bluuebunny/crossref_metadata_2025 huggingface dataset:
Flower initiation in pasture legumes. IV. Flower initiation in Trifolium pratense L.
Authors: Aitiken Y
Published: November 2004

An early strain (Cowgrass) and a late-maturing strain (Montgomery) of red clover (Trifolium pratense L.) were grown at Melbourne, lat. 38°S., to study flower initiation and the relationship between initiation and flowering, because of the importance of flowering to the use of the species as a source of hay. The terminal inflorescence in red clover arises from a lateral bulge at the shoot apex, and the main shoot of the plant is strongly vegetative, only becoming reproductive in a proportion of plants under long photoperiod, particularly continuous light. In both strains, whether first-year or older plants, flower initiation and therefore flowering were confined to a short period of the year, the early strain having the longer period. Sowing the two strains at intervals through the year in the field, under natural and long photoperiods, showed the importance of both photoperiod and temperature to initiation. Both strains were hastened by a long photoperiod whatever the temperature, and initiated at a similar low leaf number, but the early strain was able to initiate at a shorter photoperiod than the late one. Seed vernalization had almost no effect; but at photoperiods of 14 to 11 hr, high temperatures strongly retarded Cowgrass and appeared to prevent initiation in Montgomery. The capacity of Cowgrass to initiate at a shorter photoperiod and at higher temperatures than Montgomery explains its longer flowering season in temperate latitudes. These genetic differences suggest that an appropriate environment can be used to differentiate early and late-flowering strains for seed certification, and that late strains would stay vegetative at low latitudes and would therefore be less useful as a source of hay than early ones.
Soil fertility changes in the long-term experimental plots at Kybybolite, South Australia. IV. Changes in certain moisture characteristics
Authors: Russell JS , Shearer RC
Published: November 2004

A study of soils from various pasture treatments at Kybybolite has shown that changes in soil moisture characteristics have occurred in association with increases in organic matter. The 15 atmospheres (atm), 0.33 atm, and available water capacity (A.W.C.) values have all shown increases which can be related to organic matter changes. The largest increase has occurred in soil moisture-holding capacity (0.33 atm). Less than half of this increase, however, is available for plant growth, owing to corresponding increases in 15 atm values. Calculations of A.W.C. in terms of depth of soil water has shown that the magnitude of the change has been relatively small in relation to the large increases in organic matter. The results indicate that the scope for substantially increasing A.W.C. in coarse-textured soils by pasture improvement is limited. Possible beneficial and deleterious effects on plant growth due to observed changes in moisture characteristics of the surface soil are discussed.
Body composition in vivo. V. The use of antipyrine and N-acetyl-4-aminoantipyrine for the estimation of gut water in living ruminants
Authors: Panaretto BA , Reid JT
Published: November 2004

The differences between the simultaneously determined antipyrine and N-acetyl-4-aminoantipyrine spaces underestimated total gut water in ruminants; measurements made on seven sheep and 13 goats, which had been deprived of feed and water for 48 hr, were so variable that they could not be used to predict the volume of water in the gut. The variability encountered appeared to be due not only to the differing quantities of the compounds which appeared in the rumen, but also to the fact that their concentrations in the gut increased with time following their intravenous injection. These compounds cannot be used to measure the total intraluminal water, with precision, in ruminants.
The oestrogenic isoflavones of subterranean clover
Authors: Beck AB
Published: November 2004

A number of strains of subterranean clover has been examined for isoflavone content in an attempt to explain the differences of oestrogenic potency in sheep and cattle under field conditions. A method of thin-layer chromatography has been developed which allows a rapid semiquantitative estimation of the main isoflavones present in this species. The isoflavones are present in a combined form, probably as glycosides, and the free isoflavones are rapidly released after crushing the leaf. The percentages of formononetin, genistein, and biochanin A in the leaves are very much higher than reported by earlier workers and vary widely between strains. Moreover, the ratios of the isoflavones differ greatly among strains. The relevance of these plant data to the oestrogenic potency in the animal is discussed.
The residual value of superphosphate on a red-brown earth in South Australia
Authors: Piper CS , de Vries MPC
Published: November 2004

The residual value of superphosphate on a red-brown earth naturally deficient in phosphate has been determined by means of a field experiment. pot trials. and chemical extractions . In a field experiment on a site where 24½ cwt of superphosphate per acre had been previously applied over a period of 23 years, it was found that wheat. in a wheat-barley-fallow rotation. could be grown for 5 years before a clearly defined response developed to superphosphate currently applied at 11 lb (P1) or 22 lb (P2) phosphorus pentoxide (P2O5 ) per acre . Stubble-sown barley showed a response after the first year.
The effects of length of oestrus and number of inseminations on the fertility and twinning rate of the Merino ewe
Authors: Dunlop AA , Tallis GM
Published: November 2004

In a flock of 512 Merino ewes all were inseminated on the first day of oestrus. On the next day half of those still in oestrus were re-inseminated, as were half of those no longer in oestrus. Based on numbers of lambs born subsequently, estimates were made of the separate and joint effects of number of times inseminated and number of days in oestrus. A second insemination significantly increased the proportion of ewes bearing twins by 4.7%. Other effects were not significant, but suggested that ewes with longer oestrous periods produced slightly more lambs, and that ewes in oestrus on a second day benefited most from re-insemination.
Comparative breed studies of beef cattle. II. Changes in size and shape
Authors: Tulloh NM , Maritz JS
Published: November 2004

A comparative growth study of changes in shape was made of Hereford, Aberdeen Angus, and beef Shorthorn cattle. In addition to recording body weight, 10 surface body measurements were made, at regular time intervals, on every animal in the experimental group. Changes and differences in shape were studied by examining the functional forms of the relationships between surface body measurements and body weight for every animal. The breed and sex differences presented in this paper have also been composed with a re-analysis of the limited data available from the literature, and in general the results are similar.
Digestion of food by the grazing sheep. II. The production of ammonia in the rumen
Authors: Hogan JP
Published: November 2004

High concentrations of ammonia have been found in the rumen in grazing sheep at all seasons of the year. It has been established that the mean concentration of ammonia sustained in the rumen during a 24 hr period depends on the crude protein intake. Other factors which may affect the production of ammonia in and its removal from the rumen are also discussed.
The effects of soil moisture stress on the growth of barley. I. Vegetative development and grain yield
Authors: Aspinall D , Nicholls PB , May LH
Published: November 2004

The effects of soil moisture stress on tillering, stem elongation, and grain yield of barley (cv. Prior) have been studied by subjecting the plants to periods of stress at different stages of development. Soil moisture stress treatments consisted of repeated short cycles of stress, single short cycles (both in large pots), or single long cycles (in large lysimeters). The data collected support the contention that the organ which is growing most rapidly at the time of a stress is the one most affected. Grain numbers per ear were seriously affected by stress occurring prior to anthesis, an effect probably associated with the process of spikelet initiation and, later, with the formation of the gametes. Grain size, on the other hand, was reduced more by stress at anthesis and shortly after. Elongation of the internodes was reduced mostly by stress at or just before earing, and was less seriously affected by earlier or later stress. Tillering, although being suppressed during a drought cycle, was actually stimulated upon rewatering. The effect was greater the earlier the period of stress, and was probably related to nutrient uptake and distribution within the plant.
Effect of adverse nutrition on the skin and wool follicles in Merino sheep
Authors: Lyne AG
Published: November 2004

The effect of adverse nutrition on the body weight, skin thickness, and wool follicles of five groups of five Merino wethers has been observed over a period of 64 months in an experiment on the utilization of low quality roughage. All animals on the poorest diet (roughage containing 2.6% crude protein, ad lib.) were transferred to a recovery ration of lucerne chaff, wheat, linseed meal, and meat meal (33 : 33 : 20 : 13) at 6–9 weeks after the commencement of the experiment. Only three animals on the better diets needed this recovery ration. In general, changes in skin thickness paralleled changes in body weight. A marked increase in skin thickness which followed shearing was probably due to cold stress. Fibre shedding was a major feature of the reaction of the follicle population to adverse nutrition, but all afflicted follicles regenerated their fibres when the recovery ration was given. Primary (P) and secondary (S) follicles responded differently to adverse nutrition. Approximately 20 000 P follicles and 155 000 S follicles were examined. 1.4% of the P follicles and 9.%% of the S follicles showed evidence of shedding.
Effects of stress on ovarian morphology and oestrus cycles in ewes
Authors: Braden AWH , Moule GR
Published: November 2004

Observations involving over 600 sheep and extending over 4 years were made on the effect of acute stress on the oestrous cycle and ovarian morphology of ewes. In anoestrous ewes ovulation unaccompanied by oestrus was often induced by severe stress. Injections of ACTH did not induce ovulation in anoestrous ewes. During the breeding season severe stress appeared sometimes to lengthen the oestrous cycle by a few days. The presence of a large cavity in the corpus luteum (C.L.) often seemed to have been induced by stress, but the amount of luteal tissue and its microscopic appearance did not usually appear much different from solid C.L. Oxytocin injections did not affect oestrous cycles or ovarian morphology, but in some circumstances injections of ACTH or stilboestrol appeared to cause an increase in cycle length.
Inheritance of three marker characters in Medicago truncatula Gaertn. (M. tribuloides Desr.)
Authors: Simon JP
Published: November 2004

The inheritance has been studied of three morphological characters which could be used as markers in the "pure seed" certification of commercial varieties of barrel medic, M. truncatula Gaertn. The leaf anthocyanin pigmentation pattern, as found in accession No. 2829, and the clockwise form of pod coiling characterizing accession No. 3309, are determined by single dominant genes. The spineless character of the pod of accession No. 2822 is due to a recessive gene. The simple inheritance of these characters and the complete penetrance of the genes concerned indicate that the anthocyanin marker and the spineless pod could be used for certification. Since the clockwise-anticlockwise pattern of coiling occurs in both forms in commercial barrel medic varieties, it is likely to be useful only as a marker in genetic studies. Details are given of a satisfactory procedure developed for crossing medic varieties
Crimp in wool : the skin histology of normal and doggy-fleeced sheep
Authors: Chapman RE , Short BF
Published: November 2004

The association between the frequency of wool follicles with grossly enlarged outer root sheaths and the severity of staple crimp abnormality, previously observed in adult Merino and Polwarth sheep, has been substantiated for adult sheep in Merino, Polwarth, and Corriedale flocks in five Australian States. In young sheep the association is somewhat less obvious.Whereas in the skin of adult sheep gross enlargement of the outer root sheath was always present in those follicles producing poorly crimped fibres (identified by plucking), the outer root sheaths of the majority of follicles producing well-crimped fibres were normal or only slightly irregular.This association between follicle outer root sheath enlargement and staple crimp abnormality is discussed.
The influence of the growing season and the following dry season on the hardseeedness of subterranean clover in different environments
Authors: Quinlivan BN
Published: November 2004

The length of the growing period in the spring months appears to be a critical factor in the development of hardseededness in subterranean clover (Trifolium subterraneum L.). Environments with relatively long spring growing periods cause a higher proportion of hard seeds to form at field maturity, and increase the resistance which these hard seeds are capable of offering to the softening effects of the following summer environment. During the dry summer period the rate of softening of hard seeds is determined, not only by the previous growing season but also by the summer environment itself. Hot summer environments with wide soil surface temperature fluctuations are conducive to a relatively rapid rate of softening. Grazing or removal of the dry topgrowth from a pasture during the summer increases the daily soil surface temperature fluctuations, and results in the hard seeds softening at an increased rate. Differences in the overall environment manifest themselves in terms of site and seasonal variation in the proportion of hard seeds which survive beyond the opening of the following growing season. The scope for variation is wide, and this has agronomic significance from the aspect of long-term persistence of the species.
Inheritance patterns in hybrids between Sorghum almum Parodi and perennial sweet Sudan grass
Authors: Pritchard AJ
Published: November 2004

Juicy stem and brown plant colour are mainly tetrasomically inherited in hybrids between Sorghum almum (2n = 40) and perennial sweet Sudan grass (2n = 40). Tetrasomic inheritance is also indicated for weak midrib development and dwarf habit. The juicy stem and brown plant colour characters are linked, and the chromosomes on which these genes are situated may pair preferentially and give a 15 : 1 segregation ratio, instead of pairing at random and giving a tetrasomic segregation ratio of 35 : 1. The capacity of these chromosomes to pair preferentially may be under genetic control. It is possible that preferential pairing is part of a general diploidization process, which has led to a reduction in quadrivalent formation and increased meiotic stability in the tetraploid sorghums.
Soil acidity and growth of a legume. III. Interaction of lime and phosphate on growth of Medicgo sativa L. in relation to aluminium toxicity and phosphate fixation
Authors: Munns DN
Published: November 2004

On some acid sandy loam soils, lucerne required large additions of phosphate to grow normally unless lime was also applied. Plant symptoms, and analyses of plants, soil solutions, and 0.01M calcium chloride extracts, supported the hypothesis that, in the unlimed soils, additions of phosphate overcame aluminium toxicity as well as phosphorus deficiency. Both lime and large additions of phosphate lowered the concentrations of aluminium in the soil solutions and in the plants. Lime did not significantly affect either the equilibrium concentrations or the rates of release of phosphate in the soils. Yet at rates of phosphate adequate in the presence of lime, plants without lime looked phosphate-deficient, grew poorly, and usually contained deficient concentrations of phosphorus. The principal effects were consistent with effects of aluminium and phosphate in solution culture at the same concentrations as those observed in the soils. Aluminium toxicity was associated with 10 to 100 µM concentrations of aluminium in the soil solution and 3 to 10 µg atoms/g dry weight in the plant tops. Phosphorus deficiency was associated with phosphate concentrations of the order of 1µM or less in the soil solutions and 100 µg atoms/g or less in the plant tops.
Dormancy and time of bud burst in the sultana vine
Authors: Baldwin JG
Published: November 2004

Time of bud burst for sultana vines at Merbein has been closely related to sums of daily temperatures at four periods during bud dormancy by a multiple regression covering 17 years, the result being supported by field trials of vine heating. Bud burst is delayed by higher daily maximum temperatures in May. Higher daily minimum temperatures in late June and in July, or higher daily maximum temperatures in August and until burst, are associated with earlier bud burst. Studies of bud dry weight and moisture have suggested that the change-over between the association of higher daily minimum temperatures and higher daily maximum temperatures with earlier bud burst occurs at a specified sum of degrees by which daily minimum temperatures fall below 50°F, giving dates ranging from July 5 to August 7 for the years of the regression. This appears to be the beginning of imposed dormancy. Use of the regression for predicting time of bud burst is discussed.
The relationship between evapotranspiration and growth in the wheat crop
Authors: Fischer RA , Kohn GD
Published: November 2004

In trials conducted in 1961 and 1962 at Wagga in southern New South Wales, to investigate the yield physiology of wheat, the variety Heron was grown under various cultural treatments. This paper deals with the relationship of evapotranspiration to crop growth. Vegetative growth at a given date in the spring was influenced markedly by time of sowing and fertilizer application, and to a lesser extent by sowing rate. Large differences in vegetative growth caused relatively small differences in evapotranspiration rate when soil moisture was adequate. An increase in total dry weight of 100 g/m² in early October was associated with an increase in cumulative evapotranspiration up to that time of about 0.50 in. It was concluded that although a reduced fertilizer application and reduced sowing rate (below 3b lb seed per acre) permitted higher soil moisture levels at flowering, this necessarily involved a considerable reduction in total dry weight at flowering. With delayed time of sowing, the post-flowering moisture status of the crop can be expected to deteriorate, primarily because of delayed flowering date.
Pharmacology and toxicology of carbon tetrachloride in the sheep. III. Effect of cold and heat stress on toxicity and rates of elimination
Authors: Kondos AC , McClymont GL
Published: November 2004

The effect of cold and heat stress on the susceptibility of sheep to intoxication by carbon tetrachloride (CCl4) has been studied by following changes in plasma levels of isocitric dehydrogenase (ICD), glutamic oxalacetic transaminase (GOT), and bilirubin, and by other criteria. Cold stress (exposure to 4°C for 18 hr) considerably increased the toxicity of CCl4 in newly shorn sheep in medium condition but not of unshorn sheep in similar condition. The susceptibility of both shorn and unshorn sheep in poor condition was increased. Heat stress (40–41°C at 55–60% relative humidity for 12 hr) applied before, or before and after administration of CCl4 rendered the drug appreciably less toxic. This reduced toxicity was associated with increased respiration and increased elimination of CCl4 during the first 30–45 min as a result of the prior heat stress. Heat stress applied only after CCl4 administration did not reduce susceptibility. The findings confirm the suggestion from field observations that cold stress may increase the degree of intoxication of sheep by CCl4.
Association of ovulation rate and twinning in Merino sheep
Authors: Packham A , Triffitt LK
Published: November 2004

Merino sheep from two groups selected for single and multiple births were examined by laparotomy. Comparison of observed corpora lutea with previous lambing records suggests that differences in fecundity obtained by selection are due to genetic differences in number of eggs shed.
The histopathology of the reactions of calves to experimental infection with the nodular worm, Oesophagostomum radiatum (Rudolphi, 1803). I. Host reaction to re-infection with single large doses of larvae
Authors: Elek P , Durie PH
Published: November 2004

The histopathological aspects of the host response to Oesophagostomum radiatum were investigated following the reinfection of previously exposed calves. The elimination of third-stage larvae 18–22 hr after administration of the reinfecting dose was associated with oedema, hyperaemia, and hypersecretion in the intestine and was followed by a transient but intense diarrhoea. The infiltration of the oedematous intestinal tissues with eosinophil and neutrophil leucocytes and the vasculitis in the vicinity of the histotropic larvae indicated an Arthus type reaction. During the development of the third-stage larvae the exudative hyperergic inflammation changed to a proliferative granulomatous type. The moulting of the larva to the fourth stage was associated with a recurrence of oedema and vasculitis, and was followed by isolation and elimination of the larva and surrounding necrotic host tissue. If the larva was not discharged the healing was delayed and the nodular lesion persisted. The diarrhoea during the elimination of fourth-stage larvae was associated with oedema of the gut wall, hypertrophy, and profuse secretion of the mucosal glands. These changes developed to an excessive degree in the proximal 2 ft of the colon following the termination of the histotropic phase. The varying course of the enteric process was accompanied by simultaneous changes in the regional lymphatic tissue. Cell destruction, phagocytosis, and depletion of follicles during the acute phases alternated with lymphopoiesis during the proliferative reparative periods. The tissue damage from the exaggerated response to reinfection of a sensitized host resulted in anorexia and weight loss.
Interralations in the growth and development of Lolium. II. Tiller number and dry weight at low density
Authors: Silsbury JH
Published: November 2004

Relations between plant dry weight and tiller number have been examined in Lolium rigidum and Lolium perenne grown in the field at low density, and in controlled environments. Between plants within a cultivar, dry weight of tops and tiller number were positively related at all developmental stages throughout the growing season. Between four cultivars of L. perenne and L. rigidum, the relationship was positive in the vegetative stage but became negative when plants were reproductive. It is shown that an allometric relation exists between plant dry weight and tiller number during the vegetative stage. This relation did not differ markedly between cultivars, and for L. rigidum and for L. perenne cv. S.24 was not altered when plants were grown in different seasons or in controlled environments.
Isoflavone mutations in subterranean clover. II. Assessment of oestrogenic activity by ewe bioassay
Authors: Millington AJ , Francis CM , Davies HL
Published: November 2004

Four chemically induced mutations and the parent Geraldton variety of subterranean clover (Trifolium subterraneum L.) were bioassayed for oestrogenic activity with the use of ovariectomized ewes. Mutant 972 demonstrated the ability of the sheep to hydrolyse isoflavone glycosides, and mutant A258 the likelihood that daidzein is a plant oestrogen active in the sheep. In contrast to all known strains of subterranean clover, the mutants B763 and L858 contained less than 0.25% isoflavones, and had negligible, if any, oestrogenic activity.
Genetics of rust resistance in tetraploid wheats. III. Genes for resistance to stem rust in certain Durum wheats
Authors: Ataullah M
Published: November 2004

The inheritance of resistance to stem rust in four durum wheats, namely P.I.168921, P.I.173401, Gaza, and C.I.7809 was studied. The variety P.I.168921 was found to possess two dominant genes Srt1 and Srt5, P.I.173401 two recessive genes srt6 and srt7, Gaza two dominant genes Srt8 and Srt9, and C.I.7809 genes Srt33 and Srt10, for resistance to Australian strains of Puccinia graminis tritici Erikss. & Henn. It was observed that the genes srt6, srt7, Srt9, and Srt10 were independent of genes already identified. Varieties Khapli, St.464, C.I.7778, and P.I.168921 had gene Srt1Srt1 in common; and varieties St.464, C.I.7778, and C.I.7809 gene Srt3 in common.
Mineral elements in temperate crop and pasture plants. I. Zinc
Authors: Gladstones JS , Loneragan JF
Published: November 2004

Twenty-five annual crop and pasture plant varieties, from 21 species, were grown on a lateritic gravelly sand at each of three rates of a trace element mixture containing copper, zinc, manganese, molybdenum, cobalt, selenium, and iodine. The plant tops were sampled at three stages during the growing season, and at maturity. Zinc concentrations in the tops fell with increasing age in all species and trace element treatments. Total amounts of zinc in the tops rose throughout the growing season in all species except lupins, which showed marked declines after flowering. Trace element applications increased the zinc contents of most species by similar relative amounts, so that rankings of species on the basis of the zinc concentrations varied only slightly among treatments. Yield responses to trace elements other than zinc did not appear to affect changes in zinc concentration due to treatment. Nor did the species rankings vary appreciably among harvests. Compared on the basis of their geometric mean concentrations over all treatments and harvests, species varied widely in their zinc contents. Legumes and herbs had higher concentrations than cereals and grasses. Within taxonomic groups other than the grasses, species adapted to sandy or acid soils had generally higher concentrations in the tops than those adapted to medium- or heavy-textured soils. It is suggested that species differ characteristically in their feeding power for zinc, and that relative differences among species are probably maintained over a wide range of soil types and nutritional levels. These differences, being considerably greater than apparent differences in zinc requirement, are probably the major factor governing susceptibility to zinc deficiency in the field. Possible bases for species differences in their feeding power for soil zinc are discussed.
Phosphate sorption by soils as a measure of the phosphate requirement for pasture growth
Authors: Ozanne PG , Shaw TC
Published: November 2004

Development of a laboratory method for predicting the phosphate requirements of pasture plants, in pounds phosphorus per acre, is described. Measurement of the phosphate sorption by soil at a standard equilibrium concentration was used. Predictions made by using this method in the following year on different soils accounted for over 85% of the variability in phosphate requirement. A good correlation between phosphate sorbed and phosphate required was found. The relationship was linear over the range 0–500 p.p.m. of sorbed P. While different sampling depths, equilibrium concentrations, and degree of soil mixing affected the relationship, it remained linear and the correlation coefficients close to 0.9.
Pharmacology and toxicology of carbon tetrachloride in the sheep. IV. Reduction and augmentation of toxicity by selenium
Authors: Kondos AC , McClymont GL
Published: November 2004

Susceptibility of sheep to toxic effects of carbon tetrachloride (CCl4) was assessed by determining the increase in plasma levels of isocitric dehydrogenase (ICD) and glutamic transaminase (GOT) and by other criteria. Susceptibility was increased by oral administration of 1 mg of selenium (Se) as sodium selenite plus 100 i.u. of tocopherol acetate on alternate days for 120 days, 2 mg Se per day for 21 days, and 6 mg Se per day for 6 days, before dosing with CCl4. Susceptibility was reduced by smaller total amounts of Se, and by oral doses of 6 mg Se per day for 3 days, a single oral or intramuscular dose of 5 or 12 mg c. 20 hr, or 5 or 12 mg orally 10–20 min, before dosing with CCl4. One 5 mg dose at 20 hr and a second 20 min before CCl4 was more effective than either alone. Sheep from two different sources differed considerably in their susceptibility to CCl4. In the more susceptible sheep Se administration reduced susceptibility to a level comparable with that shown by the naturally resistant animals. Administration of Se to sheep dosed with CCl4 and then given a high-protein diet resulted in lower GOT levels, milder clinical signs, and a great reduction in mortality. In field tests on properties with a recent history of CCl4 poisoning, oral administration of 5 mg Se about 20 min before CCl4 significantly reduced susceptibility. Administration of Se to fluke-infested sheep did not protect the liver fluke (Fasciola hepatica) against CCl4.
The effects of inbreeding, maternal handicap, and range in age on 10 fleece and body characteristics in Merino rams and ewes
Authors: Lax J , Brown GH
Published: November 2004

Estimates have been made of the influence on 10 fleece and body characteristics of dam's phenotype, range in age of offspring, inbreeding of offspring and dam, type of birth of offspring, and age of dam. The data came from rams 10–11 months old and ewes 15–16 months old, which had previously been shorn as weaners; the animals belong to an unselected control flock run at Cunnamulla, south-western Queensland. The dam's phenotype showed a high positive relationship with that of her offspring in all 10 characteristics, the values of the regression coefficients confirming the levels of heritability previously estimated on the same flock but without removing all the effects included in the present analysis. Younger animals in a group had lower greasy and clean wool weights and body weights, even at 15–16 months, but the effects were slight, except for body weight. For each 1% increase in the offspring's own level of inbreeding, the regression coefficients for rams and ewes respectively were -0.042 and –0,051 lb for greasy wool weight, –0.025 and –0.025 1b for clean wool weight, and –0.431 and –0.541 1b for body weight. These figures represent a decrease of 5–10% in clean wool weight and 8–10% in body weight for the progeny of half-sib matings. Inbreeding of the dam had a negligible effect on the characteristics examined. Animals born in multiple births in this environment suffer penalties which were still evident up to 15–16 months of age, resulting in both sexes in lower wool and body weights, lower wrinkle scores, fewer fibres per unit skin area, and fewer crimps per inch of staple. Fibre diameter was slightly higher for the multiple birth animals, but �he signs for the effects on other characteristics differed between sexes. The handicaps for rams and ewes respectively were 9 and 5% for clean wool weight and 7 and 5% for body weight. Dams were separated into four age groups (2, 3, 4–7, and 8–10 years). Greasy and clean wool weights and wrinkle score rose for offspring of both sexes to a peak at 4–7-year-old dams, then fell slightly. Body weight reached a peak at 3 years for rams and 4–7 years for ewes, while fibre diameter and staple length reached a peak at 3 years for ewes and 4–7 years for rams. In no case was the fall for the older dam age groups sufficient to invalidate the usual practice of adjusting only the progeny of 2-year-old dams. Other characteristics showed no consistent pattern.
Breed and nutritional effects of the composition of faeces, urine, and plasma from Hereford and Brahman X Hereford steers fed on high and low quality diets
Authors: Vercoe JE
Published: November 2004

A comparison is presented of the composition of the faeces, urine, and plasma when Hereford and Brahman x Hereford steers were fed two different quality diets at three levels of intake. On a high quality diet (lucerne hay), the Brahman x Hereford steers produced significantly less faecal dry matter, total nitrogen, and non-dialysable nitrogen than the Hereford steers, but there were no significant differences between the breeds or between animals within a breed in total urinary nitrogen or any of its major constituents. On a low quality diet (blue grass–spear grass hay) the two breeds were not significantly different in faecal dry matter, total nitrogen, or non-dialysable nitrogen. The Brahman x Hereford steers excreted more total nitrogen, urea, and creatinine in their urine, part of which could be attributed to a higher liveweight; and they had significantly lower nitrogen balances. In animals of the same breed, water intake and urine volume were negatively correlated with plasma urea and nitrogen balance and positively correlated with urinary total nitrogen, creatinine, and uric acid.
The effect of defoliation on nitrogen stress and its relation to leaf nitrogen in young Lolium rigidum Gaud.
Authors: Greenwood EAN , Titmanis ZV
Published: November 2004

Defoliation, whether by cutting or by grazing, substantially reduced nitrogen stress provided that this stress was evident before defoliation. Defoliation had little effect on the relation of nitrogen stress to the concentration of either total nitrogen or ninhydrin nitrogen of the youngest, intact, fully expanded leaf.
A potassium and sodium balance study in two breeds of sheep
Authors: Beal AM , Budtz-Olsen OE
Published: November 2004

A balance experiment measuring potassium and sodium intake and excretion was carried out on Romney Marsh and Merino sheep. For either potassium or sodium the correlation between total intake and total excretion was high and no difference was found between the two breeds in the relative importance of the urinary and faecal routes of excretion. A mean value of 11% of the total potassium excretion and 12% of the total sodium excretion appeared in the faeces, with the respective remainders, 89 and 88%, being voided in the urine. The relative importance of cutaneous losses of the two cations in suint is discussed briefly. Neither total intake of potassium nor gain or loss in weight by the sheep could be shown to influence the relative importance of the two routes of potassium excretion investigated in this work. This was also true of sodium.
The effect of frequency of feeding on the utilization of roughage diets by sheep
Authors: Faichney GJ
Published: November 2004

A diet of 800 g of lucerne pellets was fed to three sheep at 24 hr intervals and compared with a diet of 100 g of lucerne pellets fed to the same three sheep at 3 hr intervals. There were no significant differences in digestibility and nitrogen balance. It was suggested that the significant (P < 0.05) difference in body weight gain may have been due to an increase in total body water. Increasing the frequency of feeding decreased the range of values observed between feeding for pH and VFA concentrations. There were no changes in the molar proportions of the VFA or in the proportion of the digested energy accounted for by the VFA. The results suggest that the sheep did not benefit substantially from frequent feeding.
Pituitary adrenal interactions in shorn sheep exposed to cold, wet conditions
Authors: Panaretto BA , Ferguson KA
Published: November 2004

Newly shorn sheep were exposed to a cold (3°C) wet environment for 8 days; six out of 10 untreated animals died but there were no deaths in a group of 10 that was treated with cortisone. In two other experiments, nine out of 15 control sheep died, but only four out of 15 sheep treated with adrenocorticotrophin (ACTH). In a final experiment approximately one-third of exposed controls died compared with one-tenth of sheep treated with dexamethasone trimethylacetate. A significantly greater proportion (P < 0.05) of sheep given ACTH or 1.5 mg or more of dexamethasone trimethylacetate per kg had rectal temperatures higher than 37.8°C during the first 96 hr of exposure than the comparable controls. The adrenal glands of sheep that died in the cortisone and ACTH experiments were heavier than those taken from survivors that were killed after the experiment; macroscopically, the cortices of some of the adrenals from sheep that succumbed were haemorrhagic and resembled the glands seen in the Waterhouse-Friderichsen syndrome in man; all were heavily infiltrated with lipid when compared with the cortices of survivors. ß-Glucuronidase activity in the serum of cortisone-treated sheep (and in untreated survivors) was elevated during the first 2–3 days of exposure and returned to pre-exposure levels; untreated sheep that succumbed showed continuously increasing enzymatic activity. Acid phosphatase activity was initially depressed in steroid-treated sheep and returned to pre-exposure levels, whereas activity increased continuously in controls that died. Total leucocytes were lower during the first 72 hr of exposure in sheep treated with 1.5–2 mg dexamethasone trimethylacetate per kg, compared with untreated controls. We suggest that the enlarged, fat-laden haemorrhagic adrenals found in sheep that died from cold exposure resulted from excessive ACTH stimulation prior to death. The results suggested a state of adrenocortical insufficiency during the first 96 hr of cold exposure.
The influence of subterranean clover pastures on soil fertility. III. The effect of applied phosphorus and sulphur
Authors: Watson ER
Published: November 2004

The total nitrogen content of the soil was significantly increased at each of four levels of superphosphate applied to a densely sown subterranean clover pasture on a coarse-textured sand at Kojonup, W.A. During the first 4 years of the experiment nitrogen build-up was similar for all four treatments, but over the 11 year term the build-up was significantly slower at the lowest level of superphosphate. The relationship between the age of the pasture and soil nitrogen was linear at the lowest level of fertilizer but curvilinear at all other levels. The relationship between total superphosphate applied and soil nitrogen was curvilinear. There were no differential effects of the fertilizer treatments on either the bulk density or the pH of the soil. At the two lower levels of superphosphate a high percentage of both phosphorus and sulphur was retained in the major plant root zone (0–10 cm) of the soil. At the two higher levels most of the phosphorus was retained but there were heavy losses of sulphur. The results of pot trials with soil taken from the experiment at the end of the 11 year period showed that the different levels of superphosphate had induced large differences in the phosphorus status of the soil but had had much smaller effects on the sulphur status. The possible effect of this loss of sulphur on the accumulation of soil organic matter is discussed.
Pigmentation of sheep. III. Piebald pattern in Merinos
Authors: Brooker MG , Dolling CHS
Published: November 2004

Piebald Merino sheep have one or more rounded areas of light grey to black fibres in an otherwise white coat. Spotting was found on all body regions except the tail and there was considerable variation between animals in the size and number of spots. It was usually possible to distinguish between Black and Piebald phenotypically. The pigmented and white areas of a Black animal were usually distributed over the body according to a set pattern while the location of the spots on Piebald sheep did not conform to any recognizable pattern and invariably showed positional asymmetry. One animal which was both Black and Piebald is described. Piebald spotting is not determined by factors at the Black locus; the only exception is a Piebald phenotype produced by a somatic mutation involving this locus. It is most probable that the Piebald pattern in Merinos is controlled by a recessive gene which does not show full penetrance. A possible explanation for this incomplete penetrance is discussed.
Frenching of tobacco in Australian soils and in soil leachates
Authors: Mandryk M
Published: November 2004

In Australia frenching occurred consistently in tobacco plants grown in sandy soils that tend to remain wet for long periods. At Katherine, N.T. and Manjimup, W.A., plants grown in soils taken from a depth of 0–6 in. frenched readily, but in soils from a depth of 6–12 in. frenching symptoms in plants were less severe, appeared later, or were absent. Cultivated soils were shown to cause frenching in tobacco plants more readily than uncultivated soils. Under glasshouse conditions frenching occurred in "active soils" at a wide range of temperatures (18–45°C); high soil temperatures increased the severity and decreased the time to appearance of symptoms. Various minerals added to the soil did not influence frenching, but excess nitrogen delayed the onset of symptoms up to 3 weeks. Prolonged storage of active soils did not affect their ability to induce frenching symptoms in plants. Frenching could not be transmitted from plant to plant by grafting, mechanical means, or dodder, but could be readily transmitted from active to inactive media by inoculation. Leachates of soil from Katherine and sand from Molonglo, A.C.T. induced frenching in plants. Severity of frenching was decreased by centrifugation, flocculation, or Seitz filtration of the leachates. Heat and chemical sterilization of active media (leachates, soils, sand, and vermiculite) eliminated their ability to induce frenching in plants. A biological origin of frenching disorder is suggested.
Sulphur metabolism in sheep. III. The movement of blood inorganic sulphate across the rumen wall of sheep
Authors: Bray AC
Published: November 2004

The movement of intravenously injected sodium [35S]sulphate into the rumen was studied in three sheep in which the normal rumen digesta had been replaced with buffer solutions hypotonic, isotonic, and hypertonic to blood. It was shown that inorganic [35S]sulphate was transferred to the rumen by passage across the rumen wall and that the rate of passage of sulphate was apparently increased by the influx of water into the rumen. Only 0.3–1.4% of the injected [35S]sulphate passed into the rumen by this route over a 4 hr period. It was suggested that the utilization of recycled urea nitrogen may be severely limited in sheep on low sulphur and low nitrogen intakes unless sulphur is recycled to the rumen by other routes or in other forms across the rumen wall. Mixed saliva was collected and analysed and the total sulphur content was found to range from 16 to 43 µg/ml. An average of 79% of this sulphur was present in the residual (protein) sulphur fraction. The sulphate space (extracellular fluid volume) was calculated for each sheep from the dilution of the injected [35S]sulphate. The sulphate space, calculated from the dilution of 35S 30 min after injection, averaged 27% of the body weight. For each sheep the volumes calculated from three determinations lay within ± 5 % of the median value.
The effect of waterlogging on the growth and isoflavone concentration of Trifolium subterraneum L.
Authors: Francis CM , Devitt AC
Published: November 2004

Seventy-five cultivars were used to determine the effect of waterlogging on the yield and isoflavone content of three subspecies of Trifolium subterraneum L. The 21-day flooding treatment affected root growth more than shoot growth. The relative tolerance of the subspecies to waterlogging was yanninicum > subterraneum > brachycalycinurn. These results were in keeping with ecological evidence. The flooding treatment resulted in a general increase in leaf isoflavone concentrations. As with plant growth there was a significant subspecies x waterlogging interaction, the relative increase in isoflavone concentration being least for subsp. yanninicum.
Chromosome numbers in some species of Trifolium
Authors: Pritchard AJ
Published: November 2004

The chromosome numbers of 31 species of Trifolium are reported, 18 for the first time. A reduction in basic chromosome number has occurred only in the three most highly specialized subgenera, and polyploids occur mainly in one of the more primitive subgenera.
The feed intake of sheep supplemented with varying quantities of wheat while grazing pastures differing in herbage availability
Authors: Langlands JP
Published: November 2004

Diets containing various quantities of lucerne chaff and wheat grain were given to three sheep in a digestibility trial. Daily faecal output was related to daily intakes of chaff and wheat by regression analysis. The partial regression coefficient for wheat was used to estimate the faecal output attributable to wheat in a grazing trial in which flocks of five sheep grazed at five stocking rates and received either 0, 100, 200, 300, or 400 g wheat per day. The sheep were allocated to treatments and periods at each stocking rate in a Latin square design. Herbage intake was estimated in each period. Herbage intake decreased when supplementary feeding or stocking rate was increased. Supplementary feeding increased the nutrient intake of grazing sheep by an average of 54% of the nutrient content of the wheat given. This percentage was greater when pasture availability was low. At high stocking rates the decline in herbage intake was less than at low stocking rates in absolute terms although greater when expressed as a percentage of the herbage intake of the unsupplemented sheep
Responses of grain growth and malting quality of barley to short periods of high temperature in field studies using portable chambers
Authors: Savin R , Stone PJ , Nicolas ME
Published: November 2004

Although environmental conditions during grain filling are often cited as the reason for decreases in malting quality of barley, little is actually known about the specific effects of different environmental conditions on grain yield and quality of barley. In the present study, an attempt was made to assess in the field the effects of short periods of high temperature (>35�C), using portable chambers with thermostatically controlled electric heaters, on grain yield and quality of barley. Two experiments were carried out in 2 consecutive years, involving the malting barley cultivars Schooner (first year) and Parwan (second year). The treatments were (i) control (no chamber, no heating) during the whole grain-filling period, (ii) plots with chambers heated to ca. 40�C for 6 h per day over 5 days starting 17 days after anthesis, and (iii) plots with non-heated chambers for 5 days from 17 days after anthesis. High temperature treatments reduced individual grain weight by 14% in Schooner and 25% in Parwan. There was a reduction in starch content and an increase in nitrogen content in the heat treatments compared to the control, but the G-glucan content was similar to the control. The resulting malt extract was reduced from 79 to 73% in Schooner and from 68.4 to 66.2% in Parwan in ,the heat stress treatment. The starch granule size distribution was also measured. Results indicate that decreases in grain dry matter were due to reductions in number rather than size of starch granules. It is concluded that high temperature reduced the amount of 'maltable' grain by reducing grain size and increasing the screening percentage, and also reduced malt extract by 3-7%, which represents a large decrease for the malting industry.