bluuebunny/crossref_metadata_2025 huggingface dataset:
Germination and seedling growth at low temperature: comparisons of Lotus species and effects of selection and seed source in L. pedunculatus Cav.
Authors: Kelman W. M. , Forrester R. I.
Published: November 2005

The association of seed size, type of life cycle (annual/perennial), and
ploidy (diploid/tetraploid) with low temperature (5˚C), germination
rate, and seedling growth was examined under controlled conditions in 9
Lotus species. Seeds harvested at 2 localities from 2
populations of L. pedunculatus, one selected for early
flowering and the other unselected for flowering time, were included in the
study to examine the influence of selection history and seed provenance on
cold temperature germination rate and seedling growth. Seed size and ploidy
level were not significant factors influencing germination rate of the
Lotus species, but both seed size and life cycle had
significant associations (P< 0.01) with seedling dry
weight. Seed of the selected, early flowering population of
L. pedunculatus germinated significantly faster than
that of the unselected population (P< 0.01), and this
difference was more pronounced in seed from the site where early flowering
would confer advantages of better seed production and the potential for better
persistence through seedling recruitment. Anarrow-sense heritability estimate
for the germination rate of L. pedunculatus was high at
the 2 localities (0.84 ± 0.17 and 0.65 ± 0.16) and it was thus
promising as a selection criterion for improved establishment. If
interspecific hybridisation can be achieved between the annual and perennial
species, a longer term prospect exists to utilise the high capacity of annual
species to germinate and grow at low soil temperatures.
Supplemental skim milk before and after weaning improves growth performance of pigs
Authors: Dunshea F. R. , Kerton D. J. , Eason P. J. , King R. H.
Published: November 2005

Twelve Large White × Landrace sows nursing litters of 6 boars and 6
gilts were used in this study. Six litters suckled the sow only, whereas the
other 6 litters received supplemental liquid skim milk (200 g/L)
ad libitum from Day 10 until Day 20. On Day 20 the 4
heaviest pigs of each sex were allocated to 2 pairs and were weaned. Each pair
was offered either pelleted or pelleted plus liquid feed. For the first 2 days
post-weaning, each pair of liquid-supplemented pigs received liquid skim milk
(250 g/L). On Day 23, pelleted feed was added to the milk. The ratio of
liquid to pelleted feed was adjusted daily until, on Day 28, pigs were
provided with pelleted feed only until 41 days of age. Supplemental skim milk
increased growth (223 v. 291 g/day,
P < 0.001) between Days 10 and 20 of age so that by
weaning supplemented pigs were 10% (6.13 v. 6.74
kg, P = 0.038) heavier than unsupplemented pigs.
Skim milk intake increased linearly from 190 to 600 g/day per pig over the
10 days of supplementation. Supplemental milk feeding did not alter sow
liveweight change (−31.9 v. −30.3 kg for
sows nursing litters with and without supplementation, respectively,
P = 0.894) or change in P2 backfat thickness
(−5.3 v. −4.2 mm, P = 0.279) between
farrowing and Day 20 of age. Pigs weaned onto skim milk and pellets ate more
(257 v. 30 g dry matter (DM)/day,
P < 0.001) and grew better (213
v. −151 g/day, P <
0.001) over the first 2 days post-weaning than pigs weaned onto only pellets.
Piglets provided with liquid feed after weaning continued to grow faster
beyond Day 22, resulting in the benefit of weaning onto liquid feed being
maintained until at least 41 days of age (14.1 v. 12.8
kg, P < 0.001). In conclusion, skim milk feeding
before and after weaning can result in cumulative improvements in growth
performance in the nursery.
Survival and biomass of exotic earthworms, Aporrectodea spp. (Lumbricidae), when introduced to pastures in south-eastern Australia
Authors: Baker G. H. , Carter P. J. , Barrett V. J.
Published: November 2005

The earthworm fauna of pastures in south-eastern Australia is dominated by
exotic lumbricid earthworms, in particular the endogeic species,
Aporrectodea caliginosa and
A. trapezoides. Anecic species such as
A. longa are very rare. All 3 species were introduced
within cages in 10 pastures on a range of soil types within the region. Five
months later, A. longa had generally survived the best
and A. trapezoides the worst. The survivals and weights
of individual worms varied between sites for all 3 species. The survivals of
A. caliginosa and A. longa, and to
a lesser extent A. trapezoides, were positively
correlated with soil clay content. The weights of
A. caliginosa and A. longa, but
not A. trapezoides, were positively correlated with soil
P content. The survivals and weights of A. longa and
A. trapezoides and the weights only of
A. caliginosa decreased with increasing inoculation
density, suggesting increased intraspecific competition for resources,
particularly in the first two species. A. longa reduced
the abundance and biomass of the exotic acanthodrilid earthworm,
Microscolex dubius, at one site, and the total biomass
of 3 native megascolecid species at another, when these latter species
occurred as contaminants in A. longa cages. The addition
of lime had no effect on the survivals and weights of
A. caliginosa, A. longa, and
A. trapezoides, although the soils were acid at the
sites tested. The addition of sheep dung increased the survival and weights of
some species at some sites. Mechanical disturbance of the soil within cages
reduced the survivals of A. longa and
A. trapezoides. A. longa was
released without being caged at 25 sites within one pasture in South
Australia. Four years later, it was recovered at all release points.
A. longa has the potential to colonise pastures widely
throughout the higher rainfall regions of south-eastern Australia.
Influence of earthworms, Aporrectodea spp. (Lumbricidae), on pasture production in south-eastern Australia
Authors: Baker G. H. , Carter P. J. , Barrett V. J.
Published: November 2005

Most of the earthworms now found in agricultural fields in south-eastern
Australia are exotic, patchily distributed, mineral soil dwellers (endogeic
species). The influence of two of the most common endogeic species,
Aporrectodea caliginosa and
A. trapezoides, on pasture production was compared with
that of another exotic, surface-feeding, deep-burrowing (anecic) species,
A. longa, which is essentially restricted in its
Australian distribution to Tasmania. Comparisons were made by introducing 4
different densities of the worms in cages at 10 field sites and measuring
pasture production for approximately 5 months. All 3 species increased pasture
production at most of the 10 sites. Increases in pasture production were
greatest where original pasture production was low. Pasture production
increased with earthworm density. Averaged across sites, earthworms increased
pasture production by up to 61%. Significant increases in yield were
detected with ≥214 A. longa/m
2 and ≥429 A. caliginosa or
A. trapezoides/m 2.
A. longa is a much bigger worm than
A. caliginosa and A. trapezoides.
If the initial number of worms introduced to the cages was taken as the
measure of earthworm ‘abundance’, then
A. longa increased pasture production more than the 2
endogeic species. If the biomass of introduced worms was taken as the measure
of abundance, then the reverse was the case. A. longa
reduced nitrogen levels in some soils. Phosphorus levels were not affected. No
residual effects on pasture production were detected when soil that had been
improved by earthworms was potted and resown with ryegrass. Broad scale
introduction of A. caliginosa,
A. longa, or A. trapezoides to
sites lacking them in south-eastern Australia is likely to improve pasture
production significantly. Addition of A. longa to
existing communities of endogeic species should further increase pasture yield
by enhancing functional diversity.
Trends in skeletal muscle biology and the understanding of toughness in beef
Authors: Harper G. S.
Published: November 2005

This review focuses on recent developments in the field of muscle biology that
reflect on the problem of toughness in beef. Meat science has shown that
post-mortem processing can make a large contribution to beef tenderness.
However live-animal factors such as growth path and genotype also influence
the toughness of beef either directly or indirectly through interactions with
processing technologies. This review sets out to integrate recent developments
in the field of meat science into a mechanistic overview of toughness, while
still highlighting the biology of some important contributors. These
contributors are discussed at several levels of order between the molecular
and the whole animal. The myofibrillar component of muscle is identified as
the major contributor to initial toughness particularly through the effects of
variation in sarcomere length. Muscle fibre-types whilst important to the
growth and development of the animal are yet to be linked convincingly with
toughness. Connective tissue is seen to play a dominant role in the sensation
of toughness in muscles where its content is high. In muscles that are
generally used for table beef, the contribution of connective tissue is less
significant. In either case its contribution to measurable toughness cannot be
easily separated from that of the myofibrillar component and the review
discusses various levels of interaction between these 2 major components of
beef. The review covers aspects of muscle ultrastructure as far as they are
pertinent to the problem of beef toughness. In particular it deals with
current knowledge of post-mortem metabolism of muscle and the degradation of
costameric structures. Molecules are considered that are likely to propagate
tensional forces from sarcomeres across the sarcolemma to the extracellular
molecules of the endomysium. While much of the research around these molecules
has not been performed by meat scientists, the insights developed are likely
to be important to our understanding of beef toughness.Technological
approaches to the objective measurement of toughness are discussed, as well as
recent developments in the field.
The review takes an integrative approach to features of the life of the bovine
that might impact on the toughness of beef derived from its carcass. Features
of the animal's pre-slaughter experience, including stress and physical
activity, have been shown to influence markedly the toughness of beef through
mechanisms that are described at the tissue level. Features of the growth path
that the animal followed during its development have also recently been shown
to significantly reduce the toughness of beef and properties of the connective
tissue component have been implicated. Areas of strategic research are
identified that, in the author's opinion, will facilitate commercial-
scale improvements in the tenderness of beef.
Effect of pod burial, light, and temperature on seed softening in yellow serradella
Authors: Taylor G. B. , Revell C. K.
Published: November 2005

Studies were made on the preconditioning stage (which produces latent soft
seeds) and the final stage of seed softening in newly ripened seeds of the
GEH72-1A accession of yellow serradella
(Ornithopus compressus L.). Pods grown at Yelbeni,
Western Australia, in 1996 were collected in December and placed on the soil
surface or buried at a depth of 0.5 cm at a site near Perth. Other pods were
subjected to a gradual diurnal temperature fluctuation of 60/15°C in
darkness in a laboratory chamber. Pod samples were taken from the field at
intervals from January to June in 1997, and over 336 days from the
60/15°C treatment. Pods were broken into segments and the number of
soft seeds determined. Numbers of latent soft seeds were then determined by
subjecting residual hard seeds to 7 gradual diurnal temperature cycles of
48/15°C in darkness and retesting for permeability. In a second
experiment, seeds preconditioned at the soil surface until 3 March were
subjected to a range of light levels in the field in March before testing for
permeability. The time taken for seeds to precondition under a range of
constant temperatures between 30° and 70°C was determined in a third
experiment.
Preconditioning commenced early in summer in both surface and buried seeds.
All buried seeds that preconditioned completed the softening process to
produce about 80% soft seeds, with most seeds softening in March when
diurnal temperatures fluctuated between maxima of 45–50°C and minima
of 10–20°C. Only 15% of the seeds at the soil surface
softened so that relatively few preconditioned seeds completed the softening
process. Preconditioning occurred more rapidly than did the completion of
softening in the 60/15°C treatment, indicating that this temperature
regime was above optimum for the final stage of softening. Reversal of the
preconditioning process took place in the field as temperatures declined
during May. Effects of reduced temperatures in causing this reversion were
confirmed in the laboratory on seeds preconditioned at 60/15°C. The
final stage of softening was inhibited in some seeds by light levels as low as
0.3% of daylight, and in all seeds at a light level between 5 and
25%. A close negative linear relation was obtained between the log of
the time taken for 50% of seeds to precondition and the constant
temperature treatment between 30°C and 70°C, with the rate of
preconditioning doubling with every 5.2°C rise in temperature within this
range.
Although many seeds preconditioned at the soil surface, the main constraint to
completion of the seed softening process during autumn was the inhibitory
effect of light.
Influence of xylanase supplementation on the apparent metabolisable energy and ileal amino acid digestibility in a
diet containing wheat and oats, and on the performance of three strains of broiler chickens
Authors: Ravindran V. , Hew L. I. , Ravindran G. , Gill R. J. , Pittolo P. H. , Bryden W. L.
Published: November 2005

A commercial xylanase product was assessed for its effects on the performance of, and apparent metabolisable energy (AME) and ileal amino acid digestibility in, 3 commercial broiler strains (Strain A, B, and C) fed on a diet containing wheat (407 g/kg) and oats (78 g/kg). Exogenous xylanase improved weight gains (P = 0.07) and feed/gain (P < 0.04) of broilers, irrespective of genotype. Performance parameters significantly differed among the broiler strains. Strains A and C consumed more (P < 0.04) feed, and grew faster (P < 0.01) and more efficiently (P = 0.07) than Strain B. Enzyme supplementation resulted in 2.8% improvement (P < 0.05) in the AME of the wheat-based diet. The AME tended to be higher (P = 0.09) with Strain A (13.46 MJ/kg dry matter) and Strain C (13.57 MJ/kg dry matter) than with Strain B (13.10 MJ/kg dry matter). The apparent ileal digestibility of all amino acids was 1–2 percentage units higher in birds fed on the enzyme-supplemented diet than in those fed on the unsupplemented diet (controls), but the differences were significant (P < 0.05) only for threonine, methionine, isoleucine, arginine, aspartic acid, serine, and glutamic acid. Highly significant (P < 0.001) strain effects were observed for apparent ileal digestibility of all amino acids, with Strain A recording the highest (0.807–0.945) and Strain B the lowest (0.710–0.912). Mean ileal digestibility coefficients of the 15 amino acids in wheat-based diets for Strains A, B, and C were 0.858, 0.791, and 0.828, respectively. Ileal digesta viscosity was low, and was not affected by dietary enzyme, suggesting that other factors were responsible for the observed improvements in bird performance.
Effect of length of growing season on development of hard seeds in yellow serradella and their subsequent softening at various depths of burial
Authors: Revell C. K. , Taylor G. B. , Cocks P. S.
Published: November 2005

Effects of withholding water at 4 (W4) and 8 (W8) weeks after commencement of
flowering on seed development in 2 accessions of yellow serradella
(Ornithopus compressus L.), cv. Avila and accession
GEH72-1A, were investigated in swards at a site near Perth, Western Australia.
Softening of resulting hard seeds during the following summer and autumn was
then studied in newly ripened pods placed at the soil surface, and at depths
of 0.5 and 2 cm in the soil at Merredin in the first week of January.
Proportions of soft seeds were determined in the original seed populations and
in pods taken from the field in March and June. In 2 further treatments,
proportions of soft seeds were determined in June in (i)
pods that had been at the soil surface until they were buried at 2 cm in
March, and (ii) in pods that had been buried at 2 cm
until March, when they were returned to the soil surface.
Seed yields from W4 were about 35% of those from W8 owing to reductions
in pod numbers (partly as a result of more flower shedding in W4), number of
seeds per pod, and seed size. Developing seeds became germinable between 21
and 29 days after anthesis when seed dry weights were between 0.9 and 1.4 mg,
which was about the same time that they developed the capacity for seed coat
impermeability. Viability of hard seeds was almost 100% from W8 but
only 65% from the W4 treatments. Less than 5% of the newly
ripened viable seeds were soft in any of the treatments.
Length of growing season had no effect on seed softening at the soil surface
and only a relatively small and variable effect on softening in buried pods.
At the June sampling, up to 16% of Avila and 5% of GEH72-1A
seeds had softened at the soil surface. Burial of pods increased proportions
of soft seeds up to 85% in Avila and 53% in GEH72-1A. Whereas
most of the seed softening in Avila occurred before March, similar amounts of
softening occurred before and after the March sampling in GEH72-1A. Burial of
pods in March increased seed softening by June in GEH72-1A but reduced
softening in Avila, whereas transfer of buried pods to the soil surface in
March had the reverse effect. This seed softening behaviour is explained in
terms of the 2-stage seed softening mechanism.
Burial of newly ripened seeds by tillage or stock trampling during the first
summerŒautumn appears a feasible management option for improving first
year regeneration in at least the softer seeded accessions of yellow
serradella.
Effects of molasses on mimosine metabolism in goats fed fresh and dried Leucaena with barley straw
Authors: Elliott R , Norton BW , Milton JTB , Ford CW
Published: November 2005

The effect of molasses supplementation on the metabolism and excretion of mimosine by goats was studied. Goats were fed barley straw and Leucaena (31.0 g mimosine kg-1 dry matter) throughout experiment 1 with and without a molasses supplement (400 g day-1). Four groups of four goats fed barley straw (13 days) were supplemented with either 0, 100, 200 or 400 g molasses day-1 for 6 days (experiment 2). Two goats on each molasses treatment were then offered similar quantities of Leucaena dry matter (DM) (10.0 g mimosine kg-1 DM) as either fresh or dried material for a further 18 days. Unsupplemented goats excreted appreciable quantities of mimosine and 3-hydroxy-4-(1H)-pyridone (DHP) in faeces. In experiment 1, 57% of the ingested mimosine was recovered, principally as conjugated DHP, in faeces and urine of goats supplemented with molasses, compared to 39% for unsupplemented goats. Molasses supplementation also increased the faecal excretion of conjugated DHP in experiment 2, particularly with goats fed dried Leucaena. Urinary excretion of mimosine in all goats was largely as conjugated DHP (negligible free DHP). The highest outputs of conjugated DHP in urine were associated with greater reductions in serum T4 levels, but 400 g of molasses supplement in experiment 2 prevented depressions in serum T4 levels. In both experiments a considerable proportion (c. 40%) of the ingested mimosine was not excreted.
Nutritional evaluation of south-west Queensland pastures. 3. The amino acid composition of pasture plants in a Mitchell grass association and their digestibility by grazing sheep
Authors: McMeniman NP , Kondos AC , Beale IF
Published: November 2005

The amino acid composition of the plants in a Mitchell grass pasture was determined, together with estimations of the rate of intake and extent of digestion of amino acids by fistulated and intact sheep grazing these pastures; two grazing systems were examined, one where the sheep were grazed at the district average stocking rate of one sheep to 1.5-2 ha, and the other at a 20% higher stocking rate. Plant amino acid compositions were reasonably constant, although the cyst(e)ine content of the green leaf fraction of Queensland blue grass (Dicanthium sericeum), Flinders grass (Iseilema spp.) and Enneapogon spp., and the green stem and dead leaf fractions of curley Mitchell grass (Astrebla lappacea), was low. The amino acid concentrations in the oesophageal fistulae boluses were higher than the concentrations found in the green fraction of any plant growing in the pasture. The quantity of amino acids flowing into the small intestines of the sheep in the higher stocking rate group exceeded by 16.4 g/kg DOMI the quantity consumed, while in those in the lower stocking rate group the flow was 24.8 g/kg DOMI less than the quantity ingested; reduced amino acid flow into the small intestines was associated with a higher forb content in the diet.
The tolerance of wheat to high temperatures during reproductive growth. I. Survey procedures and general response patterns
Authors: Wardlaw IF , Dawson IA , Munibi P , Fewster R
Published: November 2005

Selected cultivars of wheat from both a wide geographic and genetic background were examined under controlled conditions in the Canberra phytotron, for their response to high temperature at three stages of development: booting (late ear development), anthesis (pollination and fertilization) and grain growth (from 6 days after anthesis to maturity).The overall response to temperature, based on 28 cultivars from Afghanistan, Australia, Europe, India, Mexico, the Middle East and north Africa, demonstrated the sensitivity ofgrain number to high temperature during booting and the sensitivity of weight per grain to high temperature after anthesis. The data indicate a general reduction in yield per ear of 3-4% for each 1�C rise in temperature above a mean of 15�C. The response to temperature varied with the stage of development, and some cultivars sensitive to high temperature at booting were amongst the least sensitive during grain development. Also, the temperature response was found to be dependent on light, with an enhanced sensitivity to high temperature at low irradiance (<10 MJ m-2 day-1). The data did not reveal any clear relationship between the response to temperature, and weight per grain, the number of grains in a head or grains per spikelet of control (18/13�C) plants.
The tolerance of wheat to hight temperatures during reproductive growth. 2. Grain development
Authors: Wardlaw IF , Dawson IA , Munibi P
Published: November 2005

A study was undertaken in the Canberra phytotron of the response of 66 cultivars of wheat to high temperature (30/25�C) imposed throughout the period of grain development. The results from 20 Australian cultivars and their parental lines showed half of these to be clustered in the range where grain dry weight was reduced by 30-35% in response to high temperature when compared with 18/13�C controls. The non-Australian lines were more normally distributed in their response to high temperature and included some cultivars that were less sensitive to high temperature than the best of the Australian lines. It was concluded that there is a need for a wider assessment of genetic variation if a response to high temperature is to be incorporated in a breeding programme. A more specific study on Kalyansona, one of the better cultivars under high temperature conditions and high radiation levels, failed to reveal a specific source of temperature insensitivity in the background of Kalyansona. A comparison of the response to high temperature during grain development of twoF1 hybrids with their parental lines (Banks, Kalyansona and Pinnacle) provided some evidence that traits such as high grain number per ear, large grains and low sensitivity to high temperature could be effectively combined to produce a high grain weight per ear under high temperature conditions.
F3 response to F2 selection for quality and its effect on F3 yield distribution
Authors: O'Brien L , Panozzo JF , Ronalds JA
Published: November 2005

Seed of F2 single plant selections from two crosses was evaluated using a number of small-scale quality tests.F2 quality test values were significantly correlated with farinograph and extensograph properties in the F3, but no one test was correlated with all of the physical dough measures. The Pelshenke time and the proportion of residue protein were the small-scale measures most consistently correlated with dough strength (farinograph dough breakdown and extensograph maximum resistance) in the F3 and between the F2 and F3 generations.Applications of independent culling in the F2 for each test did not alter the subsequent nature of the F3 yield distribution except for flour protein content and Zeleny volume, where there was a preferential loss of lines from the higher yielding end. This resulted from the negative correlations between flour protein content and yield, both within the F3 (r=-0.66**) and between the F2 and F3 (r= -0-44**). The negative relationship between grain yield and Zeleny volume was due to the effect of protein content on Zeleny volume.Application of quality testing regimes that estimated grain hardness, protein content and dough strength in the F2 did not adversely affect the nature of the F3 yield distribution, yet permitted up to 71% of the population to be removed because of unsatisfactory balance of quality attributes. These results have considerable implications for the planning of wheat breeding programmes.Additional keywords: Bread wheat (Triticum aestivum L.), sodium dodecyl sulfate sedimentation volume, Zeleny sedimentation volume, Pelshenke wheatmeal fermentation time, residue protein content.
Effectiveness of incomplete resistance to Pyrenophora tritici-repentis in wheat
Authors: Rees RG , Platz GJ
Published: November 2005

Severe epidemics of yellow spot (Pyrenophora tritici-repentis) reduced grain yield by c. 60% in the highly susceptible wheat cv. Banks in two experiments. About two-thirds of the yield loss was associated with reduced grain size. Milder epidemics developed in cultivars with incomplete resistance and resulted in substantially smaller effects on grain yield. The value of the resistance in a high-yielding background was illustrated by yield advantages over Banks of c. 230% for Genaro 8 1 and c. 190% for Vicam 7 1, under heavy disease pressure. Lines selected from crosses of Genaro 81/2*Banks and Vicam 7!/2*Banks had less disease than Banks and only small to moderate yield losses occurred in the best selections under heavy disease pressure. This illustrates that the resistance from these sources can be transferred readily into adapted Australian wheats and should greatly reduce yield losses from yellow spot.
Effect of soil pH and texture on the growth and nodulation of lupins
Authors: White PF , Robson AD
Published: November 2005

Lupins characteristically grow poorly on fine-textured, alkaline or poorly drained soils. Little, however, is understood about which components of these soils affects lupin growth.Lupinus .sangustifolius, L. albus and L. cosentinii were grown at both an acid and an alkaline soil pH on a sandy clay loam and a sand with or without additional NH4NO3. Plant growth was poorest on the fine-textured, alkaline soil where emergence was inhibited and plants were chlorotic. Plant growth was also lower on the acidified fine-textured soil compared to the acid sand. Problems were related to the poor physical structure of the sandy clay loam. Poor growth and chlorosis of plants appeared to be caused by Fe deficiency and was unlikely to be due to Mn, Zn or Cu deficiencies. There was no effect of NH4NO3 on the growth of plants.Poor emergence and Fe deficiency therefore appear to be important factors restricting growth of lupins on the alkaline, sandy clay loam used in this experiment. Nitrogen fixation docs not appear to be a limiting factor.
Poor soil aeration or excess soil CaCO3 induces Fe deficiency in lupins
Authors: White PF , Robson AD
Published: November 2005

The poor growth and chlorosis suffered by lupins when grown on fine-textured alkaline soils appears primarily related to Fe deficiency which is affected by the level of HCO3-; and CaCO3 in the soil.Plants of Lupinus angustifolius were grown on an alkaline, sandy clay loam which was either acidified or limed. Additionally, plants received either adequate water (field capacity) or excess water to adjust the aeration of the soil.Plant growth was closely related to the concentration of Fe within the young leaves. Liming the soil or watering above field capacity reduced the Fe concentrations in shoots, induced chlorosis and reduced growth. Chlorosis and reduced growth was not caused by Mn deficiency, even though treatments that reduced growth also reduced Mn concentrations in shoots.The lime chlorosis disorder in lupins therefore is primarily caused by an inability of the plants to obtain Fe in calcareous soils and not caused by Mn deficiency or by inactivation of Fe within the shoots.
External calcium requirements for growth and nodulation of six tropical food legumes grown in flowing culture solution
Authors: Bell RW , Edwards DG , Asher CJ
Published: November 2005

Six tropical food legumes, peanut cv. Red Spanish, pigeonpea cv. Royes, guar cv. Brooks, soybean cv. Fitzroy, and cowpea cv. Vita 4 and CPI 282 15, were grown for 20 days at six constant solution calcium concentrations (2, 12, 50, 100, 500 and 2500 8M ) in flowing solution culture with adequate inorganic nitrogen (500 8M NO3 and with controlled nutrient concentrations. Bradyrhizobium CB756 was added at a rate of approximately 105 cells/ml of nutrient solution. Growth of all genotypes except guar was satisfactory at >12 8M calcium, with 75-100% of maximum root and shoot yield being obtained. Solution calcium concentrations required for maximum top growth were 12 8M for cowpea CPI 28215, 50 8M for peanut, 100 8M for soybean, and 2500 8M for cowpea cv. Vita 4, guar and pigeonpea. Root growth responded to solution calcium concentrations in the same way as top growth, except for cowpea cv. Vita 4 and pigeonpea, which both produced maximum root dry matter at 12 8M calcium. External calcium requirements for unrestricted growth may have been overestimated in guar because phosphorus deficiency appeared to limit growth at <500 8M calcium. Effects of suboptimal calcium concentrations included prevention of nodulation, delays in nodule appearance and a reduction in both nodule numbers and the proportion of plants which nodulated. Guar and pigeonpea formed nodules only at a 50 8M calcium, whereas cowpea and peanut formed nodules at 2 8M calcium. Maximum nodule numbers were recorded at lower (peanut), higher (cowpea cv. Vita 4, CPI 28215 and pigeonpea) or the same (guar) solution calcium concentration as that required for maximum root growth. Nodule formation in peanut was satisfactory at solution calcium concentrations as low as 12 8M. The results are discussed in relation to reports on the adaptation of these legumes to highly weathered soils low in calcium.
Effects of ameliorating exposed subsoil prior to sowing on the water relations and productivity of pasture during an irrigation cycle
Authors: Blaikie SJ , Kelly KB , Mason WK
Published: November 2005

Adding organic matter or replacing topsoil have been shown to improve the growth of pasture on areas where subsoil is exposed during landforming. Intensive experiments were carried out in each of the 1985-86 and 1986-87 irrigation seasons to examine the basis of improvements in the productivity of pastures after such amelioration. Measurements were collected during the period between two irrigations which were separated by approximately 70 mm of cumulative Class A pan evaporation. Treatments included (i) high rates of nitrogen and phosphorus (NP); (ii) NP + organic matter (OM); (iii) NP + topsoil (TS); and (iv) NP +Well watered (WW).Compared to NP, pasture production in OM and TS treatments was improved in the first year, but in the second year only the TS treatment gave significant improvement. These increases in dry matter yields were reflected in rates of leaf elongation, canopy conductance, evapotranspiration and photosynthesis that were up to 50% greater than those in WW during the first half of an irrigation cycle, but there were no differences in leaf water potential. There was a strong relationship between canopy conductance and photosynthesis, and it appears that the plants in the TS and OM treatments were responding to an improved root perception of soil water availability. It is hypothesised that this allowed them to maintain canopy conductance and therefore photosynthesis at higher levels than in NP and WW. The improved performance of the TS and OM treatments represents an increase in the productive potential of exposed subsoil areas that cannot be achieved by improving fertilizer and irrigation management alone.
Spotted alfalfa aphid survival and reproduction on annual medics with various levels of aphid resistance
Authors: Lake AWH
Published: November 2005

Annual medics (Medicago spp.) with resistance to spotted alfalfa aphid (Therioaphis trifolii (Monell) fm. maculata) (SAA) are progressively replacing older susceptible cultivars in new sowings in Australian pastures. Six lines and cultivars from the species M. truncatula and M. littoralis with varying degrees of SAA resistance were studied for their effect on SAA survival, development and reproduction.Antibiosis in the form of decreased nymph and adult survival, increased developmental times and decreased nymph production per adult and production rate were detected. In the resistant lines tested, Sephi and 2-243 had very high levels of antibiosis to SAA: sufficient to prevent any nett multiplication of SAA. Two less resistant lines, Parabinga and SA 12591, also had significant antibiosis to SAA compared to the susceptible cultivars Harbinger and Borung, but aphid survival and multiplication were still moderately high. Behavioural patterns suggest antixenosis is insignificant as a resistance mechanism in all these lines in a no-choice situation.
Anatomical characters and digestibility of leaves of Panicum and other grass genera with C3 and different types of C4 photosynthetic pathway
Authors: Wilson JR , Hattersley PW
Published: November 2005

The relation between leaf anatomical structure and some nutritive quality attributes was investigated in a range of grasses of different photosynthetic pathway. The species sample comprised 12 Panicum species and 12 species from other grass genera. Dry matter digestibility (DMD), and cell wall and lignin content were determined on dried, ground samples of leaf blade.Leaves grown outdoors were smaller and had higher specific leaf weight than those from the glasshouse, but leaves from the two environments did not differ in anatomical characteristics or DMD.Anatomical differences between the leaf structural groups were consistently expressed, with C3 species having higher proportions of mesophyll (53-67%) and lower proportions of bundle sheath (5-20%) and vascular tissue (3-9%) than the C4 groups (28-47%, 12-33%and 6-12%, respectively). Within the C4 groups the 'classical' NADP-ME type had a lower mean proportion of 'Kranz' bundle sheath (14.9%) and vascular tissue (7.1%) than the 'classical' PCK and NAD-ME leaf-structural types (average values 24.3 and 9.3%, respectively). Conversely, species of the latter two C4 groups usually showed lower proportions of mesophyll and epidermal cells than those of the NADP-ME group. Leaf morphology was not consistently related to leaf-structural group, except that the C3 species in the sample usually had a smaller midrib relative to the cross-sectional area of the blade than the C4 species.The C3 group, with the notable exception of Panicum rivulare, generally had a lower cell wall content (37-49%) and higher DMD (67-74%) than the C4 groups (49-67% and 53-67%, respectively).The quantitative anatomical differences between C3 and C4 grasses accounted for a significant part of the generally higher DMD of C3 grasses (but exceptions can occur).
Selecting salt-tolerant citrus rootstocks
Authors: Gallasch PT , Dalton GS
Published: November 2005

The salt-tolerance of 28 imported rootstocks was compared with three citrus rootstocks used widely in South Australia. The experiment was conducted in a shadehouse, using highly saline irrigation water (8700 8S/cm conductivity) applied to vigorous, chloride-excluding genotypes.Fifteen of the imported rootstocks showed no significant growth reductions after 84 days of salt treatment and were therefore considered as being highly salt tolerant. All fifteen outperformed the three locally used rootstocks (Paramatta sweet orange, Cleopatra mandarin and Troyer citrange), which experienced significant growth reductions during salt treatment. Seventeen rootstocks showed no significant difference from each other in leaf chloride (Cl-) concentrations on day 84 and were therefore identified as the best Cl- excluders. Ten rootstocks had the combined attributes of salt tolerance on the basis of growth response, Cl- exclusion ability and absence of phytotoxic leaf symptoms. The relationship between growth response of plants during salt treatment and Cl- -accumulation in leaves was not significant.The three locally used rootstocks were not significantly different (P < 0.05) in their growth response to high salinity, but differed from each other in their Cl exclusion ability.Investigation of nutrient interrelationships showed that chloride uptake was negatively correlated with nitrogen (N) uptake and positively correlated with calcium (Ca) and sodium (Na) uptake. Sodium uptake was negatively correlated with N, potassium (K) and manganese (Mn) uptake.
Utilization of urea and molasses supplements by cattle grazing cereal stubbles
Authors: Coombe JB , Mulholland JG
Published: November 2005

Responses of cattle to urea and molasses supplements while grazing cereal crop stubbles were studied in two experiments.In experiment 1,2.5-year-old Friesian cows in early pregnancy grazed an oat stubble (6800 kg DM ha-1) for 12 weeks at a stocking rate of 3.8 cows ha-1. In addition, some were offered liquid supplements of molasses, or urea-molasses. Liveweight gain (mean 18 kg) was not significantly different between treatments during the first 6 weeks. Thereafter, unsupplemented cows lost weight at 1.6 kg day-1 compared with 0.5 kg day-1 for supplemented cows (P(0.05).In experiment 2, 1.5-year-old Angus X Friesian cows in early pregnancy, and rumen-fistulated Friesian steers, were grazed on wheat stubble for 15 weeks and were unsupplemented, or offered supplements of a urea-mineral block, a molasses lick, or a urea-molasses lick. The stubble initially contained c. 6000 kg DM ha-1 of crop residues, and at all times at least 100 kg DM ha-1 of mainly green stemmy weeds of digestibility (0.45. The diet selected contained >50% dead plant material except during the final week, and ranged in digestibility from 0.53 initially to 0.31 in the 12th week.Intakes of all supplements were highly variable among individuals with coefficients of variation usually >50%. Mean intakes of digestible organic matter (DOM) were generally increased by supplementation.During the first 11 weeks, mean liveweight gains ranged from 3.5 to 27 kg for the unsupplemented and urea-mineral block fed cattle. respectively, but thereafter all cattle lost weight rapidly (mean 1.33 kg day-1).Mean concentrations of rumen volatile fatty acids (VFA) fell during the experiment from 80.3 to 47.4, and from 90.9 to 56.4 mmol l-1 in the unsupplemented and supplemented steers, respectively. Rumen VFA levels were not related to molasses or urea intakes, and overall there was no relationship between liveweight change and levels of VFA in the rumen. Mean rumen ammonia levels, which were generally < 100 mg N l-1 in unsupplemented and molasses-fed steers, were increased by both urea supplements, particularly in the second half of the experiment.Although various parameters indicated likely deficiencies of energy and N in the diet, these supplements were generally of little benefit to cattle grazing cereal stubbles.
The effect of diet on the metabolism in sheep of the tritiated isoflavones formononetin and biochanin A
Authors: Davies HL , Hill JL
Published: November 2005

The metabolism of tritiated formononetin was studied in vivo and in vitro in the sheep and the metabolism of biochanin A studied in vitro.In vivo. Most of the formononetin was metabolized to equol and 81% of the administered radioactivity was excreted in the urine within 48 h, the main component being equol. Little or no daidzein was found in either rumen, plasma or urine samples. Some metabolites appeared on the TLC chromatograms in small amounts (never more than 10%); these were probably desmethylangolensin and O-methylequol, and their role in isoflavone metabolism is unknown.In vitro. The rate of metabolism of formononetin and biochanin A added to rumen samples from sheep varied with diet, being more rapid in samples from sheep fed on lucerne chaff or clover. Formononetin was converted to equol. Biochanin A was converted to genistein in rumen liquor from sheep fed on oaten chaff, but was further metabolized if the sheep had been fed on clover. A metabolite of RF 0.1 was observed which with a longer incubation time was converted to a non-volatile compound at RF 0.9.
The effect of selection for resistance to clover infertility on the reproductive performances of Merino ewes grazed on oestrogenic pastures
Authors: Croker KP , Lightfoot RJ , Johnson TJ , Adams NR , Carrick MJ
Published: November 2005

Rams were bred from ewes which had either maintained their fertility after grazing highly oestrogenic pastures for three to seven years. or, over the same period grazed �control� on or lowly oestrogenic pastures In 1977 and 1978 these rams were joined with a random selection of ewes, which had been grazed on lowly oestrogenic pastures, to produce contemporary Resistant and Control ewes.The Resistant and Control ewes were split at weaning into groups which subsequently were grazed on oestrogenic or non-oestrogenic pastures during each pasture growing season (May to October) of the experiment During the dry spring-summer period the ewes were regrouped and entire rams were joined with them for 42 days from early in January to determine whether resistance to the development of clover infertility had been inherited.The reproductive performances of the ewes were measured from two until eight years of age over the period from 1979 to 1986. In addition, the masculinization of the vulvas was monitored, mucus product ion was measured in the second last year, and the histology of the cervixes was observed when the experiment was terminated.The fertility of the Resistant ewes was affected by the oestrogenic pasture in the later years of the experiment, but the level of depression was significantly lower than that measured in the Control ewes grazed on oestrogenic pasture The realized 'heritability' of the ewes' fertile lifetime on oestrogenic pasture was estimated to be 0.73 with a standard error of 0.30.This resistance was associated with histological changes, which confirmed that the Resistant ewes were protected against oestrogen-induced damage. These results support the hypothesis that res istance to the development of clover infertility was present in these ewesA more intensive selection programme involving both ewes and rams may impart a higher level of resistance to ewes This would reduce the adverse effects of oestrogenic pastures on ewe flock productivity.
Variability in shading behaviour of sheep
Authors: Sherwin CM , Johnson KG
Published: November 2005

During summer, a flock of 20 mature Merino sheep on irrigated pasture made virtually no use of shade, although similar sheep on adjacent pastures used shade regularly. In the following year on dry pasture and under comparable climatic conditions, the same experimental animals shaded frequently. In the second year. individual animals had consistent patterns of shade use, some animals shading for approximately 40% of the time, others scarcely at all. Unexpectedly, the extent of shade use was not significantly related to daily environmental heat load. For individual animals, the use of limited shade was not related to their position within a dominance hierarchy or a leadership rank in the flock. The results indicate that, even in summer, shading is not of high priority for all sheep. Animals vary in their inclination to use shade. This inclination may be modified by factors including possibly, microclimate in the pasture, preference for particular camp-sites, and aversion to human observers.
Trace element nutrition of grazing ruminants. 3. Copper oxide powder as a copper supplement
Authors: Langlands JP , Donald GE , Bowles JE , Smith AJ
Published: November 2005

Hepatic copper (Cu) storage was determined in grazing sheep and cattle supplemented with copper oxide powder, oxidized Cu particles or Cu-calcium EDTA. Cu storage was significantly increased when particles or the EDTA complex were given, but responses in hepatic Cu concentration were small in animals given copper oxide powder. Sheep dosed with copper oxide particles retained particles in the abomasum at 44 days from dosing, but those given copper oxide powder did not retain measurable quantities in the abomasum and excreted about half the dose in the faeces within 4 days of administration.
Recombinant growth hormone in growing lambs: effects on growth, feed utilization, body and carcass characteristics and on wool growth
Authors: Zainur AS , Tassell R , Kellaway RC , Dodemaide WR
Published: November 2005

Groups of six crossbred lambs, three wethers and three ewes, about 22 kg liveweight (LW), were injected subcutaneously with 0, 50, 150 and 250 pg (kg LW) d a y 1 of recombinant DNA-derived bovine growth hormone (rebGH) for 60 days. From blood sampled twice weekly 4.5 h after injection, the mean plasma concentrations of growth hormone (GH) (P<0.01) and insulin (P<0.05) were significantly increased. The mean concentrations of GH were 2.9, 7.1, 9.4 and 8.8 8g/l, while insulin concentrations were 24.2, 29.5, 46.8 and 68.2 mU/l for the respective treatments. Maximum concentrations of plasma GH were recorded about 3 h after injection. Rates of liveweight gain were 180, 217,238 and 261 g/day (P<0.001), fccd conversion ratios were 5.71,4.97,4.66 and 4.05 g feed/g gain ( P < 0.001), and warm carcase weights were 14.4, 16.4, 16.6 and 16.8 kg (P < 0.0 1) for the respective treatments. The linear change in warm carcase weights became a quadratic response (P<0.05) when adjusted to an empty body weight (EBW) of 28.8 kg. Wool growth was not affcctcd by treatments. Of the non-carcase components, major organs including the head (P<0.01), feet (P<0.05), heart (P<0.05), liver and gallbladder (P < 0.05), reticula-rumen (P < 0.05), omasum (P<0.05) and blood (P<0.01) showed linear increases in weight with increasing dosage of rebGH, but no significant differences when data were adjusted to a standard EBW. The chemical composition of the carcase showed that crude protein increased linearly (P<0.001) with increasing doses of rebGH. When adjusted to 28.8 kg empty body weight, there was 16.0�/o more carcase protein (P<0.01) with 250 than with 0 8g (kg LW)-1 day-1 of rebGH.