Veld Research Articles

The effects of the bont tick, Amblyomma hebraeum, on milk production of Sanga and Sanga x Brahman cattle.

The effects of adults on the bont tick, Amblyomma hebraeum on the milk production of Sanga and Sanga x zebu (Brahman) cattle were measured over a period of 11 weeks in the low veld of Zimbabwe in the summer of 1986. Four groups of lactating cows, consisting of two breeds, each divided into a high and low tick treatment, were exposed to very low or high challenges of ticks and their milk production measured by weighing their calves before and after suckling. The liveweight gains (LWG) of the calves were also measured. Tick burdens on the infested groups averaged around fourteen engorging females of A.hebraeum per day, which amounted to infestations of about 150 adult ticks. This is greater than most observed field infestations. This caused no significant reduction in milk yield or calf growth over the whole period, provided the teats of the dams had not been damaged by ticks. Mismothering occurred when teats were damaged. No breed differences were observed so all data was pooled for further analysis. Average calf LWGs of the high tick groups were reduced by 2.2 kg (P < 0.01) during one 4-week period but overall the 3.9 kg difference in LWG of the tick treatment groups was not quite significant (P < 0.10). Although there was a poor relationship between tick numbers and reduced milk yield or calf LWG, the effects were always in the direction expected. The effects averaged 6 +/- 10 g reduction of milk and 2.6 +/- 1.8 g loss of LWG of calves for every female tick that engorged. it was concluded that milk production is not an important consideration when estimating the losses in production caused by A.hebraeum on Brahman x Sanga or Sanga breeds of cattle. Losses due to teat or udder damage could be much more important and need to be quantified.

Synthesis of 14C-labeled levamisole and 13C-labeled tetramisole

The syntheses of 14 C-ring labeled levamisole ([-]-2,3,5,6-tetrahydro-6-phenyl[ 14 C-UL]imidazo[2,1-b]thiazole) from acetophenone-ring-UL- 14 C in 5 steps plus resolution with a 7.5% overall field, and 13 C 6 -ring labeled tetramisole ([±]-2,3,5,6-tetrahydro-6-phenyl[ 13 C 6 ]imidazo[2,1-b]thiazole) from benzene- 13 C 6 in 6 steps with a 9.0% overall veld are described.

Production of plantlets from tissue cultures of Lotononis, a southern African veld legume1

A simple procedure is described for the production of large numbers of rooted plantlets from callus cultures of Lotononis bainesii Baker. Highest frequency of shoots was obtained from somatic embryos formed in initiation cultures on Murashige & Shoog medium plus 1 mg/l benzylaminopurine plus 1 mg/l naphtaleneacetic acid. The somatic embryos from these initiation cultures were transferred to media containing 0, 5, 10 or 20 mg/l isopentenyladenine or 0, 1 of 5, 0 mg/l kinetin (1, 8 to 3, 1 shoots per culture) where they re-callused and produced shoots. All shoots obtained from the cultures on media containing 0, 5, 10 or 20 mg/l isopentenyladenine or 0, 1 mg/l kinetin were rooted; 35% of shoots from the cultures on medium containing 5, 0 mg/l kinetin were rooted. Rooting of unrooted shoots from other treatments was readily induced on medium containing 0, 1 mg/l indoleacetic acid. Keywords: callus cultures; forage legume improvement; legumes; lotononis bainesii; plantlets; procedure; rooting; somatic embryos; tissue culture

Towards objective veld condition assessment

Abstract The derivation of explicit goals and the quantification of the degree of their attainment are essential for purposeful management. Present methods in regard to the grazing use of South African veld may be improved in objectivity, efficiency and generality by resort to methods of multivariate analysis. Meaningful interpretation of the results of field assessment is not possible without a compatible model of the dynamic interaction between plants and herbivores. Such a model includes a zero isocline for proportional species composition of the veld in relation to grazing intensity, and a zero isocline for herbivores in relation to proportional species composition of the veld.

Feed and habitat preferences among some large herbivores on African veld

Abstract Impala and springbok are attracted to disturbed areas, while kudu are adaptable to degraded vegetation. Springbok, impala, nyala, warthogs, blue and white‐tailed gnu prefer short grass, whereas buffalo, zebra and waterbuck prefer taller grass. Blesbok, white‐tailed gnu and sheep are markedly area selective. Blue gnu, zebra, blesbok, sheep, impala, buffalo and white rhinoceri show a decided preference for burnt areas. During winter and dry periods springbok, sheep and white‐tailed gnu include more karoo shrub relative to grass in their diets, and impala more savanna trees and shrubs. The diet often consists of 25 to 80 plant species, but only 10 to 20 are preferred and principal forage species. The literature indicates a large degree of overlap in the browse and graze species selected by different domestic and wild herbivores, as well as in habitat preference and feeding height. Browsers select between plant species as markedly as grazers do. Carrying capacity should be determined for different se...

Progress with vegetation studies in the Sourish Mixed Bushveld of the western Transvaal

The Sourish Mixed Bushveld of the western Transvaal is being studied using the Braun-Blanquet method. The vegetation includes: (a) woodland of cooler sites on crests and steeper south-facing slopes; (b) woodland of warmer sites on gentle north-facing slopes; and (c) grassland and woodland of plains with slight relief on calcareous substrata. Six vegetation types are provisionally described in terms of their main structure, floristic composition (dominant and characteristic species) and habitat. The syntaxonomic relationships between these types are mentioned briefly and the types are considered in terms of Acocks’s classification of South African veld types.

Species-Area Relationship and Plot Size: with Some Examples from South African Vegetation

A short review is given of mainly recent literature dealing with the problem of minimal area and plot size for sampling vegetation. A procedure to determine optimal plot size on the basis of the information content given by different plot sizes is demonstrated on 15 examples from eight different South African veld types.

Book Reviews : The Citizen and the Administration in a Developing Democracy. By SAMUEL J. ELDERS VELD, V. JAGNNADHAM, and A. P. BARNABAS. (Glenview, Illinois: Scott, Foresman and Company, 1968. Pp. 170. Appendix. $6.00.)

Book Reviews : The Citizen and the Administration in a Developing Democracy. By SAMUEL J. ELDERS VELD, V. JAGNNADHAM, and A. P. BARNABAS. (Glenview, Illinois: Scott, Foresman and Company, 1968. Pp. 170. Appendix. $6.00.)

Non‐selective grazing as a means of veld reclamation

Non‐selective grazing as a means of veld reclamation

The Economic Geography of Swaziland

arose once again in the Press concerning the South African Protectorates, and the question of their transfer to the Union. I know little of conditions in either Basutoland or Bechuanaland, but I would like to bring forward some aspects of the geography of Swaziland, in the hope that they may perhaps serve to clarify the issue, at least where this Protectorate is concerned. The territory is about the size of Wales, and since I cannot hope to deal with all the problems, I propose to survey briefly the physical geography and historical development of Swaziland in relation to its economic development. It is this economic aspect which is likely to figure most prominently if and when terms for the transfer of the Protectorate to the Union are drawn up. Swaziland lies about 3 degrees south of the Tropic of Capricorn. On travelling through or flying over the country one is struck by the four welldefined topographical units into which the region falls. These physical divisions are determined mainly by geological structure, and themselves give rise to variations in the natural vegetation. Firstly, in the west the rim of much dissected mountainous country varying from 4000 to 6000 feet above sea-level is known as the high veld. Secondly, east of the high veld there is a perceptible drop into the deep valleys of the broken, rolling middle veld, which lies between 4000 and 1500 feet above the sea. This region is transitional to the third division, the low veld, which stretches eastward, a monotonous practically level plain across which thorn and bush dominate the landscape; this region is sometimes termed the bush veld. This last area varies from 800 to 2ooo feet above sea-level, while its continuity towards the sea is broken by the fourth division, the sheer face of the Lebombo rising abruptly from the bush-clad flats to 2500-3000 feet above the sea and forming a continuous range along the eastern boundary of Swaziland, breached only by the narrow but conspicuous gorges worn by the rivers, practically all of which drain eastward to Delagoa Bay. The rivers differ from most South African rivers in one respect which is of great importance-the main Swaziland rivers are perennial, and only those tributaries which rise within the bush veld dwindle to a string of muddy puddles during the dry season (Map i). From the geological map it appears that most of Swaziland is built of ancient granitic rocks (Map 2). Since very little is known concerning the geology I do not claim that this map is accurate. The mountainous region on the northwest border is a geological unit, and although the old rocks do not all lie within Swaziland, it is convenient to discuss the mountainland as a whole. From the map one can trace the relationship of the Barberton mountainland to the geology of the surrounding areas. It is a fragment of a series of sedimentary strata, presumably Pre-Cambrian in age, surrounded by the Old Granites, which cover immense areas in Southern Africa. The Pre-Cambrian beds reappear in the south of Swaziland. The Barberton mountainland is a most important physiographic element, for it has a marked influence on

Veldt shoes: A South African saying

Veldt shoes: A South African saying

Three new South African Xenopsylla (Siphonapt.)

The examination of a collection of fleas, obtained during the last two years in the course of the investigation of plague amongst the rodents of the South African veld, has resulted in the finding of three new species of Xenopsylla, which are described below.My thanks are again due to Dr. K. Jordan and to Dr. G. A. K. Marshall for advice and help kindly given to me.

THE ZULU: THE GENTLEMAN OF THE AFRICAN VELD1

Journal Article THE ZULU: THE GENTLEMAN OF THE AFRICAN VELD Get access H. M. MEYLER H. M. MEYLER Search for other works by this author on: Oxford Academic Google Scholar African Affairs, Volume XXIV, Issue XCV, April 1925, Pages 202–212, https://doi.org/10.1093/oxfordjournals.afraf.a100131 Published: 01 April 1925

The Aeroplane in African Exploration

IT is often said that the aeroplane might be used for making extensive photographic maps of the lesser-known and unexplored regions of Africa. In spite of the lack of suitable machines and efflcient photo? graphic equipment, our experience during the East African campaign demonstrated the possibility and the difficulties of such work. Also it was proved that for making a first reconnaissance of a district, not previously mapped, the aeroplane carrying a well-trained observer gave better results within an hour than a ground party might do in a week. Air photographs give, by careful study, almost as much general information on the type of vegetation, occurrence of water, game, and human habitation as the explorer could obtain on the ground. Thick scrub, open bush, forest, elephant grass, and swamp are clearly differentiated in a good photograph. To know exactly how far and in what direction a patch of impenetrable bush or forest extended, and the exact whereabouts of the thin patches (if any), is information which would be of incalculable value to a prospecting party. The presence of water is in? dicated in the photograph by certain associations of vegetation, and the concentration of game-paths, which show up like the veins of a leaf, and signs of human habitation are recognized with ease. Almost any type of modern aeroplane with a water-cooled engine of at least 200 h.p. would take one to the requisite height; but during the daytime terrific air pockets or bumps are encountered in tropical Africa up to a height of 6000 feet, ld in cloudy weather higher even than this. To take a series of photographs under such conditions is an impossibility, and we had to do our photography in the early morning or late evening when the air is comparativestill. The light is not too good at this time, how? ever, and with the sun (ow in the sky objects on the ground east long and intensely black shadows. But with a good machine on a cloudless day still air would be reached in all probability at 7000 feet, and operations might be carried out ad day long. To connect two aero-photographs together each must overlap slightly and show at least twe bjects in common. As there are hundreds of square miles of African veldt which contain neither house, path, nor any definite object other than tr< i$ or bushes, it will be recognized what a difficult problem this is. One might take dozens of pictures over the bush or forest