bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal changes in growth and nodulation of perennial tropical pasture legumes in the field. I. The influence of planting date and grazing and cutting on Desmodium uncinatum and Phaseolus atropurpureus
Authors: Whiteman PC , Lulhan A
Published: November 2004

Plantings of D. uncinatum and P. atropuvpureus were made in October and December 1965 and February and April 1966, and subsequently the plots were either rotationally grazed by sheep, cut with a mower at 3 inches, or left undefoliated. Monthly samples were taken to determine individual plant dry weight, nodule weight per plant, nodule number, and mean weight per nodule. Three samples for plot dry matter yield were also taken. Individual plant dry weight was higher in the October and December sowings, although by the end of the second growing season dry matter yield per plot was higher in the December and February sowings. Dry matter yield of legume was depressed by April planting. D. uncinatum began regrowth in spring 2 months earlier than P, atropurpureus, when minimum temperatures exceeded 48-50�F compared with 57' for P. atropurpureus. Both species had marked seasonal peaks in nodule and plant dry weight. The rapid decline in nodule weight could not be directly related to the onset of flowering or frosts. Grazing caused a greater reduction than cutting in terms of plant and nodule weight and legume yield. In P. atropurpureus nodule weight per plant was reduced through a decline in mean weight per nodule, while in D. uncinatum grazing and cutting reduced nodule number per plant.
Genetic and phenotypic parameters for wool characteristics in fine-wool Merino, Corriedale, and Polwarth sheep. II. Phenotypic and genetic correlations, heritability, and repeatability
Authors: Mullaney PD , Brown GH , Young SSY , Hyland PG
Published: November 2004

Estimates of heritability, repeatability, and phenotypic and genetic correlations were calculated from data involving about 1050, 720, and 250 dam-daughter pairs for Merino, Corriedale, and Polwarth breeds respectively; data on daughters were taken at both 18 and 30 months of age. Phenotypic and genetic correlations in general were of the same order of magnitude and similar between breeds; the estimates substantiated the results obtained by other workers. Estimates of repeatability of most fleece traits between 18 and 30 months of age were significantly lower than estimates based on later ages. However, the differences were not large, and the use of a single figure for repeatability, either the younger age estimate or a pooled estimate, would give a reliable prediction for subsequent performance. Estimates of heritability of all traits in each breed were high; however, the heritabilities of greasy and clean wool weights of Merino and Polwarth ewes were about 40% smaller at 18 months than at 30 months, the estimates at 30 months being generally similar to previous estimates at 18 months. Relative to selection at 18 months, wool production, either greasy or clean, would increase at a greater rate per annum with selection of Merinos and Polwarths at 30 months; for Corriedales, selection at 30 months is more efficient for greasy, but not for clean wool production.
The effect of saline water ingestion on water turnover rates and tritiated water space in sheep
Authors: Jones GB , Potter BJ , Reid CSW
Published: November 2004

Tritiated water has been used to compare the water turnover rates and water spaces in sheep which had become accustomed to consuming 1.3 % salt water with those of sheep allowed to drink fresh water. The sheep drinking the saline water (mean body weight 42.0 kg) had mean turnover rates of 207 ml/kg/day compared with 90.3 ml/kg/day for sheep drinking fresh water (mean body weight 38.3 kg). The sheep on salt water revealed a mean tritiated water space of 27.5 kg while that of the sheep on fresh water was 23.5 kg.
Studies on the productivity of tropical pasture plants. III.* Stand structure, light penetration, and photosynthesis in field swards of Setaria and green leaf Desmodium
Authors: Heslehurst MR , Wilson GL
Published: November 2004

Inclined point quadrat analysis was applied to pure swards of two pasture species, Desmodium intortum and Setaria sphacelata. Canopy structures are described in terms of the denseness and inclination of foliage and stems. Light penetration patterns throughout the day were calculated. The two species differed greatly in these characteristics. Desmodium leaf was oriented at a uniform mean angle to the horizontal throughout the height of the canopy, but leaf occurred predominantly in the upper layers. In contrast, leaf angles in Setaria varied down the profile, with most of the leaf in the middle layers. There were diurnal variations between and within the species in the amounts and distribution of sunlit leaf area index.Diurnal patterns of canopy photosynthesis were estimated from calculated leaf and light profiles, photosynthesis-illuminance data, and records of incident radiation. There was an overall 1.8 : 1.0 advantage in sward photosynthesis by Setaria, arising from a greater than two-fold superiority at high angles of the sun, falling to a 1.6 : 1 .0 advantage at low angles. This trend follows the diurnal patterns of light penetration into the two canopies. From calculated sward photosynthesis, concurrently measured dry matter production, and other data it was concluded that the relative magnitude of productivity corresponded very closely to the relative photosynthetic capacities of the leaves. Therefore, canopy structures were comparatively unimportant as determinants of yield differences.

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*Part II, Aust. J. Agric. Res., 21: 183 (1970)
Balances of energy and matter in growing sheep at several ages, body weights, and planes of nutrition
Authors: McC Graham N , Searle TW
Published: November 2004

Energy, carbon, and nitrogen balances in young sheep (aged 5, 10, and 14 months) given a roughage-concentrate mixture were measured in closed-circuit respiration apparatus. Animals of diverse weight but the same age and vice versa were studied at levels of feeding between half maintenance and ad libitum. Digestibility decreased by 7 units between the lowest and highest feeding level but was not shown to depend on weight or age. Methane production was lower at 5 months of age than subsequently and, in consequence, metabolizable energy decreased from 3.8 kcal/g digestible organic matter at 5 months of age to 3.6 kcal/g at 10 and 14 months. Net availability of metabolizable energy was measured directly in 10-month-old sheep only, and was then 52 and 62% in animals of 44 and 28 kg respectively. Otherwise, storage of metabolizable energy was not found to vary with weight or age. The young sheep had higher maintenance requirements and therefore lower overall efficiency than adults would have, but had higher net availability of metabolizable energy. Neither appetite nor efficiency was depressed by obesity in 14-month sheep. The fraction of energy balance accounted for by protein did not depend on age but varied inversely with body weight. Two obese animals continued to store a large fraction of energy in fat.
The effect of seed size on seedling growth in subterranean clover (Trifolium subterraneum L.)
Authors: Taylor GB
Published: November 2004

The effect of seed size on seedling growth in a single population of Daliak subterranean clover was studied by growing individually weighed seeds to the third trifoliate leaf stage in three controlled environments. The environments were: 18°C at high light intensity (27,000 lux), 12° at high light intensity, and 18° at low light intensity (5400 lux). Plant weight at emergence exceeded the weight of embryo in the original seed, owing in part to the utilization of endosperm. At emergence the ratio of plant weight to seed weight increased with increasing seed size. Nevertheless, in all environments the smaller seeds ultimately produced relatively larger plants owing to a higher relative growth rate, particularly during the cotyledon and unifoliate leaf stage of growth. Higher relative growth rates in seedlings from smaller seeds were associated with higher leaf area ratios resulting from the production of relatively larger cotyledon and individual leaf areas in all environments. More rapid leaf expansion in seedlings from larger seeds progressively offset this advantage.
Studies on the productivity of tropical pasture plants. IV.* Separation of photosynthetic and respiratory components of net assimilation rate by growth analysis and gas exchange techniques under natural lighting
Authors: Heslehurst MR , Wilson GL
Published: November 2004

The growth analysis technique for the separation of photosynthetic and respiratory components of net assimilation rate used in previous controlled environment studies of early vegetative growth was extended to natural lighting conditions. The use of short-wave radiation rather than days in the light as the quantification of photosynthetic opportunity in the regression analysis improved the accuracy of estimation of photosynthesis and respiration. In one experiment, concurrently with the growth analysis procedure, carbon dioxide exchange measurements were made on one grass and one legume. There was good agreement between the two methods in the estimates obtained. The data support conclusions from previous experiments concerning the superior growth rate of grasses. Species rankings were similar in both sets of experiments.

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*Part III, Aust. J. Agric. Res., 22: 865 (1971).
Physiological responses of semiarid grasses. IV.* Photosynthetic rates of Thyridolepis mitchelliana and Cenchrus ciliaris leaves
Authors: Christie EK
Published: November 2004

Photosynthesis response curves of mulga and buffel grasses to irradiance and to carbon dioxide concentration, together with studies of leaf anatomy and chloroplast structure, showed that the former was a C3 and the latter a C4 species. This is held to account for the large differences in growth rate between the two species. Although Mitchell grass has the anatomy of a C4 species, its photosynthetic responses were not examined. As its net assimilation rate is high at high temperatures, its generally low growth rates are associated with the poor development of its leaf surface.

*Part III, Aust. J. Aguic. Res., 26: 447 (1975).
Corrigendum - Humidity, free water and light in relation to development of Kabatiella caulivora (Kirchn.) Karak in Trifolium subterraneum L. cv.Yarloo
Authors: Helms K
Published: November 2004

The effects of moisture conditions on disease development and plant growth were examined in subterranean clover plants which were inoculated with K. caulivora 4 weeks after sowing and were maintained after inoculation at 20°C and with a light intensity of 2000 f.c. In plants which received 100% relative humidity (RH) with free water on leaves, for at least 4 days after inoculation, 15–20% of leaves developed lesions within 11 days. In plants which received continuously 90% RH with free water on leaves, or 100% RH without free water on leaves, less than 1.5% of leaves developed lesions within 11 days. There was no evidence of spread of infection in plants maintained for 11 or 25 days after inoculation. The effects of light intensities of 2000, 500 and 125 f.c. on disease development and plant growth were examined in plants which received 100% RH with free water on leaves and were grown for 25 days after inoculation, either in simulated swards or in standard pots. In most treatments a reduction in light intensity from 2000 to 500 f.c. reduced the growth of plants but had no effect on the percentage of diseased leaves, whereas a reduction in light intensity from 500 to 125 f.c. reduced growth and increased the percentage of diseased leaves of plants grown in swards from 30 to 70% and in standard pots from 10 to 35%. There were mortalities among both inoculated and control plants grown under 125 f.c. : in swards, 80–90% of inoculated plants and 30–40% of control plants died, whereas in standard pots 20–30% of inoculated plants and only occasional control plants died. The data show that environmental conditions favourable for the development of the disease were unfavourable for growth of control plants.
Symbiotic characteristics of Rhizobium trifolii from Israel in association with 10 species of Trifolium*
Authors: Brockwell J , Katznelson J
Published: November 2004

The symbiotic properties of 25 isolates of Rhizobium trifolii were tested in bacteriologically controlled culture with populations of 10 Trifolium species. The rhizobia had been isolated from nodules of the same 10 populations grown on three soil types occurring in Israel. All host plant x R. trifolii isolates formed nodules, but the symbiotic effectiveness varied greatly. Twenty-one isolates formed at least one highly effectivc symbiotic combination and the two best isolates each formed four. On the basis of similar symbiotic behaviour, the 25 isolates fell into not less than 10 distinct groups. Some degree of strain specificity in effectiveness of nitrogen fixation existed in all species except T. repens. Bacterial associations with T. batmanicurn, T. pauciflorum and T. spumosum were highly specific. Over all isolates, T. alexandrinurn was more effective in symbiosis than other species. T. repens performed poorly. T. echinatum, T. alexandrinum, and T. spumosum were similar in their patterns of symbiotic response, and so were T. pauciflorum, T. glomeratum, and T. brachycalycinum. Howeker, host groupings were less well defined than R. trifolii isolatc groupings. Some confirmation was obtained of earlier reports that, in the presence of a heterogeneous soil population of R. trifolii, a clover plant tends to be nodulated by the more effective strains. A negative correlation was found between the mean effectiveness of rhizobia isolated from a particular species and the mean response of that species to all of the isolates.

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*Publication of the Agricultural Research Organization (State of Israel, Ministry of Agriculture), 1975 Series, No. 235-E.
Production, composition, and manufacturing properties of milk from grazing cows fed on a formaldehyde-treated sunflower seed supplement
Authors: Bartsch BD , Ellis NJS , McLean DM , Radcliffe JC
Published: November 2004

Eight cows in each of four treatment groups grazed regulated areas of green oats and consumed either 0, 1.3, 2.5 or 3.1 kg of a formaldehyde-treated sunflower seed supplement (FSS) per head per day. The digestible energy content of the rations was balanced with hammer-milled barley. Milk fat percentages and milk fat yields were higher from cows fed on FSS, responses being in proportion to the amount of FSS eaten. Protein percentages were significantly lower in milk from cows fed on FSS. Milk and protein yields did not differ significantly between treatments. The linoleic acid (C18:2) content of milk fat was three to five times as high in cows fed on FSS as in those not fed on FSS. The stability to oxidation and the rennet curd firmness of the milk decreased as the percentage of C18:2 in milk fat increased. Changes in the heat stability of milk were associated with the introduction of FSS feeding. Plasma cholesterol levels increased with increasing intakes of FSS. Milk of high C18:2 content can be produced by dairy cows fed on FSS and grazed on green oats. The milk readily oxidizes and its properties for cheese and skim milk powder manufacture are altered.
Milk replacers for preruminant lambs: protein and fat interactions
Authors: Gibney MJ , Walker DM
Published: November 2004

Seventy male crossbred lambs, aged between 2 and 5 days at the start of the experiment, were given milk replacers in which the source of protein was either dried skimmed milk (DSM) or isolated soybean protein (ISP). The diets provided either 0.10 or 0.25 of the total energy as protein. Fat provided either 0.80 or 0.50 of the total gross energy and was added as butter oil, olive oil, safflower oil, groundnut oil or coconut oil. When ISP replaced DSM there was a significant reduction in the apparent digestibiIities of nitrogen and fat, and in the digestibilities of the component fatty acids (corrected for metabolic fat losses) for all diets, irrespective of the source of dietary fat. When the protein energy concentration was reduced from 0.25 to 0.10, there was a reduction in the above digestibilities for all diets, except those containing butter oil. The corrected digestibilities of the saturated fatty acids invariably decreased with an increase in chain length. The digestibility of an unsaturated fatty acid was usually, but not always, greater than that of its saturated counterpart. The digestibility of any given fatty acid was independent of the concentrations of other fatty acids in the same fat.
Ecosystem processes in semiarid grasslands. II.* Litter production decomposition and nutrient dynamics
Authors: Christie EK
Published: November 2004

Changes in tissue nutrient concentration and nutrient uptake of a C3 native grassland and a sown C4 buffel grassland community, growing on infertile sandy red earth soils near Charleville, were studied. The seasonal pattern of litter production of grasslands in the grazed and ungrazed situation was also investigated. Studies in litter decomposition of Mitchell grass are reported. The decline in the above-ground biomass growth rate of both communities over the summer growing period corresponded with a similar trend in the uptake of nitrogen and phosphorus. Moreover, tissue shoot phosphorus concentrations of all perennial grass species were always low. The total amount of nutrient absorbed (nitrogen, phosphorus) was about 35% greater for the buffel compared with the native grassland community. Both communities could be contrasted with respect to the efficiency of nutrient absorption and nutrient utilization. Continued overgrazing led to a reduction in litter and root yield. As little biomass was produced by the community over the autumn-winter period, the litter production rate could be expressed as a function of herbage yield at the commencement of the period and was found to be relatively independent of grazing pressure. The agronomic and ecological implications of these results are discussed in relation to the management of these grasslands.

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*Part I, Aust. J. Agric. Res., 29: 773 (1978).
The nutrition of ruminants grazing native and improved pastures. IV.* Long-term effects of the quantity of superphosphate applied on the nutritive value of the diet selected by sheep grazing a pasture originally sown to Phalaris aquatica and Trifolium repens
Authors: Langlands JP , Bowles JE , Donald GE
Published: November 2004

Small plots sown to Phalaris aquatica–Trifolium repens in 1967 were fertilized with either 0, 188 or 375 kg superphosphate ha-1 year-1 from 1967 to 1976; the plots were grazed uniformly between 1967 and 1975 and at three stocking intensities during 1975 and 1976. The composition of the forage on offer and of the diet selected by grazing sheep were measured at 2-monthly intervals during 1976. Phalaris largely died out from plots which did not receive superphosphate. Available forage, and its content of clover, nitrogen and most minerals were substantially greater on plots that received fertilizer, as were the digestibility and nitrogen content of the diet selected. The nutritive value of the diet selected was greatest on plots which received 375 kg superphosphate ha-1 year-1. The nitrogen content of the diet selected generally increased with increasing stocking intensity, but this trend was not evident for digestibility; interactions between the quantity of fertilizer applied and stocking intensity were not significant. Digestibility and nitrogen content of the diet varied between months, with the quantity of green forage and clover on offer, and with the nitrogen content of the available forage.

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*Part III, Aust. J. Agric. Res., 29, 1301 (1978).
Effect of nutrition, genotype, lactation and wool cover on response by grazing sheep to methionine esters and polymer-encapsulated methionine
Authors: Wheeler JL , Ferguson KA , Hinks NT
Published: November 2004

Esters of methionine added to the diet of penned sheep have been reported to increase wool growth. Four experiments were undertaken in which grazing sheep were drenched with methionine derivatives. In experiment 1 methyl methionine hydroxy analogue (MeMHA) and ethyl methionine hydrochloride (EMHCl) increased wool growth similarly, by about 30% (P < 0.001) on native pasture and 4% (P > 0.05) on improved pasture. Dosing three times per week was as effective as dosing six times per week. In experiment 2, wool growth of unsupplemented sheep on improved pasture in spring was c. 12 g/d and was not increased by the administration of MeMHA to fine- or strong-wool sheep whether lactating or dry. Daily weight gain by young lambs declined from 258 to 215 g/d when their dams were given MeMHA at 4 g/d 5 days per week (P < 0.05). Administration of methionine as MeMHA or EMHCl or in a polymer-encapsulated form at 1.25 gld gave c. 1 g/d additional wool in experiment 3; 2.5 g/d increased wool growth by c. 1.5 g/d (P < 0.001). In experiment 4, MeMHA doses of 1.25 and 2.5 g methionine equivalent per day produced no response in sheep in full wool. In shorn Merinos wool growth increased by 1.2 and 0.4 g/d, and Dorset Horn x Merinos showed a decrease of 0.5 and an increase of 1 .3 g wool/d at the two dose levels (P < 0.01). Wool growth was increased by c. 1 g/d by 1.25 g MeMHA in sheep that had received 10 mg selenium but not in control sheep. These responses are less than those reported from pen experiments in which methionine derivatives were incorporated in the diet. It is concluded that at current prices it would not be profitable to supplement grazing sheep with any of these forms of methionine.
Studies on pigs prepared with re-entrant cannulas. 1. Effects of protein source on flow rates of dry matter, nitrogen and amino acids in digesta
Authors: Alimon AR , Farrell DJ
Published: November 2004

Eleven pigs were fed on one of six diets containing wheat alone or supplemented with either meat meal, fish meal, peanut meal, soybean meal or sunflower meal. Digesta were collected from the re-entrant cannulas at the mid-point and the terminal ileum of the small intestine at 2, 4, 6, 9 and 12 h after feeding. Measurements were made of flow rates of digesta, dry matter, nitrogen and amino acids at both locations in the small intestine. Peak values were usually observed for all parameters, at 2 h and from 4 to 6 h after feeding, at the mid-point and the terminal ileum respectively. Flow rates and the amounts of components in digests were often characteristic of the protein source in the diet and the location of the cannula. High concentrations of some free amino acids were observed in digesta at the mid-point, and lower concentrations at the terminal ileum in the small intestine; the significance of endogenous secretions in the small intestine is discussed.
Corrigendum - Effects of a water stress on the photosynthesis and respiration of wheat ears
Authors: Marshall B , Sedgley RH , Biscoe PV
Published: November 2004

An experiment was conducted on Huntsman winter wheat to investigate the effects of a water stress applied at anthesis on the carbon dioxide exchange of the ears during grain filling. The water stress was created by excluding rain from the soil, not the foliage, of plants growing in the field. Control plants were well watered throughout the period when the treatment was imposed. At intervals for 32 days after anthesis, detailed measurements were made of the photosynthetic rate of ears at different irradiances and rates of ear dark respiration. The measurements were analysed by using the photosynthesis-light response model developed by Marshall and Biscoe (1980) for wheat leaves with a modification for the pathway of respiration from the grains to the glumes. The model is a non-rectangular hyperbola and uses four parameters: Pn,max (maximum rate of net photosynthesis), Rd (rate of dark respiration), � (photochemical efficiency at low light), and F (ratio of physical to total resistance to diffusion of carbon dioxide). Analysis showed that in wheat ears during grain filling, photosynthesis can be treated as occurring predominantly in the glumes and respiration in the grains. The shape of the photosynthesis-light response curves for ears from both treatments were similar, but differed from those for wheat leaves because the maximum rates of photosynthesis were reached more gradually with increasing irradiance. However, the measured response curves were still better fitted by the model than a rectangular hyperbola which has often been used in the past. The water stress at anthesis decreased the maximum rate of ear photosynthesis by 0.8 g carbon dioxide m-2 h-1 throughout the grain-filling period. Initially, the rates of ear respiration were the same, but 32 days after anthesis the treatment had decreased ear respiration rate from 0.04 to 0.01 g carbon dioxide h-1/grain.
Genetic control of resistance to Kabatiella caulivora in Trifolium subterraneum subspecies yanninicum II. Variation in segregation populations
Authors: Beale PE , Thurling N
Published: November 2004

Variation in resistance to K. caulivora in F, and backcross populations was examined in six crosses amongst lines of T. subterraneum ssp. yanninicum representative of the known range in resistance. Frequency distribution patterns indicated that resistant lines were differentiated from the other lines by a single major gene, resistance being completely dominant to susceptibility. Populations derived from a cross between two moderately resistant lines and a cross between two susceptible lines exhibited marked transgressive segregation towards susceptibility in the former and higher resistance in the latter. At least four genes of relatively minor effect were presumed to be contributing to differences in resistance amongst the moderately resistant and susceptible lines. Analyses of population means for each of the six crosses showed that gene interactions were not significant in any of the crosses. Significant additive gene effects were detected only in crosses between the resistant line on the one hand and a moderately resistant and a susceptible line. The results of these analyses were generally in agreement with a diallel analysis of resistance involving lines used in this study. Genetic information obtained from this study is discussed with respect to the prospects of transferring effective resistance to agronomically superior ssp. yanninicum cultivars by backcrossing.
Milk replacers containing a soybean protein concentrate for preruminant lambs: interrelationships between methionine, cystine and choline
Authors: Malouf NM , Walker DM
Published: November 2004

Preruminant male crossbred lambs, aged 2-5 days at the start of the experiment, were fed on milk replacers containing a soybean protein concentrate (as the sole source of protein) to supply 25 % of the total dietary energy as protein. The minimum intake of methionine plus cystine (M+C) that was coincident with maximum nitrogen balance was estimated (mean�s.e.) at 38.5�1.8 mg/100 kJ diet (equivalent to 3.6�0.2 g sulfur amino acids/16 g nitrogen). When the concentration of M+C was raised to this level by supplementation with DL-methionine, the addition of choline chloride, in amounts to give final concentrations varying from approximately one-seventh up to twice the concentration in cows' milk, did not affect nitrogen balance. The maximum replacement value of cystine for methionine (as judged by the effect on nitrogen balance), in milk replacers adequately supplen~ented with choline chloride and sulfur amino acids, was 47% on a weight basis, or 52% when calculated on the basis of moles of sulfur.
Germination characteristics of several grass species as affected by limiting water potentials imposed through a cracking black clay soil
Authors: Watt LA
Published: November 2004

The effects of limiting water potentials on the germination characteristics of 12 grasses were studied. Germination proper was prevented in all species at water potentials well short of wilting point and different species had their germination prevented at different potentials. Generally the native grasses required wetter conditions to germinate than the exotic grasses, although there were some exceptions. A partial germination condition, caused by limited water availability, occurred to differing degrees amongst the species. Some species retained their viability when desiccated in the partially germinated condition, but other species lost their viability. The partial germination phenomenon appears important to the germination ecology of some species but not to others.
Seed coating and localized application of phosphate for improving seedling growth of grasses on acid, sandy red earths
Authors: Silcock RG , Smith FT
Published: November 2004

The seedling growth of tropical grasses on acidic, sandy red earths was improved greatly by the application of small amounts of phosphate fertilizers in close proximity to the seed. Fertilizer had to be applied within 5 cm of the seed of Anthephora pubescens to have any effect. Many phosphorus sources stimulated seedling growth of Cenchrus ciliaris when applied as coatings to the fascicle (the propagule containing the grain). Water-soluble orthophosphates proved the best phosphorus sources for the purpose. Optimum rates of coating ranged up to 2 mg phosphorus per fascicle (10 mg monosodium phosphate), depending on the availability of surface soil moisture. Valuable grasses such as C. ciliaris could be introduced into millions of hectares of native pastures on infertile, sandy soils in north-eastern Australia, at reasonable cost, if a suitable commercial coating process can be developed.
The mycotoxins dash 4-deoxynivalenol, zearalenone and aflatoxin dash in weather-damaged wheat harvested 1983-1985 in south-eastern Queensland
Authors: Blaney BJ , Moore CJ , Tyler AL
Published: November 2004

A survey for various mycotoxins was carried out on samples of all wheat delivered to nine storage and marketing depots in south-eastern Queensland, selected as most likely to receive mycotoxin-contaminated grain. All wheat was surveyed during 1983, when the degree of weather damage was high. Samples of the poorest grade of wheat from these depots were also surveyed in 1984 and 1985. The surveys included all regions where head scab of wheat caused by Fusarium graminearum Schwabe Group 2 had been reported to occur at significant levels. 4-Deoxynivalenol was detected in nearly all pooled samples representing bulk wheat at concentrations ranging from traces of <0.01 up to 1.7 mg kg-l. The highest concentration of zearlenone detected in a pooled wheat sample was 0.04 mg kg-l. In a few samples representing individual wheat deliveries and with up to 2.8% by weight of pink grains, 4-deoxynivalenol concentrations ranged up to 11.7 mg kg-1 and zearalenone up to 0.43 mg kg-l. Aflatoxins B1, B2, G1 and G2 were detected in only one pooled sample of wheat, at a total aflatoxin concentration of 0.003 mg kg-1. Ochratoxin A, sterigmatocystin and T-2 toxin were not detected. Higher concentrations of mycotoxins were found in the poorer grades of wheat.
Factors affecting the growth of kikuyu. II. Water supply
Authors: Murtagh GJ
Published: November 2004

The influence of water supply on the growth of a kikuyu (Pennisetum clandestinum) pasture was estimated from field measurements of growth rate. A model was used to separate the confounded effects on growth of light interception, temperature, nitrogen and water supplies, and maintenance respiration. Water supply for growth was expressed as a function of both the soil water content and evaporative demand (potential evapotranspiration). The growth of kikuyu was very sensitive to water supply. On a wet soil (soil water potential > -20 kPa), an evaporative demand above 3.2 mm day-1 slowed growth. With optimum temperatures and a sward yield which gave the best balance between light interception and rate of maintenance respiration, a low evaporative demand of 2 mm day-1 reduced growth rates only when the soil water potential was less than - 134 kPa. However, with a medium-high evaporative demand of 5 mm day-1, growth was reduced by 39% on a wet soil, and ceased at a soil water potential of - 101 kPa.
Food intake and levels of rumen metabolites in cattle grazing wheat or oat stubble
Authors: Coombe JB , Mulholland JG
Published: November 2004

Yearling Friesian steers, fitted with rumen fistulas, were grazed for 11 weeks on wheat or oat stubbles at a stocking rate of 1.2 steers ha--1. Following rain in the third week, half of each stubble area was sprayed with desiccant herbicide to establish weed-free stubbles. The stubbles initially yielded c. 2200 kg DM ha-1 of crop residues, plus up to c. 200 kg DM ha-1 of fallen grain. Green herbage was always <50 kg DM ha-1 on weed-free stubbles, but on weedy plots increased from c. 100-500 kg DM ha-l after the fourth week. On weed-free stubbles, the diet selected contained 80-100% dead plant material, with mean OM digestibility (in vitro) ranging from 0.54 to 0.45, and from 0.63 to 0.52 for wheat and oat stubbles respectively. On weedy plots, at levels of green herbage > 100 kg DM ha-1, cattle diets contained 60-70% green herbage, with a mean OM digestibility of 0.66. Over the whole experiment, estimated mean intakes of digestible organic matter (DOM) varied from 2.0 to 3.8 and from 3.5 to 7.5 kg day-1 on the weed-free and weedy stubbles respectively, and were consistently higher on the oat stubble than on the wheat stubble. The maintenance requirement of DOM (12 g per kg live weight) was acheived with green herbage levels of 10-25 kg DM ha-1. Steers grazing the weed-free stubbles generally maintained weight, while those on the weedy stubbles gained 34-48 kg during the experiment.Mean concentrations of ammonia in the rumen were always < 100 and often <50 mg N l-1 on the weed-free stubbles except at the end of the experiment, while those on the weedy stubbles were generally > 100 mg N l-1. Concentrations of rumen volatile fatty acids (VFA) were generally <80 mmol l-1, and fell to <50 mmol l-1 on the weed-free stubbles in the second half of the experiment.The observations are discussed in terms of the utilization of the dead plant material in crop stubbles by grazing cattle, and likely responses to supplements.
Management options for increasing the productivity of tropical savanna pastures. IV. Population biology of introduced Stylosanthes spp
Authors: Mott JJ , Winter WH , McLean RW
Published: November 2004

In a large-scale grazing experiment in the Monsoon Tallgrass savannas of the Northern Territory, Townsville stylo (Stylosanthes humilis), Caribbean stylo (S. hamata) and perennial stylo (S. scabra + S. viscosa) were sown into native pasture and grazed at three stocking rates, under two fertilizer rates and with trees killed and unkilled. These treatments, together with the occurrence of anthracnose, led to the rapid decline in both yield and numbers of plants in those pastures sown to Townsville stylo. In contrast, yields of Caribbean stylo and Perennial stylo stabilized after three years in both fertilized and unfertilized swards. While total legume yield of these latter two treatments was similar, the dominant contribution in Caribbean stylo was made by annual plants, while in Perennial stylo swards individuals more than 18 months old contributed 80% of the yield.There were marked differences between all species in their population biology. Townsville stylo declined in numbers with death of individuals prior to seed set and the rapid depletion of the soil seed pool which had little long-lived seed. In contrast, in swards of Caribbean stylo a large amount of hard seed rapidly built up in the soil seed pool and ensured continuity of productivity even if seed was not set in some years. In the perennial stylos, seed softened quickly, and the soil seed pool remained small and short-lived. In these latter Stylosanthes spp., long-term stability depended on the survival of perennating plants rather than seed.Pasture management must take into account these different patterns of population dynamics. In particular, while fire is a potentially useful tool in renovating Caribbean stylo swards with their large soil seed pool, it can be extremely detrimental to perennial stylo swards where individuals are susceptible to burning and there is little soil seed available to re-establish the sward.
A field comparison of sunflower (Helianthus annuus) and sorghum (Sorghum bicolor) in a long drying cycle. II. Plant water relations, growth and yield
Authors: Bremner PM , Preston GK
Published: November 2004

Growth and water use were studied in field-grown sunflower and sorghum, mainly in a long drying cycle, though other water treatments were included. When water was plentiful, sorghum was the more productive, but in the drying cycle the order was reversed, largely because sunflower extracted more water. This, together with a smaller leaf area and close control of transpiration rate through stornatal sensitivity to air humidity, ensured a far more favourable leaf water status in sunflower, contributing to its much faster net assimilation rate. In view of the species' different photosynthetic pathways and the large difference in water use efficiency generally associated with these pathways. an unexpected outcome was the smallness of this difference. In the drying cycle, sunflower had the further advantages of a strongly determinate habit and a phenology which was unaffected by drought, even when very severe. Consequently, all plants flowered. In sorghum, drought arrested development, which proved disadvantageous in a continued drought, but turned to dramatic advantage in a late break, when sorghum grain yield increased by 75%, while sunflower responded not at all.
Effect of soil environment on infection of subterranean clover by Meloidogyne arenaria
Authors: Pung SH , Barbetti MJ , Sivasithamparam K
Published: November 2004

The effect of environmental factors on Meloidogyne arenaria and its infectivity on subterranean clover were investigated both in a naturally infested subterranean clover pasture and under controlled conditions in a pot experiment. In the field, the nematode population was altered by seasonal changes during the sampling periods in 1987 and 1988. The hatching of M. arenaria was determined by the germination of subterranean clover brought about by the opening seasonal rains in April or May. The first generation of M. arenaria in subterranean clover roots appeared to develop and reproduce more rapidly while the soil temperature was still relatively high (>15�C) in May-June and the second generation developed as soil temperature increased between September and November. These findings were consistent with observations from the pot experiment, where M. arenaria gall production and its development and reproduction in both the tap and lateral roots were greater at 20/15�C and 25/20�C than at 15/10�C. In 1987, egg masses of M. arenaria were first observed approximately 6 weeks after the commencement of the growing season, while in 1988 they appeared only after about 15 weeks. This may be attributed to a delay in the opening seasonal rains in 1988 compared with 1987, as well as cooler soil temperatures in 1988. The pF values in the field soils sampled in this study ranged from non-inhibitive to inhibitive suction, with values from 1.8 to 4.8. Greater nematode infection in the tap roots at moisture levels of pF 1.28 and 0.97, but not at 0.71, may be related to better nematode mobility at the higher soil moisture content and its preference for tap roots under more favourable conditions.
The yield of wheat following lupins: effects of different lupin genotypes and management
Authors: Hamblin J , Delane R , Bishop A , Adam G
Published: November 2004

More nitrogen is fixed by grain lupins (Lupinus sp.) than is removed in the harvested grain. Differences in residual N after different lupin species and genotypes (L. albus, L. cosentinii, L. angustifolius) and different agronomic treatments (harvesting, sowing dates, sowing rates and fertilizer treatments) were estimated using a simple nitrogen (N) balance. For six experiments, the relationship between the estimated residual N value and the yield of the following wheat crop was also examined. L. albus grew poorly on the infertile sandy soils and had the lowest estimated residual N value, whereas L. cosentinii had a high estimated residual N value and L. angustifolius was intermediate. Across sites and seasons, the estimated residual N value of L. angustifolius varied from 37 to 165 kg N/ha. For an individual experiment the greatest range for L. angustifolius was from 59 to 114 kg N/ha. Despite the wide range in residual N across genotypes, there was a poor relationship between estimated residual N value and yield of the following wheat crop. Except for lupin crops which grew poorly, the impact of agronomic treatment on the residual N from lupins had little effect on yield of the following wheat. On the basis of these results there seems to be no reason to manage the lupin crop for high residual N value, and any improvements to the nitrogen harvest index of lupins through breeding or management are not expected to reduce the residual effect.
Effect of the mycotoxins, nivalenol and zearalenone, in maize naturally infected with Fusarium graminearum on the performance of growing and pregnant pigs
Authors: Williams KC , Blaney BJ
Published: November 2004

Maize naturally infected with Fusarium graminearum and containing 11.5 mg nivalenol (NIV) kg-1 and 3 mg zearalenone (ZEA) kg-1 was fed to grower and pregnant pigs in five experiments. Inclusions of infected maize at 500 and 750 g kg-1 in diets for grower pigs caused a deterioration of all performance traits in a 14 day experiment: voluntary feed intake (VFI) from 2-17 kg day-1 (control) to 1.45 and 1.09 kg day-1; average daily gain (ADG) from 0.79 kg day-' (control) to 0.50 and 0.45 kg dayV1; and feed conversion ratio (FCR) from 2.45 (control) to 3.49 and 3.23 respectively. In a paired-feeding experiment of 8 weeks duration, the VFI, ADG and FCR of grower pigs progressively worsened with increasing infected maize content. However, when pigs were fed a nutritionally similar control diet at intakes matched to those achieved by pigs given the mycotoxin-containing diets, their ADG and FCR were not significantly different (P > 0.05). The nutrient similarity of these diets was confirmed in an independent metabolism study measuring apparent digestibility and nitrogen retention. Feeding pigs with infected maize caused a marked and dose dependent depression (P < 0.05) in white cell and neutrophil counts. In two studies with sows, a comparison was made between a control diet and one containing 600 g kg-1 infected maize when each diet was formulated to the same nutrient content and sows fed at 2 kg day-1. In one study, diets were offered from when pregnancy was confirmed at 30 days post-mating until slaughter approximately 35 days later. In the second study, the diets were offered either from day of mating or from 30 day post-mating with all sows being slaughtered approximately 35 days later. In both studies, the infected maize diet had no adverse effect on the conception rate nor on the number and weight of foeti at slaughter compared to controls. In the second study, total white cell and lymphocyte counts were lower (P < 0.05) in sows fed the infected maize diet.
Xylem sap flow, growth and flower production of cultivated Geraldton wax with different vigour under semi-arid conditions
Authors: Akilan K , Considine JA , Marshall JK
Published: November 2004

Diurnal and seasonal water use and the effects of different levels of irrigation on growth and flower production were studied using commercially cultivated Geraldton wax (Chamelaucium uncinatum Schauer cv. Purple Pride) under semi-arid conditions. Water use and growth responses to increased irrigation differed widely with vigour. Vigorous plants had extensive root systems and used more water than less vigorous plants whether irrigated or unirrigated and responded to increased irrigation by producing more shoots, secondary stems and flowers. In vigorous plants, marketable stem length and flower number were increased from 63 to 89 cm and 61 to 226 when irrigation was increased from 25 to 75% of pan replacement respectively. Less vigorous plants had distorted root systems (i.e. curling and circling) and showed no significant growth response to increased irrigation. Increase of stem length to a desirable length of 90 cm in less vigorous plants, which are wide-spread in commercial plantings, was unlikely. The results highlight the significance of good propagation and establishment techniques to aid vigorous growth. The sap flow study shows that Geraldton wax is a high water using species. A single plant can use in excess of 20 L per day under high evaporative demand when root growth is not limiting.
Effect of tillage and stubble management on soil water storage, crop growth and yield in a wheat-lupin rotation in southern NSW
Authors: Chan KY , Heenan DP
Published: November 2004

The effects of tillage (conventional tillage v. direct drilling) and stubble management (stubble retained v. stubble burnt) on soil water storage, growth and yield of wheat were assessed over two seasons (1989-1990) in a wheat-lupin rotation on a red earth at Wagga Wagga, NSW. Soil water storage and efficiency of water use were different for the two seasons. Both direct drilling and stubble retention maintained the soil surface (0-0.1 m) at higher water content at sowing time. However, their effectiveness in increasing soil water storage at sowing was evident only in the 1990 season which, with average rainfall during the summer fallow, was drier than 1989. Average wheat grain yield was similar (4.02 v. 4.08 t/ha) for the two seasons even though the 1989 season had 245 mm more rain, the difference mainly occurring in March-April. Most of the excess water in seasons like 1989 was likely to have been lost by deep drainage, with implications for leaching of soluble nutrients, increasing subsoil acidity and rising watertables. Poor early growth of wheat when the stubble was retained and the crops direct drilled was season dependent. It was observed in the wheat crop only in the 1989 season which had a wet autumn. In that season, poor early growth which resulted in a significant yield reduction of 0.5 t/ha was associated with reduced water extraction before anthesis despite the availability of adequate soil water. No corresponding differences in growth and yield were observed for the lupin crop.
Vitamin E treatment of weaner sheep. II. The effect of vitamin E responsive subclinical myopathy on liveweight and wool production
Authors: Fry JM , McGrath MC , Harvey M , Speijers EJ
Published: November 2004

Nutritional myopathy occurs as both a clinical and subclinical disease in weaner sheep in Western Australia during summer and autumn. The effect of subclinical nutritional myopathy (SCNM), caused by vitamin E deficiency or combined vitamin E and selenium deficiency, on liveweight and wool was investigated. During the period of SCNM there was no significant difference in liveweight gain in sheep with and without the disease in any of the experiments. Initial liveweight in one experiment was significantly (P < 0.05) higher in sheep that were to develop SCNM during the course of the experiment. In vitamin E deficient-selenium adequate SCNM, there was no difference in wool growth over the period of the disease and no differences in any of the wool measurements at shearing. At 2 sites, the greasy and clean fleece weights were significantly (P < 0.05) greater in a group of sheep diagnosed with more severe SCNM compared with sheep without SCNM. It was concluded that unlike the clinical disease, SCNM was unlikely to cause any economic loss.