The disease of road accidents

No Abstrac

Shaft Mucker Design

The mucking principle employed in the design of this mucking machine is that of a continuous operation instead of an intermittent one. The mucker was primarily designed for operation in shafts (vertical or inclined) and winzes but the mucker is not restricted to these

A study of the mineral content and feeding value of natural pastures in the Union of South Africa (Final report)

(1) The chemical composition of grass pastures differs in many respects considerably from that of bush pastures. Especially is this the case in connection with the changes to which the composition of pastures are subject with changing meteorological conditions from January to December. (2) Hush pastures are on the whole richer in all the constituents determined than are grass pastures. Another distinguishing feature in the two veld types is the difference in chemical composition between winter and summer pasturage: whereas the former type shows only minor fluctuations in the course of the year, the difference in the percentage contents of certain constituents during winter and summer are considerable in the case of grass pastures. (3) Qualitative differences in the pastures of specific regions within any one of the two main veld types are also encountered. (4) Expressed as percentages of the dry matter the phosphorus content of grass pastures is 0.12-0.17 during summer and 0.05-0.07 during winter. In the pastures composed mainly of bushes this constituent varies between 0.11 and 0.20 per cent. Crude protein values of the grass pastures fall from 7.0-9.0 per cent. in summer to 3.3-4.0 per cent. in winter, while the percentage of this constituent in those pastures composed mainly or wholly of bushes varies between 7.0 and 10.0 in the course of the year. (5) Calcium and magnesium values show only minor seasonal variations. Differences in the percentage contents of these constituents are, however, appreciable in the pastures of one region as against those of another. Expressed as an annual mean the variation in the calcium and magnesium contents of grass pastures in different regions are 0.25-0.48 per cent. and 0.12-0.21 per cent., respectively. Similarly, the calcium and magnesium averages for bush pastures are 0.60-1.05 per cent. and 0.21-0.37 per cent., respectively, depending on the region. (6) Maximum potassium and chlorine values occurring during summer in the grass pastures are 1.32-2.31 per cent. and 0.32-0.59 per cent., respectively. During winter the former constituent varies between 0.29 and 0.63 per cent. and the latter between 0.06 and 0.22 per cent. in the grass pastures of different regions. Sodium average figures fall from a maximum of 0.08 per cent. to a minimum of only 0. 0 per cent. in some grass pastures while in others these values vary between 0.10 and 0.25 per cent. in the course of the year. (7) The percentage potassium remains comparatively high throughout the year in most bush pastures. Values seldom are below 1.00 per cent., while most figures fluctuate between 1.40 and 2.00 per cent. Sodium and chlorine averages are exceptionally high in some of the pastures composed mainly of bushes. Thus, for the greater part of the year figures for sodium are 1.00-1.86 per cent., and chlorine values exceed 0.70 per cent. (8) Crude fibre averages are lowest in pasture at the younger stages of growth, the mean annual variation is 3.6-37.2 per cent. for grass pastures and 32.0-35.0 per cent. for bush pastures. (9) Calcium-phosphorus ratios ranging from 2.00:1 to 11.60:1 occur in the dry matter of South African pastures. (10) Judged by the estimated requirements of cattle and sheep for growth all South African natural pastures, composed mainly or wholly of grasses are deficient in phosphorus, crude protein and, in certain areas, sodium for a period ranging from five to nine months of the year, depending on the area. There are indications that in certain of these regions the pasture may be deficient in phosphorus throughout the year. Furthermore, on the basis of the average values for phosphorus these grass pastures contain at no time of the year sufficient of this nutrient to provide in the requirement for an additional function (e.g., gestation or lactation) of the animal, superimposed on growth. (11) Provided sufficient food is available an intake of phosphorus, crude protein or sodium below the optimum requirements for growth will seldom occur on pastures composed mainly of bushes. (12) The requirements of calcium, magnesium and potassium for growth and moderate milk production will at all times be met by the amounts of these constituents present in South African pastures. Especially is the danger of a potassium and magnesium deficiency extremely remote. (13) The pastures of the Union are at no time deficient in chlorine. A cow producing two gallons of milk may, however, not ingest sufficient of this constituent on the winter pastures of some of the grassland regions.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

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

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.The articles have been scanned in colour with a HP Scanjet 5590;300dpi. adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

A study on the possibility of cystine synthesis in the rumen of sheep together with the effect of cystine supplementation on the nitrogen utilization of lucerne in young stock

By means of metabolism experiments on rats it was shown that the biological value of the rumen ingesta is better than that of lucerne. When rumen ingesta are supplemented by cystine their biological value is significantly enhanced. In sheep experiments it was shown that the inclusion of cystine in a lucerne ration for mature sheep did not influence the biological value of the latter. For growing sheep the supplementation of lucerne by cystine increased its biological value by 10 per cent. It is concluded that the action of the micro-organisms is purely a question of interception, that is, utilizing exogenous protein for its own use and supplying it back to the animal in the bacterial and infusorial form.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

A study of the mineral content and feeding value of natural pastures in the Union of South Africa. Third report

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.The articles have been scanned in colour with a HP Scanjet 5590;300dpi. adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Phenology and reproductive biology of Acacia karroo Hayne (Leguminosae : Mimosoideae)

The architectural development of Acacia karroo conforms to Troll’s model. Growth of the branches is modular and sympodial with heteroblastic leaves on all long shoots of the tree, including the seedling. Axillary buds tend to proliferate especially on flowering shoots where they form fascicles consisting of up to 10 inflorescences arranged in two parallel serial rows per leaf axil. Most axillary buds are sylleptic and basal buds which give rise to short shoots, each producing two to five cataphylls each season, but no flowers. Inflorescences are only produced on long shoots (modules) of the current season. After flowering the terminal part of the module aborts, trees are usually andromonoecious with capitate inflorescences containing 40 to 100 flowers each, with some male and some hermaphrodite. Some trees produce only male flowers. Anthesis in the same inflorescence, the same tree as well as amongst trees of the same community are synchronised and occur at intermittent intervals, each lasting three or more days at a time. Flowers are protogynous and pollen is produced in polyads, each consisting of 16 pollen grains. Ovaries contain 10 to 14 ovules each. The concave stigma has space for only one polyad which can fertilise all ovules in the ovary after a single pollination event. Fruit set is low with 0 to 10 fruits (pods) per inflorescence.http://www.scirp.org/journal/ajpshb201

A study of the mineral content and feeding value of natural pastures in the Union of South Africa (Final report)

(1) The chemical composition of grass pastures differs in many respects considerably from that of bush pastures. Especially is this the case in connection with the changes to which the composition of pastures are subject with changing meteorological conditions from January to December. (2) Bush pastures are on the whole richer in all the constituents determined than are grass pastures. Another distinguishing feature in the two veld types is the difference in chemical composition between winter and summer pasturage: whereas the former type shows only minor fluctuations in the course of the year, the difference in the percentage contents of certain constituents during winter and summer are considerable in the case of grass pastures. (3) Qualitative differences in the pastures of specific regions within any one of the two main veld types are also encountered. (4) Expressed as percentages of the dry matter the phosphorus content of grass pastures is 0.12-0.17 during summer and 0.05-0.07 during winter. In the pastures composed mainly of bushes this constituent varies between 0.11 and 0.20 per cent. Crude protein values of the grass pastures fall from 7.0-9.0 per cent. in summer to 3.3-4.0 per cent. in winter, while the percentage of this constituent in those pastures composed mainly or wholly of bushes varies between 7.0 and 10.0 in the course of the year. (5) Calcium and magnesium values show only minor seasonal variations. Differences in the percentage contents of these constituents are, however, appreciable in the pastures of one region as against those of another. Expressed as an annual mean the variation in the calcium and magnesium contents of grass pastures in different regions are 0.25-0.48 per cent. and 0.12-0.21 per cent., respectively. Similarly, the calcium and magnesium averages for bush pastures are 0.60-1.05 per cent. and 0.21-0.37 per cent., respectively, depending on the region. (6) Maximum potassium and chlorine values occurring during summer in the grass pastures are 1.32-2.31 per cent. and 0.32-0.59 per cent., respectively. During winter the former constituent varies between 0.29 and 0.63 per cent. and the latter between 0.06 and 0.22 per cent. in the grass pastures of different regions. Sodium average figures fall from a maximum of 0.08 per cent. to a minimum of only 0.01 per cent. in some grass pastures while in others these values vary between 0.10 and 0.25 per cent. in the course of the year. (7) The percentage potassium remains comparatively high throughout the year in most bush pastures. Values seldom are below 1.00 per cent., while most figures fluctuate between 1.40 and 2.00 per cent. Sodium and chlorine averages are exceptionally high in some of the pastures composed mainly of bushes. Thus, for the greater part of the year figures for sodium are 1.00-1.86 per cent., and chlorine values exceed 0.70 per cent. (8) Crude fibre averages are lowest in pasture at the younger stages of growth, the mean annual variation is 34.6-37.2 per cent. for grass pastures and 32.0-35.0 per cent. for bush pastures. (9) Calcium-phosphorus ratios ranging from 2.00:1 to 11.60:1 occur in the dry matter of South African pastures. (10) Judged by the estimated requirements of cattle and sheep for growth all South African natural pastures, composed mainly or wholly of grasses are deficient in phosphorus, crude protein and, in certain areas, sodium for a period ranging from five to nine months of the year, depending on the area. There are indications that in certain of these regions the pasture may be deficient in phosphorus throughout the year. Furthermore, on the basis of the average values for phosphorus these grass pastures contain at no time of the year sufficient of this nutrient to provide in the requirement for an additional function (e.g., gestation or lactation) of the animal, superimposed on growth. (11) Provided sufficient food is available an intake of phosphorus, crude protein or sodium below the optimum requirements for growth will seldom occur on pastures composed mainly of bushes. (12) The requirements of calcium, magnesium and potassium for growth and moderate milk production will at all times be met by the amounts of these constituents present in South African pastures. Especially is the danger of a potassium and magnesium deficiency extremely remote. (13) The pastures of the Union are at no time deficient in chlorine. A cow producing two gallons of milk may, however, not ingest sufficient of this constituent on the winter pastures of some of the grassland regions.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Salvation

Item does not contain fulltex