Iodine in the nutrition of sheep. Final report

1. Two groups of 10 merino ewes were fed the same adequate basal ration with the exception that one group received an addition of 0.05 gms. each daily of potassium iodide. 2. A slight depression of weight and greater irregularity in regard to the reproduction was shown by the group that received the iodine supplement. The detrimental effects, however, were not as marked as recorded in previous work where other deficiencies, especially vitamin A, undoubtedly exercised an aggravating influence on reproductive abnormalities. 3. The indiscriminate use of iodine supplements for sheep is not recommended.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

Studies in mineral metabolism. XXXIII. Iodine in the nutrition of sheep. Second report

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 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 (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

Studies in mineral metabolism XXXV. The role of iodine in the nutrition of sheep

When the daily ration of Merino ewes contained 0.05 gm. KI for a period of about twelve months no effects were observed in bodyweight and food consumption. Reproduction was, however, abnormal in all the groups receiving the KI supplement, the effects of which were more pronouncedly deleterious in sheep on a carotene low diet than when 200 grm. greenfeed were supplied daily. The response to increased protein feeding in the form of bloodmeal was marked by the detrimental effect of KI on reproduction. As all the rations can easily be improved both in quality and palatability it cannot be inferred that the quantity of KI given will affect reproduction in sheep adversely under ideal feeding conditions. The conclusion is justified, however, that when greenfeed is absent or inadequate as frequently happens in practice good quality protein is not available and the incorporation of KI in sheep licks is distinctly dangerous and may even cause losses due to abnormal reproduction.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

Studies in mineral metabolism XXXVII. The influence of variations in the dietary phosphorus and in the Ca:P ratio on the production of rickets in cattle

1. Young heifers and steers were fed basal rations supplemented with CaCO₃ and Na₂HPO₄ in such a manner that the intakes of Ca and P were different in the respective groups. Vitamin D was present in abundance. 2. The basis of the experiments was respectively deficiency and sufficiency of P with varying amounts of Ca in the rations. 3. The experiments continued for approximately 24 months. during which period observations were recorded on weight increase, food consumption, blood analysis for P, Ca and phosphatase, clinical symptoms of disease and bone analyses – both chemical and histological. 4. The outstanding result of the experiments is that under the conditions mentioned P deficiency in bovines invariably leads to rickets or osteomalacia and that osteodystrophia fibrosa is not produced by P deficiency per se. With regard to the latter condition the suggestion is made that Ca deficiency may be the responsible factor. 5. Erdalkali-alkalizitat, like Ca:P ratio of which it really is a modification, is not the factor which determines whether rickets will or will not develop under conditions of P deficiency but both are associated with the severity of the complex result produced; for instance if they are not always associated with the severity of the microscopical bone lesions then with the earlier effects upon food consumption, growth and the development of clinical symptoms. 6. From the data available it would appear that a ratio of CaO:P₂O₅ of 2.5:1, when P was present in adequate amounts did not affect the animals significantly in regard to the observations registered. 7. A daily intake of 19 gm. P₂O₅ of which 53 per cent. was retained by the steers and of 24.0 gm. P₂O₅ with a retention of approximately 63 per cent. by the heifers provided sufficient P for normal growth and development while 13 gm. and 10 gm. were insufficient for the steers and heifers respectively. 8. Decreased food consumption which has invariably been observed in cattle receiving insufficient amounts of P in their diets is not wholly due to the inadequacy of the P but is also associated with the calcium content of such a diet or apparently therefore an effect of a disturbance in the Ca:P metabolism of the animal. 9. With regard to blood analysis the phosphatase and the inorganic P content of the blood afford valuable assistance in following the development of rickets but Ca determinations have been found to be of little help in presence of vitamin D. The periodic removal of portions of ribs causes the animal very little inconvenience and has advantages even over X-ray photography for studying the development of osteodystrophic diseases in the experimental animals.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

Studies in mineral metabolism. XXXVI. Fluorine metabolism in rats and bovines

1. Appreciable amounts of fluorine is retained by bovines and rats on rations to which fluorine has been added. Bovines retain approximately 0.2 grm. and rats 1 mgm. of F per day under the conditions of the experiment. 2. The percentage F occurring normally in ash of rats varies from 0.039 to 0.05. 3. The ash per 100 grams empty weight in rats is increased by fluorine feeding. 4. Fluorine causes a decreased retention of both calcium and phosphorus in rats, a slight increase in calcium retention and a pronounced decrease in the phosphorus retention of bovines.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

Studies in mineral metabolism. XXXII. The effect of different forms of sulphur in the diet upon the growth and wool production of sheep

(1) Details are presented of an experiment on the effects of sulphur and of compounds containing sulphur on the food consumption, weight increase, wool yield and disease of young wethers kept on a production ration for two years. (2) The sheep were fed in individual feeding boxes except for the hay which was given ad lib. (3) The supplements given were dosed daily except Sundays and were given as follows:-Group I: No supplement. Group II: Cystine. Group III: Sulphates. Group IV: KCNS. Group V: 5 gm. sulphur. Group VI: •12 gm. sulphur. (4) No significant effects of the supplements on the sheep could be detected after 12 months' supplementary feeding nor did the experimental groups differ significantly from the control group at the end of the experimental period. (5) The supplement of cystine had no effect on the quantity of wool produced. (6) The mortality and disease due to the presence of urinary calculi were apparently not associated with the supplements. (7) The analyses of the wool will be reported on in due course.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. 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

The SARAO MeerKAT 1.3 GHz Galactic Plane Survey

We present the SARAO MeerKAT Galactic Plane Survey (SMGPS), a 1.3 GHz continuum survey of almost half of the Galactic Plane (251○ ≤l ≤ 358○ and 2○ ≤l ≤ 61○ at |b| ≤ 1 5). SMGPS is the largest, most sensitive and highest angular resolution 1 GHz survey of the Plane yet carried out, with an angular resolution of 8″ and a broadband RMS sensitivity of ∼10–20 μJy beam−1. Here we describe the first publicly available data release from SMGPS which comprises data cubes of frequency-resolved images over 908–1656 MHz, power law fits to the images, and broadband zeroth moment integrated intensity images. A thorough assessment of the data quality and guidance for future usage of the data products are given. Finally, we discuss the tremendous potential of SMGPS by showcasing highlights of the Galactic and extragalactic science that it permits. These highlights include the discovery of a new population of non-thermal radio filaments; identification of new candidate supernova remnants, pulsar wind nebulae and planetary nebulae; improved radio/mid-IR classification of rare Luminous Blue Variables and discovery of associated extended radio nebulae; new radio stars identified by Bayesian cross-matching techniques; the realisation that many of the largest radio-quiet WISE H II region candidates are not true H II regions; and a large sample of previously undiscovered background H I galaxies in the Zone of Avoidance