bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of ovulation, storage of semen, and artificial insemination of fibre-producing goats in Australia: a review
Authors: Ritar AJ
Published: March 2005

Artificial insemination (AI) allows individual bucks to be exploited widely and so is a potentially useful tool for the rapid genetic improvement of fibre goats. In Australia, where there is a desire by farmers to improve the productivity of their goats, AI may best be adopted under extensive grazing conditions using control of ovulation to allow efficient and accurate timing of the deposition of frozen-stored semen. Although ovulatory activity is influenced by the manipulation of environmental factors, the time of ovulation is synchronised most accurately by the combined use of intravaginal progestagens and pregnant mares' serum gonadotrophin. However, the costs of these exogenous hormones remain high, which justifies investigation of alternative methods to control ovulation. Bucks show strong seasonality in the quality and quantity of their sperm production, and so there is limited time in which semen may be collected for storage and AI, but this can be extended by optimising nutrition and management. There appears to be no improvement in the fertility of stored semen when seminal plasma, which contains egg yolk coagulating enzyme, is removed and an extender containing only a low concentration of egg yolk is used for dilution. Simple methods have been developed for 1-step dilution and freezing of buck semen. However, the post-thawing viability of spermatozoa frozen in pellets on dry ice is higher than for semen frozen in straws in liquid N2 vapour, although straws are preferred for commercial trade. For frozen-thawed semen, fertility after laparoscopic insemination is high, whereas the fertility after cervical insemination is considerably lower but improves by the deeper placement of semen into the reproductive tract. Does are best inseminated 5-10 h before the expected time of ovulation. A dose as low as 1 x 106 motile spermatozoa may be used for laparoscopic insemination of thawed semen that was previously diluted at rates (semen: diluent) of 1:2 to 1:23. However, for the cervical method, a low dilution rate of 1:2 allows a sufficiently small, highly concentrated dose of at least 120 x 106 motile frozen-thawed spermatozoa t o be deposited into the reproductive tract of the doe. Cervical insemination is cheaper and simpler than the laparoscopic method, and this warrants the development of an improved technique for the consistent, deep deposition of frozen-thawed semen through the cervix in a high proportion of does.
Estimation of the week of conception in Merino ewes using real-time ultrasonic imaging
Authors: Johns MA
Published: March 2005

Real-time ultrasonic imaging was used to estimate the week of conception in a flock of 4- and 5-year-old Merino ewes. Rams were joined with ewes for 6 weeks after the ewes were 'teased' for 2 weeks by testosterone-treated wethers. The ewes were scanned 92 days after the introduction of the rams to determine litter size, then, based mainly on the sizes of the heads and bodies of the fetuses. the week of conception was estimated. These results were compared with the actual week of conception determined from weekly mating and daily lambing records. The week of conception was correctly estimated for 71% of the ewes. The consecutive 2-week period from the start of joining within which conception occurred was correct for 91% of the ewes. The correct half of the joining period within which conception occurred was diagnosed for 98% of the ewes.
Efficacy of ivermectin jetting fluid for control of the sheep biting louse (Damalinia ovis)
Authors: Eagleson JS , Thompson DR , Scott PG , Cramer LG
Published: March 2005

Nine field trials were conducted to evaluate the efficacy of ivermectin jetting fluid applied by hand jetting against the biting louse, Damalinia ovis (also referred to as Bovicola ovis), in long-wooled sheep. The trials included 7632 sheep with 3-9 months wool growth. Louse counts were obtained periodically from 23-25 monitor sheep selected from each treated flock for up to 15 weeks after treatment. Overall reductions in louse counts at 4-6, 8-10, 11-13, and 15 weeks after treatment compared with pretreatment values were 98.7, 99.0, 98.9, and 99.8%.
Effect of cutting interval and winter dormancy on yield, persistence, nitrogen concentration, and root reserves of irrigated lucerne in the Queensland subtropics
Authors: Gramshaw D , Lowe KF , Lloyd DL
Published: March 2005

The use of fixed interval or growth stage (crown bud elongation) cutting management for lucerne was studied for cultivars with dormancy characteristics ranging from highly winter-active to winter-dormant. Fixed cutting intervals ranged from 3 to 8 weeks and were imposed on irrigated stands in a subtropical environment. Persistence, dry matter yield, weed yield, nitrogen (N) concentration and yield, and root reserves were measured over a 2-year period. For cultivars from all dormancy classes, persistence was highest with either 5- or 6-weekly cutting, while dry matter yield was maximised with 5-weekly cutting. Nitrogen concentration was highest with 3-weekly cutting but N yield was greatest under 4-weekly cutting. Root reserves were not maintained unless the cutting interval was extended beyond 7 weeks. Growth stage cutting produced equivalent yields and persistence but lower N concentrations and root reserves than the best fixed interval cutting treatment. There was no evidence that cultivars of different dormancy classes require different cutting management to obtain optimum performance. Therefore, a fixed cutting frequency of 5 weeks throughout the year is an acceptable management compromise for all lucerne cultivars, combining high dry matter and N yields with acceptable levels of foliar N and root reserves. Although the more complex management decisions associated with growth stage cutting appear unwarranted, dry matter yield could be maximised by using a flexible cutting schedule which matched cutting interval with growth rate (4 weeks in summer and 7 weeks in winter).
Estimating mass of temperate and tropical pastures in the subtropics
Authors: Fulkerson WJ , Slack K
Published: March 2005

The feasibility of estimating, with acceptable precision, temperate and tropical pasture mass in a subtropical environment was evaluated. For the tropical grasses kikuyu (Pennisetum clandestinum) and setaria (Setaria ancepts), 3 different pasture meters were calibrated against 1 of 3 dry matter (DM) estimates. Temperate pastures (predominantly Lolium perenne and Trifolium repens) were evaluated using the Ellinbank rising plate meter (RPMl) calibrated against DM to ground level. A single regression equation was developed for syegrass-white clover pasture from data pooled within season over first- and second-year swards. The s.e. of estimate (s.e.e.) for assessing tropical grass pasture mass using RPMl was similar to that for a heavier Ellinbank meter and substantially lower than that for the electronic pasture probe. Using RPMl, separate regression equations were required for early (November-February) and late (March-May) season determinations for both kikuyu and setaria. The regression equations were based on calibrations against shoot DM (>5 cm stubble height for kikuyu and 6 cm for setaria) and are only applicable to well-managed and highly utilised pastures. Calibrations of all pasture meters over all months to green DM (senescent leaf and stem removed) gave a lower s.e.e. than total DM (kikuyu 138 v. 177 kg DM/ha, n = 171; setaria 211 v. 224 kg DM/ha, n = 177) whilst shoot DM gave a more substantial reduction in s.e.e. (kikuyu 95 v. 147 kg DM/ha; setaria 140 v. 193 kg DM/ha).
Population dynamics of false wireworms (Gonocephalum macleayi, Pterohelaeus alternatus, P. darlingensis) and development of an integrated pest management program in central Queensland field crops: a review
Authors: Robertson LN
Published: March 2005

False wireworms (particularly Pterohelaeus alternatus and Gonocephalum macleayi) are major pests of seedling field crops in central Queensland. Population densities are spatially and temporally dynamic, with high densities (>2/m2) of large larvae and adults generally not persisting at a location for more than 1 year. Adult movement in summer in response to changes in habitat suitability is suggested as the cause of population changes. Natural enemies, particularly entomopathogenic fungi, may also have a role in suppressing high population densities. One-half to three-quarters of fields that have grown summer crops including sorghum, sunflower, soybeans, and mungbeans in the preceding season are infested at densities that could cause economic losses in subsequent crops sown in wide rows with a low seed-sowing rate. Winter-grown wheat results in a significantly lower infestation rate (one-quarter of the fields sampled), but winter chickpea is a suitable crop for development of false wireworm infestations. Cultivation per se does not reduce numbers of false wireworms, but stubble removal may depress densities. False wireworms feed on stubble, and crop damage may be increased in low-stubble fields (following long fallows for example) despite low false wireworm numbers, due to lack of alternative food. The dynamic nature of false wireworm population size makes prediction of pest levels difficult. The presence of false wireworms should be assessed in each fallow field before planting. Management strategies based on preplanting sampling, economic injury levels, stubble management, crop rotation, and insecticide control are discussed.
Soil testing and plant analysis in Australia
Authors: Peverill KI
Published: March 2005

During the past 3 4 decades, there has been a modest growth in the demand for soil amd plant testing services in Australia. Such development reflects an increasing awareness by farmers that there are tangible benefits from the regular use of soil and plant analysis. Concomitant with these changes, there has been an increasing breadth and sophistication in the range of available services, instrumental advances that permit more rapid analytical throughput, evolution of computer management systems (including computer-generated reports), and a general decrease in reporting time to primary producers. These developments have not always been matched with adequate quality control and uniformity in sampling, analysis, interpretation, and fertiliser advice procedures. There is need for further research and method development leading to the introduction of universal reagents or ion exchange resin extractions, or new test procedures into laboratory routines, to enhance laboratory capacities and turnaround times or to improve interpretation skills. Advances in decision support software are also required in order to refine fertiliser advice to primary producers. The challenge for the future is the standardisation of procedures and maintenance of adequate quality control by the various agencies offering soil and plant testing services. The Australian Soil and Plant Analysis Council (ASPAC) will play a pivotal role in this process.
A review of soil sampling for chemical analysis
Authors: Brown AJ
Published: March 2005

A review of soil sampling for chemical analysis is presented for farm paddocks, orchard blocks and experimental plots with relevance to Australian and New Zealand conditions. Basic principles concerning field variability and its determination, sampling equipment, sample handling and sampling techniques are given. Detailed examination of both published and unpublished data on spatial and temporal variation in cultivated and uncultivated soils is also provided. Deficiencies and conflicts in the database are highlighted and provide a basis for future work.
Soil analysis: a review
Authors: Rayment GE
Published: March 2005

This paper reviews most aspects of soil analysis, with particular emphasis on soil chemical testing in Australia. Water quality, sample contamination, and the effects of soil drying, soil storage, and particle size are recognised as important components in the laboratory preparation of soil samples for analysis. The subsequent effects of choice of soil to solution ratio, leaching v. equilibration, soil shaking equipment, and the choice of extracting and digesting solutions are reviewed with examples.The review includes an overview of key chemical soil tests including pH, electrical conductivity, chloride, phosphate, sulfur, exchangeable cations, and cation exchange capacity. There is an examination of field v. laboratory tests and comment on analytical quality assurance. The recent release of the Australian Laboratory Handbook of Soil and Water Chemical Methods and the emerging activities of the Australian Soil and Plant Analysis Council should ensure the direction of soil testing in Australia remains positive.
Factors affecting the interpretation and adoption of plant analysis services
Authors: Lewis DC , Grant IL , Maier NA
Published: March 2005

A review of the factors affecting the interpretation of plant analysis is presented. The development of plant test criteria is discussed in relation to plant part and age, seasonal nutrient changes, diurnal trends, Piper-Steenbjerg curvature, nutrient interaction and ratios, plant genotype, and environmental and crop management factors. The value of both diagnostic and prognostic plant tests is reviewed with specific emphasis on the role of prognostic tests in farmer decision making. Rapid sap testing is discussed in relation to development, utilisation, and role in agriculture. Factors affecting the utilisation of plant testing are reviewed. Within Australia the use of plant analysis services is low. Reasons for this low adoption and methods by which usage can be increased are discussed.
A review of fertiliser advice in Australia
Authors: Sparrow LA
Published: March 2005

Fertiliser advice is provided in many ways in Australia today. There has been a move away from blanket recommendations to recommendations for particular paddock-crop-farmer combinations. Emphasis has been on phosphorus for pastures and on nitrogen and phosphorus for cereals because of the importance of these elements and production systems in Australian agriculture. Soil tests are a major tool used in formulating recommendations, but plant tissue testing and nutrient budgets are playing increasing roles both in addition, and as alternatives, to soil tests. Variability within our agricultural systems places limits on the capacity of any or all of these techniques to predict precise fertiliser needs. We know very little about farmer attitudes to fertiliser advice, both for the minority of farmers who use advisory services and, more so, for the majority who do not. Farmers have not been questioned enough about why they have, or have not, adopted available technology. If better fertiliser management is to be more widely practised, the needs of our clients must direct future research and extension in soil fertility more than they have in the past. Resources for research will be increasingly difficult to justify unless serious consideration is given to the application of that research in agriculture and its adoption by farmers.
Midseason oranges for juice production
Authors: Sarooshi RA , Hutton RJ
Published: March 2005

Juice quality, yield performance, and cropping efficiency of 6 midseason orange varieties (Hamlin, Parramatta, Pineapple, Joppa, White Siletta, and Mediterranean Sweet), together with Seedless Valencia on 4 rootstocks [Troyer citrange, Poncirus trifoliata, rough lemon, and either Benton citrange (coastal) or sweet orange (inland)], were studied for their suitability for both processed and fresh orange juice production. Promising midseason varieties for processed orange juice were Parramatta and Hamlin on Troyer citrange, and Parramatta on P. trifoliata, when grown in coastal districts. Debittered juice of Joppa on Troyer citrange could also be used for processing by early September on the coast. Preferred inland varieties for production of processed orange juice were Mediterranean Sweet and Harnlin on Troyer citrange. Midseason oranges grown inland had higher citric acid levels than the same variety grown on the coast. This resulted in inland fruit having lower ratios of total soluble solids (TSS) to acid, and later maturities, than fruit grown on the coast. Acceptable fresh orange juice was produced from fruit of Parramatta, Hamlin, White Siletta, and Mediterranean Sweet varieties grown on Troyer citrange rootstock in coastal districts; inland, fruit of Mediterranean Sweet, Joppa, Parramatta, and White Siletta varieties on Troyer citrange rootstock produced good quality, fresh orange juice. Hamlin can also be marketed as fresh fruit. In coastal production areas, harvesting can commence from mid July for Hamlin, from mid to late August for Parramata, and from early September for White Siletta and Mediterranean Sweet. Harvest in inland districts for processed juice should commence in mid July for Hamlin and in early September for Mediterranean Sweet, whilst harvest for fresh juice and/or fruit should proceed in early September for Mediterranean Sweet, and in late September for Parramatta, White Siletta, and Joppa. Highest fruit yields and large trees were produced by Parramatta and Joppa on Troyer citrange and rough lemon rootstocks. Most quality characteristics were better for fruit produced on Troyer citrange than on rough lemon. Both Benton citrange and sweet orange performed poorly and are not recommended as rootstocks for midseason oranges. All varieties on Troyer citrange had better yield and TSS/ha than those on P. trifoliata rootstock, which produced smaller but highly cropping efficient trees.
Irrigation frequency for white clover and lucerne on a cracking clay in the Murrumbidgee Valley, New South Wales
Authors: Lattimore MAE , Thompson JA , O'Callaghan KL
Published: March 2005

A field experiment was undertaken to study the effect of irrigation frequency on dry matter production of 2 perennial pasture legumes on a grey cracking clay soil (Ug 5.28). This soil has a higher water-holding capacity than the red-brown earths of most previous Australian studies. One-year-old swards of luceme (Medicago sativa L.) cvv. Maxidor II and Pioneer brand 581 (P581), and white clover (Trifolium repens L.) cvv. Haifa and Irrigation, were flood-irrigated at 75, 100, 150, and 200 mm of cumulative net potential evapotranspiration during 3 irrigation seasons. White clover was more sensitive to water stress than lucerne, with yield reductions at the 2 longer intervals of 13% in the first season, 37% in the second, and 39% in the third. Lucerne showed little effect of irrigation frequency during the first 2 seasons, but yields were substantially reduced (by 27%) at the 2 longer intervals in the third season. The 2 white clover cultivars differed in seasonal production and growth habit, Haifa being more productive and withstanding water stress better than Irrigation in the first season. Production was similar in the second season, but Irrigation was able to maintain a denser sward and outyielded Haifa in the third season. There was little difference between the 2 lucerne cultivars. A combination of higher available soil water content and a considerably deeper effective rooting depth (0.8 m at the 100-mm interval), both of which were strongly influenced by soil type, enabled productivity to be maintained at a longer irrigation interval (100 mm) than reported in other Australian studies. Measurements of leaf relative water content reflected the water stress imposed by the treatment intervals. It is considered that in order to maximise production, an irrigation interval up to 100 mm is appropriate for white clover on this soil type. The optimum frequency for lucerne will depend on the life of the stand desired, balanced against productivity and irrigation costs.
Concentrations of elements in wheat grains grown in Australia, North America, and the United Kingdom
Authors: Batten GD
Published: March 2005

Concentrations of elemental nitrogen, phosphorus (P), potassium (K), magnesium (Mg), sulfur, calcium (Ca), manganese (Mn), zinc, sodium (Na), boron, copper (Cu), and iron were compared in 47 samples of wheat grain collected from 17 grain terminals and a commercial flour mill in Australia and 38 samples of wheat obtained from a range of sites in North America and the U.K. The Australian samples included grain from the Prime Hard, Australian Hard, Australian Standard White, Australian Soft, and Durum grades, while the overseas samples included wheat of Hard Red Winter, Hard Red Spring, Soft Red Winter, Soft White Winter, Western White, and Canadian Red Spring grades. The Australian wheats, with the exception of 1 sample of Durum, contained less P, K, Mg, and Cu, but more Na, than most of the wheats grown overseas. The concentrations of P, K, Mg, Ca, and Mn in wheats grown overseas appear to have declined since earlier surveys were conducted. The relations between elements suggest that the amount of P deposited in the grain determines the concentrations of other elements, especially Mg and K. The P data presented in this study indicate that Australian wheats contain only 59-77% as much phytic acid as white and red wheats grown overseas. The claim that Australian wheats contain little Na compared with wheat from America is refuted. Consumers of unleavened, wholemeal products may be less likely to suffer nutritional imbalances if they use Australian wheat.
Degradation of trifluralin in three Victorian soils under field and laboratory conditions
Authors: Jolley AV , Johnstone PK
Published: March 2005

The effects of soil moisture and temperature on trifluralin degradation were investigated in 3 Australian soils under field and laboratory conditions. For the field trials, the amount of trifluralin persisting over 1 year into the next cropping season varied from 9 to 24%. From laboratory experiments, separate relationships were derived for the effects of temperature and moisture 1 on trifluralin degradation. Trifluralin degradation I increased with both increasing moisture and increasing temperature. The results indicate potential for unusually long persistence of trifluralin in years of low rainfall when the soil becomes very dry. It is therefore recommended that analysis for trifluralin residues or activity be undertaken if a sensitive crop such as oat, sorghum, or millet, or a sensitive pasture species such as phalaris or ryegrass, is sown after very dry climatic conditions following trifluralin application. The wheatbelt regions of Australia do not experience cold conditions for long enough periods for low temperatures to be a major factor contributing to trifluralin persistence. Degradation was compared for trifluralin applied as a formulation of the herbicide and as the active ingredient alone, to determine the validity of results obtained using the pure herbicide. In half of the 6 field and laboratory studies, there was a statistically significant difference between degradation of trifluralin as the active ingredient and as the formulation. This indicates a need to use the formulated compound in laboratory experiments if results are to reflect normal agricultural practices.
Reducing denitrification loss with nitrification inhibitors following presowing applications of urea to a cottonfield
Authors: Chen DL , Freney JR , Mosier AR , Chalk PM
Published: March 2005

The effects of the nitrification inhibitors nitrapyrin, acetylene (provided by wax-coated calcium carbide), and phenylacetylene on nitrogen (N) transformations and denitrification losses following presowing applications of urea were determined in a cottonfield in the Namoi Valley of New South Wales. The study used 0.05-m-diameter microplots to follow the changes in mineral N, and 0.15-m-diameter microplots fertilised with 15N-labelled urea (6 g N/ m2; 5 atom % 15N) to assess losses of applied N. When urea was applied in February (34 weeks before sowing), 84% of applied N was lost from the soil. Loss of applied N was reduced by addition of nitrapyrin and phenylacetylene, to 53 and 57%, respectively. In the absence of nitrification inhibitors, less N was lost (72% of that applied) from an application in May than from the February application. Addition of acetylene, phenylacetylene, and nitrapyrin reduced losses over the 24 weeks to sowing to 57, 52, and 48%, respectively. These experiments show that N loss from presowing applications of urea can be significantly reduced by the use of nitrification inhibitors, but that the losses of N are still substantial.
Effect of calcium infiltration on ripening of avocados of different maturities
Authors: Yuen CMC , Caffin N , Boonyakiat D
Published: March 2005

Mature but unripe Fuerte and Hass avocados harvested at 3 stages of maturity were vacuum-infiltrated with 4 and 8% calcium chloride (CaCl2) solutions and stored at 20�C. The fruit were assessed for ripening and injury development and analysed for Ca content. Postharvest application of Ca to fruit harvested 2 weeks before prime harvest elicited a greater delay in ripening and caused less fruit injury than application at prime harvest or 2 weeks after prime harvest. Fruit maturity did not have a significant effect on the amount of Ca taken up by fruit when infiltrated with each CaCl2 solution. Vacuum infiltration with 8% CaCl2 solution greatly enhanced the uptake of Ca by both Hass and Fuerte fruit but did not delay ripening further than 4% CaCl2 treatment.
A strategy for reducing russet in Red Fuji apples while maintaining control of black spot (Venturia inaequalis)
Authors: Jones KM , Bound SA , Oakford MJ , Wilson D
Published: March 2005

A trial at the Grove Research Station in southern Tasmania examined methods of protection against black spot and the effect of these treatments on russeting of Red Fuji apples. An untreated control was compared with sprays of cupric hydroxide (wettable powder and dry flowable forms, 2.5 g/L) and copper oxychloride (4.0 g/L), and with dithianon (wettable powder 5 g/L, or suspension concentrate 5.0 or 7.5 gL). All sprays were applied at greentip, and dithianon was also applied at 10-day intervals for 5 sprays (spring program). Copper treatments were followed, or not, by a spring program of thiram, and all treatments were with or without a following summer program of thiram. Control of black spot (95% fruit with no spot) was not achieved with copper sprays at greentip alone, although control was better than on the unsprayed treatment. All dithianon programs, and cupric hydroxide sprays followed by thiram, controlled black spot. No difference was found between formulations for either cupric hydroxide or dithianon. Copper oxychloride increased the incidence of severe russet to >50% compared with the unsprayed control (28.5%). All other treatments were satisfactory, with similar incidence of russet to the control treatment, and could be used in commercial practices.
Treatment of sweet narrow-leafed lupin crops to reduce phomopsin-induced liver damage (lupinosis) in Merino wether weaners
Authors: Croker KP , Allen JG , Wood PM , Dhaliwal S
Published: March 2005

An experiment was carried out with 4 methods of utilising sweet narrow-leafed lupin crops (unharvested, stubble, cut before leaf drop, cut and conserved as rolls), to compare the development of lupinosis in wether weaners at 2 stocking rates while they were growing during the summer period. Growth of weaners grazed on the cut lupin treatments was greater than on lupin stubbles at both 25 and 50 weaners/ha (grazing period 98 and 63 days, respectively). Weaners grazed on unharvested lupin crops gained the most liveweight at the lower stocking rate; at 50/ha, weaners on unharvested lupin grazed for longer than those in the other 3 treatments (98 v. 63 days). After 63 days of grazing over all lupin treatments, weaners at 50ka had more (P<0.05) liver damage than did those at 25ka. Amongst lupin treatments, weaners given fodder rolls had the least liver damage, whereas those on the stubbles had the most (P<0.05). After 98 days, the weaners grazed at 50ka on the unharvested crop and 25ka on stubble had the most liver damage. Those grazed at 25ka on the unharvested crop or on lupin fodder rolls had very little liver damage. Although fodder rolling of lupins did offer some protection against development of liver damage associated with the intake of phomopsins in lupins, larger liveweight gains were obtained on unharvested lupin crops. Therefore, greater flexibility would be available to farmers by leaving lupin crops to mature before deciding how to use them. This would avoid the cost of preparing fodder rolls, which provided no marked advantage in this experiment.
Persistence and productivity of tropical pasture legumes on three cracking clay soils (Vertisols) in north-eastern Queensland
Authors: Clem RL , Hall TJ
Published: March 2005

There are few commercial legumes available for sowing on the cracking clay soils of northeastern Queensland, where legumes are needed to improve quality of perennial native grass pastures and to arrest nitrogen decline in cropping land. To evaluate introduced legumes from heavy-textured soils, a replicated row experiment was established in 3 environments to assess the adaptation of 56 accessions from 37 species (22 genera). The sites were on 3 dark cracking clay soils supporting the following grasslands: Dichanthium -Bothriochloa- Astrebla; Dichanthium aristatum; and Cenchrus ciliaris on cleared Acacia harpophylla (brigalow) country.The main selection criteria during the 4-year evaluation were persistence, regeneration, production, and spread, with green leaf retention, nutrient concentrations, and pest susceptibility also being considered. The perennial legumes Clitoria ternatea (CPI 47 187 and CPI 49963), Desmanthus virgatus (CPI 78373), Leucaena leucocephala (CPI 61227 and cv. Cunningham), Stylosanthes scabra (CPI 55868), and Indigofera schimperi (CPI 69495), and annuals Centrosema pascuorum (CPI 55697), Desmodium dichotomum (CPI 47 186), and Vigna trilobata (CPI 47510), showed promise as pasture or short-term ley species for these clay soils (Vertisols) in subcoastal, north-eastern Queensland. Other species were identified that require evaluation of a wider range of genetic material. The role of perennial and annual sown legumes in pasture and cropping systems on these cracking clay soils is discussed.
A survey of fallow practices and weed floras in wheat stubble and grain sorghum in northern New South Wales.
Authors: Felton WL , Wicks GA , Welsby SM
Published: March 2005

A survey undertaken in northern New South Wales after the 1989 wheat harvest investigated the effects of cultural practices used by dryland farmers on summer weed flora. Only 50% of fallow paddocks surveyed between December and February were weedfree, and by mid January 65% had inadequate stubble cover (<1000 kg/ha) for protection from soil erosion, mainly because of excessive tillage. By February, only 10% of paddocks were being sprayed with a herbicide to control weeds. Examination of 65 uncultivated fallow wheat stubble paddocks and 25 grain sorghum crops identified 87 and 51 different weed species, respectively. In fallow paddocks where no herbicide had been used, 69 and 61 species were found in ungrazed and grazed paddocks, respectively. Where glyphosate had been used the number of species was 37 (grazed) and 39 (ungrazed), and for glyphosate plus atrazine, 23 and 18 species. The number of weed species found in grain sorghum was 29 for cultivated without atrazine, 35 for cultivated with atrazine, and 35 for no-tillage with atrazine, The most important weeds found in fallow were liverseed grass, native millet, common sowthistle, wireweed, and barnyard grasses. Black bindweed was a problem where atrazine had not been used. Native millet was the most abundant species where atrazine had been applied. In grain sorghum the most common broadleaf weeds for cultivated paddocks with no atrazine treatment were Tribulus spp., Australian bindweed, pigweed, and Bathurst burr, while the most common grass weeds were barnyard grasses, liverseed grass, stinkgrass, and native millet. When cultivation plus atrazine was used, barnyard grasses, native millet, wild oats, and liverseed grass were the most common weeds. In minimum tillage or no-tillage paddocks treated with atrazine, native millet, Queensland blue grass, liverseed grass, common sowthistle, Australian bindweed, and windmill grass were the most common weeds.
Effect of bunch trimming and leaf removal at flowering on maturity bronzing, yield, and other aspects of fruit quality of bananas in North Queensland
Authors: Daniells JW , Lisle AT , Bryde NJ
Published: March 2005

This study examined the effects of bunch trimming and leaf removal on rate of bunch filling, severity of the maturity bronzing fruit peel disorder, and other yield and quality paramaters. There were 4 levels of leaf removal (4, 7, 10, 13 leaves retained) and 4 levels of bunch trimming (male bud retained, male bud removed, male bud and 2 hands removed, male bud and 4 hands removed) imposed on banana bunches at flowering. The experiment was carried out at South Johnstone, North Queensland. The 320 plants in the trial produced a range of fruit-filling rates that were largely unrelated to the imposed treatments. With the exception of the duration of fruit filling and extra large fruit weight, leaf removal and bunch trimming acted independently on the attributes measured. Leaf removal reduced maturity bronzing and bunch trimming increased it. Increased bronzing was associated with increased finger length, possibly due to epidermal cells in the fruit peel elongating beyond their elastic limit. Bunch trimming reduced bunch weight and but did not improve the quantity of extra large fruit. Leaf removal reduced bunch weight when <10 leaves remained, due largely to a reduction in finger length throughout the bunch. Fruit greenlife was also reduced by leaf removal. Therefore, the reduction in maturity bronzing achieved by leaf removal is of no immediate benefit to growers. Removal of the male bud increased bunch weight due to an increase in finger length. Dry weight analysis indicated that the male bud represented a significant competing photosynthetic sink. For maximum yield of quality fruit, growers should remove the male bud, practice no bunch trimming, and ensure the retention of at least 9-10 leaves from flowering to harvest.
Growth, yield, and fruit quality of two non-astringent persimmon (Diospyros kaki) cultivars, Izu and Fuyu, in subtropical Australia
Authors: George AP , Collins RJ , Nissen RJ
Published: March 2005

Growth, yield, and fruit quality of 2 non- astringent persimmon (Diospyros Inaki) cultivars, Izu and Fuyu, were evaluated under subtropical conditions of coastal Australia. Although maximum tree yields for Izu and Fuyu were high (24 and 37 t/ha, respectively) the percentage of fruit suitable for export was low and variable (range: Izu 8.547%; Fuyu 2844%). Main fruit quality defects were wind rub, petal adherance marks, fruitfly stings, calyx cavity, sunburn, and bird damage. Without fruit thinning, both cultivars were susceptible to overcropping in some seasons, which resulted in a high percentage (>40%) of small fruit (<150 g). Most fruit (80% for Izu and 90% Fuyu) had Brix levels higher than the recommended export standard of 14�.
Heat stress in cattle and the effect of shade on production and behaviour: a review
Authors: Blackshaw JK , Blackshaw AW
Published: March 2005

At high temperatures, evaporative cooling is the principal mechanism for heat dissipation in cattle. It is influenced by humidity and wind speed and by physiological factors such as respiration rate, and density and activity of sweat glands. Following exposure to heat, cattle appear to acclimatise within 2-7 weeks. The failure of homeostasis at high temperatures may lead to reduced productivity or even death. Knowledge of characteristic behavioural signs of increasing heat stress may alert cattle handlers to impending heat distress, particularly in areas of potential climatic extremes of high temperatures and humidities. Reduction of the heat increment of feeding by dietary manipulation may partially protect cattle from forecast heat stress. Under high heat stress, Bos indicus breeds and their crosses have better heat regulatory capacities than Bos taurus breeds, due to differences in metabolic rate, food and water consumption, sweating rate, and coat characteristics and colour. Also, because Bos taurus have a higher heat loading at the skin, they must evaporate substantially more sweat than Bos indicus to maintain normal body temperatures. Welfare concerns exist about heat stress and the provision of shade for feedlot cattle. In hot weather, cattle actively seek shade, which may reduce the radiant heat load by 30% or more. Under conditions of extreme heat load, shading may maintain production and reduce deaths from heat stroke. Shading of feed and water also offers production advantages for British and European breeds of cattle.
Effect of level of concentrate fed once or twice daily on the milk production of cows grazing tropical pasture
Authors: McLachlan BP , Ehrlich WK , Cowan RT , Davison TM , Silver BA , Orr WN
Published: March 2005

A group of 40 Holstein-Fresian cows grazing tropical pastures were supplemented from 14 days after calving with a grain-based concentrate containing 15% protein. Concentrate was given at nil, 2, 4, 6, and 8 kg/cow. day fed once daily after morning milking, and 4, 6, and 8 kg/cow.day in 2 equal feeds, after morning milking and before evening milking. The experimental period was 250 days for cows fed once daily and 150 days for those fed twice daily. Over 250 days of lactation, the milk yield of cows fed once daily was significantly increased with increasing grain feeding, from 12.8 kg/day for the nil group t o 20 kg/day for the 8 kg group. Milkfat percentage was lower (P<0.05) for cows given 8 kg grain concentrate daily than for those given 2-4 kg, and total fat yield increased (P<0.1) with up to 4kg/cow.day. Protein percentages were similar across treatments, and protein yield increased (P<0.05) with grain level. Lactose percentage was increased (P<0.05) with concentrate feeding, and lactose yield increased (P<0.05) with increasing concentrate level. Fat-corrected milk (FCM) increased (P<0.05) from 3046 kg at nil concentrate to 4465 kg at 8 kg/cow. day. Over the first 150 days of lactation, milk yield increased from 19.5 kg/day for cows fed once daily to 21.7kg/day for those fed twice daily. Milkfat and protein percentages were similar. Greatest responses to twice-daily feeding occurred at 6 kg concentrate/cow.day. It was concluded that total milk yield increased linearly to 8 kg concentrate/cow.day, but FCM yield was at a maximum at 6 kg concentrate1cow.day. There were advantages in feeding 6 kg concentrate twice daily.
Effect of lithium chloride intake in drinking water on bulls fed lucerne hay
Authors: O'Kelly JC , Spiers WG
Published: March 2005

Four experiments were conducted to examine the effects of administering lithium chloride (LiCl) in a portion of the drinking water on feed intake and blood electrolytes of bulls fed lucerne hay at either restricted intake or ad libitum. In Hereford bulls on restricted intake, LiCl at 1 mmol/kg LW. day caused gross inappetence when given dissolved in 1 L water, but did not affect feed intake when given dissolved in a larger volume of water (10 L). This volume was subsequently used for administration of all doses of the salt. Lithium chloride (1 mmol/kg LW. day) given for 5 days to Hereford bulls on restricted intake did not affect body temperature or haematocrit. Lithium concentrations (mmol/L) of 0.62 and 0.31 were established in plasma and red blood cells, and Li+ was excreted at the rate of 14.2 mmol/L urine. Lithium chloride (0.5 mmol/kg LW. day) given for 30 days to Brahman bulls on either restricted intake or ad libitum feeding established Li+ concentrations (mmol/L) of 0.31 in plasma and 0.16 in red blood cells without altering blood concentrations of Na+ or K+. However, lithium treatment of bulls on ad libitum feeding caused a 10% reduction in feed intake, with an associated 15% decrease in liveweight gain. It is proposed that reduction in feed intake due to lithium treatment of bulls on ad libitum feeding was mediated through the calming effect of the drug decreasing eating activity.
Measuring supplement intake in the field using ytterbium as a marker
Authors: Curtis KMS , Holst PJ , Murray PJ
Published: March 2005

Two experiments were conducted: pen experiment 1, to determine the distribution of the recovery over time of ytterbium (Yb) for diets with high and low dry matter digestibility; field experiment 2, to measure lupin seed intake using Yb as a marker. The diets in experiment 1 consisted of wheaten chaff plus lupins in the following amounts (g): 700 + 0,525 + 175, 175 + 525. The marker was applied using an adhesive solution made with methyl cellulose to which Yb acetate had been added. Total faecal collections were made for at least 5 days following feeding with the marked supplement. Mean retention time of Yb was not affected by diet in experiment 1. Estimated average lupin seed intake in experiment 2 was slightly less (9.5%) than expected from the difference between that offered and refused. Possible reasons for this difference include losses during handling (1.3%) and incomplete recovery (2.9%). It is concluded that the technique is suitable for estimating intake of lupin seed by sheep grazing in a group. A less laborious technique using faecal grab samples instead of total collections was evaluated and found to be unsuitable for estimating individual or group intakes. Faecal grab samples could be used to rank individuals on supplement intake.
Effect of superphosphate, or its component elements (phosphorus, sulfur, and calcium), on the grazing preference of steers on a tropical grass-legume pasture grown on a low phosphorus soil
Authors: Jones RJ , Betteridge K
Published: March 2005

A Stylosanthes-based mixed tropical grass-legume pasture, grown on a phosphorus (P) deficient (<5 �g/g of available P) yellow earth soil near Townsville, north-eastern Queensland was used to assess the effects of fertiliser application on grazing preference. Unfertilised plots and plots fertilised with Pssulfur (S)+calcium (Ca) (superphosphate), P+S+Ca+sodium (Na), P+Ca+Na, P+S+Na, P+Na, P+Ca, S+Ca, S+Na, and S+Ca+Na were grazed by steers, and the grazing pattern was observed. Steers preferred plots fertilised with P (P+) in both autumn (May) and summer (February); no preference was shown for plots fertilised with S, Ca, or Na, or mixtures of these, compared with unfertilised control plots. Although P+ plots had higher herbage yields than plots not fertilised with P (P0), removal of the effects of yield and of P concentration in the herbage by covariance analysis at the May grazing still resulted in large significant (P<0.01) differences in grazing preference between the P treatments. Furthermore, there was no correlation (r2 = -0.024 to +0.072) between yield and grazing preference within either the P+ or P0 treatments.
Evaluation of wax to extend the postharvest storage life of honeydew melons (Cucumis melo L. var. inodorus Naud
Authors: Edwards M , Blennerhassett R
Published: March 2005

This experiment evaluated Citruseal wax at 50 and 80% (v/v wax/water) for effects on storage life on Honeydew melons (Cucumis melo L. var. inodorus). Waxing reduced weight loss after 4 and 6 weeks storage at 3�C and 6�C and chilling injury at 3�C. Waxing did not reduce breakdown caused by bacteria or fungi (largely Alternaria and Fusarium spp.) at 3�C. These results indicate that diluted Citruseal wax can be used to reduce water loss and chilling injury at low temperatures.
Thyroid hormone concentrations in the plasma of fed and fasted Brahman and Hereford steers
Authors: O'Kelly JC , Spiers WG
Published: March 2005

Plasma concentration patterns of thyroxine (TJ, free T4 (FT4), triiodothyronine (T3), and free T3 (FT3) were determined in Brahman steers fed lucerne hay ad libitum and in Brahman and Hereford steers fed restricted intakes of lucerne hay at the rate of either 208 g/h before fasting for 72 h or 250 g/h before fasting for 96 h. In Brahmans fed ad libitum, the plasma concentrations of all thyroid hormone fractions were significantly (P<0.01) correlated with one another and with feed intake. Within breeds, the concentrations of thyroid hormones were higher (P<0.001) when animals were fed at 250 g k than at 208 g/h. During both hourly feeding regimes T4, FT4, T3, and FT3 concentrations were higher (P<0.001) in Brahmans than in Herefords. Fasting after both hourly feeding regimes lowered (P<0.001) the concentrations of T4 about 53% in Brahmans and 30% in Herefords, while FT4, T3, and FT3 were lowered about 68% in Brahmans and 50% in Herefords. Consequently, thyroid hormone concentrations were significantly lower in Brahmans than in Herefords after 72 h fasting but did not differ significantly between breeds after 96 h fasting. The present results, together with those of our previous work showing breed differences in rumen metabolism, support the concept that, in Hereford and Brahman steers fed the same amount of hay in a thermoneutral environment, breed differences in plasma concentrations of thyroid hormones originate from quantitative differences in the supply of nutrients from the rumen to body tissues.
Production and heart rate responses of chickens beak-trimmed at hatch or at 10 or 42 days of age
Authors: Glatz PC , Lunam CA
Published: March 2005

Heart rate was monitored before and after beak trimming in restrained chickens to measure responses to beak trimming at hatch and at 10 and 42 days of age. Immediately after trimming chickens sham-trimmed (control) and trimmed at 10 and 42 days of age had an increase in heart rate, with the 42-day-old chickens showing the greater change. Chickens sham-trimmed and trimmed at hatch showed no change in heart rate. No difference between trimmed and sham-trimmed chickens occurred at any age for heart rate response. These data indicate that heart rate at trimming may be inadequate as a measure of the stress response associated with beak trimming, especially with the concurrent stressors of handling and restraint. Beak trimming and handling of chickens at hatch is either less stressful than trimming at 10 and 42 days of age, as indicated by the lack of a heart rate response, or heart rate is already at a maximum in chickens at hatch, due to stress associated with hatching. Food intake and body weight were measured for 3-4 weeks after trimming to assess the longer term effects of age and level of trimming on performance of the chicken. Removal of 3 mm of beak at hatch or 4.5 mm at 10 days of age depressed feeding levels and a reduced body weight, indicative of a chronic stress associated with beak trimming.