleen, lung and the central nervous system; also the urine. (8) In two out of three dogs, which had received strychnine as a tonic, strychnine was detectable in the liver and stomach (plus contents). (9) A large number of chemical substances, which resemble strychnine chemically and biologically, are discussed.
Chemical investigations of the "Gifblaar" Dichapetalum cymosum (Hook) Engl. I
(Pretoria : Government Printer, 1935) Rimington, C.; Du Toit, P.J.
Although the investigations recorded in this paper have not resulted in the isolation of the toxic principle of the Gifblaar, Dichapetalum cymosum in a state of chemical purity, it is felt that certain valuable information has been obtained relative to the nature of this toxin. In addition, some interesting substances have been isolated from the plant in the course of chemical manipulations. These include: (1) A catechol tannin. (2) A yellow colouring matter, shown to be a methylpentoside, yielding rhamnose on hydrolysis. (3) A histidine-like base. (4) A base probably identical with choline. (5) The alkaloid trigonelline, the methyl-betaine of nicotinic acid. Various specialised methods were tried for the purification of the toxin, including: (1) Dialysis. (2) Ultrafiltration under pressures up to 80 atmospheres of nitrogen. (3) High-vacuum distillation and sublimation. (4) Continuous extraction with butyl alcohol, etc. Certain other chemical operations led to the conclusion that the following groups are definitely absent from the toxin molecule: Carboxyl –COOH; Ketonic >CO; Aldehyde –CHO; Hydroxyl –OH; Amino –NH₂; Imino >NH. The active principle almost certainly contains nitrogen and it is suggested that this may be included in some cyclic structure. It may possibly occur as in tertiary bases but the molecule, as a whole, does not evince basic characters. Preparations, still highly toxic to rabbits, have been prepared containing no protein, amino-acid, or carbohydrate material, impurities which had not before been successfully removed. The chemical stability or inertness of the toxic substance is very remarkable in view of its pronounced physiological action. Thus, it resists boiling for one hour with 1 per cent. sulphuric acid or 1 per cent. sodium hydroxide solutions; it is not oxidised by potassium permanganate or by hydrogen peroxide in the cold and it is thermostable. In view of this stability and the absence of any substance known to combine with or precipitate the toxin, the hope of finding any specific prophylactic or curative substance for use in Gifblaar poisoning becomes very remote indeed.
The lethal dose of the toxins of some anaerobes for sheep
(Pretoria : Government Printer, 1935) Mason, J.H.; Du Toit, P.J.
The lethal dose of the toxins of four anaerobes has been ascertained in mice, sheep, and in two instances in guinea-pigs also. The mouse : kilogram-body-weight-sheep ratio is as follows: Cl. septique 1:17.5, Cl. welchii, Type B 1:60, Cl. welchii, Type D 1:12.5 and Cl. oedematiens 1:100. The last ratio was arrived at by the use of only six sheep and is thus approximate.
On the metacercaria and adult of Clinostomum van der horsti sp. n., a trematode parasite of fishes and herons
(Pretoria : Government Printer, 1935) Ortlepp, R.J.; Du Toit, P.J.
From the above description it will be noted that the morphology is very similar to that of C. lophophallum Baer, 1933; it, however, differs from this species in that a pharynx is absent and the intestinal caeca open to the exterior through the excretory pore. These two characters together are of sufficient importance to separate this species from all the known species of this genus, and the writer has great pleasure in naming it after the donor through whose interest and kind service the material was made available for study.
The transmission of Spirochaeta theileri to a blesbuck (Damaliscus albifrons)
(Pretoria : Government Printer, 1935) Neitz, W.O.; Du Toit, P.J.
It was possible to infect the blesbuck with Spirochaeta theileri from cattle.
Studies in native animal husbandry. 13. A note on the three parent stocks of African cattle
(Pretoria : Government Printer, 1935) Curson, H.H.; Du Toit, P.J.
Hamitic Longhorn stock, Brachyceros stock and Longhorned Zebu stock are discussed.
Wool studies. I. The variation and interdependence of Merino fleece and fibre characteristics
(Pretoria : Government Printer, 1935) Malan, A.P.; Van Wyk, C.M.; Botha, M.L.; Du Toit, P.J.
1. A statistical analysis is given of the fleece and certain fibre attributes of a shoulder sample of a group of wethers sent from Grootfontein to Onderstepoort for experimental purposes. The data comprise values obtained for three successive years. 2. It is shown that a considerable decrease occurred in the mean values from the first to the second year, and then again an increase to mean values exceeding those existing in the first year. The nature of the change in fibre thickness is given in more detail. 3. The values obtained for each characteristic in the different years are highly correlated, from which fact is deduced the importance of a pre-experimental period. 4. The correlation coefficients between the fleece weight and the fibre attributes are, though significant, not very high, and. the shoulder sample is, therefore, a poor indication of the total amount of wool produced. 5. The ratios of the standard deviations to the corresponding mean values of the group were constant for the three years. 6. Within a shoulder sample a high correlation exists between the coefficients of variability of fibre length for two years, and also between the coefficients of variability of fibre length and fibre thickness for the same year. 7. The interrelationships of the changes in the various attributes are given. 8. The bearing of the above results on experiments in which wool is being investigated, is discussed.
The carotene content of some South African feeds
(Pretoria : Government Printer, 1935) Myburgh, S.J.; Du Toit, P.J.
1.Details are given of the method employed at this Institute for the determination of Carotene in some animal foodstuffs. 2. The Carotene content of pasture diminishes rapidly as the pasture matures and becomes dry during winter or during dry periods of drought. 3. The Carotene content of the Cereals included in the determinations is low, yellow maize being the highest and the sample in question containing 0·74 mgms. Carotene per 100 gms. dry material. 4. The existence of an A-avitaminosis in stock entirely dependent on natural pastures during periods, when only dry pasture exists, is discussed.
The occurrence of cyanogenetic glucosides in South African species of Acacia. II. Determination of the chemical constitution of acacipetalin. Its isolation from Acacia stolonifera, Burch
(Pretoria : Government Printer, 1935) Rimington, Claude; Du Toit, P.J.
1. The cyanogenetic glucoside Acacipetalin has been isolated by an improved method from Acacia stolonifera Burch. 2. Tetra-acetylacacipetalin has been prepared. 3. Pinit, inositol monomethyl ether, has been identified as a constituent of Acacia stolonifera. 4. The constitution of Acacipetalin has been elucidated. It is the glucose ether of dimethylketenecyanhydrin. 5. The facts upon which this conclusion is based are recorded and include the identification of the following breakdown products of the glucoside. On enzymic hydrolysis, hydrogen cyanide, glucose, acetone and acidic substances. On acid hydrolysis, hydrogen cyanide, glucose and isobutyric acid. After alkaline followed by acid hydrolysis, ammonia, glucose and isobutyrylformic acid, isolated as the 2:4 dinitrophenylhydrazone. This latter substance was prepared synthetically and found to have M.P. 190°. The 2:4 dinitrophenylhydrazone of isobutylideneacetone crystallises in orange-red prisms and melts at 163-5⁰. 6. Catalytic hydrogenation using colloidal palladium as catalyst leads to deep-seated changes in the glucoside. Among the reaction products were detected acetone, glucose and amino substances. 7. A comparison with other glucosides containing unsaturated aglycones is made and a suggestion put forward as to the possible mode of origin of Acacipetalin in the plant.

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