bluuebunny/crossref_metadata_2025 huggingface dataset:
The toxicity of oil herbicides to Paspalum dilatatum Poir.: Effect of composition of the oil
Authors: Myers LF
Published: November 2004

Hydrocarbon oils of varying boiling range and percentage "aromatic" fraction were tested for their toxicity to Paspalum dilatatum in the field and glass-house.Contact injury and final toxicity are separate phenomena and are controlled by different factors. The contact effect of oil herbicides depended on the proportion of aromatic fraction in the oil. The minimum percentage of aromatics required to produce rapid contact injury increases with increasing boiling-point of the oil. Mid boiling-point was shown to be an important and consistent factor in oil toxicity as measured by regrowth. Oil toxicity increases with mid boiling point of the oil. Toxicity in the field decreases with increasing aromatics. In the glasshouse the reverse is the case.
The copper and molybdenum contents of some pasture species in the Murray Valley.
Authors: Dick AT , Moore CWE , Bingley JB
Published: November 2004

Fourteen of the more commonly occurring natural pasture species in the Murray Valley area have been examined over a period of four years for their copper and molybdenum contents. The results of the analyses show that there are significant differences in copper and molybdenum contents between species. The mean values are tabulated and discussed.
Movement of salts in isolated soil columns.
Authors: West ES , Howard A
Published: November 2004

Movement of salt in a semi-arid soil (Hanwood sandy loam) was studied in isolated columns of soil one metre in diameter and four metres deep. Where a water-table was maintained approximately 60 cm. from the surface by the addition of rain-water to the surface, salt was washed out of the surface layers and did not return. Where a water-table was maintained one metre from the surface by the addition of water from below there was a small increase in the salt concentration of the surface 10 cm. of soil. In view of these results it is suggested that some circulation of water involving lateral movement is generally associated with salt accumulation that is commonly found under field conditions.
Selection for economic characters in Australian Merino sheep. 3. Inheritance of skin-fold score in Merino sheep and problems of scale.
Authors: Morley FHW
Published: November 2004

A study of published data on the fold scores of certain breed crosses, backcrosses, and filial generations suggests that causes of variation in skinfold score act geometrically. A logarithmic transformation increased the accuracy of prediction of F2 and backcross scores. Data from selection experiments on Merinos at Trangie were analysed using both arithmetic and logarithmic scales. Heritability of breech fold score was estimated as 0.45 on an arithmetic scale, 0.55 on the logarithmic scale. The mean and variance within groups of Merinos with different means were strongly correlated on the arithmetic scale, but this correlation was removed by the logarithmic transformation, resulting variances being approximately constant. Freedom from folds showed strong potence on both arithmetic and logarithmic scales. Theoretical implications of potence and geometric action appear to be confirmed by available data.
The control of sucker growth in tobacco by growth substances and mineral oils.
Authors: Calvert J
Published: November 2004

Indoleacetic acid ranging in concentration from 50 to 10,000 p.p.m. significantly reduced the growth of suckers on plants which had had the apical leaves and inflorescence excised. Five mineral oils significantly reduced the suckering in tobacco grown in the glass-house. Twelve mineral oils tested in north Queensland under conditions similar to commercial growing were all highly effective in reducing sucker growth. As the concentration of indoleacetic acid increased, the epinastic effect on the leaves became more pronounced. The mineral oils did not produce epinasty. No pathological reactions were observed with any of the treatments. Maleic hydrazide was the only growth regulator used in the field that significantly reduced sucker growth.
Development of the follicle population in N-type sheep.
Authors: Ross JM
Published: November 2004

The development of the follicle population in N-type sheep is described for the period from 40 days of gestation to birth. No major differences from the description given for the non-N-type Romney or the Merino were found. The development and growth of follicles after their first initiation appear to be slightly faster in N-type. The tips of fibres which had pierced the skin at 113 and 119 days' gestation were examined and found to belong to all birthcoat fibre types except hiserotrichs. Since it has been shown that secondary follicles form, in addition to histerotrichs, only curly-tips, it follows that primary follicles form some types of fibres which do not grow in secondary follicles.
Studies on fluorosis of sheep. II. The toxicity of water-borne fluoride for mature grazing sheep.
Authors: Peirce AW
Published: November 2004

Three groups each of 16 mature sheep were allowed to graze on sown pasture for 26 months. One group was given reservoir water, containing approximately 0.3 p.p.m. F, to drink, but the other two groups were offered similar water to which had been added sufficient sodium fluoride to give final concentrations of 10 or 20 p.p.m. F. During the winter months the treated groups drank only 0.5 1. or less of water per day and ingested virtually no fluoride. During the summer months the daily consumption of water by the groups which received 10 and 20 p.p.m. F rose to between 3 and 4 l., and the daily intake of fluoride, expressed as fluorine, to approximately 30 and 60 mg F respectively, equivalent to 0.4 and 0.8 mg F per kg body weight. The overall mean daily intakes of fluoride for the whole experiment by the two groups were 18 and 33 mg F or 0.24 and 0.44 mg F per kg body weight respectively. The ingestion of the amounts of fluoride supplied by drinking water containing as much as 20 p.p.m. F appeared to have no adverse effect on general health, body weight, or wool production of mature sheep over a period of 26 months. A brown deposit was present on the incisor teeth of all sheep throughout the experiment but was more pronounced during periods when the pasture was green; it did not appear to be related to fluoride intake, for it was as severe among the control sheep as among the treated ones. No mottling of the incisors or molars was observed, nor was there any evidence of excessive or uneven wear on these teeth. Ingestion of fluoride brought about increases up to threefold in the fluoride content of the bones and teeth.
Studies on allergic dermatitis (Queensland Itch) of the horse: the origin and significance of histamine in the blood and its distribution in the tissues.
Authors: Riek RF
Published: November 2004

Studies were made of the distribution of histamine in the blood of susceptible horses and those not susceptible to allergic dermatitis. In the non-susceptible horses there was no difference in total histamine in the circulating blood during summer and winter. In the susceptible horses there was a rise in histamine content of whole blood in the summer. Analysis of the components of the blood showed that increase of histamine in the plasma is considerably greater than its increase in the white cell layer. Histamine, taken up by the eosinophils, is regarded as being bound to the cells and inactive, whereas plasma histamine remains free and is responsible for the cellular reactions in the skin and the accompanying irritation characteristic of the early stages of the disease. Plasma histamine is rapidly detoxified. The probable method of detoxification is discussed. The examination of body tissues obtained during the summer from a limited number of susceptible and non-susceptible horses showed higher values for histamine in the liver and in the skin of susceptible animals, but the differences did not reach statistical significance. It would appear, however, that, a t least with the skin, a more extensive series of observations would probably have demonstrated significance, as an increase in the concentration of histamine occurred in the skin of susceptible animals after intradermal injection of specific antigen.
A sensitive temperature and humidity probe.
Authors: McIlroy IC
Published: November 2004

A new instrument for the measurement of wet- and dry-bulb temperatures (and hence the calculation of humidity), which is now in use at several Australian agricultural research stations, incorporates miniature platinum resistance thermometers especially suitable for use in confined spaces or under "still air" conditions.
The heat tolerance of two breeds of calves from 1 to 12 months of age.
Authors: Klemm GH , Robinson KW
Published: November 2004

Two grade Australian Illawarra Shorthorn bull calves and two Zebu- Hereford cross bull calves were exposed for 7 hr twice a week to each of several atmospheres having dry-bulb temperatures ranging from 86°F (30°C) to 108.5°F (42.5°C) and absolute humidities ranging from 6.5 to 16.6 gr moisture/cu.ft. dry air (vapour pressure 15-40 mm Hg). Such exposures were carried out a t different ages: 1-3 months, 6-8 months, and 12-13 months. The following reactions were studied: rectal temperature, pulse rate, respiratory rate, evaporative loss, skin temperature (Zebu-Hereford only), and behaviour. For air temperatures above 95°F the rise in rectal temperature was greater and equilibrium was reached more slowly in Illawarra Shorthorns than in the Zebu-Hereford. Increase in humidity at temperatures over 80°F produced more stress in the animals than increase of dry-bulb temperature. Pulse rates changed little during heat exposure, but there was a fall in rate with age under all circumstances. As the calves increased in age the panting rate decreased for a given hot environment (markedly so for the Zebu-Hereford crossbred). Evaporative loss increased as dry-bulb temperature was raised. The Zebu-Hereford showed a high transcutaneous water loss soon after birth with a continued increase up to 12 months. Skin evaporation was relatively small in the Illawarra Shorthorn at 1-2 months but increased a t 6-8 months, although it did not attain the high rate of the crossbred. In the Zebu-Hereford cross, sweat glands became active a t a skin temperature of approximately 96°F. With the onset of sweating a fall in skin temperature was observed. A comparison of the reactions of the Illawarra Shorthorn and the Zebu-Hereford crossbred with four Jersey calves aged 1-3 months, exposed to similar conditions by Riek and Lee, shows that the Zebu-Hereford has a better heat tolerance than either of the other breeds. Evidence is presented to indicate that this superiority of the Zebu crossbred is associated with at least two factors, ( a ) a better sweating mechanism and (b) decreased heat production. The Jersey and Illawarra Shorthorn calves have similar reaction values a t this age.
Studies of the water relations of crop plants grown under natural rainfall in northern Australia.
Authors: Slatyer RO
Published: November 2004

Studies of the water relations of cotton, peanuts, and grain sorghum were made at Katherine, N.T., on crops grown under natural rainfall during the 1952-53 rainfall season. In the early part of this season, rainfall was more or less normal and little evidence of stress was seen in the plants. The latter part, however, was abnormally dry and resulted in the appearance of severe water stress symptoms in all crops. The water balance of the plants through the season was followed using Weatherley's (1950) "relative turgidity" technique of leaf turgor measurement. In each crop the relative turgidity level was maintained at a fairly high level until the onset of dry conditions, when a progressive decline commenced. This decline, although continuous, appeared to be in two stages. It was felt that the lag of absorption behind transpiration which resulted in loss of turgor was initially due to the rapid rise in transpiration, which followed the increase in atmospheric aridity with the onset of the dry period. As atmospheric conditions became more static, the continued decline in turgor was attributed primarily to the influence of soil moisture stress, in limiting absorption. Of the three crops, grain sorghum appeared to have the best-developed root system and also the most effective internal control over transpiration. Cotton appeared to be least well equipped in these respects. These features were reflected in generally higher turgor levels in grain sorghum than in other crops, and in a slower rate of decrease in turgor with the onset of dry weather. This decrease was particularly rapid in cotton. This relative resistance to turgor loss was in turn reflected in growth rate reductions in cotton as soon as soil moisture stress appeared, but not in grain sorghum until severe soil moisture stress was evident. The peanut responses throughout appeared intermediate between those of the other two crops.
Observations on the removal of Oesophagostomum columbianum Curtice from sheep grazing on green oats and on pastures.
Authors: Southcott WH
Published: November 2004

Field trials in 1951 and 1952 confirmed previous observations on the evacuation of adult Oesophagostomum columbianum Curtice from sheep which graze continuously on green oats. Ingestion of phalaris-subterranean clover or red clover pasture also resulted in the evacuation of some O. columbianum but was much less effective in this regard. Evacuation of O. columbianum from sheep on green oats was not complete and was associated with softening, and lowering of the pH, of the faeces. The phenomenon occurred both with and without a considerable increase in liveweight. Some of the factors associated with oat-grazing which may influence removal of O. columbianum are discussed.
The effect of unequal intervals between milkings upon milk production and diurnal variation in milk secretion.
Authors: Turner HG
Published: November 2004

Five pairs of twin heifers were milked twice daily at intervals of either 11 and 13 hr or 8 and 16 hr for a period of 16 weeks. Total milk and fat production were recorded and, from determinations of residual milk, secretion rates during each interval were estimated. Total milk production was slightly, not significantly, higher in the group subjected to unequal intervals. It was estimated that any depression of production due to intervals even as widely disparate as these is likely to be very small. Fat percentage was unaffected by treatment. Evidence of diurnal variation in milk or fat secretion under the influence of a schedule of 8 and 16-hr intervals was not conclusive, but overall there was no significant evidence that secretion rates were lower during the longer interval.
Genetic parameters associated with characters effecting egg production in the domestic fowl. I. Heritability of total egg production during the pullet year
Authors: Sheldon BL
Published: November 2004

Egg production records of White Leghorn pullets hatched a t the Poultry Research Centre, Werribee, Vic., during 1947 to 1950 inclusive have been analysed both on a hen-housed (Production Index) and a survivor basis. Estimates of heritability were obtained by two methods: (1) by the analysis of components of variance between families of full sibs and half-sibs; (2) by estimating the intra-sire regression of the mean performance of offspring on dam's performance. Heritability, in the narrow sense, of Production Index during the pullet year is shown to be 23-30 per cent. with a reasonably low standard error, while heritability of survivors' production is slightly lower but not significantly so. Possible reasons are advanced for the low estimates of heritability of survivors' production.
Witches' Broom disease of Lucerne. II. Field studies on factors influencing symptom expression, disease incidence, and mortality rate
Authors: Helms K
Published: November 2004

Field surveys and ratings of individual lucerne plants (Medicago sativa L.) for severity of symptom expression in the Lachlan and Murrumbidgee Valleys, N.S.W., showed that each year there was a seasonal variation in observed incidence of the disease. This was due to masking of symptoms of diseased plants in the spring. Shoots from plants with masked symptoms contained virus. Maximum symptom expression developed in the late summer and early autumn. Rainfall and temperature (for which day length and light intensity are possible alternatives) appeared to be factors influencing both time and intensity of symptom expression; during the growing season severe symptoms were associated with hot dry conditions and mild symptoms with high rainfalls. Green flowers were associated with the disease in midsummer in some but not all infected plants. Disease incidence and rate of infection were influenced by local environment; more diseased plants and more mortalities of diseased plants occurred on river terraces than on river flats. Disease incidence and rate of infection were greater in old stands and in young thin stands than in young dense stands. Witches' broom was an important factor associated with mortality of plants in 10-year-old lucerne stands in the Lachlan Valley. The minimum observed life of infected plants was less than 2 months. The maximum was 33 months in the field and 54 months in the greenhouse. The economic importance of the disease in Australia is discussed.
A comparison of normal concentrations of reducing sugar, volatile fatty acids, and ketone bodies in the blood of lambs, pregnant ewes, and non-pregnant adult ewes
Authors: Kronfeld DS
Published: November 2004

Concentrations of reducing sugar, volatile fatty acids, and ketone bodies were estimated in blood drawn from six normal Merino ewes before and during pregnancy and on their lambs from birth until 4 months of age. During pregnancy the concentrations of glucose and volatile fatty acids remained within the pre-pregnant range. A significant rise in blood ketones (P < 0.001) occurred with some values as high as 8.8mM (35 mg/100 ml) during the last month of pregnancy, indicating that the normal ewe is predisposed to ketosis during the pre-partum period. In the lambs the blood glucose range was 79-115 mg/100 ml for the first 2 weeks. There was a gradual fall until adult values (39 ± 6.2 mg/100 ml) were assumed at 13 weeks. This fall commenced 2-4 weeks before rumination was observed and so it was probably not entirely due to the development of rumen function. The volatile fatty acids were always within the adult range, which indicated that lambs have a major source of volatile fatty acids other than the rumen. Ketone concentrations of (2.5 ± 1.14) mM found in lambs between 1 and 90 days old were higher than those of adults ((1.5 ± 0.84)mM). The katabolism of dietary milk f a t might be responsible for the high concentrations of circulating volatile fatty acids and ketone bodies.
Decomposition of oxalic acid in vitro by rumen contents
Authors: Watts PS
Published: November 2004

The rumen contents of sheep habituated to the intake of small quantities of oxalic acid are able to decompose considerably increased amounts of this substance. The presence of excess calcium decreases the amount decomposed.
Effect of diet on individual volatile fatty acids in the rumen of sheep, with particular reference to the effect of low rumen pH and adaptation on high-starch diets
Authors: Reid RL , Hogan JP , Briggs PK
Published: November 2004

Detailed data are presented on changes in the proportions of acetic, propionic, and butyric acids in the rumen after feeding on various diets. Pre-feeding proportions were constant on each diet but varied from a mixture of 72-76 per cent. acetic, 14-16 per cent. propionic, and 10-12 per cent. butyric acid on all-roughage diets to one of 63-65 per cent. acetic, 18-20 per cent. propionic, and 16-18 per cent. butyric acid on a diet containing 70 per cent. wheat grain. On all diets the proportion of propionic acid increased after feeding and reached a peak which coincided with the maximum level of total volatile fatty acids. The response of butyric acid was variable, low levels being recorded on a diet of lucerne chaff and on one containing a high proportion of cracked maize. The proportion of acetic acid always declined after feeding. These responses were modified in experiments on rations containing high proportions of wheaten starch, in which rumen pH fell below 5.0 as a result of lactic acid accumulation. When animals were first fed on such diets, a decline in rumen pH below 5.0-5.5 after feeding was always associated with a pronounced decline in the proportions of propionic and butyric acids, to levels as low as 8 and 5 per cent. respectively. Continued feeding of such diets did not affect the response of butyric acid, but there was evidence of a change in propionic acid production in response to low pH conditions, both in respect to short-term change during experiments in which low rumen pH levels were maintained for considerable periods and to long-term change when such diets were fed intermittently over considerable periods. The implications of these findings are discussed with respect to the effects of pH on individual volatile fatty acid production in the rumen, and on the qualitative nature of the microbial population and on their metabolic patterns.
Boron content of sultana vines in the Mildura area
Authors: Sauer MR
Published: November 2004

Sultana vines on Mallee soils in the Mildura district show a high boron content, which frequently reaches toxicity levels. The concentration of boron in the vine is related to the soil type, and is highest on loam soils, lowest on sands. Vines on grey alluvial soils in the area show lower, but adequate, boron content. Boron accumulates principally in the lamina of the leaf, where there is a rapid increase in concentration during the growing season. symptoms of boron toxicity on sultana leaves are described. These symptoms are found on leaves with 300 p.p.m, boron or more. Agricultural tile drains play a big part in keeping boron concentrations below toxicity levels. Drainage waters commonly show 5 p.p.m. boron. Data collected suggest that applications of sulphate of ammonia and superphosphate tend to increase the level of boron in sultana leaves.
The influence of temperature and humidity in storage on seed viability and hard-seededness in the west Australian, Blue Lupin, Lupinus digitatus Forsk
Authors: Gladstones JS
Published: November 2004

Freshly harvested seeds of L. digitatus were stored for up to 11 months at all combinations of six constant temperatures and five constant relative humidities. Testing for hard-seededness was by soaking in water at 15°C, and for viability by emergence tests in seed boxes. Permeability was found to be governed by seed moisture content. All seeds with more than 14 per cent. moisture (wet weight basis) remained fully permeable. Below 14 per cent., permeability decreased with decreasing moisture content until at 11 per cent. all seeds were virtually impermeable. Impermeability was readily reversible under humid conditions down to 12 per cent. moisture content, but practically irreversible below 9 per cent. Softening of semi-hard seeds took place no more rapidly at 94 per cent. R.H. than at 76 per cent. Seed which was air-drying in the laboratory remained fully soft for about 1 week after harvest, and thereafter hardened only slowly. Seed which had been kept permeable for 12 months hardened at the same rate. Viability was impaired by both high moisture content and high temperature.
Heat and water in tropical Merino sheep
Authors: Macfarlane WV , Morris RJH , Howard B
Published: November 2004

The relation between environment and the water intake and output of young Merino sheep living in the hot dry tropics on lat. 21° S. has been studied for 3 years. The tip wool of sheep standing in the sun heats to 189°F by absorption of radiant energy, most of which is re-radiated. Wool, especially when it is more than 3 cm long, assists in protecting sheep from radiant energy. The respiratory rates of sheep shorn during summer were more than twice those of unshorn sheep standing in the sun. On the open plains summer shearing appears to add to the thermal strain. Acclimatizing sheep respired more rapidly in the sun than tropical sheep. Evaporative cooling, by panting, increases water demand, and in summer merinos drank on the average 12 times as much water as in winter, when they took 7.3 ml/kg/day. Water intake is related closely to respiratory rate. Urine output was lower in summer than in winter.
Differences among Merino strains in resistance to fleece-rot
Authors: Dunlop AA , Hayman RH
Published: November 2004

The incidence of fleece-rot was observed in a number of strains of Merino sheep distributed variously over fire sets of field conditions. In three locations rainfall was sufficiently high to cause moderate to high incidence of fleece-rot among susceptible sheep. In two other locations conditions were such that its occurrence in susceptible sheep was either negligible or absent. In two of the former localities South Australian strong-wool Merinos proved to be highly susceptible, while in two medium-wool Peppin strains the susceptibility varied from moderate to high. In a medium-wool non-Peppin strain the incidence was less than in the Peppin and South Australian strains; in a fine non-Peppin strain the incidence was moderate to low; while in a flock of Camden Park fine-wools the incidence was low.
Temperature regulation in the new-born lamb. I. Changes in rectal temperature within the first six hours of life
Authors: Alexander G , McCance I
Published: November 2004

Changes in rectal temperature during the first 6 hr of life of lambs born under adverse weather conditions are described. The rectal temperature of lambs at birth was slightly above that of the ewe (av. 0.35°C higher). The subsequent changes varied from zero to a fall of 11°C within 30 min of birth. Temperature usually fell by 2 or 3°C during the first hour after birth and commenced to rise again in many Iambs, even though the coat was still wet. It had returned to 39–40°C by 3 hr after birth in most lambs. In some lambs the temperature continued to fall until death. There was a significant inverse relationship between birth weight and rate of cooling. Cooling was more pronounced in twins than in single lambs, and in lambs that subsequently died than in lambs that survived. In two series of observations, under-nutrition of the pregnant ewe resulted in the birth of lambs that appeared to cool more rapidly than lambs from well-fed ewes. The possible mechanism of the changes observed is discussed, together with practical implications of the observations.
Further breeding experiments with New Zealand Romney N-type sheep to 1956
Authors: Dry FW
Published: November 2004

Another NS-grade sheep, a horned ewe from an ordinary Romney flock, is judged on progeny to have been N/+. Further breeding results are consistent with the simple genetic basis of horns in N/+ ewes previously postulated, namely, a fortifier gene F. Additional evidence is given for a genetic basis of the comparative scarcity of halo-hairs on the main area of the body of low-N N/+ lambs. It is a reasonable guess that selection would fairly quickly build up a stock in which the gene N could be called recessive, in that its expression in heterozygotes fell short of VI. In work with low-N sheep two horned rams, twin sons of a low-N ram with very large horns, have proved not to possess N. Horns in these rams clearly have a simple genetic basis. One N-grade ram has been shown to be +/nr, and it is likely that his twin brother, which closely resembled him, was also +/nr. The N-type characterization of these twin rams was feeble in several respects. There is evidence that the nr gene is helped to N-grade expression by multiple factors which are thus dominigenes. This is a third possible way, in addition to picking up N from a low-N or nr from a carrier, in which an nr/nr sheep mated with non-N may have an N-grade lamb. The original hypothesis of a main dominigene remains unproved. Better evidence is given that the nr gene helps horns to grow in N/+ . +/nr ewes. After repeating the back-cross, N/ +. +/nr x + / + .nr/nr, the conclusion is adopted that N and nr are independent, residing on different chromosomes. Results from that back-cross have strengthened the belief that at least the great majority of sheep of both sexes of the high-dosage genotype N/+ .nrlnr have the complete halo-coverage and hornedness of N/N. +/ +
Copper-molybdenum-sulphate-manganese interaction and the copper status of cattle
Authors: Mylrea PJ
Published: November 2004

The influence of molybdenum, inorganic sulphate, and manganese upon the copper status of cattle was investigated. The mean liver copper concentration increased for steers on a basal diet containing 7.6 p.p.m. copper, 2.4 p.p.m. molybdenum, 91 p.p.m. manganese, and 0.03 per cent. sulphate. In steers on a similar diet but with the sulphate content increased to 0.55 per cent., with or without an increase in the manganese content to 391 p.p.m., there was a highly significant reduction (P=0.01) in the liver copper concentrations but not to low levels. There was also a significant (P=0.01) increase in the serum inorganic sulphate levels. On increasing the molybdenum content to 9.2 p.p.m. there was a further reduction, to low levels, in the liver and blood copper concentrations of steers on the high sulphate diets but there was no definite effect on those on the low sulphate diet. Manganese again appeared to be without effect. It was concluded that there was a molybdenum-sulphate interaction with copper in cattle but that, under the conditions of this trial, manganese was without effect. Despite the very low liver and blood copper levels attained, and maintained for 15 weeks, there was no clinical evidence of hypocuprosis. The mineral and sulphate levels applied in some of these treatments are similar to those found in pastures from areas in New South Wales where copper deficiency in cattle occurs. The levels in pastures, as related to the results of this trial, are discussed.
Adjustments for faecal worm egg counts from cattle based on faecal consistency and on age and body weight of host
Authors: Riek RF , Turner HN , McKevett M , Roberts FHS
Published: November 2004

Results are reported of studies to determine whether interpretations of worm egg counts per gram of faeces as an indication of the population fluctuations among gastro-intestinal helminths of cattle would benefit from adjustments to the egg counts for faecal consistency, and for changes in faecal output associated with the age and body weight of the host. Adjustments for faecal consistency proved of little value. Adjustments for age or body weight, however, were found to be important, and factors for adjustment to a standard age or weight are tabulated. Under field conditions age is more readily ascertained than weight, and estimates showed that prediction of faecal output from age varied only slightly from prediction from body weight.
Studies in controlled artificial insemination of Merino sheep
Authors: Robinson TJ
Published: November 2004

A total number of 507 ewes were inseminated at the rate of approximately 100 per day for 5 days, in a factorial experiment with variables: rams (5), treatments (5), days of insemination (5), volume of semen (2). Treatments were: (1) control; (2) progesterone daily for 16 days, PMS on 17th, inseminated on teasing; (3) progesterone every 2 days, PMS on 17th, inseminated on teasing; (4) as for (2), but inseminated 2 days after PMS; (5) as for (3), but inseminated 2 days after PMS. The overall lambing rate was low (31-6 per cent.). There were significant differences between rams, treatments, and day of insemination. Relative infertility of one ram was related to high incidence of sperm with curled tails. Treatment effects were: (1) 40.8 per cent. of ewes lambed; (2) 33.7 per cent.; (3) 32.9 per cent.; (4) 30.2 per cent.; (5) 15.0 per cent. Insemination was less efficient on the first day. Volume of undiluted semen used (0.05 or 0.1 ml) had no effect.
Studies on the carbohydrate metabolism of sheep. VIII. Hypoglycaemia and hyperketonaemia in undernourished and fasted pregnant ewes
Authors: Reid RL , Hogan JP
Published: November 2004

Relationships between blood levels of glucose, ketone bodies, volatile fatty acids (V.F.X.), and citrate have been studied in ewes fed on a submaintenance diet of wheaten chaff during the last 5 weeks of pregnancy. Pre-feeding levels, changes during S hr after feeding, and changes during fasting were studied. Pre-feeding hypoglycaemia was consistently more severe and the post'-prandial increase in blood glucose was less in ewes carrying twins than in ewes carrying single lambs. Blood citrate consistently increased after feeding, the magnitude of the increase depending on the extent of the increase in blood glucose. Mean citrate levels after feeding were highly correlated with mean glucose levels, which suggested that blood citrate reflected the activity of the tricarboxylic acid cycle in tissues. Pre-feeding ketone levels tended to vary inversely as blood glucose when hyperlietonaemia was moderate (less than 20 mg per cent. ketones) hut the correlation disappeared v-hen hyperketonaemia was severe (20-53 mg per cent.). When glucose increased appreciably after feeding, ketones usually declined and V.F.A. levels were normal, but when the increase in glucose was small and levels remained below 30 mg per cent. after feeding, ketone levels often did not change and V.F.A. levels were high. Mean values for ketones over a period of 8 hr after feeding were highly correlated with mean values for V.F.A. over a wide range. This can be explained on the basis of present knowledge of the metabolism of the acetyl-coenzyme A (acetyl- Co4) derived from absorbed acetate and from oxidation of higher fatty acids; it is suggested that the oxidation of acetyl-CoA is impaired as a result of depression of tricarboxylic acid cycle activity. During fasting, blood ketones varied inversely with glucose, but very high ketone levels (above 30 mg per cent.) were probably not due simply to the hypoglycaemia. The hypothesis is advanced that an excess of circulating hydrocortisone further depressed acetyl-CoA metabolism. The apparent correlations between blood glucose and ketones would then be due largely to the fact that the magnitude of the adrenal response, at any particular time in these experiments, was a function of the severity of hypoglycaemia and of the period during which it was previously maintained.
The influence of earthworms on soil fertility. II. Consumption of soil and organic matter by the earthworm Allolobophora caliginosa (Savigny)
Authors: Barley KP
Published: November 2004

When a population of the common peregrine lumbricid Allolobophora caliginosa (Sar.) was maintained in a moist loam at l5°C the worms consumed 200–300 mg dry weight of earth per gram body weight per day. The ingested earth moved through the gut in about 20 hr. When given a choice between various foods the worms consumed 10 mg dry weight of dung per gram body weight per day, together with smaller amounts of leaf litter. The worms gained weight more rapidly when fed with dung than when fed with partly decayed leaves or roots of herbage plants. Estimates are made of the rates at which soil and dung are likely to be consumed in the field.
The actions and interactions of a number of factors on the response of the growing lamb to oestrogen implants
Authors: Robinson TJ
Published: November 2004

A multifactorial experiment using 576 lambs is described, designed to determine the potential value of oestrogen implants in the Australian fat lamb industry. Actions and interactions of age at implantation (5 or 9 weeks), type of oestrogen (hexoestrol or stilboestrol), dose (15 or 30mg), crossbreed (Border Leicester x Merino or Dorset Horn x Corriedale), sex (ewe or wether), and type of birth (single or twin) were examined. Owing to drought conditions nutrition was only moderate. Sixty-three lambs were lost. Mortality tended to be concentrated on 30mg-oestrogen, Dorset Horn x Corriedale, male lambs (P < 0.05). Oestrogen-treated lambs (15 and 30 mg) reached 75 lb liveweight 2.5 and 1.9 weeks earlier than untreated lambs (P < 0.001). Wether lambs grew faster than females (P < 0.01). Treatment reduced dressing percentage and carcass weight by 1.8 per cent. and 1.1 lb respectively (P < 0-001). The dose of oestrogen was unimportant but the deleterious effect of stilboestrol was greater than that of hexoestrol. Treated carcasses were downgraded (P < 0.001) and there was a highly significant interaction between sex and treatment (P < 0.001). Carcasses of ewe lambs were more seriously affected than those of wethers. Treated carcasses were longer in the leg (P < 0.05) and thinner in the loin and flank than untreated carcasses (P < 0-001). The general effect was seriously to delay maturity and market quality, with a reduction in weight of carcasses despite increased liveweight gains. It is concluded that oestrogen implantation is unlikely to have wide commercial application in fat lamb production in Australia.
The significance of the coat in heat tolerance of cattle
Authors: Dowling DF
Published: November 2004

The heat tolerance of two strains of cattle, one with a strongly medullated coat, was measured with aid without previous clipping and with and without a plastic coat. The results supported the hypothesis that the difference in heat tolerance of the same animal at different seasons can be attributed to correspond in changes in the hair coat. Animals in a long, woolly winter coat were not heat-tolerant, whereas the same animals clipped were. Animals in a medullated coat were relatively heat-tolerant, both clipped and unclipped. Clipping improved their temperature control to some extent, but the difference made by clipping was nowhere as great as in animals with a non-medullated coat.
The development of the fruit of the Washington Navel orange
Authors: Bouma D
Published: November 2004

A study is presented on the development of the Washington Navel orange fruit in a factorial field experiment. The development of the fruit was similar in the two cultural systems studied, but the level of nitrogen supply had pronounced effects in the later stages of development. Peel thickness reached a peak early in January, but became thinner till the end of March. The rate of thinning was higher, the lower the level of nitrogen supply. From March onwards the peel thickness increased again at the highest nitrogen level, but it continued to decrease at the lowest level. Dry weight of the peel increased much faster at the higher than at the lower nitrogen levels. The level of nitrogen supply had a relatively small effect on nitrogen moving to the pulp. Considerable differences, however, were found in the nitrogen going to the peel, particularly during the period in which major differences in peel thickness and weight developed. Leaf analyses suggested that at least part of the nitrogen going to the peel at the highest nitrogen levels came from the leaves. Total phosphorus in the pulp was much higher than in the peel during the later stages of development. The quantities of phosphorus moving to the pulp were considerably higher at the lower than at the higher nitrogen levels. The results are discussed in relation to some cultural and fertilizer practices. These should aim at a nitrogen supply just sufficient to maintain yields, and so avoid the excessive accumulation of nitrogen in the tree, with its consequent detrimental effect on fruit quality.
Interactions of silicate and phosphate in a lateritic soil
Authors: Raupach M , Piper CS
Published: November 2004

The use of silicates to improve the efficiency of phosphate utilization from a lateritic soil in pots produced only transient effects which, at the best, did not last longer than 1 year. Laboratory investigations with this soil in dilute potassium chloride and calcium chloride systems showed that the proportion of phosphate left in solution increased with the pH and varied as follows for the different treatments: phosphate and silicate added together >phosphate after silicate pretreatment >phosphate alone >silicate after phosphate pretreatment >water after phosphate pretreatment. The levels of phosphate in solution were smaller for the calcium chloride than for the potassium chloride systems but the levels of silicate in solution were similar for the two systems and varied with the pH as found previously. The silicate did not appear to change the type of reaction by which phosphate is fixed but rather altered the equilibrium constants involved.
Biochemical studies on ovine pregnancy toxaemia. I. Enzymic activities of liver and brain
Authors: Gallagher CH
Published: November 2004

Enzymic activities in vitro of liver and brain tissue of sheep with pregnancy toxaemia were measured. Anaerobic glycolysis and oxidations of tricarboxylic acid cycle intermediates and related substrates were normal for both brain and liver enzyme preparations. Fatty acid oxidation by liver mitochondria was abnormal. Liver mitochondria from cases of pregnancy toxaemia were invariably incapable of oxidizing octanoate and palmitate, and frequently unable to oxidize propionate. The rate of propionate oxidation was low even when this substrate was oxidized. Butyrate oxidation was not much reduced by pregnancy toxaemia. Starvation of ewes in late pregnancy did not inactivate the fatty acid oxidation chains of liver mitochondria. Possible reasons for the failure of lipid metabolism are discussed. The dependence of sheep liver metabolism upon fatty acid oxidation is discussed. Insignificant amounts of glucose are absorbed from the alimentary canal in sheep and, even if absorbed, are not catabolized to supply acetyl coenzyme A for oxidation in the tricarboxylic acid cycle. Consequently sheep liver is prone to failure from interference with fatty acid oxidation. Pregnancy toxaemia is discussed in relevance to the disturbance of fatty acid metabolism which is thought to be of considerable significance in the disease.
Plasma non-esterified fatty acids in sheep
Authors: Annison EF
Published: November 2004

Concentrations of plasma non-esterified fatty acids (NEFA) in sheep were found to be within the range 0.1–0.9 m-equiv/l. Relatively high levels (1.0–2.5 m-equiv/l) occurred in pregnant and non-pregnant sheep when fasted. Intravenous injection of glucose (1.0 g/kg body wt.) depressed KEFA concentrations to levels of about 0.05 m-equiv/l. Insulin, injected intravenously, caused an initial fall in the NEFA level, followed by a sharp rise which was maintained throughout hypoglycaemia. These results suggest that in sheep, as in many other species, NEBA are of major metabolic importance.
The influence of rams on onset of oestrus in Merino ewes in the spring
Authors: Watson RH , Radford HM
Published: November 2004

Association with rams had a stimulating influence on the onset of oestrus after anoestrus in the spring. Smell and sound of the rams was sufficient to provide the stimulating influence. Direct contact with rams certainly was not necessary. Ewes which had been held well separated from rams from the beginning of July were permitted varying degrees of association with rams for 11–12 hr daily for 2 weeks in November. Some could smell, hear, see, and have actual contact with the rams; others could smell, hear, and see them only; others could smell and hear them only. These ewes, along with others which had remained well separated from rams during the same period, were then run together with raddled vasectomized rams continuously. Almost all ewes experienced oestrus during the following 26 days. However, most ewes which had previously had some association with rams experienced it first within 17 days whereas most of those which had been previously kept separate from rams did so between the 18th and the 26th day. The results in all groups which were associated with rams were closely similar irrespective of the nature of the association.
The effect of ammonium suphate usage on the availability of soil phosphorus to citrus
Authors: Bouma D
Published: November 2004

Glass-house experiments were carried out to study the effect of soil acidification, caused by the continuous use of ammonium sulphate, on the availability of soil phosphorus to citrus plants. The soils for the glass-house experiments were sampled in a tilled and a permanent sod treatment of a factorial field experiment, each at several levels of ammonium sulphate. Nitrogen levels in the soil were equalized by application of ammonium nitrate solutions. Growth and phosphorus uptake of lemon cuttings and orange seedlings were considerably better in soil from the no-ammonium sulphate plots than in soil from the high ammonium sulphate plots. Application of phosphate caused a marked increase in growth and phosphorus uptake only of plants grown in soil from the no-nitrogen plots. Increasing levels of superphosphate had very little effect if applied to the soil from the high ammonium sulphate plots. A considerably better response to superphosphate was obtained if applied to soil from limed plots, or applied together with a mixture of calcium and magnesium silicate. A good response was also obtained to crushed rock phosphate. Analysis of soils indicated that in the acid, high ammonium sulphate soil a greater proportion of soil phosphorus was present as aluminium phosphate than in the no-ammonium sulphate soil. The results are discussed in relation to citrus fertilizer practices and their effect on fruit quality aspects.
Studies on the carbohydrate metabolism of sheep. XI. The role of the adrenals in ovine pregnancy toxaemia
Authors: Reid RL
Published: November 2004

Plasma cortisol levels in fed and fasted non-pregnant and in undernourished pregnant ewes were consistently less than 1.5 µg per 100 ml. Most values were considerably above this level in 20 field cases of pregnancy toxaemia, 31 of 52 values being greater than 3 µg per 100 ml. These levels must be regarded as abnormally high in sheep. Pregnancy toxaemia was induced in two experiments by fasting after a period of severe under nutrition and in two by fasting previously well-nourished ewes in the presence of severe psychological stresses. The onset of clinical signs was associated with marked increases above normal in plasma cortisol. In three experiments involving a total of 23 previously well-nourished ewes, 11 of which carried twins or triplets, only one mild case of pregnancy toxaemia was induced by complete fasting in late pregnancy for up to 6 days, in the absence of any additional environmental stress. Pregnancy toxaemia was readily induced in 24 of 38 ewes in three experiments when severe psychological stresses accompanied fasting in late pregnancy. Adrenal hypertrophy, indicating sustained adrenal hyperactivity, was most pronounced in field cases of pregnancy toxaemia induced primarily by sustained under nutrition. Fresh adrenal weights (total of two adrenals) averaged 6.7 g compared to 3.8 g in normal non-pregnant ewes. Mean plasma cortisol levels in ewes with pregnancy toxaemia were significantly correlated with fresh adrenal weight. The suggestions that abnormalities of carbohydrate and fat metabolism in ewes with pregnancy toxaemia are those of adrenal steroid diabetes, and that cerebral depression may be largely a consequence of a cortisol-induced inhibition of glucose utilization, are discussed in the light of the probable metabolic effects of cortisol in the undernourished pregnant ewe.
Corrigendum - Water consumption by lucerne in central Australia
Authors: Jackson EA
Published: November 2004

Observations on the loss of water from soil under irrigated lucerne have been made over a 12 month period at Alice Springs. The relationship between this water loss and tank evaporation has been determined and used to calculate mean monthly requirements of lucerne in this environment. The mean annual requirement is 90 in. Data are also presented showing the rate of water loss at different soil water contents, growth stages of the crop, and soil depths.