bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of cysteine ethyl ester supplements on wool growth rate
Authors: Radcliffe BC , Hynd PI , Benevenga NJ , Egan AR
Published: November 2004

L-Cysteine ethyl ester hydrochloride (CEE) was evaluated as a dietary sulfur amino acid supplement for increasing wool growth rate. In Experiment 1, eight sheep were offered 800 g chopped lucerne hay daily and wool growth was measured over a three-week control period. These sheep were then given a continuous infusion of either CEE per rumen, CEE per abomasum, cysteine per abomasum or continued on the basal diet alone, for three weeks, and wool growth was measured again. All supplements were equivalent to 25 mmol/day. Wool growth rate on tattooed patches in sheep given CEE per rumen or abomasum increased 67% and 75% respectively above the rates prior to infusion, while that of animals given cysteine increased 45%. Wool growth rate in the control sheep increased by only 15% in the same period. In Experiment 2, wool growth was measured in 24 sheep offered 800 g/day lucerne chaff, and again when CEE, cystine, or Na2SO4, each providing 21 mmol S/day, were combined with mineral mix and offered with the feed. CEE and cystine increased wool production by 1.9 g/sheep/day (P < 0.01) and 1.0 g/day (P < 0.05), respectively, above that measured in the control groups (nil- or Na2SO4- supplemented) which did not differ.
Fate of urea-nitrogen from cattle urine in a pasture-crop sequence in a seasonally dry tropical environment
Authors: Vallis I , Peake DCI , Jones RK , McCown RL
Published: November 2004

The fate of urea-N in cattle urine applied during the dry season (in August) to the pasture phase of a pasture-crop sequence at Katherine, N.T., was investigated. Cattle urine labelled with 15N-urea was applied to three sets of microplots to measure the following parameters: (a) amount and distribution of 15N remaining in the microplots during the remainder of the dry season with 0, 0.5, 1.0 and 5.0 t ha-1 of pasture residues present initially; (b) the effect of placing the urine 5 cm below the soil surface on the amount of 15N remaining during the dry season; (c) uptake of 15N by the pasture during the early part of the wet season (October to December) and uptake by sorghum sown directly into the killed pasture in January. Residual 15N in the surface soil (0-15 cm) after the sorghum crop was also measured. Of the applied 15N, 26% was lost after 1 day, 32% after 7 days and 46% after 63 days. Losses were not affected by the amount of pasture residues on the microplots when the urine was applied. Almost all of the I5N remaining in the microplots was in the 0-7.5-cm layer of soil, and 65-75% of this was mineral N. The dry-season losses of 15N were presumably through volatilization of ammonia, because leaching was absent and no loss of 15N occurred when the urine was placed 5 cm below the soil surface. Pasture growth killed at the end of December contained 6.2% of the applied 15N, the sorghum crop recovered only a further 2.1%, and after harvest of the sorghum crop the 0-15.0-cm layer of soil contained 23%. Thus about half of the 15N remaining in the soil-plant system to the 15.0 cm soil depth at the end of the dry season disappeared during the following wet season, either as a gaseous loss or by leaching deeper into the soil.
Acid tolerance in the Rhizobium meliloti - Medicago symbiosis
Authors: Howieson JG , Ewing MA
Published: November 2004

Several strains of Rhizobium meliloti that originated from acid soils in Sardinia, Italy, were markedly superior in colonizing a moderately acid loamy sand (pH 5.0 in 1:5 0.01 M CaCl2) than two Australian commercial inoculant strains (U45 and CC169), and a group of strains that originated from alkaline soils in Syria and Iraq. Six Medicago hosts also varied greatly in their ability to achieve nodulation in this soil. M. polymorpha and M. murex were far superior in this respect to M. littoralis, M. truncatula and M. tornata. The most acid-tolerant strains of R. meliloti, WSM419 and WSM413, were able to nodulate a high proportion of plants of M. polymorpha and M. murex sown in the second year between 11 and 20 cm from the point of introduction of the rhizobia into the soil the previous year. It is suggested that these more saprophytically competent isolates of R. meliloti, combined with the species of Medicago more able to nodulate readily in acid soil, will extend the range of soils suitable for successful regenerative growth of these species.
Role of the dog, fox, cat and human as carnivore vectors in the transmission of the Sarcosporidia that affect sheep meat production
Authors: Ford GE
Published: November 2004

The roles of six carnivores as potential sources to sheep of the sarcosporidial parasites causing cysts in meat were compared in a series of experiments carried out between 1973 and 1980. The research was concomitant with other studies that confirmed the prey-predator-prey-predator cycle of transmission. Infected carnivores act as vectors, excreting in their faeces coccidial sporocysts infective to the meat animal. For 60 experimental infections, sheep meat containing sarcocysts or sarcocysts removed from sheep meat were fed to experimental carnivores. Faecal samples were examined for sporocysts over 60 days post infection. Neither macroscopic (visible) sarcocysts nor microscopic sarcocysts from sheep carcasses were transmissible by humans or by ferrets (domestic polecats). Microscopic sarcocysts were readily infective to dogs, both domestic and dingo, as well as to foxes, but not to cats. Large numbers of sporocysts that could contaminate the environment were excreted. Both fat and thin visible sarcocysts were transmitted exclusively to cats. Although cats responded with relatively low levels of sporocysts, these were considered adequate to provide sufficient pasture contamination for the life cycle to be perpetuated. It is concluded that, while domestic dogs may be the greatest source of infection for sheep with microscopic sarcocysts, foxes as vectors also pose a threat to sheep production. Similarly, due to their widespread presence, feral cats play a role as well as domestic or semi-domestic cats in the spread of sarcocysts causing visible carcass lesions.
The effect of successive crops of wheat on the availability of copper fertilizers to plants
Authors: Brennan RF , Robson AD , Gartrell JW
Published: November 2004

Successive cropping with wheat on an acid sandy loam and a calcareous sand rapidly decreased the availability of applied copper sulfate to wheat plants grown in pots. The amount of copper removed in grain and straw was only approximately 10 per cent of the amount of copper applied. Ammonium oxalate-extractable copper also declined with successive crops. Moreover, the relationship between copper uptake and extractable copper also changed with successive crops. The amount of ammonium oxalate-extractable copper required for maximum growth increased with successive crops from 0.2 to 0.4 8g/g soil on the acid sandy loam and from 0.6 to 0.8 8g/g on the calcareous sand.
Effects of grain shape and size on milling yields in wheat. II. Experimental studies
Authors: Marshall DR , Mares DJ , Moss HJ , Ellison FW
Published: November 2004

The relationships between grain size and shape and milling yield were examined in samples of 11 current commercial cultivars and breeding lines of wheat grown at several sites in northern New South Wales. In addition, the effects of segregation within samples for grain size and test weight were studied. For samples that had been segregated for test weight, there was a strong positive correlation between test weight and milling yield. This correlation was much weaker for samples of different varieties grown at a particular site although over all sites the correlation was significant. Similarly, in samples stratified for grain size, there was a consistent positive correlation between seed size and milling yield as expected on theoretical grounds. In contrast, in samples of different cultivars grown at the one site, grain size was not correlated with milling yield. These contrasting results were taken to indicate that the contribution of differences in seed size to genotypic difference in milling yield were small relative to the effects of other factors. The effects of some of these other attributes of wheat grains, which may influence milling yield (e.g. the amount of germ tissue, thickness of bran, depth of crease), were also studied. Free-milling wheats appeared to differ from their poorer milling counterparts in several of these factors, each of which appeared to make a minor but cumulative contribution to differences in milling yield. No one factor studied here appeared on its own to make a major contribution to genotypic difference in milling yield.
Boron toxicity in South Australian barley crops
Authors: Cartwright B , Zarcinas BA , Spouncer LR
Published: November 2004

Boron toxicity was identified in barley crops grown on a range of soils at 16 widespread locations in South Australia, and also at one site in western Victoria. The soils on which boron toxicity occurred included red-brown earths (Calcic Natrixeralf), calcareous earths (Xerollic Calciorthid and Calcic Paleorthid), and calcareous sands ('Petrocalcixerollic' Xerochrept). At one site the soil was a grey clay (Palexerollic Chromoxerert). The properties of some examples of normal and high-boron soils which were sampled in close proximity are discussed. For individual high-boron soil profiles it was possible to demonstrate statistically significant relationships between extractable boron and ESP, CEC and clay content. However, these relationships did not hold generally for comparisons between normal and high-boron soils. Boron concentrations in affected barley ranged from 56 mg/kg in mature straw to 323 mg/kg in whole tops at Feekes stage 10.1. In control samples the mean boron concentration was 22.8 mg/kg. The concentrations of other nutrient elements (P, K, S, Mg, Cu, Zn, Mn, Mo) were within normal ranges, and did not differ between control samples and plants with toxicity symptoms. Barley plants affected by the toxicity had increased concentrations of Na and Cl, and decreased concentrations of Ca compared with control plants. These effects were small, but statistically significant, and were consistent with the notion that the toxicity was associated with sodic soils. The findings extend our earlier work on boron toxicity at a single site, and demonstrate that the toxicity is widespread in South Australia.
The role of calcium in alleviating aluminium toxicity
Authors: Alva AK , Asher CJ , Edwards DG
Published: November 2004

Effects of varying calcium (Ca) concentration at constant or varying solution ionic strength on root elongation of soybean (Glycine max (L.) Merr.) and subterranean clover (Trifolium subterraneum L.) were determined in aluminium (Al) free nutrient solution or solutions containing monomeric Al activities (+aAl mono) of 8-10 8M for subterranean clover and 20-22 8M for soybean. In Al-free solutions, the root length for subterranean clover was not significantly influenced by Ca or ionic strength. However, soybean root length was greater at 500 8M Ca than at higher Ca concentrations. Raising the ionic strength at 500 and 5000 8M Ca significantly decreased root length. In the presence of Al, maximum root length of both species occurred at 15 000 8M Ca. Soybean root length at 500 and 5000 8M Ca was 35% and 87% respectively of that at 15000 8M Ca. The corresponding values for subterranean clover were 53% and 81%. The positive effect of Ca concentration on root length, despite a nearly constant +aAL mono, confirms the existence of a protective action of Ca against Al toxicity. Raising the solution ionic strength at 500 8M Ca in the presence of Al improved the root growth of soybean by 86% and that of subterranean clover by 45%. At 5000 8M Ca, a small beneficial effect of increased ionic strength (14%) was found only in subterranean clover. Increasing Ca concentration in solution decreased water extractable and 0-1 M HNO3 extractable Al in roots of both plant species. Transfer of soybean seedlings to Al-free nutrient solutions containing 500, 1500 or 5000 pM Ca after 24, 48 or 96 h in a solution containing +aAL mono of 22 8M resulted in a substantial recovery in primary root growth. Relative root lengths were in each case significantly higher at 5000 8M Ca than at 1500 or 500 pM Ca. Roots transferred to 500 8M Ca after exposure to Al for 6 or 18 h underwent a period of accelerated elongation after a lag period of 30-40 h. By 138 h there were no significant differences in root length between the unstressed control plants and those subjected to 6 or 18 h Al-stress.
Genetic variability in sunflower cultivars under drought. I. Yield relationships
Authors: Fereres E , Gimenez C , Fernandez JM
Published: November 2004

Field experiments were conducted between 1981 and 1983 at Cordoba, Spain, to evaluate the yield responses to drought of 53 sunflower genotypes. There was substantial variability among genotypes both in dryland yield and in yield potential, estimated as the yield under frequent irrigation. No association was found between yield potential and the drought susceptibility index, suggesting that drought resistance and high yield potential may be combined in improved sunflower cultivars. Water deficits reduced harvest index (HI) in all genotypes but the decrease in HI varied among genotypes. Excellent correlations were found between HI and grain yield under dryland conditions for genotypes with similar length of season. The reduction in HI due to water deficits was mostly due to adjustments in seed number with less variation in individual seed weight. In turn, the reduction in seed number was due to a combination of reduced head size and of the area having viable seeds. The length of season of the genotypes apparently affected the yield component adjustments in response to water deficits.
Field evaluation of some factors affecting nitrogen fixation in pastures by 15N isotope dilution
Authors: Steele KW , Littler RA
Published: November 2004

15N enrichment in Lolium perenne L. and Trifolium repens L. herbage and the proportion of nitrogen in the latter derived from symbiotic N2-fixation (PN) were measured in a temperate pasture following single or repeated applications of 50 mg N/m2 as NaNO3, (NH4)2SO4 or urea containing 10, 50 or 95 atom % 15N. In a second experiment 50 mg N/m2 as NaNO3 (50 atom % 15N) was injected either onto the soil surface or 50 mm or 100 mm below the soil surface. 15N enrichment in Lolium perenne L. herbage was generally higher on plots receiving a single application of NaNO3 after the harvest preceding measurement than on equivalent plots receiving (NH4)2SO4 or urea. Estimates of P, were consistently higher on NaNO3 plots than on (NH4)2SO4 or urea plots. Significant differences in estimates of PN between NaNO3 and (NH4)2SO4 or urea plots frequently persisted to the second harvest following 15N application, but by the third or subsequent harvest differences in estimates of P, between chemicals were only occasionally significant and showed no apparent trend. With increasing depth of 15N placement the 15N enrichment in Trifolium repens L. herbage decreased, whereas that of Lolium perenne L. remained similar. PN values therefore increased with increasing depth of 15N placement.
Food intake, water intake, urine output, growth rate and wool growth of lambs accustomed to high or low intake of sodium chloride
Authors: Hamilton JA , Webster MED
Published: November 2004

Lambs artificially reared were given either no salt supplement (LS lambs) or 2.0 g NaCl supplementation (kg body weight)-1 (HS lambs) by oral route from an early age. The food intake, water intake, urine output, growth rate and wool production were measured for several months to identify any changes in the performance of the lambs. Growth rate of HS lambs, although relatively high, was significantly less (P < 0.001) than in LS lambs, owing mainly to HS lambs having a reduced food intake. Linear relationships between water and food intakes were maintained, but shifted to a new plane for the HS lambs. The high intake of NaCl caused water intake to increase, which appeared to be mostly used to excrete the NaCl through increased urine output. Lambs given a high intake of NaCl had a lower food intake, but the reasons for the reduction could not be defined in this experiment. Wool production was reduced, but not significantly, by a high intake of NaCl. Diarrhoea was observed on more than one occasion in HS lambs during the experimental period.
Corrigendum - Inoculation methods for assessing resistance in wheat to crown rot caused by Fusarium graminearum group 1
Authors: Dodman RL , Wildermuth GB
Published: November 2004

A range of inocululatron methods for assessing resistance in wheat to crown rot caused by Fusarium graminearum Group 1 was evaluated in the glasshouse and in the field. When grain was colonized with the pathogen, ground and applied with the seed at planting or spread around young plants as an aqueous suspension, high levels of crown rot were produced, but resistance (usually measured as per cent diseased plants or tillers) was still expressed. Similar results were achieved with induced field inoculum obtained by inoculating an area of wheat to obtain a high incidence of disease and incorporating the stubble into the soil. Natural field inoculum and inoculation of seed with spores produced lower levels of disease, although differentiation of resistant and susceptible cultivars was still possible. Other methods, suitable only for plants in pots and often for more specific purposes (for example, for inoculation at different stages of plant growth) were also studied. Resistance was best expressed where inoculum was applied onto or into soil, rather than directly onto or into plants. Currently, the resistance of all potential cultivars for release in Queensland is assessed in the field by sowing seed dusted with benomyl into furrows along which ground, colonized grain is distributed. Crown rot severity is then determined at maturity.
Seed production by skeleton weed (Chondrilla juncea L.) in Western Australia in relation to summer drought
Authors: Dodd J , Panetta FD
Published: November 2004

Seed production in Forms A and C of C. juncea was measured at 11 wheatbelt sites in Western Australia and under glasshouse conditions. Most field-grown plants produced abundant viable seeds, even without substantial summer rainfall. Up to 27.6 x l03 seeds per plant were recorded, and their viability was frequently between 80 and 90%. Even in their first year, some plants produced more than 10000 seeds each. Through the summer, seed production often followed either a positively skewed, or a bimodal curve. Falls of rain in summer did not increase seed output or affect its quality in established plants. Exceptionally high air temperatures appeared to depress seed numbers and/or viability at several, but not all, sites. At the end of summer, when young plants were 9-12 months old, soil water extraction had occurred to 310 cm, indicating root penetration to this depth. Conservative water use by C. juncea during summer was indicated by low values of soil water depletion. In glasshouse-grown plants, simulated drought reduced seed numbers, viability, primary dormancy and seed weight, although the two forms responded differently. Given adequate winter rainfall to recharge soil water storage, C. juncea appears capable of producing large quantities of viable seeds throughout the Western Australian wheatbelt.
Defoliation regrowth and dry matter partitioning in the two arid zone grasses, Aristida armata and Thyridolepis mitchelliana
Authors: Brown RF
Published: November 2004

Plants of the desirable rangeland grass, Thyridolepis mitchelliana, and its undesirable companion, Aristida armata, were defoliated at various ages, and their subsequent regrowth and seed production compared with that of intact plants. Young plants of T. mitchelliana, but not A. armata, often failed to survive severe defoliation. Seed production by A. armata greatly exceeded that of T. mitchelliana and was much less affected by defoliation. In both defoliated and intact plants, the proportion of dry matter in inflorescences was several times greater for A. armata than T. mitchelliana, but the reverse occurred with leaf production. Root growth was little affected by defoliation, and there was no evidence of export of root material to support tops regrowth. Total plant production of both species was unaffected by the loss of half the tops, but was depressed by more severe defoliation. The differences between the two species in their reaction to defoliation seem sufficient to explain the displacement of T. mitchelliana by A. armata which followed the introduction of domestic livestock. Under grazing, A. armata is likely to have a reproductive advantage, and the implications of this for pasture management are examined.
Some effects of field history on the relationship between grass production in subterranean clover pasture, grain yield and take-all (Gaeumannomyces graminis var. tritici) in a subsequent crop of wheat at Bannister, Western Australia
Authors: MacNish GC , Nicholas DA
Published: November 2004

The relationship between grass production in subterranean clover pastures with two different rotation histories and take-all in a subsequent wheat crop following barley was studied. Grass production in the pastures ranged from 0 to 1700 kg ha-1. The incidence of take-all in the wheat crop ranged from 10 to l00%, while the take-all severity percentage ranged from 4 to 99.In one rotation series (pasture 9 years; barley, barley, pasture, wheat), each kilogram increase in grass production in the last pasture year caused a 0.087% increase in the take-all severity rating. In the second series (pasture 7 years; oats, pasture 3 years; barley, wheat), each kilogram increase in grass production caused a 0.040% increase in severity. These figures are significantly different (P < 0.05). Thus the field history ranging back at least four seasons influenced the effects that grass level in the last pasture year had on take-all severity. Reductions in wheat yields ranged from 8.6 to 10.5 kg ha-1 for each 1% increase in take-all severity rating.
Nitrogen fixation activity by white clover pastures during flood irrigation cycles
Authors: Mundy GN , Jones HR , Mason WK
Published: November 2004

The effect of flood irrigation on clover nitrogen fixation (acetylene reduction activity) was investigated in unfertilized pastures and pastures fertilized with 100 kg N/ha as NH4N03. During the experiment acetylene reduction activities were monitored between successive flood irrigations. The rate of ethylene production increased with decreasing soil water content, peaking 13 days after irrigation. Measured nodule activity then declined, possibly owing to water stress. Nitrogen fertilizer reduced acetylene reduction activities to about half that of the unfertilized pastures. For most of the irrigation cycle acetylene reduction by the pasture was below the measured maximum.
Seed and pollen transmission of tobacco streak virus in tomato (Lycopersicon esculentum cv. Grosse Lisse)
Authors: Sdoodee R , Teakle DS
Published: November 2004

ELISA tests showed that 40-7670 of the seeds of tomato (Lycopersicon esculenturn cv. Grosse Lisse) contained tobacco streak virus (TSV) when either the female (ovule) parent only, the male (pollen) parent only, or both parents were virus infected. When seeds with either or both parents infected were soaked in distilled water overnight and dissected, TSV was found more frequently in the endosperm (40-90%) than the embryo (10-50%), and little or no TSV was present in the seed coat. The seeds which had an infected female (ovule) parent were lighter in weight and had a lower germination rate (3-27%) than seeds which had either an infected male (pollen) parent or two healthy parents (germination rate of 88-96%). Only about 10% of seedlings which had one or both parents infected were found to be infected. TSV was not transmitted to the leaves of healthy tomato plants when flowers were pollinated with pollen from infected tomato plants.
Rates of passage of solutes, microbes and particulate matter through the gastro-intestinal tract of ewes fed at a constant rate throughout gestation
Authors: Faichney GJ , White GA
Published: November 2004

The rates of passage of solutes, microbes and particulate matter were measured at different stages of gestation in multiparous Corriedale ewes. The mean retention times (MRT) of each of these constituents in the rumen decreased as gestation progressed. There was an increase in the MRT of digesta distal to the stomach which was sufficient to compensate for the decrease in solute MRT in the rumen. Thus, for the whole tract, only the MRT of particulate matter decreased during gestation. There were good relationships between the rate of passage from the rumen of microbes and of particulate matter and that of water, reflecting the importance of water as the vehicle for passage from the rumen. The fractional outflow rate of the particle-associated marker 103Ru-phen was greater than the net value for microbes, but was similar to the calculated value for non-microbial, non-ammonia nitrogen. The proportion of the rumen microbial population that was free-floating declined to a minimum of 0.18 as the fractional outflow rate of water increased. A peristaltic activity index showed a tendency to decline, particularly in the duodenum, as gestation progressed.
Influence of manganese intake on body, wool and testicular growth of young rams and on the concentration of manganese and the activity of manganese enzymes in tissues
Authors: Masters DG , Paynter DI , Briegel J , Baker SK , Purser DB
Published: November 2004

Four groups of 10-month-old Merino rams of similar liveweights were fed identical diets, except that the manganese contents were either 13, 19, 30 or 45 pg/g of dry matter. The basal diet (13 8g Mn/g) was fed to all rams for 14 days, then the treatment diets were fed for a further 84 days. All rams were slaughtered at the end of the experiment and tissues were collected. The intake of manganese had no affect on liveweight gain, dry matter intake, apparent digestibility of the diet or clean wool production. Although the size of testicles at slaughter was not related to manganese intake, testicular gain as a ratio to liveweight gain was higher in the rams fed 19 and 30 pg Mn/g, but not 45 8g Mn/g, than those fed 13 8g Mn/g. Also in rams fed the basal diet, the large rumen bacteria (12.90 to 16.24 pm in diameter) made up less of the bacterial biomass than in other groups. The treatments did not affect the total number of rumen bacteria or the size structure of bacteria population in the rumen. Rams fed the least amount of manganese had low concentrations of manganese in heart and lung and a lower activity of manganese superoxide dismutase in heart than rams fed 45 8g Mn/g. The concentration of manganese in these tissues, and the activity of manganese superoxide dismutase in the heart increased linearly as the concentration of manganese in the diet increased. An intake of 13 8g Mn/g of dry matter therefore caused some biochemical changes in rams, but was adequate for growth and wool production under the conditions of this experiment.
Feed intake and digestion responses in sheep to the addition of inorganic sulfur to a herbage diet of low sulfur content
Authors: Weston RH , Lindsay JR , Purser DB , Gordon GLR , Davis P
Published: November 2004

Young sheep were used in feed intake and digestion studies with a wheaten straw diet of low sulfur (S) content (0.71 g S kg-1 organic matter) fed without additional S (low S diet) or containing sodium sulfate (high S diet). With the high S diet, relative to the low S diet, (i) the levels of sulfide in rumen liquor were elevated, (ii) less time was spent in ruminating activities, (iii) rumen liquor volume tended to be lower (-l0%), (iv) indigestible markers were cleared more rapidly from the rumen (approx. +16%), (v) more organic matter (OM) and acid detergent fibre were digested in the stomach and in the alimentary tract as a whole (+8-16%), (vi) more non-ammonia nitrogen (NAN) flowed into the intestines (+13%) and this NAN had a higher content of sulfur amino acids (+ 17%), (vii) a greater quantity of NAN was digested in the intestines per unit of digestible OM intake (+ 12%), (viii) the concentrations of various amino acids in venous blood were substantially lower, and (ix) fungal activity in the rumen was higher. The number of bites performed on each rumination bolus was inversely related to fungal activity in the rumen, but the latter was not related to OM digestibility or to the sulfur amino acid content of the NAN flowing into the intestines. The OM digestibility was inversely related to the rate of clearance of markers from the rumen with the low S diet but not the high S diet. Voluntary feed consumption was similar with both diets, and in the low S diet it was inversely related to OM digestibility and positively related to marker clearance rate from the rumen. Digestible OM intake under conditions of ad libitum feeding was higher with the high S diet (+11%) and positively related to fungal activity in the rumen and to the sulfur amino acid content of the NAN flowing into the intestines. The data indicate that an inadequate amount of S in the low S diet impaired the metabolism of the rumen microbiota which in turn affected variables relating to digestion and metabolism. A quantitatively significant role for the anaerobic fungi in the structural degradation of fibre is suggested and attention is drawn to the need for studies on both feed consumption regulation with low S diets and the relation between herbage S status and the sulfur amino acid content of the rumen microbiota.
The effect of supplements of formaldehyde-treated casein on the partitioning of nutrients between cow and calf in lactating Bos indicus × Bos taurus heifers fed a roughage diet
Authors: Hunter RA , Magner T
Published: November 2004

The effect of a supplement of formaldehyde-treated casein on partition of nutrients and productivity of Bos indicus x Bos taurus (50% x 50%) first-calf heifers was studied. Sixteen pregnant heifers were fed a long-chopped roughage diet (13 g N/kg organic matter) ad lib. for approximately 3 weeks before calving and for 16 weeks after calving. Half the animals were supplemented with formaldehyde-treated casein (300 g per day). There were also 8 non-pregnant, non-lactating controls, half of which were supplemented with formaldehyde-treated casein. Supplementation had no significant effect on intake, irrespective of the physiological state of the heifers. There was a significant (P < 0.05) positive multiple regression between peak intake during lactation and the weight change of both heifer and calf in the first 8 weeks of lactation. Milk yield was not significantly affected by supplementation for the first 8 weeks. In the second half of lactation supplemented heifers produced significantly (P < 0.05) less milk, but not less milk solids, than unsupplemented heifers. During the latter half of lactation there was a highly significant (P < 0.001) positive relationship between milk yield and lactose secretion. The mean (� s.e.m.) length of the period of anoestrus after calving was 17 � 2.5 and 12 � 1.7 weeks for unsupplemented and supplemented heifers respectively. The length of the period of anoestrus was positively related to milk production (P < 0.01) and peak intake during lactation (P < 0.05). Supplemented lactating heifers had significantly (P < 0.05) higher plasma insulin concentrations and significantly (P < 0.01) lower plasma growth hormone concentrations than unsupplemented lactating heifers. In supplemented heifers in the second 8 weeks of lactation plasma insulin concentration was significantly (P < 0.01) negatively correlated with milk yield and yield of milk constituents. Supplementation with formaldehyde-treated casein did not increase roughage intake but did affect the partition of nutrients via a positive insulin and negative growth hormone response. Nutrients were preferentially diverted into maternal body growth rather than milk synthesis in the second half of lactation.
Lupins and energy-yielding nutrients in ewes. 1. Glucose and acetate biokinetics and metabolic hormones in sheep fed a supplement of lupin grain
Authors: Teleni E , King WR , Rowe JB , McDowell GH
Published: November 2004

Measurements were made of metabolism of glucose and acetate and changes in plasma hormones in sheep fed a basal ration to meet maintenance requirements for metabolizable energy (ME) or fed the same level of basal ration and given either a supplement of 750 g day-1 lupin grain (Experiment I) or intravenous glucose infusions over periods of 17 h (Experiment 2).In ewes given supplementary lupins, concentrations of volatile fatty acids (VFAs) in rumen liquor increased but molar proportions of VFAs were unchanged. Plasma concentrations of glucose, acetate and propionate increased; entry rates of glucose, acetate and CO2 increased and glucose oxidation (but not acetate oxidation) increased during supplementation with lupins. Other changes measured during lupin supplementation included increased plasma urea, a transient and marked increase in plasma insulin and a concomitant decrease in plasma growth hormone during the first three days, and an increase in plasma tri-iodothyronine (T3) with no changes in plasma thyroxine (T4).When glucose was infused intravenously at rates ranging from 0 to 46.8 mmoles h-1 (cf. 31 mmoles h-1 due to lupins) endogenous entry rate of glucose only increased at the highest infusion rate. There was a negative linear relationship between infusion rate of glucosc and plasma urea, whereas positive linear relationships were found between glucose infusion rate and both plasma insulin and T3.It was concluded that ewes on a maintenance basal diet and fed a supplement of 750 g day-1 lupin grain would rapidly switch to the anabolic mode concomitant with increases in glucose entry rate by more than 100% and acetate entry rate by more than 50%. Long-term intravenous infusion of the amount of glucose equivalent to that promoted by the lupin grain supplement would probably not suppress endogenous glucose production.
A breeding program to reduce the diameter of the major xylem vessel in the seminal roots of wheat and its effect on grain yield in rain-fed environments
Authors: Richards RA , Passioura JB
Published: November 2004

It is thought that the man xylem vessel in the seminal roots of wheat crop will regulate crop water use if water is available in the subsoil but the top soil is dry. This should result in more water being used after anthesis, and a higher harvest index and yield. A backcross breeding program using two Australian commercial wheat varieties is described that reduced their xylem vessel diameter from about 65 8m to less than 55 8m. In field trials conducted on fallow land in eastern Australia over five years, comparing selections with narrow xylem vessels against unselected controls, narrow vessel selections yielded between 3 and 11% more than the unselected controls, depending upon their genetic background, in the driest environments. Yield differences in the wetter environments were largely not significant. This yield increase in the narrow vessel selections was associated with a significantly higher harvest index, also higher biomass at maturity and kernel number.
Early generation selection in wheat. II. Grain quality
Authors: Fischer RA , O'Brien L , Quail KJ
Published: November 2004

In order to test early-generation selection for grain quality, random F1-derived progeny from a multiple convergent cross of 16 high-yielding bread wheats were grown in F3 generation, along with the parents, as spaced plants in a glasshouse under optimal conditions. Progeny lines were then advanced without selection to F7 when 58 random lines were sown with the parents in a replicated yield experiment at Griffith under irrigation and optimal management. Small-scale grain quality tests were performed on grain from the F3 plants, the F7 plots and the parents. The tests comprised particle size index (PSI), grain and flour protein content (GP, FP), sodium dodecyl sulfate sedimentation volume (SDS), Pelshenke wheatmeal fermentation time (PEL) and flour milling yield (MY).There were significant genotypic effects for all quality traits in each generation. Phenotypic correlations in F3 and in F7 showed positive correlations between protein content and SDS and PEL, and in F7 a strong negative correlation between grain yield and grain quality (GP, FP, SDS, PEL). Across generations (F3 versus F7), the relationship was strong for PSI, moderate for SDS and PEL, but nonsignificant for the other traits.The realized heritability was high for PSI (77%), moderate for SDS (44%) and PEL (47%), but low (18-24%) in the other cases. Selection at an intensity of 26% for the first three mentioned traits did not significantly change grain yield, plant height or flowering date, although for GP and FP it did lower grain yield by 7%. Desirable quality types were defined within the three hardness (PSI) classes, namely, hard, intermediate, and soft (gluten type not biscuit type). Retrospective selection in F3 for desirable types significantly and markedly increased the frequency of desirable types in each class by three- to eight-fold. It is concluded that in wheat early generation selection for PSI, SDS and PEL, even when practised upon glasshouse-grown plants, gives useful progress without prejudicing grain yield.
Effect of phosphorus supply on three perennial Stylosanthes species in tropical Australia. III. Potassium, calcium, magnesium and sodium concentrations and implications for grazing animals
Authors: Gilbert MA , Jones RK , Shaw KA , Edwards DG
Published: November 2004

Thc effect of phosphorus application (0 and 50 kg P ha-1 as triple superphosphate) on potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na) concentrations in three Stylosanthes species (S. scabra cv. Seca, S. pianensis cv. Schofield and S. viscosa CPI 34904) was examined in a field experiment. Regular measurements were made of these cations in the leaves, stems, inflorescence, seed and litter of established plants during the wet and dry seasons of 1978-79.Phosphorus supply did not affect K, decreased Ca, increased Mg, and in some fractions increased Na concentration. It decreased the ratio of Ca to P. Applied P had no effect on the changes in cation concentration through time. With increasing plant age, K decreased in leaves of all species, Ca decreased in Seca and Schofield (but remained constant in CPI 34904), Mg was relatively steady in all species, and Na decreased in Seca and CP134904 but not Schofield. A comparison of cation concentrations in intact leaves and leaf litter suggests there was remobilization of K, and to a lesser degree, Na and Mg, but not Ca from old leaves prior to senescence.Potassium and Ca in leaf and green stem were generally considered adequate for cattle requirements throughout the year. However, Mg and Na often fell below the level required for cattle growth. The wide Ca/P ratio combined with low P concentration in all species suggests that cattle grazing these pastures would respond to P supplementation.
The effect of temperature on in vitro germination and germ tube growth of urediniospores of Tranzschelia discolor
Authors: Ellison PJ , Cullis BR , Bambach RW , Kable PF
Published: November 2004

The effect of temperature on in vitro germination and germ tube growth of urediniospores of Tranzschelia discolor was studied over time under constant temperature conditions. Studies were carried out on 1% water agar in the dark at 3�C, 5�C, 8�C, 10�C, 15�C, 20�C, 25�C, 28�C, 30�C and 32�C. Germination was observed at all temperatures between 5 and 30'C, and occurred rapidly over most of this range. At 2 h, germination exceeded 80% at temperatures between 10 and 28�C, and this level was reached at 3 h at 8�C. Germination at 5 and 30�C was much reduced and at 7 h reached only 44% and 38% respectively. Germ tube growth occurred most vigorously at 15 and 20�C, reaching lengths in excess of 500 8m at 9 h. The optimum range was narrower than that for germination, and growth was reduced or poor at 8�C, 10�C, 25�C and 28�C, which were favourable temperatures for germination. Average germ tube lengths at 9 h at these temperatures were 55, 245, 273 and 62 8m, respectively. Three-dimensional models were derived relating germination and germ tube growth to time and temperature.
Evidence for differences between cultivars in responsiveness of wheat to applied nitrogen
Authors: Anderson WK , Seymour M , D'Antuono MF
Published: November 2004

Three cultivars of wheat were grown using five levels of applied nitrogen (N) fertilizer at five locations in the central wheatbelt of Western Australia during 1986, 1987 and 1988. The cultivars were Gamenya (old, tall), Gutha (new, tall) and Aroona (new, semidwarf). The aim of the experiments was to determine if the newer cultivars responded more to applied N fertilizer than the older ones. At 10 out of 15 sites there was a yield increase to applied N. The semi-dwarf cultivar Aroona out-yielded the two tall cultivars apd responded more to added N at 6 of the 15 sites. The average initial response to applied N at these six sites was 16, 18 and 31 kg of grain per kg of N applied for Gamenya, Gutha and Aroona. Aroona's increased initial response to applied N was not evident at five of the sites that received less than 250 mm of rainfall during the growing season. The increased responsiveness of Aroona was associated with a greater apparent net uptake efficiency, a larger concentration of N in the tops, the production of more ears and kernels per unit area at larger concentrations of N in the tops, and an ability to maintain kernel size at the larger kernel numbers produced by an increased N supply.
Lime responses by barley as related to available soil aluminium and manganese
Authors: Conyers MK , Conyers MK , Poile GJ , Poile GJ , Cullis BR , Cullis BR
Published: November 2004

Twenty-three surface soils (0-10 cm) sampled from major New South Wales lime trials were incubated at six lime rates, from 0 to 10 t/ha, and used in pot trials with barley (Hordeurn vulgare cv. Schooner) which was grown for five weeks. Each replicate pot was soil tested for exchangeable cations (Ca, Mg, K, Na, Mn, Al), pH in 0.01 M CaCl2, and Al in the 0.01 M CaCl2 extract by pyrocatechol violet (total Al) and by reaction for 15 s in 8-hydroxyquinoline (monomeric Al). The latter was also converted to the activity of Al3 in the 0.01 M CaCl2 extract. The soil tests were compared for their prediction of the dry matter yield of whole tops of barley. The four tests for aluminium (exchangeable Al as Al/ECEC; total 0.01 M CaCl2 extractable Al; monomeric 0.01 M CaCl2 extractable Al; and Al3+ activity in 0.01 M CaCl2) were each better indicators of the infertility of the acid soils than soil pH. The prediction of the dry matter yield of barley by the four aluminium tests was improved by the inclusion of exchangeable soil manganese in the statistical analysis. The use of 0.01 M CaCl2 is recommended as a routine extraction procedure for diagnosing Al toxicity. Soil Mn should also be measured and included in correlations with barley growth. Pyrocatechol violet is the recommended analytical procedure for Al owing to its comparative simplicity.
Intake and digestion of lucerne hay and wheat straw by cattle 14 to 56 weeks of age
Authors: Leibholz J
Published: November 2004

Eight Friesian calves, 8 weeks of age, were prepared with rumen and abomasal cannulae. Four calves were given lucerne and four calves were given wheat straw sprayed with urea and minerals. The diets were changed over between the calves every 6 weeks until the calves were 56 weeks of age. The particles in the rumen that passed through a 1 mm screen during wet sieving were 66 to 73% of the total particles in the rumen of calves given lucerne and 77 to 84% of the particles in the rumen of the calves given wheat straw. The digestion of organic matter in the stomach was 71 to 79% of the total organic matter digested in the calves given lucerne. In the calves given wheat straw, between 82 and 95% of the total organic matter digestion occurred in the stomach. The apparent digestion of dry matter in the calves given lucerne was 61-6856 and did not change with age of the calves. The apparent digestion of dry matter when the calves were given wheat straw was 42% at 14 weeks of age, and it increased to 53% at 56 weeks of age. The digestion of nitrogen in the intestine in the heifers given wheat straw increased to 26 weeks of age while that of heifers given lucerne hay decreased.
The life-history and control of Hapatesus hirtus Candeze (Coleoptera: Elateridae) in Victoria
Authors: Horne PA , Horne JA
Published: November 2004

The incidence and life-history of potato wireworm, Hapatesus hirtus Candeze, in Victorian potato crops were studied, and insecticidal control measures assessed. Larval stages were present and active throughout the year. Ten larval instars were identified, probably requiring several years to complete development. Egg development occurred in October-November and the most likely timing of oviposition was December. The relative numbers of larval H. hirtus detected in soil samples, pre-planting baits and harvested tubers are presented. Baiting with halves of potatoes provided an efficient means of detecting areas likely to suffer wireworm damage. One formulation of chlorpyrifos ('Lorsban') was effective in reducing damage to, and larval numbers in, potatoes in field trials. The granular formulation of tefluthrin and the controlled release chlorpyrifos were not effective in protecting potato tubers.
Effects of pH and aluminium on the growth of temperate pasture species. II. Growth and nodulation of legumes
Authors: Edmeades DC , Blamey FPC , Asher CJ , Edwards DG
Published: November 2004

Ten temperate pasture legumes inoculated with appropriate rhizobia were grown for 31 days in flowing solution culture. Solution ionic strength was approximately 2700 8M and contained inorganic nitrogen (150 , 8M NO3-) only at the commencement of the experiment. Solution pH was maintained at 4.5, 5.0, 5.5 and 6.0. Also, five aluminium (Al) treatments were imposed, with nominal Al concentrations of 0, 3, 6, 12 and 24 8M (2.5, 7.1, 8.3, 11.2 and 24.7 8M Al measured) at pH 4.5. Solution pH <6 . 0 markedly reduced total dry mass (TDM) in all cultivars of white clover (Trifolium repens) cvv. 'Grasslands Pitau, Huia, G18 and Tahora' and red clover (Trifolium pratense) cvv. 'Grassland Turoa and Pawera', and to a lesser extent in the two subterranean clover (Trifolium subterraneum) cvv. 'Tallarook and Woogenellup'. In contrast, solution pH had no effect on the growth of Lotus corniculatus cv. Maitland, while Lotus pedunculatus cv. Maku grew best at pH 4.5. Lotus pedunculatus cv. Maku grew best in solution where the sum of the activities of the monomeric Al species {Alm} was maintained at 5.9 8M. The growth of all other species was decreased with Al in solution, a 50% reduction in TDM being associated with c. 6 8M {Alm] for white clover and subterranean clover, and c. 3 8M in red clover and Lotus corniculatus cv. Maitland.