bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of seed size and seeding rate on the growth of two strains of subterranean clover (Trifolium subterraneum L.)
Authors: Lawson EH , Rossiter RC
Published: November 2004

The results of a field experiment are presented in which large and small seeds of two strains of subterranean clover, Dwalganup and Mt. Barker, were sown at equal weights of viable seed per unit area. Two seeding rates were examined, and four harvests made during the winter-early spring period. The general conclusion is drawn that seed size has no effect on the growth rate of a subterranean clover sward, provided that sowing rate is held constant. It was found that the earlier strain Dwalganup outyielded the mid-season Mt. Barker strain in terms of total tops weight per unit area, although leaf production was higher in the mid-season strain. Root production, however, was consistently greater in Mt. Barker than in Dwalganup, and in fact total yields (of both tops and roots) were very slightly higher in the Mt. Barker strain. Growth rates are discussed in relation to net assimilation rates and leaf weights, and it is suggested that differences in root weight ratios between subterranean clover strains have not received adequate attention in the past.
Studies in soil fertility with special references to organic manures. IV. Effects of glucose on phosphate availability
Authors: Williams RF , Bromfield SM , Williams CH
Published: November 2004

The results of pot culture experiments, laboratory incubations, and soil chemical studies on phosphate availability are reported for a neutral loam from Griffith, N.S.W. Phosphorus-free organic matter (glucose) was incubated aerobically and anaerobically in soil to which known, relatively unavailable phosphorus sources had been added. These included rock phosphate, strengite (FePO4.2H20), and variscite (AlPO4. 2H2O). Native soil phosphate and added strengite became more available following anaerobic incubation. This effect was sometimes but not always increased when glucose had been incubated with the soil. Added rock phosphate and variscite were rendered less available following anaerobic incubation. These effects were prevented when glucose had been present. The organic acids produced during the anaerobic incubation of glucose in the soil seem to have played little part in determining the availability of phosphate in these experiments. Anaerobic conditions as such appear to have played a major role.
Studies on the carbohydrate metabolism of sheep. VII. Intravenous glucose and acetate tolerance tests
Authors: Reid RL
Published: November 2004

Intravenous glucose and acetate tolerance tests have been carried out on shoop fed on a variety of diets. The disappearance of injected glucose and acetate appears to follow an exponential function with respect to time. On all diets used, the rate of disappearance of acetate appeared slower then in non-ruminants. The rate of glucose disappearance was slow in sheep fed on roughage diets but rates as high as those normally observed in man were recorded on high intakes of a diet containing 50 per cent. of cracked maize. On varying dietary regimes, variations in the rate of disappearance were in the same direction and of a similar order of magnitude for both glucose and acetate. Rates were considerable decreased daring fasting. The data are discussed ill the light of other data on tissue utilization of glucose and acetate in ruminants and in relation to present knowledge of metabolic differences between ruminants and non-ruminants.
Herbage intake of grazing sheep in South-western Australia
Authors: Fels HE , Moir RJ , Rossiter RC
Published: November 2004

Estimates of the intake of pasture organic matter by grazing sheep were made for two types of pasture, clover-dominant and grass-dominant, at three growth stages. These estimates were made from faecal nitrogen index equations which were derived from data on penned sheep. One of the equations was found to be remarkably close to Lanoaster's (1954) regression of feed/faeces ratio on percentage faecal nitrogen content. The dry mature clover pasture was anomalous, and a separate "local" regression was derived for it. Organic matter intakes for grazing sheep of about 110 lb body weight ranged from 900 to 1300 g/day, except on dry clover pasture, where the intake was only about 700 g/day. Contrary to common belief, subterranean clover was eaten at least as readily as grass during the growing season. Evidence is presented that sheep grazing on pastures with a total nitrogen content of 2 . 5 per cent. or less select material of higher than average nitrogen content, whereas if the nitrogen content of the pasture exceeds 3.5 per cent. there is no such selection. The anomalous characteristics of the dry mature clover are discussed in some detail, and further evidence is given suggesting that the material was of poorer digestibility than usual.
Further studies on the determination of cold hardiness in Trifolium repens L. and Medicago sativa L.
Authors: Greenham CG , Daday H
Published: November 2004

This paper deals with probe measurements of low frequency resistance (RLF), high frequency resistance (RHF), and resistance index (= 100 x RLF/RHF), for the determination of cold hardiness or the injury caused by cold treatments. Populations of white clover (Trifolium repens L.) were subjected to different periods of freezing. Discrimination between treatments could be made in terms of RLF, RHF, and resistance index, though discrimination in terms of RHF is poor. The rest of the paper deals with lucerne (Medicago sativa L.). Measurements were made after a cold treatment on field plants consisting of four commercial strains and their F1 crosses, and also on F2 seedlings. RLF and the resistance index appear to be equally good predictors for the recovery of strains or of individual plants from such populations. The Appendix deals with measurements on commercial (tetraploid) plants, diploids, and colchicine-produced tetraploids.
Studies on the carbohydrate metabolism of sheep. IX. Metabolic effects of glucose and glycerol in undernourished pregnant ewes and in ewes with pregnancy toxaemia
Authors: Reid RL
Published: November 2004

The rate of utilization of injected glucose by fasted pregnant ewes or ewes with pregnancy toxaemia is much more rapid than by fasted non-pregnant ewes. An apparent relation between the rate of utilization and the number of fetuses was observed; much of the injected glucose may be removed by the foetus(es). The pronounced rise in blood glucose recorded after lambing and when foetuses apparently died in utero is also considered to reflect sudden cessation of high foetal demands for glucose.
Intravenous administration of glucose consistently reduced blood ketones in ewes with a moderate hyperketonaemia and showing no clinical signs of pregnancy toxaemia. Ketones declined in ewes fasted 1–3 days as soon as blood glucose began to increase at lambing. In ewes with pregnancy toxaemia there was usually no reduction of ketones in response to injected glucose; blood acetic acid levels, if previously high, did not decline; blood citric acid failed to increase.
Glycerol given per os to ewes with pregnancy toxaemia always caused a rapid decline in blood ketones, and in acetic acid if the latter was previously high; a, pronounced increase in blood citric acid always occurred. These changes were recorded although no clinical improvement was observed.
Glucose administered parenterally over 48 hr appeared to be less efficiently utilized by ewes with pregnancy toxaemia than by fasted pregnant ewes showing no clinical signs. Blood ketones declined to normal levels within 48 hr; in probable contrast to fasted ewes, this is considered to have occurred in the ewes with pregnancy toxaemia only because hyperglycaemia was continuously maintained. These results are considered to support the hypothesis that gluoose metabolism is depressed in ewes with pregnancy toxaemia and that the metabolic abnormalities are consistent with those characteristic of a diabetic-like syndrome.
The chemical composition of the soil in a factorial experiment with citrus. II. Extractable ammonium
Authors: Groenewegen H , Connor Jane
Published: November 2004

Data are presented on the ammonium content of soils in a factorial field experiment with citrus, involving different cultural treatments and ammonium sulphate levels. This is an experiment under spray irrigation, located in a semiarid area with high summer temperatures. In the 0–4 in. layer of a no-tillage, bare surface treatment, extractable ammonium persisted long after the ammonium sulphate application. Below a depth of 4 in. this treatment also gave higher extractable ammonium and lower nitrate contents than the tilled treatment. Some short-term experiments indicated that the absence of mixing in the 0–4 in. layer was a contributing factor in the reduced nitrification of the bare surface treatment. It was also found, however, that the nitrifying capacity of the soil from the area between the trees of the bare surface treatment was reduced as compared with those of the rest of the experiment. It is concluded that under the experimental conditions nitrification was rapid in the soil of the tilled plots, even in those which had a soil pH as low as 4.3.
Comparison of estimates of repeatability and heritability for some production traits in Merino rams and ewes. I. Repeatability
Authors: Young SSY , Newton Turner H , Dolling CHS
Published: November 2004

Repeatabilities of 10 traits, namely, greasy wool weight, clean scoured yield, clean wool weight, body weight, wrinkle score, face cover score, fibre population density, fibre diameter, staple length, and crimps per inch, were estimated in ewes and rams. Estimates ranged from 0.4 to 0.7 for the 10 traits in both sexes. In general, body weight was the most repeatable trait and face cover the least. There is no evidence of sex differences in repeatability of the traits studied. Correlations between pairs of records obtained at different ages were high in both rams and ewes. This finding, together with the high repeatability values for all the traits, suggests that selection of sheep based on a single record is probably sufficiently accurate for lifetime performance of these 10 traits in Merinos. The correlations between yearling records and subsequent records in ram were found to be in agreement with correlations between records taken at older ages. Early selection of rams for lifetime performance therefore is probably almost as efficient as selection at a later age, and it is suggested that this finding might also be found to apply to ewes.
Changes in the dilatability of the ovine vagina in relation to oestrus and anoestrus
Authors: Wodzicka M
Published: November 2004

Changes in the dilatability of the ovine vagina have been measured during the breeding season and during anoestrus. An increase in apparent vaginal volume occurs at the time of oestrus. There is little change in volume over the remainder of the oestrous cycle. In anoestrus, the dilatability is smaller than at any time during the breeding season. It is suggested that these changes in the dilatability of the ovine vagina could be used in studies of the breeding season of ewes in which the use of the ram is not desirable.
Efficiency of conversion of food to wool. I. Correlated response to selection for high and low clean wool weight
Authors: Dolling CHS , Moore RW
Published: November 2004

The offspring of two families of medium Peppin Merino sheep, one family being selected for high and the other for low clean wool weight per head at 15-16 months of age under grazing conditions, have also been shown to differ significantly in the ratio of wool production to food eaten in pens, on a ration slightly above maintenance. These ratios were in the proportion 108 : 100, and the difference between the families can be taken as reflecting closely a difference in net efficiency of conversion of food to wool. It may be concluded that selection for high clean wool weight per head under grazing conditions had also resulted in the selection of more efficient animals. Clean wool production per head in the two families was in the ratio 110 : 100 in the pens, compared with 124 : 100 under grazing. The difference under grazing probably results from both the higher efficiency of the family selected for high clean wool weight and a higher grazing intake by this family.
Variation in symbiotic effectiveness in subterranean clover (Trifolium subterraneum L.)
Authors: Nutman PS
Published: November 2004

(1) The symbiotic effectiveness of 15 varieties and of four tetraploid lines of subterranean clover were examined in association with several strains of nodule bacteria.(2) Relatively- small but significant differences in yield occurred between host' varieties, and the varietal order of response depended somewhat on the bacterial strain, but not enough to shorn- any well-defined variety-strain specificity. (3) Hybridization between varieties increased yields slightly in F2, less in F3, and the effect disappeared in F4. (4) With one doubtful exception all attempts to alter effectiveness by selection or breeding within hybrid material failed.
Studies on ensilage. I. A comparative laboratory study of molasses and sodium metabisulphate as aids to the conservation of lucerne
Authors: Lanigan GW
Published: November 2004

The relative effects of molasses and sodium metabisulphite on changes occurring in ensiled lucerne have been investigated. Under certain conditions, both additives have been shown to be of great benefit to the conservation process: molasses by increasing the intensity of the lactic fermentation, and metabisulphite by preferential inhibition of undesirable fermentative changes. The proportion of molasses needed for best results has been found to vary with the maturity of the lucerne at harvest, but the effects of metabisulphite are less dependent on this factor. Benefits which accrue from both additives are adversely affected by silage temperatures of 30°C and above, especially in the case of metabisulphite. Some practical implications of these observations are discussed.
Studies on the carbohydrate metabolism of sheep. XVI. Partition of ketone bodies in blood, tissues, and urine
Authors: Reid RL
Published: November 2004

Acetone comprised 0–40% (average 18%) of the acetoacetic acid plus acetone fraction in sheep blood, in which the level of this fraction was 0.6–5.2 mg % (as acetone). Acetoacetic acid was largely converted to acetone during storage of blood at –20°C, with intermittent thawing for analysis. Concentrations of acetoacetic acid in red cells were similar to those in plasma, but those of ß-hydroxybutyric acid were considerably lower. In contrast to acetoacetic acid, ß-hydroxybutyric acid was virtually absent from foetal blood and from brain tissue. Concentrations of both ketone fractions in liver and muscle tissue were about one-half the blood concentrations. The renal clearance of acetoacetic acid plus acetone in hyperketonaemic pregnant ewes was independent of blood level up to 20 mg % and was little affected by rate of urine flow. Clearance values were in the range of 4–9 ml per min, which indicates that most of the acetoacetic acid filtered at the glomeruli is absorbed by the renal tubules. Renal clearance of ß-hydroxybutyric acid was dependent on blood level and was more affected by rate of urine flow than that of acetoacetic acid. Very little ß-hydroxybutyric acid appeared in the urine when blood levels were below 15 mg %. Clearance increased as blood concentration rose above this level, and reached maximum values, mostly of 3–5 ml per min, at blood levels exceeding 30 mg %.
Soil moisture conditions and pine failure at Waarre, near Port Campbell, Victoria
Authors: Poutsma T , Simpfendorfer KJ
Published: November 2004

The pines in the Forests Commission plantation at Waarre, near Port Campbell in Victoria, are marked by large and widespread differences in vigour, and in some cases even by virtual failure. To investigate this condition the presence of and changes in free water levels in the soils were followed at 16 sites on the plantation. This was done by means of shallow wells 30 in. deep, and piezometers sunk to a depth of 5½ ft. Observations extended over 28 months. The results showed that surface waterlogging is widely present on the plantation. This surface waterlogging is seasonal, and it varies in severity from year to year in accordance with the rainfall. "Free" ground-water is absent from nearly all the deep subsoils. The vigour of the pine cover was found to vary significantly with the degree of surface waterlogging. For Monterey pine (Pinus radiata D. Don) the correlation coefficient for nine sites was 0.82**, and for maritime pine (P. pinaster Ait.) the correlation coefficient for six sites was 0.81*. This relationship appears to be modified by the lateral movement of free water through the surface horizons. Nutrient trials have also shown a slow but marked response to additions of superphosphate.
An alternative hypothesis to account for the generally low phosphate content of Australian soils
Authors: Beadle NCW
Published: November 2004

It is postulated: (1) That the generally low phosphate content of Australian soils is due to the occurrence over extensive areas either of phosphate-low rocks which are largely sedimentary and built up from coarse particles which are left behind after the finer particles (which are richer in phosphate) were removed by water or wind, or of unconsolidated parent materials derived from such rocks or from other rocks with an average or low phosphate content. (2) That the process of sorting, resulting in the removal of the finer particles, is more important as a phosphate-depleting process than is leaching. (3) That significant phosphate losses may also result from the removal of surface soil and of organic matter during the process of erosion; and that this phosphate accumulates in valleys and swamps, in drainage basins in the interior, or it may he washed into the ocean. Laterite formation does not appear to be a phosphate-depleting process but, during the formation of laterite, phosphate may move within the profile, being ultimately fixed in bands rich in iron. Under conditions of impeded drainage, loss of phosphate is regarded as improbable over large areas, and it is suggested that apparent losses, such as have been reported for small areas, may be accounted for by removal of the phosphate from the soil by plants. The more obvious factors responsible for the removal of phosphate are briefly discussed, and the values for leaching obtained by certain authors are queried, chiefly on the grounds that the authors have not taken into consideration the amount of phosphate that is held in the vegetation. These views are opposed to those put forward by Wild, who suggested (1958) that the generally low phosphate values in Australian soils are due to "losses by leaching, especially under poor drainage conditions" rather than to low phosphorus in the parent rocks. This view was somewhat modified (1961) to read: "over most of the continent leaching, if this was the cause of the loss, had taken place in wetter periods of the past".
The application of the technique of egg transfer to sheep breeding
Authors: Moore NW , Shelton JN
Published: November 2004

During the autumns of 1960 and 1961, 86 first- and second-cross (backcross to polled rams) polled Merino ewes were treated with a horse anterior pituitary extract (HAP) to induce multiple ovulation. Of the 86 ewes, 78 were served within 96 hr of the cessation of treatment. Laparotomies, performed for the pqrpose of egg recovery, showed that 74 of the ewes served had ovulated, shedding a total of 841 eggs of which 667 were recovered and of these 482 had been fertilized. A total of 441 fertilized eggs were transferred at rates of one to three per animal to the uterine horns or Fallopian tubes of 262 recipient horned Merino ewes of which 177 subsequently lambed, producing 236 lambs. Irrespective of the number transferred per recipient, the proportion of eggs which developed into lambs following tuba1 transfers was significantly less than that following uterine transfers. The survival of transferred eggs was not significantly affected by the number transferred per recipient. The practical value of the technique of egg transfer in the ewe is briefly discussed.
Studies on the relationship of saliva to rumen function of sheep on low feed intakes
Authors: McManus WR
Published: November 2004

Seven in vivo experiments are reported in which the effects of diverting alkaline mixed saliva from the actively fermenting contents of the rumen of anaesthetized and conscious sheep fed on a standard ration were studied for periods up to 6 hr. The absence of various quantities of saliva (225–1349 ml) was associated with profound alterations in the rumen environment: rumen liquor volatile fatty acid (V.F.A.) levels were consistently and substantially elevated, and rumen pH levels depressed. These changes in the rumen environment began about 40–60 min after saliva diversion commenced, and were sustained long after such values for the control animals had inflected towards fasting levels. Rumen movements were recorded in two experiments. Rumen movement was reduced, but not entirely suppressed, some 60 min after the minimal pH values obtained. It is suggested that this reduction in rumen movement was a consequence of depressed pH values. The rumen pH-rumen V.F.A. relationship was, in six such cases, altered but the strength of this relationship was not significantly changed. It was concluded that these effects on rumen pH-V.F.A. levels and relationship were due, directly or indirectly, to the changed buffering or osmotic regime, or both, of the saliva-depleted rumen liquor. Implications of these findings are discussed in the light of rumen physiology and the field use of oesophageally fistulated sheep.
Physiological attributes of coat colour in beef cattle
Authors: Schleger AV
Published: November 2004

A system of scoring coat colours in the range from light red to dark red has been applied to cattle at the National Cattle Breeding Station, Rockhampton, Qld. The cattle were Herefords and Shorthorns and crosses between these and the Africander. Colour is affected by age, season, reproductive stake, growth phase of the coat, and sex, and also by exposure to solar radiation. Colour is a highly repeatable characteristic of individual animals and has high heritability, estimated at 53%. Melanin concentration in the hair is the chief determinant of colour, the partial regression coefficient (β) being 0.73, while the proportion of medullated hairs (β = –0.32) and the mean diameter (β = 0.17) have half and quarter the significance respectively. The relationship between coat type and coat colour is complex, varying with the season of the year. Within the range of red colours studied, there is no tendency for darker animals to exhibit any effects of higher heat load. The relationship between depth of colour and body temperature tends if anything to be slightly negative, which suggests that darker animals have some other characteristic favouring temperature regulation. Correlations between intensity of red colour and rate of gain are consistently positive. The magnitude of the relationship varies with season, and the validity of choosing an optimum season is discussed. The mean correlations between gain and colour score in the optimum period are 0.50 for Africander cross and 0.32 for British breed calves. Coat colour may therefore be more useful than a score of coat type in Africander cross calves, though less useful in British breed calves.
Number and morphology of chromosomes in African species in the genus Trifolium L.
Authors: Pritchard AJ
Published: November 2004

Chromosome numbers are reported for 14 African species and varieties in the genus Trifolium L. All species belong in that section of the genus with a basic chromosome number of x = 8. There are differences in chromosome size and morphology between species, and three are polyploids. A consideration of the karyotype, growth form, and distribution of these species suggests that some of them are primitive, and that the highlands of East Africa may be a centre of origin of the genus.
Relationship between viability and availability of Rhizobium trifoliiintroduced into seeds of Trifolium subterraneum L. by inhibition and pressure
Authors: Brockwell J , Hely FW
Published: November 2004

In an investigation into the fate of Rhizobium trifolii inoculum introduced into seeds of Trifolium subterraneum L. by imbibition, it was found that: (1) Considerable numbers of Rh. Trifolii were introduced to seeds which imbibed in a broth culture, the number apparently increasing when application of pressure was used to accelerate the imbibition. (2) Pressures up to 1600 lb/sq. in., even when released rapidly, had no apparent effect on the viability of Rh. Trifolii in broth culture, or on the subsequent germination and growth of T . Subterraneum seeds. (3) After storage of the seeds for several months, the total number of Rh. Trifolii recovered was large, especially in the case of seeds which had been subjected to pressure. (4) The Rh. Trifolii present in seeds which imbibed under pressure were remote from the seed surface, and in the field made little contribution towards colonizing the seedling rhizosphere or producing nodules.
Studies on the artificial insemination of Merino sheep. III. The effect of frequent ejaculation on semen characteristics and fertilizing capacity
Authors: Salamon S
Published: November 2004

(1) Fifty-five ejaculates were collected from each of two Merino rams over a period of 5 days (11 per day per ram at intervals of 20 min). Ejaculates were examined for semen characteristics and for fertilizing capacity following artificial insemination, a total of 300 ewes being used. (2) Volume, density, and number of sperm declined on successive days, and in successive ejaculates within days (P <0.001). Motility and percentage of abnormal sperm were not affected by frequent collection. (3) Fertility following insemination with a standard volume of diluted semen showed a significant linear decline with successive ejaculates, both within and between days of collection ( P <0.01, <0.001). (4) The decline in fertility could be accounted for entirely on the basis of sperm numbers. There was no evidence of a decline in the fertilizing capacity of spermatozoa with frequent ejaculation. (5) There was a highly significant linear relationship between sperm numbers and lambing percentage, over the range of 28 to 128 X 106 sperm (27–118 x 106 normal; b = 0.27; r = 0.69; P <0.01). (6) It is concluded that a dose of approximately 120–125 x l06 normal sperm is necessary for maximum fertility to artificial insemination; and that each 25 x 106 reduction down to a dose of 25 x 106 may be associated with a drop in lambing rate of about 13%.
The influence of diet on the development of paratid salivation and the rumen of the lamb
Authors: Wilson AD
Published: November 2004

The development of the parotid glands and the rumen were studied in four groups of lambs, 91–98 days old, each group being reared on a different diet. One group received an all milk diet; and the others received — in addition to milk — hay, wood shavings, or a purified diet consisting of starch, fortified whole milk powder, and 3% sodium bicarbonate. The criterion of parotid development was the stimulated secretion rate per gram of parotid gland, in anaesthetized lambs. Rumen development was recorded in terms of the growth of mucosa and muscle, the growth of the papillae, and the changes in the volume of rumen contents and the rumen capacity. In another experiment the same comparisons were made between lambs of 63 days of age which had grazed with their mothers, and lambs that were grazed until 63 days of age, but were then confined to a milk diet for a further 70 days. The parotids of the lambs fed on wood shavings secreted 0.50 g saliva/g parotid/min, compared with a secretion of 0.51 g/g/min by the lambs fed with hay. The parotids of the lambs fed on the purified diet secreted 0.27 g/g/min, which was little more than the secretion of 0.20 g/g/min by the lambs fed on milk alone. The lambs receiving the milk or purified diets secreted significantly less saliva than those receiving the hay or shavings diets (P < 0.01). The parotids of the grazing lambs secreted 0.44 g/g/min, which was significantly greater (P < 0.05) than the secretion by the lambs returned to the milk diet (0.26 g/g/min). It was concluded that the parotid glands developed in response to the mechanical stimulation of the food, and that there was a regression of gland development when this stimulation was removed. The rumen mucosa developed in the lambs fed on the hay, grazing, and purified diets, but not in those lambs fed on the milk or shavings diets. There was a regression of the mucosa in those lambs returned to the milk diet.
The toxic action of phenothiazine and some disturbances of intermediary metabolism in undernourished sheep
Authors: Koch JH
Published: November 2004

Uncoupling of oxidative phosphorylation was found in preparations of liver mitochondria obtained from adequately fed sheep, killed 24 hr after the administration of phenothiazine. Sheep fed a low quality diet suffered considerable loss of weight and all had fatty livers at necropsy. The extent of the fatty change seemed to be related to the rate of weight loss. Liver mitochondria from sheep which had lost body weight at an average of 0.3 lb/day had normal biochemical activities. The administration of phenothiazine to such sheep caused uncoupling of oxidative phosphorylation. Animals with weight losses of 0.33 lb day or more showed depressed mitochondria] respiration rates with very little phosphorylation. Phenothiazine did not increase the Q(N)O2 values in such sheep. Glucose 6-phosphate dehydrogenase activity was found to be extremely low in sheep erythrocytes—approximately 5% of normal human red cell values. The activity of this enzyme was not affected by malnutrition, or by phenothiazine administration to either well-fed or undernourished sheep.
The inheritance of a vernalization response in Australian spring wheats
Authors: Pugsley AT
Published: November 2004

A backcrossing procedure was used in the development of a pair of near-isogenic lines which differed in their responsiveness to vernalization. When grown during the summer the two lines differed in the time taken for ear initiation and ear emergence. This difference could be reduced by vernalization treatments, either naturally under field conditions in the winter or in a refrigerator for summer sowings. Some evidence was obtained indicating that vernalization could occur during the ripening of grain in the glass-house during the winter. A single gene difference governing the vernalization response was demonstrated, so that this characteristic may readily be transferred in a breeding programme for the production of frost-tolerant varieties.
Body composition in vivo. II. The composition of mature goats and its relationship to the antipyrine, tritiated water, and N-acetyl-4-aminoantipyrine spaces
Authors: Panaretto BA , Till AR
Published: November 2004

The antipyrine, tritiated water, and N-acetyl-4-aminoantipyrine spaces were determined simultaneously in goats which had been deprived of feed and water for 48 hr. The animals were then killed, minced, and analysed for water, fat, protein, and ash contents. The compositions of the whole and empty bodies of the goats were calculated, and the relationships between the bodily components were compared with those reported for cattle, sheep, and some monogastric species. The relationships found between the components of the whole bodies compared favourably with those derived from the empty bodies. The relationships of the spaces determined in vivo to total body water, fat, and protein were found, and confidence statements were placed on predicted estimates.
Thyroid secretion rates in grazing British and Zebu cross bred steers: Seasonal effects and relationships with growth
Authors: Post TB
Published: November 2004

Marked monthly fluctuations in thyroid secretion rates and component parameters in 16 Hereford x Shorthorn, Africander x Hereford, and Brahman x Hereford steers did not follow seasonal changes in ambient temperature or day length in subtropical Queensland, but were more consistently related to changes in pasture quality. Secretion rates when the pasture was at its best were more than double those recorded when the pasture was poorest. British steers as compared with Zebu crossbreds were similar in thyroxine turnover rate, lower (P < 0.01) in thyroid secretion rate, plasma protein-bound iodine (P.B.I.), and extrathyroidal thyroxine, and higher (P < 0.01) in thyroxine volume of distribution. There were no breed x month interactions. Determinations of blood volumes and extracellular water volumes did not provide any explanation of differences in P.B.I. and thyroxine volume of distribution. Correlations betweefl thyroid secretion rates and body weight gains were positive (r = 0.85, P < 0.01, among months; r = 0.70, P < 0.01, among animals) in summer when pasture was good and gains averaged 2.06 lb per day. Correlations were negative (r = –0.78, P < 0.01, among months; r = –0.43 among animals) in winter when pastures were poor and gains averaged –0.28 lb per day. Of the different components of thyroid secretion rate, P.B.I. and extrathyroidal thyroxine were superior to thyroxine turnover rate and thyroxine volume of distribution in reflecting seasonal changes in thyroid activity and its relation with growth rates. P.B.I. and body weight contributed most and thyroxine turnover rate and thyroxine volume of distribution least to differences in thyroid secretion rate between breeds and between animals within breeds.
General and specific combining ability for forage yield in lucerne (Medicago sativa)
Authors: Daday H
Published: November 2004

The genetic control of forage yields was investigated by a combining ability analysis based on a diallel cross made up of the hybrids between nine genotypes of lucerne. Summer forage yield was found to be controlled by additive and non-additive genes, and winter yield mainly by additive genes. General combining abilities differed markedly between genotypes for both summer and winter yields, and the correlation coefficient between summer and winter yields was high (0.89).Selected F2 and F3 progenies from crosses between Du Puits, Hairy Peruvian, and African cultivars substantially exceeded parental values for summer, winter, and spring forage production under row-sward conditions. There were positive correlations between summer, winter, and spring productivity in one of the two F2 experiments and in spaced F3 plants. Heritability estiniates for summer and winter yield ranged from 22 to 28%, and for spring yield, from 14 to 18%. On the basis of the estimated genetic parameters, yield increases should be obtained by either family selection or heterosis breeding.
Nutritional status and intake regulation in sheep. I. Effects of duodenally infused single doses of casein, urea, and propionate upon voluntary intake of a low-protein roughage by sheep
Authors: Egan AR , Moir RJ
Published: November 2004

In each of two experiments, single infusions of casein administered to sheep per duodenum produced substantial and rapid increases in voluntary intake of chaffed oaten hay diets of low nitrogen content (0.62–0.70% nitrogen). The effect commenced within 16 hr of completion of the infusion, and occurred before any observed change in the rate of cellulose digestion in the rumen. When urea was infused per duodenum at the same level of nitrogen as with the casein, an increase in intake occurred on the day following infusion in one experiment. In a second experiment no such response occurred. Faster rates of cellulose digestion were observed on the day of infusion, apparently due to recycling of nitrogen to the rumen. Of the 10 g of nitrogen infused, 7.4 g of casein nitrogen and 5 g of urea nitrogen were retained. Propionate, infused in an attempt to reproduce the gluconeogenic properties of casein, did not have any major effect on daily dry matter intake, although it caused a depression in intake during the period of infusion in one experiment. Results are discussed in relation to the possible mechanism of response to the protein supplement. The possibility is suggested that the protein status of the animal is a component of a chemoregulatory mechanism governing the intake of low nitrogen diets by sheep.
Aneuploidy in Sorghum almum Parodi and Sorghum halepense (L.) Pers.
Authors: Pritchard AJ
Published: November 2004

In four aneuploid (2n = 39) plants of Sorghum almum the odd chromosome was involved in trivalent formation at first metaphase of meiosis more frequently than it was in an aneuploid (2n = 39) plant of S. halepense. Most of the gametes of the aneuploids had 19 or 20 chromosomes. Chromosome numbers of the progenies of these plants confirmed these observations, and also showed that the aneuploid lines could be maintained although in two of the S. almum lines there was selection for female gametes with the balanced number of n = 20. S, almum and S. halepense may be autotetraploid in origin. The differences in behaviour of the odd chromosome in the aneuploids are a reflection of the different levels reached in the differentiation of two pairs of preferentially pairing and genetically different chromosomes from each group of four homologues.
Rumination in sheep. III. Experimentally induced variations on the circadian pattern of rumination
Authors: Pearce GR
Published: November 2004

The circadian (24-hr) pattern of rumination of caged sheep was found to be affected: (a) by the administration of a roughage ration per fistulam; (b) by the emptying of the rumen and the subsequent return of the rumen contents; (c) by the emptying of the rumen and the replacement of the contents by a buffer solution plus roughage. The period during which no rumination occurred following feeding was progressively shortened when increasing proportions of a ration of oaten chaff and lucerne chaff were administered per fistulam. The effect was much reduced when high protein sheep cubes were added to the chaff ration. The removal of the rumen contents after voluntary feeding and then their immediate return to the rumen tended to cause an early commencement of rumination. When the rumen contents were "pasteurized" before return, however, rumination did not occur for an extended period afterwards. When the rumen contents were replaced with buffer solutions plus roughage, variable rumination responses occurred. In one instance apparently uninhibited rumination resulted.
Peyronellaea glomerata — A fungus growing within the fibres of the unshorn fleece
Authors: Mulcock AP
Published: November 2004

Fleece wool affected by the fungus Peyronellaea glornerata had dark-coloured tips similar to wool contaminated by grease and dust, but the colour could not be removed with water and detergents or extracted with solvents. Hyphae were found within wool fibres and, where fruiting structures formed, the overlying cortical and cuticular cells were ruptured. The fungus utilized nitrate, nitrite, ammonium, amide nitrogen, and wool; it grew well and sporulated with glucose, sucrose, lactose, and starch as sole carbon sources. Growth was sparse when cellulose and Wool were the sole carbon sources, but satisfactory with peptone. The fungus grew best on tryptone–glucose extract agar (Difco) at 26°C. In culture on a mineral medium with wool sterilized by ethylene oxide, only wool fibres from the distal ends of the staple were attacked by the fungus, brush ends being formed, and cortical cells were released into the medium; whereas with wool sterilized by autoclaving, the fibres were attacked throughout their entire length.
Soil acidity and growth of a legume. II. Reactions of aluminium and phosphate in solution and effects of alumminium, phosphate, calcium, and pH on Medicago sativa L. and Trifolium subterraneum, in solution culture
Authors: Munns DN
Published: November 2004

Lucerne (M. sativa L.) grew as well in solutions maintained at pH 4 as at pH 5, and its growth at pH 4 was little affected by calcium concentrations above 5 mM when aluminium was not added (< 0. l µM). Phosphate concentrations above l µM were adequate for growth if maintained, and if phosphate was kept below 5 0 µM at pH 4 or below 10 µM at pH 4.5, then aluminium concentrations of the order of 100 µM could be maintained without evident reaction between aluminium and phosphate in solution. Under these conditions, uncomplicated by precipitation or phosphate deficiency in the nutrient solution, aluminium toxicity depressed yields, root elongation, and calcium and phosphate concentrations in shoots and roots, and it made the shoots look phosphate-deficient ; but it could not be remedied by increasing phosphate supply even when this restored plant phosphate to high levels. Only where addition of phosphate caused aluminium to precipitate in the solution did it alleviate the toxicity. Increasing the calcium concentration from 1 mM to 5 mM slightly alleviated the effects of aluminium, except at highly toxic concentrations. T. subterraneum took up more aluminium than lucerne, but tolerated aluminium in the medium better. Adding ethylenediaminetetra-acetate to solutions containing 200 µM aluminium concentrations improved the growth of both species to the extent that concentrations of free aluminium were reduced by chelation.
The effect of high temperature regimes or short periods of water stress on development of small fruiting saltana vines
Authors: McEAlexander D
Published: November 2004

Poor fruit set of sultanas in the Murray Valley is sometimes attributed to excessively high temperatures around flowering time. Experiments with small fruiting sultana vines in pots suggest that water stress is the more important factor. Fruit set was significantly less when a 3-day period of water stress was imposed at flowering or 1, 2, or 4 weeks after flowering, but not when it was imposed 6 weeks after flowering. Three days with maximum temperatures above 45°C at or 1 week after flowering did not reduce fruit set when ample water was supplied. When controlled environments combining day temperatures between 21 and 30°C with night temperatures between 19 and 25° were used, no significant differences in fruit set were found, although shoot growth increased with increasing night temperature. Shoot elongation slowed down during periods of applied water stress but recovered, when the stress was ended, to a rate greater than that of plants which had not been stressed.
The effect of level of nutrition on thyroid activity in beef cattle
Authors: Post TB
Published: November 2004

Four experiments were conducted to determine the effect of different nutritional levels on thyroid activity in beef cattle. In experiment 1, plasma protein-bound iodine (P.B.I.) levels in eight steers on poor pasture increased by over 50% 24 hr after supplying a supplement of 20 lb good quality lucerne hay per animal per day. In experiment 2, 17 grazing spayed heifers given a supplement of 2 lb peanut meal per day over a 4-month period also had higher P.B.I.'s than 24 controls. In experiment 3,10 growing steers given a constant amount of lucerne hay throughout the year showed decreases in P.B.I. and thyroid secretion rate consistent with a decline in feed intake per unit of metabolic body weight. A Latin square design was used in experiment 4, to study the effects of ad libitum feeding of three different rations: lucerne hay, non-legume hay, and ground sorghum plus non-legume hay to 18 steers. All rations caused sharp first-day increases in P.B.I., the magnitude of which depended on the quality of the ration. As feeding continued the P.B.I.'s decreased somewhat. At the end of 5 weeks, P.B.I.'s and thyroid secretion rates were similar in steers fed on lucerne or sorghum plus non-legume hay, but significantly lower (P < 0.05) in those fed on non-legume hay alone. The failure of intramuscular injections of vitamin A to increase P.B.I. in animals on low-carotene pasture and hay ruled out the carotene content as a source of the nutritional effect. These studies indicate that various types of improved nutrition can have pronounced effects on the thyroid, and that seasonal and animal differences in thyroid activity could result from differences in quality or quantity of pasture intake.
Physiological and ecological studies on the oestrogenic isoflavones in subterranean clover (T. subterraneum L.). II. Effects of phosphate supply
Authors: Rossiter RC , Beck AB
Published: November 2004

Two experiments with the Mt. Barker strain of subterranean clover and one with the Dwalganup strain were conducted. In each experiment, increase in phosphate supply led to increases in total dry weight production. As phosphate deficiency became more acute in the Dwalganup strain, the leaf concentrations of two isoflavones, formononetin and genistein, increased as much as twofold; a third isoflavone, biochanin A, showed little change. In the Mt. Barker strain the concentrations of genistein and biochanin A increased about twofold with increasing severity of phosphate deficiency, while those of formononetin increased at least fourfold. It is suggested that isoflavone formation in clover leaves increases under phosphate deficiency, and that this is associated with increased carbon substrates in the leaf cells. The relations between isoflavone levels and oestrogenic potency are discussed. Phosphate deficiency may be indirectly related to oestrogenic potency through its influence on isoflavone levels.
Distribution of 65Zn in pear trees following bark injection
Authors: Millikan CR , Hanger BC
Published: November 2004

Two-year-old pear trees (cv. Packham Triumph) growing in 15-gal drums, were bark-injected with 65Zn 2 months after bud burst. To some injection doses nonradioactive zinc with or without EDTA was also added. The 65Zn only moved from the injection point when extra zinc was included in the dose. EDTA further enhanced this movement. The 65Zn was distributed to spurs and laterals on the injected leader, situated above and on the same side as the point of injection. Limited downward movement was also evident. 65Zn was detected in new growth formed after injection, and also in blossom, leaves, and new lateral growth produced on the injected leaders in the following season. It was found that 65Zn accumulated at the nodes on laterals, and in the petioles, midrib, and major veins of the leaves.
Study of the fate of phyto-oestrogens in the sheep by determination of isoflavones and coumestrol in the plasma and adipose tissue
Authors: Lindner HR
Published: November 2004

A method is presented for the specific determination in plasma or adipose tissue of sheep of the phyto-oestrogens genistein (G), biochanin A (BA), formononetin (F), daidzein (D), pratensein, and coumestrol. The method is based on selective extraction, paper chromatography, spectrophotometry and fluorometry, and use of radioactive recovery standards. A modification including gas chromatography is also described. Intraruminal administration to sheep of the synthetic isoflavones G, BA, or F gave rise within 2½ hr to detectable blood levels of the compound infused. In addition, intraruminal administration of BA and F was followed by the appearance of G and D, respectively, in blood and fat depots. Such O-demethylation at the C4 position was also observed after intramuscular injection of BA or F, and in sheep grazing subterranean clover (Trifolium subterraneum L.) and red clover (T. pratense). Plasma levels of free G above 5 µg/100 ml (excluding circulating isoflavone conjugated as glucuronide) were associated with maximal uterine growth response in ovariectomized ewes, while levels of 1–5 µg/100 ml appeared to elicit a graded uterine response; free plasma F and D levels above 0.5 �g/100 ml seem to be required for detectable uterotrophic action in the 5-day assay used. G, BA, F, and D were present in the plasma of sheep grazing subterranean clover var. Yarloop in concentrations adequate to explain the observed uterine growth response, but in sheep grazing red clover, the plasma levels seemed too low to account fully for the oestrogenic action of this pasture. No free isoflavones were detected in plasma from sheep grazing subterranean clover var. Marrar, despite the high isoflavone content of the pasture.