bluuebunny/crossref_metadata_2025 huggingface dataset:
Cottonseed meal in broiler diets. 2. Considerations of some aspects of amino acid balance and gossypol level in cottonseed meal and cottonseed-meat meal starter diets
Authors: Packham RG , Payne CG
Published: March 2005

Three broiler starter experiments investigated the inclusion of cottonseed meal in diets based on grain sorghum. In the first, 35.5 per cent cottonseed meal inclusion in lieu of 28.5 per cent soyabean meal was studied. Additional 0.05 per cent ferrous sulphate, to counteract gossypol toxicity in the cottonseed diets, increased feed consumption by 4.3 per cent and improved liveweight gain by 2.2 per cent. Dietary leucine at 1.25 per cent tended to give better performance than either 1 .I 5 or 1.35 per cent. No differences in performance occurred with isoleucine levels of 0.54 - 0.74 per cent. On the better cottonseed diets growth rate equalled that on the soya controls, though feed conversion was inferior. In the second experiment meat meal protein replaced 0, 25 or 50 per cent of the cottonseed meal protein. Growth was optimal on the cottonseed meal diet with 1.35 - 1.45 per cent total dietary lysine. On the meat meal-cottonseed meal diets, lysine levels of between 1.10 - 1.45 gave no significant differences in growth rate or feed efficiency. Leucine supplementation in addition to lysine did not affect performance. Overall, the diets with one-half meat meal protein substitution for cottonseed meal protein resulted in significantly depressed growth. In the third experiment, half the cottonseed protein was replaced by either a 'normal' meat meal or a meat meal containing blood. The cottonseed meal-normal meat meal diet was shown to be equally deficient in leucine and isoleucine, whereas the cottonseed meal-meat meal with blood diet was deficient in isoleucine only. With adequate amino acid supplementation, the performance on these cottonseed meal-meat meal diets was not inferior to that of a control diet based on soyabean meal.
Utility of a simple soil water budget model in agronomic research. 1. Effects of plant density, time of sowing and fallow water on available soil water under spring wheat
Authors: Fawcett RG , Carter OG
Published: March 2005

A simple soil water budget model was used to estimate weekly changes in available soil water as affected by plant density, time of sowing and level of available fallow water for spring wheat cultivars grown on a black earth in northern New South Wales. Estimated values of available water were mostly within �10 mm of observed values (ranging from 50-270 mm) obtained at four intervals during the growing season. The results are discussed in relation to both the interpretation of agronomic field experiments and use of the model in regions where conserved fallow water contributes significantly to cereal production.
The effect of season, stage of plant growth and leaf position on nutrient concentration in banana leaves on a krasnozem in New South Wales
Authors: Turner DW , Barkus B
Published: March 2005

At Alstonville, New South Wales, leaf position had a greater effect than season on the nutrient concentrations of N, P, K, Ca, Mn, Cu, and Zn in the laminae of Williams bananas growing on a krasnozem soil and sampled over a 4-year period. However, season was more important for Mg. The effect of stage of plant growth was significant but much smaller than the other influences. When sampling for leaf analysis, leaf position and plant age can be standardised, but a major problem in this investigation was unpredictable, significant changes in nutrient composition from one sampling date to another. If these results are true for other soils. the data do not allow critical levels to be applied.
Performance of Southern African Digitaria spp. in southern Queensland
Authors: Strickland RW
Published: March 2005

Dry matter production and quality of 45 Digitaria accessions were measured over the period 1964-70. In three experiments at Samford, south-east Queensland, the accessions were fertilized with either 336 or 672 kg ha-1 of N a year and cut four-weekly. Both total and cool season production was measured. Highest annual yields were produced by D. smutsii (40,000 kg ha-1), D. macroglossa (37,000 kg ha-1) and D. decumbens (30,000 kg ha-1). D. decumbens yielded up to 5000 kg ha-1 dry matter between May and September compared with up to 6800 kg ha-1 from D. pentzii, 6700 kg ha-1 from D. macroglossa and 6400 kg ha-1 from D. smutsii. In two other experiments persistence and production of nine accessions were compared with those of Rhodes grass (Chloris gayana) on heavy, gilgaied clay soil at Meandarra, Queensland and with Panicum coloratum var. makarikariense on a shallow, self mulching, sedentary black earth at Southbrook, Queensland. D. decumbens showed the greatest potential for persistence and production at Meandarra and one strain of D. smutsii had the greatest yields at Southbrook. Digestibility and mineral content varied little between species and were generally satisfactory for animal production. Digitaria tended to be higher in phosphorus content than P. coloratum and C. gayana.
Response of wheat to applied superphosphate; the relationship between yield increase and 'available' phosphate in the soil
Authors: Smith AN , Spence TB
Published: March 2005

Seventy-one trials were sown to wheat during the years 1964-66, and of these 54 were successfully harvested. They were of 5 x 2 factorial design with five levels of superphosphate and two levels of nitrogen ; there were three replications. Superphosphate increased grain yield in two thirds and nitrogen in about one sixth of the trials. The yield of grain and the increase in grain yield resulting from fertilizer application were markedly affected by seasonal conditions. Soil samples were taken from each site and analysed for pH, and for 'available' phosphate by ten extractant methods. The yield increase was correlated with superphosphate applied and 'available' phosphate in the model : -Y = bo+b1S+b2vS+b3P+b4P2+b5vSP and the highest coefficient of determination was 31.4 per cent. When pH and average annual rainfall were put into the equation -Y = bo+b1pH+b2RA+b3S+b4vS+b5P+b6P2+b7vSP the highest coefficient of determination was 54.4 per cent.
Reduction of brown heart in pears by absorption of ethylene from the storage atmosphere
Authors: Scott KJ , Wills RBH
Published: March 2005

Compounds that absorb ethylene, carbon dioxide and water were packed with Williams' Bon Chretien (Bartlet) pears held in sealed polyethylene bags. The effects of these compounds on the physiological disorder brown heart are reported. After storage at 1�C for 18 weeks, fruit stored in air or in bags with a carbon dioxide absorbent (calcium hydroxide) were in poor condition externally but were free of brown heart. All other fruit were stored in the presence of about 5 per cent carbon dioxide and were externally in excellent condition but were affected by brown heart. The use of an ethylene absorbent (potassium permanganate) reduced the mean level of ethylene from 395 �l/l to 1.5 �l/l and reduced brown heart from 68 per cent to 36 per cent (P < 0.01). The presence of calcium chloride tended (P < 0.10) to increase brown heart. The storage treatments also affected the level of six other organic volatiles in the fruit.
Herbage intake and production of Merino sheep grazing native and improved pastures at different stocking rates
Authors: Langlands JP , Bowles JE
Published: March 2005

Estimates were made of the herbage intake, nutritive value of the diet, liveweight, wool production, efficiency of wool production and fleece characteristics of fine wool merino sheep grazing native pastures at stocking rates of 1.9, 3.7 and 5.6 sheep ha-1. The effects of increased stocking rates on these variables, and differences between improved and native pastures were examined by regression analysis. Organic matter digestibility declined with increasing stocking rate and was consistently less on native than on improved pasture as were the N content and the ratio, N : organic matter digestibility in the diet. Organic matter intake/sheep did not differ between pasture types or stocking rates, but digestible organic matter, digestible nitrogen and nitrogen intakes were less on native pasture, and paralleled seasonal changes in nutritive value, minimum values being recorded in late winter. Both wool production/sheep and liveweight were greater on improved pastures. Wool production ha-1 was 4 to 10 times greater on improved than on native pastures at stocking rates at which wool production/sheep were similar. Efficiency of wool production expressed as g wool/100 g digestible organic matter consumed was greater on improved pasture but when expressed/100 g nitrogen intake, sheep grazing native pasture were more efficient. Possible reasons are discussed. The maintenance requirements for energy appeared to be similar on both types of pasture. Fleeces produced on native pastures were generally lighter with shorter staple lengths, and appeared to be one spinning count finer than those produced on improved pasture. They were also superior in terms of softness and colour but were less uniform.
Studies on the supplementary feeding of sheep consuming mulga (Acacia aneura). 1. The provision of phosphorus and molasses supplements under grazing conditions
Authors: McMeniman NP , Little DA
Published: March 2005

An examination was made of the effects of molasses and phosphorus supplements, either singly or combined, on the liveweight, wool growth, and reproductive performance of ewes grazing mulga, (Acacia aneura) a leguminous shrub, in the field near Charleviile, Queensland. Unsupplemented ewes lost 4.4 kg liveweight on average during the 14-month experiment, and bone analyses indicated that their dietary intake was insufficient to maintain the initial degree of skeletal mineralization. The provision of supplementary molasses increased liveweight and wool growth, and enhanced reproductive performance, but phosphorus supplements increased liveweight and wool growth only when fed in conjunction with molasses. Skeletal mineralization was not increased by a supplement of phosphorus except when molasses was also given.
Effect of previous cutting interval and of leaf area remaining after cutting on regrowth of Macroptilium atropurpureum cv. Siratro
Authors: Jones RJ
Published: March 2005

Experiments with Siratro were conducted at Samford, south east Queensland to study the effects of previous cutting and defoliation treatments on regrowth. In the first experiment, swards of Siratro were cut at 7.5 cm above ground level every 4 weeks, every 8 weeks or cut once at 16 weeks during spring and summer. Regrowth of all treatments over ten weeks was measured after varying (by leaf removal) the stubble leaf area index (LAI) of the plots cut every four weeks. Pattern of regrowth yield was similar for all treatments with a pronounced lag phase after cutting. Regrowth yield after 10 weeks differed between treatments and was linearly related (P < 0.01 ) to residual LAI in the stubble at the start of regrowth. In the absence of stubble leaves, plots previously cut at 16 weeks or at 8 weeks yielded marginally more than those cut every 4 weeks. There were no marked treatment differences in gross root morphology other than a two fold increase in stolon rooting for the 16-week treatment. Nitrogen content of the roots (mean 1.38 per cent) was unaffected by treatment, but the per cent hot water soluble sugars were lower for the 16 week defoliation treatment than for the 8-week and the 4-week treatments. In the second experiment individual plants were cut to a uniform stubble every 4 weeks and either 0, 5, or 10 leaves were left. Dry weight of regrowth and stolon development were greatest when most leaves were left. Two thirds of the plants died after six cuttings with complete defoliation but none died when either 5 or 10 leaves were retained. Plant survival was not related to plant yield or degree of stoloniferous development. However, there was a strong correlation between stolon number and plant yield under this intensive cutting regime. The practical implication of the results in the management of Siratro is discussed.
Response of oats to nitrogen and defoliation
Authors: Cook LJ , Lovett JV
Published: March 2005

Field and glasshouse trials were conducted to examine the growth responses of oats to defoliation and nitrogen fertilizer. In a field crop, nitrogen increased tillering early in the growth of the crop and slowed the rate of decline in tiller density in the spring. A dressing of nitrogen after a midwinter defoliation failed to increase the regrowth rate of the crop until early spring. The severity of the defoliation had little effect on the regrowth rate, with subsequent differences in yield being due largely to differences in residual dry matter. In glasshouse experiments, the parts of the plant responded differently to defoliation. The roots stopped growing almost immediately; did not recommence active growth for approximately two weeks, but generally maintained their dry weight during this time. The leaf sheaths declined in dry weight for seven days after defoliation, but then recovered their pre-defoliation weight after a further three days. The growth rate of the leaf laminae was apparently unaffected by the defoliation. Plants with a high nitrogen availability recovered faster after defoliation. The more severe the defoliation, the longer the plant took to recover, but once active growth recommenced, there was no difference between the growth rates of plants defoliated to different degrees. The prevailing climatic conditions also influenced the time to recommence active growth. A second defoliation imposed before the plants had replaced the weight lost by the leaf sheaths after an earlier defoliation reduced the subsequent regrowth. situation is discussed.
Efficiency of aerial techniques for long term control of serrated tussock (Nasella trichotoma)
Authors: Campbell MH
Published: March 2005

In three experiments near Rockley and Gunning, New South Wales, non-arable areas of serrated tussock (Nassella trichotoma) were aerially sprayed with 2,2-DPA in late summer and, in the following autumn, aerially fertilized and sown with pasture species. Measurements of tussock density and the botanical composition of the pastures were made for up to ten years after sowing. The experiments commenced in 1963, 1964 and 1966. About 90 per cent of the tussock plants were killed by applying the herbicide at 16.6 kg a.e. ha-l; higher rates effected little improvement. Aerially sown pastures further reduced tussock numbers and provided long term control. Best results were obtained on fertile soil and where tussock has not been retarded by burning. Of the pasture species sown Trifolium subterraneum and Phalaris tuberosa were the most effective for long term control.
Integrating sheep and wheat production: effect of substituting wheat production for pasture on the wool production of wethers
Authors: Cannon DJ
Published: March 2005

The wool production and liveweight of Corriedale wethers was measured when both stocking rate and the proportion of land to wheat and pasture varied. The nominal stocking rates (R) were 6.8, 8.6, 10.5, 12.4 and 14.2 wethers ha-1, and the proportion sown to wheat was 0, 15 or 30 per cent. Clean wool production per head declined linearly with increase in stocking rate and the proportion of land sown to crop. Generally both maxima and minima liveweights declined with increase in cropping and minima liveweights with increase in stocking rate. The effect of cropping on wool production was attributed to the increased stocking rate on the uncropped portion of land during the period when the cropped area was unavailable to grazing. 'Average' stocking rates per ha (S) were calculated on the basis of the proportion of land to crop and the fraction of the year stubbles were available for grazing. S was found to be a more useful measure of stocking rate than R, in a system of dual use of land.
The response of lucerne cultivars to levels of waterlogging
Authors: Rogers VE
Published: March 2005

Five lucerne cultivars were grown for 10 weeks during summer at two irrigation frequencies, specified by evaporation intervals of 38 and 76 mm. Changes in soil moisture were monitored by tensiometers installed at 15 and 30 cm depths. At the first harvest no significant difference in yield was found between treatments. At the second harvest, regrowth of all cultivars was depressed by frequent irrigation, but Du Puits was particularly affected. The yield depression caused by frequent irrigation continued for six months after the treatment ended. The reduced growth following frequent irrigation was related to low soil aeration. In this treatment air-filled pore space in the 15-30 cm horizon remained at or below 15 per cent, a critical level for plant growth. A period of waterlogging for 10 days when the temperature at 5 cm depth remained at approximately 30�C led to reduced production and high mortality in all cultivars. Yields of Lahontan and Siro Peruvian at the end of the waterlogging period were significantly higher than yields of the other three cultivars. The possibility is suggested of increasing the tolerance of lucerne to poor aeration by natural selection on wet soils.
Effect of planting time and plant spacing on maize production on the Swan Coastal Plain of Western Australia
Authors: Greenwood EAN , Boundy CAP , Boer ESde , Power TR
Published: March 2005

Maize was sown at 7.4, 12.4 and 17.3 seeds m-2 every 4 weeks for 12 months. The higher seeding rates gave similar yields; the low seeding rate frequently reduced yield. Dry matter yields of forage at the soft dough stage ranged from 200 g m-2 for crops planted in June to about 1400 g m-2 for crops planted between September and January. Grain yields followed a seasonal pattern similar to forage yields, with oven dry weights exceeding 800 g m-2 for crops sown between August and January inclusive. Crops sown in winter gave low yields because there were few surviving plants, few grains per cob and the grains were small. Crops sown later than February were killed by frost before maturity. Closer spacing resulted in small cobs with a few and smaller grains. Phenological phase lengths varied with planting time and could be estimated from the inverse of mean temperatures above a critical base as the predictor variable. It is concluded that the planting season for high production of maize on the Swan Coastal Plain extends from August to January and that two crops for silage, or one for grain and one for silage, could be grown in one year.
Reaction of lucerne cultivars to Phytophthora megasperma, the cause of a root rot in Queensland
Authors: Irwin JAG
Published: March 2005

The causal organism of Phytophthora root rot of lucerne (Medicago sativa) in Queensland was identified as Phytophthora megasperma var. sojae and a brief description of the organism is included. The results of disease surveys show that Phytophthora root rot is widespread and causes serious losses in lucerne in south eastern Queensland. A collection of lucerne cultivars and strains was screened for resistance to P. megasperma var. sojae both in controlled environment chambers and in a naturally infested field site. The cultivar Lahontan and the experimental strains ESI, BDSI, ECRSI and Combined showed high levels of resistance in both situations.
The pathogenicity of Fusarium avenaceum to wheat and legumes and its association with crop rotations
Authors: Kollmorgen JF
Published: March 2005

Studies were made of the pathogenicity of Fusarium avenaceum (Fr.) Sacc. to wheat (Triticum aestivum), subterranean clover (Trifolium subterraneum) and barrel medic (Medicago truncatula var. truncatula), and of the effects of crop rotation on field populations of the fungus. F. avenaceum reduced emergence and dry weight of wheat, subterranean clover, and barrel medic seedlings. Infection reduced the height of both legumes but not the height or yield of wheat. The fungus caused a greater reduction in dry weight and height in barrel medic than in subterranean clover. Barrel medic is recorded as a host of F. avenaceum for the first time. The fungus was isolated from the roots of seedlings and from 0.3 per cent of a commercial seed sample. When this infected seed was sown in wheat stubble in crop rotations of fallow-wheat (stubble burnt), fallow-wheat and fallow-wheat-pasture-pasture its incidence in seed increased to 5.2, 6.0 and 10 per cent, respectively Studies on the effects of rotations on the incidence of F. avenaceum in wheat roots and wheat soil demonstrated a relation between crop sequence and population levels of the fungus. F. avenaceum was more prevalent in fallow-wheat-pasture than fallow-wheat.
Body composition of young sheep. 3. Effect of intake and pasture species on body composition and ruminal development of Merino lambs
Authors: McManus WR , Arnold GW , Dudzinski ML , Gharaybeh HR
Published: March 2005

Four-month-old Merino lambs were fed at three levels on pelleted lucerne or tall fescue hay of similar organic matter digestibility for 42 days. Measurements were made, after slaughter, of carcase and internal organ composition and rumen characteristics. Regressions of body component weights and of percentage composition on empty body weight (EBW) were calculated. Lambs fed lucerne either to maintain weight or to gain weight had more water, protein and ash at the same empty body weight than lambs fed fescue. Although lambs fed lucerne produced a lower acetate : propionate ratio in the VFA, there were few differences in rumen characteristics of lambs on the two feeds. There was evidence that lambs fed lucerne made more efficient use of digestible energy intake for energy storage.
Summer production of sheep grazing irrigated and non-irrigated pasture
Authors: Sharkey MJ , Murphy JP , Ward RG , Winfield CG
Published: March 2005

At Werribee in southern Victoria changes in liveweight, wool growth and carcase weights were measured over a 96 day period in summer during which two-year-old Corriedale and Merino ewes grazed various combinations of irrigated perennial and non-irrigated annual pasture. To provide the different combinations of grazing, groups of each breed grazed the two pasture types for different periods of time in 8 or 32 day grazing cycles. Groups with an eight day grazing cycle spent 1, 2, 3, 4, 5, 6, or 7 days (the 32 day grazing cycle groups 4, 8, 12, 16, 20, 24 or 28 days) on the irrigated pasture before completing the grazing cycle on the non-irrigated pasture. Two other groups grazed on either irrigated or non-irrigated pasture throughout the 96 days and a further group was slaughtered on day 1 of the experiment to measure the effect of treatments on carcases. The results were examined by regression analysis and showed that both breeds declined in liveweight, carcase weight, and wool growth on non-irrigated pasture. Production improved with time spent on irrigation. Corriedales (initial liveweight 47.0 kg) fattened when grazed on irrigated pasture for 50 per cent or more of the time but Peppin Merinos (initial liveweight 40.1 kg) could not be fattened beyond their initia carcase weights on any treatment. Wool production increased linearly with time spent on irrigation and was greater in Corriedales than in Merinos. The sheep grazing pastures in consecutive 8 day cycles did not differ significantly in production from sheep on similar treatments in the 32 day cycle.
Resistance to benzimidazole fungicide in blue mould of citrus in Queensland
Authors: Muirhead IF
Published: March 2005

Two of seven isolates of Penicillium italicum Wehmer (blue mould) from different consignments of citrus were resistant in vitro to thiabendazole, benomyl, thiophanate-methyl and carbendazim. The application of thiabendazole and benomyl to Late Valencia oranges inoculated with the resistant isolates failed to prevent the development of blue mould. No resistance was found in seven isolates of P. digitatum Sacc. (green mould).
Effect of plant density on the expression of the creeping-rooted character and forage yield of the lucerne (Medicago sativa) cultivar Cancreep
Authors: Daday H , Grassia A , Peak J
Published: March 2005

The effects of plant density, grass competition and weedicide spraying on the expression of the creeping-rooted character, crown development and on forage production of Cancreep were investigated in swards of hand-planted seedlings, and in a sown experiment. Higher percentages of creeping-rooted plants and increased crown development were found at low plant density whereas high plant density suppressed both creep and crown development. Weedicide spraying treatments increased the percentage of creeping plants in the sown experiment. The best survival rates of cocksfoot and optimum expressions of creep were also found at low densities when these species were grown in competition. The minimum mean crown diameter of plants initiating creep was 9.4 cm in the planted experiment. No significant difference was found between forage production of Cancreep and Hunter River in the sown experiment. The optimum sowing rate for Cancreep is about one kg ha-1, rows 30 cm to 60 cm apart and an application of the weedicide Diuron is recommended before the commencement of the winter after establishment.
Effect of genotype on yield of narrow-leafed lupin (Lupinus angustifolius) and sandplain lupin (Lupinus cosentinii)
Authors: Farrington P , Gladstones JS
Published: March 2005

Dry matter production, pod set and seed yield were compared among five genotypes of Lupinus angustifolius and six genotypes of L. cosentinii with reduced or non-shattering pods. The genotypes differed in flowering time, alkaloid content and flower colour (L. angustifolius only). Presence of the low alkaloid gene iucundus in L. angustifolius reduced vegetative growth by 25 per cent, and did not significantly reduce seed yield. Susceptibility to 'split' seed, a disorder causing rupture of the testa of the developing seeds was also associated with the iucundus gene. The implications of this are discussed. Flower colour and maturity differences did not significantly affect yield, although there was some suggestion that the white flower and seed colour gene leucospermus reduced pod set and seed yield in earlyflowering genotypes. In L. cosentinii, the presence of the low alkaloid gene sw generally did not significantly affect dry matter or seed yield. An exception was in the very early flowering genotypes where dry matter yield was 23 per cent lower in the low alkaloid line.
Adaptation of pearl millet (Pennisetum typhoides) to coastal New South Wales. 3. Comparative productivity of pearl-millet cultivars and a Sudan grass-sorghum hybrid
Authors: Ferraris R , Norman MJT , Fussell LK
Published: March 2005

Two experiments were carried out at Camden, New South Wales, to compare the productivity under defoliation of an early-maturing (cv. Tamworth) and a late maturing (cv. Katherine Pearl) pearl millet with the sorghum-sudan grass hybrid, Sudax SX-11 A. In experiment 1, harvests were taken at 30 cm stubble height at 3 and 6-week intervals. Total forage dry matter and protein content were similar for all species. Total forage yields were higher and protein content was lower with the 6-week cutting interval. In experiment 2, cutting frequency was kept constant at 3-week intervals, while cutting height was maintained at a. 30 cm and b. above the average apical meristem height until booting and then at 30 cm. Total forage dry matter yields were highest for Sudax and lowest for Tamworth. Regrowth yields generally declined with time, though for Katherine Pearl a relatively high late-season yield was harvested from cutting treatment b. Protein content was maintained at reasonable levels at all harvests. Sudax foliage generally had the highest protein content. Estimated in vivo organic matter digestibility values were little affected by cultivar or cutting regime but showed severe mid-season depression. A significant negative association of digestibility with mean minimum temperature during the regrowth period was noted (r = -0.81 3). In both experiments, the removal of apical meristems reduced the amount of regrowth. Sudax was less susceptible to decapitation because of the substantial contribution of secondary tillers to regrowth.
Identification of Australian wheat cultivars by laboratory procedures: examination of pure samples of grain
Authors: Wrigley CW , Shepherd KW
Published: March 2005

Three laboratory procedures have been examined for the identification of about fifty wheat cultivars currently grown in Australia. The most discriminating of these methods is starch gel electrophoresis of gliadin proteins extracted from a single grain or from meal. This procedure is capable of identifying many of the cultivars directly. However, in some cases identification is complicated by the observation of more than one biotype for a cultivar on the basis of this test. By comparison, a larger number of grains can be examined by the qualitative phenol test but it is less discriminating. Additional information is provided by applying the test to glumes. Thirdly, quantitative assessment of grain hardness, measuring either particle size index or pearling resistance, gives a division of cultivars into about five groups. Specific results are listed for all methods so that the most suitable procedure can be chosen for distinguishing a particular group of cultivars.
Seasonal distribution of mineral nitrogen with particular reference to leaching
Authors: Hingston FJ
Published: March 2005

Field estimates of seasonal changes in mineral nitrogen contents of nitrogen fertilized sandy soils were made at Toodyay, Meckering, Tammin, Merredin and Bodallin in the Western Australian wheatbelt during 1970. A model was used to compute water balances at each site and estimates were made of mineral nitrogen ( NH4+ and NO3-) in the soils and nitrogen in the crop. Leaching, as indicated by the distribution of ammonium and nitrate with depth in the soils, was considered in relation to the net infiltration of rainfall and drainage from the 90 cm depth of soil. Leaching of nitrate was responsible for loss of mineral nitrogen from sowing to the first sampling at Toodyay. It was unlikely that nitrate was leached below 90 cm at Meckering or Tammin, and drainage at Merredin and Bodallin was negligible. There was no drainage or net infiltration of rainfall at any site after the first sampling, between June 30 and August 11. The decreases in mineral nitrogen in the soils was about equal to the plant uptake of nitrogen in all situations where there was no leaching, except at Merredin. At that site, during the period between sowing and the second sampling (August 27), there were unexplained decreases in soil mineral nitrogen. The results show that water balance studies can give reasonable understanding of the leaching and redistribution of nitrate and ammonium in sandy soils, and hence may be used to predict for different seasonal conditions.
Effects of dry season supplements of protein and phosphorus to pregnant cows on the incidence of first post-partum oestrus
Authors: Little DA
Published: March 2005

Pregnant multiparous Brahman cross cows grazing native pasture at Samford in south-east Queensland were allotted to three treatment groups in late winter; one group received a daily supplement of 180 g crude protein (as peanut meal) plus 10 g phosphorus (P), the second group 10 g P and the third (control) group neither protein nor P. The P and control groups received approximately 320 g DOM per day, mainly composed of sugar and grain, to balance the DOM provided to the protein + P group as peanut meal. Supplementation continued for a period approximately spanning the third to eighth months of gestation. The protein plus phosphorus supplement significantly reduced the interval from calving to first postpartum oestrus by 46 per cent; all animals in this group had exhibited oestrus within two months of calving. By three months after calving, only 50 per cent of controls and 70 per cent of those given phosphorus had exhibited oestrus. Calf growth was unaffected by the supplements. Samples of grazed pasture were collected using non-pregnant cows with oesophageal fistulae. The provision of P or P plus protein tended to render the animals less selective in their grazing. The evidence suggested that the higher feed requirements of the pregnant cows removed any possible effect of the supplements on their selectivity. Native pasture provided a slightly sub maintenance ration during the period of supplementation, and a major limiting nutrient appeared to be protein.
Production and gross margins for sheep and cattle grazed separately and together
Authors: Hamilton D
Published: March 2005

On annual pasture, ewes lambing in autumn and young steers grazed separately each at five stocking rates, and grazed together in a ratio of 4 : 1 at each of three stocking rates. Gross margin per hectare (GMH) from the sheep was greatest at the heaviest stocking rate that could be carried safely without supplementary feed, and from steers was greatest at the heaviest stocking rate at which a high proportion of carcases were first-grade, even in a year of poor pasture. Maximum GMH from the steers was obtained at a lighter equivalent stocking rate than that required for maximum GMH from the sheep. When the sheep and steers grazed together at a stocking rate where first-grade steer carcases were produced consistently, the loss in potential sheep GMH from reducing the sheep stocking rate to this level was greater than the value of any benefit from mixed stocking. This finding is discussed in relation to results from another environment where no difference was found between sheep and cattle in the stocking rate required for maximum GMH.
Effect of sowing rate and sowing method on the establishment, yield and survival of irrigated lucerne at Kyabram, Victoria
Authors: Roufail A
Published: March 2005

Hunter River lucerne (Medicago sativa) was sown at 6.7, 9, 13.4, 17.9, 22.4 or 26.9 kg ha -1, broadcast or in 15, 30 or 45 cm rows under irrigation. Seeding rate did not affect dry matter production. There were no significant differences in dry matter production between sowing broadcast or in 15 cm rows, but 30 cm and 45 cm rows produced less dry matter than 15 cm rows (P < 0.01 ). Seeding rates and sowing methods affected the plant population, which affected the morphology of the roots and the aerial growth.
Response of skeleton weed (Chondrilla juncea) to applied superphosphate and grazing management
Authors: Kohn GD , Cuthbertson EG
Published: March 2005

The influence of pasture topdressing with superphosphate and of stocking rate on the Chondrilla uncea population in a clover-ryegrass (Trifolium subterraneum-Lolium rigidum) pasture was measured in a grazing experiment at Wagga Wagga, New South Wales, over the period 1962 to 1966. Superphosphate application reduced final weed populations at all stocking rates. Continuous grazing maintained skeleton weed populations at a low level, but increasing the stocking rate from 5 to 15 sheep ha-1 had little influence on weed numbers. A management comparison at a high stocking rate-high fertilizer rate showed that rotational grazing increased the weed population compared with continuous grazing systems.
Growth performance of Brahman and Charolais × Brahman cattle in a tropical environment
Authors: Rudder TH , Seifert GW , Bean KG
Published: March 2005

Weight per day of age at weaning (175 days) and at 553 days, and post-weaning gain were collected from 159 high grade Brahman and 35 Charolais x Brahman crossbreds on a commercial property in Central Queensland and analysed by the least squares method. The primary reason was to measure the effect of Charolais infusion on high grade Brahman cattle. CharolaisxBrahman cattle were 0.280 kg and 0.168 kg heavier per day of age at weaning and 553 days respectively, and gained 0.126 kg day-1 more during the post-weaning period than the Brahmans (all P < 0.005). Older dams weaned heavier calves than younger dams (P < 0.01), but the differences were non-significant at 553 days and for post-weaning gain. Males were significantly heavier per day of age at weaning and 553 days, and gained more during the post-weaning period. The regression on day of birth was highly significant (P < 0.005) for weight per day of age at 175 days, but not at 553 days.
The pepsin soluble dry matter of leaf and stem fractions of grasses in relation to voluntary intake by sheep
Authors: Laredo MA , Minson DJ
Published: March 2005

The level of pepsin soluble dry matter (PSDM) was determined on leaf and stem fractions derived from five grasses each cut at three stages of growth. The voluntary intake and dry matter digestibility of all grass fractions had been previously determined with sheep. Mean PSDM for leaf and stem were similar (23.0 v. 23.4 per cent) despite large differences in voluntary intake (57.8 v. 39.6 g/kg W0.75 )and similar dry matter digestibility (52.6 v. 55.8 per cent). For all grass fractions the correlation between voluntary intake and PSDM was r = 0.26, P > 0.05. This poor relation was partly caused by a significant difference between the leaf and stem populations. It was concluded that PSDM was an unreliable guide for predicting the voluntary intake of grasses when compared at similar stages of growth.
Pasture dry matter reduction over the dry season due to Oncopera spp. (Lepidoptera: Hepialidae) on the Atherton Tableland, north Queensland
Authors: Quinlan TJ , Elder RJ , Shaw KA
Published: March 2005

Infestation of late instar larvae of Oncopera brachyphylla Turner and O. mitocera (Turner) (Lepidoptera : Hepialidae) in mixed pastures at four sites on the Atherton Tablelands of Queensland over a ten week period from September-October gave a mean reduction of 8.7 kg dry matter ha-1 larva-1 m-2. Mean larval populations at the four sites for the period were 29.6, 96.9, 85.0 and 76.4 larvae m-2. The pastures consisted of Nandi setaria (Setaria anceps cv. Nandi)-Greenleaf desmodium (Desmodium intortum cv. Greenleaf) and kikuyu grass (Pennisetum clandestinum) each at two sites.
Growth and carcase composition of yearling cattle fattened on combinations of hay, grain and NPN in a feedlot and on grain supplemented pastures
Authors: Corah LR , Jackson SA , Bishop AH
Published: March 2005

Hereford steers aged 10 to 12 months were fattened on a range of diets including two types of hay (pasture hay, oaten hay), three types of grain (oats, wheat, barley), four levels of oats (1/2, 1 and 1 1/2 per cent of liveweight per day and ad libitum) and non-protein nitrogen as a supplement to the oaten hay. In addition, two groups of steers were grazed on pasture and one of these was supplemented with oats at the rate of 13 per cent of liveweight per day. The experiment was conducted at the Pastoral Research Station in western Victoria. Steers fed pasture hay, either alone or with oats, gained at a faster rate than steers fed oaten hay, alone or with oats. As the level of grain in the rations increased, liveweight gains of the steers increased. The steers given the highest levels of grain (1 1/2 per cent liveweight and ad libitum) produced the most acceptable carcases as assessed by fat cover and the physical properties of the lean. As the level of grain was increased, the conversion of feed to liveweight gain was improved and the time required to reach the desired weight was reduced. Rations of barley, wheat or oats had similar effects on growth rate and carcass composition when they were fed at a rate equal to one per cent of the liveweight of the steers per day. The NPN supplement, biuret, had little effect when fed as a supplement to oaten hay. The feeding of grain as a supplement to pasture doubled the growth rate of the steers. The carcases of steers receiving oat grain on pasture were of comparable quality and produced in a similar time to those of the fastest gaining feedlot groups. The results do not provide any evidence which would justify the practice of confining such steers in a feedlot.
Rearing dairy beef calves by multiple suckling. 2. Effects on liveweight gain of calves
Authors: Kaiser AG , O'Neill GH
Published: March 2005

Three experiments were conducted in which dairy cows multiple suckled beef x dairy cross calves during early lactation. After weaning calves grazed nitrogen fertilized kikuyu grass (Pennisetum clandestinum). In the first experiment each cow suckled two, three or four calves for 12 weeks. Pre-weaning calf growth rate increased significantly (P < 0.01) as the number of calves suckled was reduced, In the second experiment, calves suckled at three per cow for 6, 9 or 12 weeks gained at similar rates to weaning, reaching weaning liveweights of 52, 64 and 72 kg respectively. Neither the number of calves suckled in experiment 1 nor the length of the suckling period in experiment 2 significantly affected post-weaning growth rates. In the third experiment there was no significant difference between the growth rates of calves sired by Friesian and Angus bulls. After weaning, stocking rate treatments were imposed, there being a significant (P < 0.05) but small linear decline in growth rate as stocking rate was increased. The post-weaning growth rates of calves in all three experiments were poor when compared with growth rates reported for calves grazing temperate pastures.
Tissue testing for assessing the phosphorus status of green panic, buffel grass and setaria
Authors: Smith FW
Published: March 2005

The possibility of using phosphorus concentrations in different parts of pasture grasses for diagnosing their phosphorus status was studied. Critical phosphorus concentrations using youngest expanded leaves of green panic (Panicum maximum var. trichoglume cv. Petrie), buffel grass (Cenchrus ciliaris cv. Biloela), or setaria (Setaria sphacelata cv. Nandi) were found to be almost identical to those assessed from the whole tops. Critical phosphorus concentrations in green panic and setaria decreased with age of plant, and for whole tops of green panic were : 0.55 per cent in plants with three to four leaves on the primary shoot, 0.32 per cent in plants with four to five leaves on the primary shoot and 0.1 5 per cent in plants with six to seven leaves on the primary shoot. Values in the whole tops of setaria were: 0.46 per cent (four leaves), 0.36 per cent (five leaves), 0.24 per cent (six leaves) and 0.14 per cent (seven leaves). A similar decline with stage of growth was observed when youngest expanded leaves were used to estimate critical phosohorus concentrations in setaria
A comparison of Vicia species for summer grazing and subsequent oat crop production in Western Australia
Authors: Anderson GW
Published: March 2005

Vicia species were grown alone, or with oats, in a continuous cropping system for summer grazing. Ten cultivars were selected from the species V. atropurpurea, V. dasycarpa, V. sativa and V. articulata. There was a maturity range of five weeks. They were sown in 1968 and allowed to regenerate for three more years. Production of dry matter and grain yield were recorded for the first three years. The liveweight trends of sheep grazing the dry herbage were measured for the first two summers. In the final two years the competitive ability of the vetches when oversown with oats, and the yields of the oat crops were measured. V. atropurpurea generally yielded most dry matter and V. articulata the least. V, sativa gave the highest seed yields. In 1968, 18-month-old sheep lost weight on all cultivars. In 1969, six-month-old sheep gained weight and these liveweight gains were positively correlated with the yield of vetch dry matter. The yield of oats was significantly correlated in both 1970 and 1971 with the 1969 vetch yield. Most of the vetches regenerated well, both on their own and when oversown with oats. The later maturing V. atropurpurea and V. dasycarpa persisted better than V, sativa and V. articulata cultivars. V. dasycarpa cultivars contained significantly higher concentrations of nitrogen than those of other species. The nitrogen concentration was higher in vetches grown alone than when grown with oats. The results suggest that V. dasycarpa and V. atropurpurea are the most suitable species in a continuous cropping system for summer grazing.
Effect of timing, concentration and stock/scion combination on chemical control of pre-harvest drop of Navel oranges
Authors: Sarooshi RA , Stannard MC
Published: March 2005

The effects of 4-chloro-2-methyl phenoxyacetic acid (MCPA) and some derivatives of 2,4-dichlorophenoxyacetic acid (2,4-D) applied at various concentrations and application times on preharvest drop from several navel orange clones and rootstocks were investigated. The trees were spray irrigated, on light soils and growing in a semi-arid region. Herps Washington navel strain on Poncirus trifoliata rootstock had a small natural drop and fruit drop from this combination was unaffected by spray treatments. Control trees of Leng navels dropped more fruit than those of GVN or Herps Washington navel strains. There were no differences in fruit drop between MCPA and 2,4-D both applied at 20 p.p.m. in mid May. In one year however, the higher concentration of 2,4-D was superior to MCPA applied at 10 p.p.m. in mid May but was not better than 2,4-D at 10 p.p.m. Two sprays of 2,4-D 10 p.p.m. applied one each in mid May and mid June had no advantage over a single spray of 2,4-D 20 p.p.m. mid May. The four forms of 2,4-D used were the sodium and amine salts (low volatile) and the isopropyl and ethyl esters (high volatile). All the forms sprayed in mid May at 20 p.p.m. proved equally effective. In all cases, fruit quality and yield were unaffected by spray treatments over a number of years.
Correction - Studies on cattle with oesophageal fistulae: comparison of concentrations of mineral nutrients in feeds and associated boluses
Authors: Little DA
Published: March 2005

Eight forages were fed in small quantities to cattle with oesophageal fistulae. The feeds and boluses were analysed for Ca, Mg, S, Mn, Mo, Cu, Zn, and Ti. Bolus composition could be used to predict dietary levels of Ca, S, Cu, and Mg with reasonable precision (error <� 9 per cent), but feed concentrations of Mo and Mn could be predicted only with an error of �15 per cent. Levels of Zn in boluses could not be used to predict dietary levels, since bolus Zn greatly exceeded that of the feed. The presence of Zn in bovine saliva was demonstrated. Concentrations of Ti in feeds and boluses were in close agreement; measurement of Ti in boluses appears to provide a potentially useful method for the identification of those contaminated with soil during grazing studies.
The effect of early weaning of Brahman cross calves on calf growth and reproductive performance of the dam
Authors: Schottler JH , Williams WT
Published: March 2005

It is shown, for a herd of Brahman cross cattle in the humid tropical lowlands of Papua New Guinea, that reducing the age of weaning from seven to four months advances the date of subsequent calving by ca 39 days. The calving interval is nevertheless always considerably shorter than that recorded from similar equatorial climates elsewhere. The 4-month calves showed an unexpected sensitivity to pasture quality, the nature of which requires further investigation.