Studies on the water requirements of farm animals in South Africa. II. The relation between water consumption, food consumption and atmospheric temperature as studied on merino sheep’

1. The consumption of lucerne hay and water by merino sheep has been recorded in two separate but identically concluded experiments under the following conditions: (i) Both food and water given ad lib. (ii) Water restricted to 2 litres, food ad lib. (iii) Food restricted to 0.6 Kg. water ad lib. 2. A highly significant positive correlation was found between the amounts of hay and water consumed when both were offered ad lib. 3. A highly significant positive correlation was also found between the amount of water consumed and the maximum atmospheric temperature for the day. This coefficient was enhanced by feeding a fixed amount of hay in the first experiment but not in the second. 4 . No direct correlation could be shown between the hay consumption and atmospheric temperature when water supply was unrestricted. In the first experiment a highly significant negative correlation was found between these two factors when a fixed amount of water was given, but this could not be confirmed in the second experiment. 5. Urine was collected from representative animals from each group. It was found that the animals on a restricted water supply maintained a low water to food ratio by passing small amounts of highly concentrated urine (urea up to 8.1 gm. per 100 c.c.). Marked variations were found between individual sheep receiving both hay and water ad lib. in respect of volume and concentration of urine.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 on the alimentary tract of the merino sheep in South Africa. XXIII. The effect of supplementing poor quality grass hay with molasses and nitrogenous salts

1. In a series of three experiments it has been shown that the supplementation of poor quality grass hay with either urea or sodium nitrate, in conjunction with molasses resulted in increased appetite and improved maintenance of body weight. 2. These beneficial effects were not only due to the extra nutriments derived from the supplements but also to an acceleration of cellulose digestion allowing of a greater utilisation of the basic hay. 3. Although the rate of cellulose digestion was accelerated the percentage of cellulose digested was not influenced. 4. The feeding of 200 gm. of lucerne hay per day also increased the rate of cellulose digestion resulting in an increased consumption of grass hay. 5. Indications that the presence of ammonia radicle is deleterious to the activity of the ruminal flora will have to be studied further. The possibility of using nitrates to supplement the rations of ruminants will also have to be explored.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 on the water requirements of farm animals in South Africa. I. The effect of intermittent watering on Merino sheep

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.(1) On a ration of poor quality grass hay sheep were found to maintain their normal intake of water when allowed to drink for one hour only every second clay. (2) When given water at 72 and 96 hour intervals the total intake was decreased to 63 per cent. and 54 per cent. of the normal, respectively. (3) This decreased intake of water, however, did not affect the consumption of grass hay although one animal actually died of dehydration. (4) On the other hand the consumption of lucerne hay was markedly suppressed by lack of water even during the first 24 hours of thirsting. (5) Sheep on lucerne hay receiving water only twice weekly still gained in body weight. This gain was, however, accelerated when water was constantly available. (6) As exercise was greatly restricted these results cannot be applied quantitatively to sheep on open grazing

The effect of diet and body condition on the heat regulating system of the merino sheep

1. It is clearly shown that the diet and general body condition of sheep markedly influenced their heat-regulating mechanism. 2. The maintenance of the body temperature of thin sheep in a cold environment was found to be closely associated with the calorific value of the diet at the time of exposure. 3. Moderately conditioned sheep maintained their body temperature when exposed to cold for a period of 10 days after being placed on an inadequate ration. 4. The control of temperature in a hot environment was found to depend largely on general body condition. 5. When the sheep were exposed to heat the following observations were made: (a) Thin sheep on a poor diet showed a suppressed panting reflex and an excessive rise in body temperature. (b) Thin sheep on a good diet showed a normal panting reflex but also an excessive rise in rectal temperature. This anomaly cannot as yet be fully explained. The ability to control the body temperature returned when the general body condition improved. 6. Contrary to expectation, continued poor feeding of sheep in conjunction with repeated exposure to cold failed to cause any clinical disturbance either in digestion or in the normal appetite of such animals. The effect of this treatment on the heat regulating system of the body, however, was both clear and pronounced.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 on the alimentary tract of merino sheep in South Africa. XIII. The role of prussic acid in the aetiology of acute bloat

It is shown that more than four times the amount of KCN is required to cause ruminal paralysis in sheep during active fermentation of lucerne in the forestomach than after a fast of 14 hours. This increased tolerance to KCN after feeding is explained on the basis of an accelerated elimination of HCN from the lungs resulting from the greater respiratory exchange, which in turn is caused by the absorption of carbon dioxide from the alimentary tract during fermentation. Similar results are reported by the artificial introduction of carbon dioxide into the rumen. Sheep showing paralysis of the rumen, caused by KCN, are able to eructate two litres of gas per minute introduced through the ruminal fistula. These observations, therefore, afford no evidence for incriminating the cyanogenetic factors in plants as being associated with the aetiology of acute bloat in ruminants.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

Editorial: Polar genomics in a changing world

Polar regions play critical roles in the function of the Earth’s climate system, many of which are underpinned by their endemic biota. Whilst being home to some of the world’s best-known charismatic megafauna such as polar bears, whales, penguins, seals and albatrosses, polar regions also harbour some of the most poorly explored and least understood biodiversity on the planet (https://www.ipcc.ch/reports, accessed on 9 June 2023). Moreover, these regions are amongst those areas of our planet experiencing the most rapid rates of warming [1,2], resulting in severe threats to their unique ecosystems [3]. With regional warming, the organisms living in these frozen ecosystems will have to adapt if they are to survive, yet we currently have a very limited understanding of polar biodiversity, or indeed of the future resilience of polar organisms in our changing world. To generate a priori predictions of biodiversity change in these regions, it is imperative to understand the true extent of polar biodiversity, including how organisms interact (for example, in food webs), the biological mechanisms by which they have adapted to polar environments, their levels of phenotypic plasticity, and how these attributes may impact their abilities to respond to change. Critical to this understanding are “genomics” approaches that exploit the high-throughput sequencing of genetic material. With the costs of sequencing DNA and RNA having decreased dramatically over recent years, our abilities to probe the genetic code of polar organisms have expanded immeasurably, such that we are now able to answer ecological and evolutionary questions that were intractable even a few years ago, as exemplified by the contributions in this Special Issue on polar genomics

Studies on the alimentary tract of the merino sheep in South Africa. XIX. The influence of sulphanilamide on the activity of the ruminal flora of sheep and cattle

(1) It has been shown that therapeutic doses of sulphanilamide depress cellulose digestion and appetite in ruminants. (2) The fermentation of sugar and gas formation are also suppressed but only by higher concentrations. (3) The absorption of sulphanilamide after intra-ruminal dosing is very slow and effective blood concentrations are not attained with recognised therapeutic dosage. (4) The absorption of sulphanilamide is further retarded by paralysis of the rumen induced by atropin. (5) These findings raise the question as to the advisability of dosing sulphonamides to ruminants in view of their deleterious effects on cellulose digestion and appetite and the low blood concentration of the drug achieved by dosing.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 on the alimentary tract of Merino sheep in South Africa. XV. The influence of different factors on the rate of cellulose digestion in the rumen and in ruminal ingesta as studied in vitro

(1) The rate of cellulose digestion in ruminal ingesta was studied both in vivo and in vitro by a new technique in which cotton threads were used as test material. (2) It was found that the rate of cellulose digestion was markedly influenced by the diet. (3) The appetite for either lucerne or grass hay was directly affected by the rate of cellulose digestion. (4) On a basic diet of poor quality grass hay both cellulose digestion and appetite were stimulated by small amounts of sugar but markedly depressed by excessive amounts. More sugar could be tolerated if protein was also given. Optimal cellulose digestion necessitated a balance between readily available carbohydrate and protein. (5) Excess protein suddenly introduced after a period on a diet low in both protein and carbohydrate caused marked inhibition of cellulose digestion and inappetence. One case of sudden death was possibly associated with ammonia poisoning.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

Saturn's icy satellites and rings investigated by Cassini - VIMS. III. Radial compositional variability

In the last few years Cassini-VIMS, the Visible and Infared Mapping Spectrometer, returned to us a comprehensive view of the Saturn's icy satellites and rings. After having analyzed the satellites' spectral properties (Filacchione et al. (2007a)) and their distribution across the satellites' hemispheres (Filacchione et al. (2010)), we proceed in this paper to investigate the radial variability of icy satellites (principal and minor) and main rings average spectral properties. This analysis is done by using 2,264 disk-integrated observations of the satellites and a 12x700 pixels-wide rings radial mosaic acquired with a spatial resolution of about 125 km/pixel. The comparative analysis of these data allows us to retrieve the amount of both water ice and red contaminant materials distributed across Saturn's system and the typical surface regolith grain sizes. These measurements highlight very striking differences in the population here analyzed, which vary from the almost uncontaminated and water ice-rich surfaces of Enceladus and Calypso to the metal/organic-rich and red surfaces of Iapetus' leading hemisphere and Phoebe. Rings spectra appear more red than the icy satellites in the visible range but show more intense 1.5-2.0 micron band depths. The correlations among spectral slopes, band depths, visual albedo and phase permit us to cluster the saturnian population in different spectral classes which are detected not only among the principal satellites and rings but among co-orbital minor moons as well. Finally, we have applied Hapke's theory to retrieve the best spectral fits to Saturn's inner regular satellites using the same methodology applied previously for Rhea data discussed in Ciarniello et al. (2011).Comment: 44 pages, 27 figures, 7 tables. Submitted to Icaru