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1
McGregor, B. A., e W. D. English. "Gross margins in Australian mohair enterprises and relationships with farm inputs, productivity and mohair quality". Animal Production Science 50, n. 6 (2010): 573. http://dx.doi.org/10.1071/an09224.
Testo completoAbstract (sommario):
In the absence of financial information on Australian mohair enterprises we aimed to determine the gross margins (per dry sheep equivalent, DSE) and their relationships with farm inputs, productivity and mohair quality in Australian mohair enterprises. Using established Victorian Farm and Sheep Monitor Project protocols we collected data for the financial years 2004–05, 2005–06 and 2006–07 from farmers in south-eastern Australia and made comparisons with data from wool enterprises of similar farm area. Over 3 years the financial returns from mohair exceeded that from wool in terms of $/DSE ($23.0 v. 11.3) and $/ha ($132 v. $116). This result was achieved despite the mohair enterprises grazing their goats far less intensively compared with the grazing intensity of sheep (5.9 v. 10.3–11.1 DSE/ha) and by using far less phosphate fertiliser than used in the wool enterprises (2.2 v. 4.6–6.1 kg P/ha). These differences were counterbalanced by higher prices for mohair compared with fine wool ($13.15/kg v. $8.35/kg clean fibre). Gross margin for the mohair enterprise did not increase as stocking rate increased. Income from mohair sales declined as the proportion of does in the flock increased. Increasing the proportion of does in the flock was associated with a decline in the average price of mohair ($16/kg greasy at 42% does to $8/kg greasy at 83% does in the flock). This decline was closely associated with the increasing proportion of the total amount of mohair coarser than 34.0 µm (either fine hair or hair) plus stained mohair. The variation in profitability between farms indicates significant scope for many mohair enterprises to increase profit. A focus on producing finer quality mohair will increase mohair profitability.
2
James, PJ, RW Ponzoni, JRW Walkley e KJ Whiteley. "Genetic parameters for wool production and quality traits in South Australian Merinos of the Collinsville family group". Australian Journal of Agricultural Research 41, n. 3 (1990): 583. http://dx.doi.org/10.1071/ar9900583.
Testo completoAbstract (sommario):
Heritabilities and phenotypic and genetic correlations for fleece traits were estimated from a data set comprising 805 male and female progeny of 44 sires of the Collinsville family group. Characteristics included in the study were greasy and clean fleece weight, yield, mean, standard deviation and coefficient of variation of fibre diameter, resistance to compression, scoured and greasy wool colour (expressed as yellowness, lightness and yellowness index), wax content, suint content, and subjectively assessed scores for greasy colour, character, handle, quality number, condition, staple formation, tip formation and density. Heritabilities of greasy and clean fleece weight, yield, mean fibre diameter and subjectively assessed fleece scores were in broad agreement with estimates from other Merino strains, but the genetic correlations of mean fibre diameter and associated characters (handle, quality number) with clean fleece weight were lower than previous estimates. Heritabilities for scoured yellowness of wool, resistance to compression and coefficient of variation of fibre diameter, which are potential additional measurements for the specification of wool in sale lots, were 0.42 (�. 0.14), 0.57 (� 0.15) and 0.47 ( � 0.15) respectively. Estimated heritabilities of wax and suint content were 0.24 (�0.11) and 0.44 ( � 0.14). Although the phenotypic correlations between measures of greasy wool colour and the corresponding measures of scoured wool colour were low (less than 0.3), the genetic correlations were moderate to high (0.4-0.9). Thus selection on the basis of greasy wool colour should lead to genetic improvements in scoured colour. The genetic correlations of resistance to compression with clean fleece weight and fibre diameter were: 0.46 (�0.21) and 0.44 (� 0.20) respectively, but there were no other strong, unfavourable correlations.
3
Li, G. D., K. R. Helyar, M. K. Conyers, L. J. C. Castleman, R. P. Fisher, G. J. Poile, C. J. Lisle, B. R. Cullis e P. D. Cregan. "Pasture and sheep responses to lime application in a grazing experiment in a high-rainfall area, south-eastern Australia. II. Liveweight gain and wool production". Australian Journal of Agricultural Research 57, n. 10 (2006): 1057. http://dx.doi.org/10.1071/ar05299.
Testo completoAbstract (sommario):
‘Managing Acid Soils Through Efficient Rotations (MASTER)’ is a long-term pasture–crop rotation experiment commenced in 1992. One of the objectives was to demonstrate the extent of crop, pasture, and animal responses to lime application on a typical acidic soil in the 500–800 mm rainfall zone of south-eastern Australia. Two types of pastures (perennial v. annual pastures) with or without lime application were established in 1992. Fifteen- to eighteen-month-old Merino hoggets were used as test animals and were changed annually. This paper reports the results of sheep responses to liming from the 4 continuous pasture treatments over 6 years from 1992 to 1997. The stocking rate was the same on all plots within a treatment during each rotation period, but was varied between treatments based on the pasture availability and sheep body condition. The most important findings from this study are that the limed treatments carried 29% and 27% more stock (up to 4 DSE/ha) than the unlimed treatments for perennial and annual pastures, respectively. As a result, the limed perennial pastures produced 27% more liveweight gain (62 kg/ha.year) and 28% more greasy wool (13 kg/ha.year) than unlimed perennial pastures, whereas the limed annual pastures produced 34% more liveweight gain (77 kg/ha.year) and 24% more greasy wool (11 kg/ha.year) than unlimed annual pastures. The significant responses to lime in liveweight and wool production were detected from the second growing season after the pastures were established. The increased sheep productivity on the limed treatment was due to a combination of increased pasture production and improved pasture quality. Perennial pastures showed a slight advantage in wool production, but not in liveweight gain. However, the seasonal variation of liveweight was greater on annual pastures than on perennial pastures. The larger variation in liveweight change could lead to more adverse effects on wool quality especially at high grazing pressures. Grazing management can be used to manipulate pasture and animal productivity to increase profits from lime use.
4
Bell, Stephen. "Aimé Bonpland and Merinomania in Southern South America". Americas 51, n. 3 (gennaio 1995): 301–23. http://dx.doi.org/10.2307/1008225.
Testo completoAbstract (sommario):
As an integrating theme in the biological or ecological expansion of Europe, merino sheep were so important that one authority on their dispersal sees the nineteenth century standing as “the century of the Merino.” Merinos produce a wool of distinctive quality, one long appreciated for providing warmth without excessive weight. Guarded for centuries by Spanish monopoly, the breed's status as something of a prize outside Spain began to change in 1808 with the Napoleonic invasion of the Iberian peninsula. By around 1820, a major new phase in merino dispersal was underway with its adaptation to some of the vast grassland ecosystems in the Europeanizing peripheries. The breed was of critical importance to the settlement and development of Australia. It was also highly important in other parts of the southern hemisphere, including in the transformation of existing cattle cultures on the great grassland regions of the Río de la Plata. Here the merino formed the leading edge of rural modernization, offering real potential for ground-up development.
5
Trompf, J. P., e P. W. G. Sale. "The paired-paddock model as an agent for change on grazing properties across south-east Australia". Australian Journal of Experimental Agriculture 40, n. 4 (2000): 547. http://dx.doi.org/10.1071/ea00046.
Testo completoAbstract (sommario):
A detailed study was undertaken on the pasture management practices of 146 producers across south-east Australia who participated in the Grassland’s Productivity Program (GPP) for 3 years between 1993 and 1997. The GPP was an extension program to assist wool producers to develop skills and gain confidence in their ability to manage more productive pastures on their farms. The program consisted of 50 farmer groups (200 farmers participating) spread across the 4 states of South Australia, southern New South Wales, Victoria and Tasmania. Each farmer established paired-paddocks on their own property to compare productive pastures with existing pastures. Productive pastures involve increased rates of fertiliser on pastures containing productive species, with stocking rate adjusted to consume available pasture. After 3 years of involvement in the GPP, there was a whole-farm increase in P fertiliser use by 6.3 kg P/ha, stocking rates by 2.6 dse/ha and annual pasture resowing by 0.9% of the farm, when averaged across the 146 participants. The participants were applying the productive pasture technology to almost a third of their properties in 1997 and the intention was to increase this to over half of their properties by 2000. The participants also changed farm management practices as the program effectively developed management skills. There were increases in the ability to assess pasture quality and quantity, livestock by weighing or physical assessment, and the ability to calculate per hectare production and per hectare gross margins. A high proportion of GPP participants were soil testing (0.92) and spring lambing (0.72) at the completion of the program. The results indicated that the adoption of productive pastures was generally consistent across south-east Australia for pastoral producers who participated in this program, although south-west Victorian and south-east South Australian GPP participants did increase whole-farm P application by more than GPP participants from outside that region. The widespread change in farming practice was attributed to the additive and interactive effect of the paired-paddock comparison, the guidance provided by the facilitator, the group interaction and the skills training. Each of these components of the paired-paddock model combined to form an effective agent for change to increase pasture productivity on these grazing properties.
6
Cottle, D., C. A. Gaden, J. Hoad, D. Lance, J. Smith e J. M. Scott. "The effects of pasture inputs and intensive rotational grazing on superfine wool production, quality and income". Animal Production Science 53, n. 8 (2013): 750. http://dx.doi.org/10.1071/an12289.
Testo completoAbstract (sommario):
A farmlet experiment was conducted between July 2000 and December 2006 as part of the Cicerone Project, which sought to enhance the profitability and sustainability of grazing enterprises on the Northern Tablelands of New South Wales, Australia. A self-replacing Merino enterprise was grazed as the dominant livestock enterprise, together with ~20% of the carrying capacity as cattle, on each of three farmlet treatments: higher levels of soil fertility and pasture renovation with flexible rotational grazing over eight paddocks (farmlet A), moderate soil fertility and pasture renovation with flexible rotational grazing over eight paddocks (farmlet B) and moderate soil fertility and pasture renovation with intensive rotational grazing over 37 paddocks (farmlet C). Prior to commencement of the trial, the three 53-ha farmlets were allocated equivalent areas of land based on soil type, slope and recent fertiliser history. This paper describes the effects of the three pasture and grazing management strategies on the production, quality and value of the wool produced per head, per ha and per farmlet. Up until 2001 there were no differences in wool production between farmlets. Thereafter, significant differences between farmlets emerged in greasy fleece weight per head and price received per kg of fleece wool. For example, the clean fleece value averaged over the 2003–05 shearings for all hoggets, ewes and wethers was 1531, 1584 and 1713 cents/kg for farmlets A, B and C, respectively. There were small but significant differences, which varied between sheep class and year, between the farmlets in average fibre diameter and staple length but less so with staple strength. In general, while the differences between farmlets in staple strength varied over time, farmlets A and B tended to have wool with longer staple length and broader fibre diameter than farmlet C and this affected wool value per kg. Differences in wool income per ha between farmlets grew in later years as the farmlet treatments took effect. In spite of farmlet A having a slightly lower wool value per kg, after taking into account its greater fleece weight per head and its higher stocking rate, the total wool income per ha was higher than on either farmlets B or C. The average gross wool income per ha from 2003 to 2005 was $303, $215 and $180 for farmlets A, B and C, respectively. The highest amount of greasy wool produced was in 2004 when 38.2, 26.5 and 21.5 kg/ha was harvested from farmlets A, B and C, respectively. The fibre diameter profiles of 2-year-old ewes showed similar profiles for farmlets A and B but a significantly finer fibre diameter profile for farmlet C ewes due to intensive rotational grazing. However, sheep on all three farmlets produced wool with high staple strength. Multivariate analyses revealed that greasy fleece weight, staple length and staple strength were significantly positively correlated with the proportion of the farm grazed at any one time, and with soil phosphorus, legume herbage and green digestible herbage thus highlighting the significant influence of pasture and soil inputs and of grazing management on wool production and quality.
7
Ayres, J. F., M. J. McPhee, A. D. Turner e M. L. Curll. "The grazing value of tall fescue (Festuca arundinacea) and phalaris (Phalaris aquatica) for sheep production in the northern tablelands of New South Wales". Australian Journal of Agricultural Research 51, n. 1 (2000): 57. http://dx.doi.org/10.1071/ar99080.
Testo completoAbstract (sommario):
The grazing value of phalaris–white clover and tall fescue–white clover pastures was compared in a temperate summer-rainfall environment in the high rainfall zone of eastern Australia. Data were derived from an experiment which evaluated pasture cultivars when grown in binary mixtures and grazed by sheep. The data were also simulated with the decision support system SheepO (Version 4.0) and validated by visual techniques, deviance measures, and statistical tests. The model generally simulated green biomass, liveweight gain, and clean fleece weight with acceptable accuracy. Pasture based on tall fescue–white clover produced more green pasture biomass in all seasons, in all years, and at both low (10 sheep/ha) and high (15 sheep/ha) stocking rates when compared with phalaris–white clover. Sheep grazing tall fescue–white clover pasture were turned off about 5 kg heavier each year and produced about 0.6 kg/head more clean fleece weight; the wool production per head of sheep grazing tall fescue–white clover at 15 sheep/ha was similar to that for sheep grazing phalaris–white clover pasture at 10 sheep/ha. These differences in wool production were accompanied by consistent effects on wool quality; the fleeces of sheep grazing tall fescue–white clover pasture were markedly sounder in tensile strength but broader in fibre diameter. These data and the SheepO simulations highlight the potential for pasture cultivars with enhanced seasonal growth and nutritive value to alleviate feed-gaps and improve the feed-base for grazing animals.
8
Thorn, CW, e MW Perry. "Effect of chemical removal of grasses from pasture leys on pasture and sheep production". Australian Journal of Experimental Agriculture 27, n. 3 (1987): 349. http://dx.doi.org/10.1071/ea9870349.
Testo completoAbstract (sommario):
Pasture production, pasture composition and quality, and liveweight, body condition and wool growth of Merino weaner wethers were monitored over 2 seasons and at 2 stocking rates (4 and 8 sheep/ha) on a mixed annual grass-legume pasture sprayed with propyzamide to control grasses. Propyzamide virtually eliminated annual grasses from the pasture (less than 5 kg/ha of grass dry matter in spring v. 403 kg/ha on untreated pasture in 1981) and this carried over into the second season (61 kg/ha v. 647 kg/ha in spring 1982). Propyzamide treated pastures had less total dry matter (P = 0.05) throughout 1981: however, except for a single sample date, there was no effect of propyzamide on total available pasture in the second season. Increased growth of clover and capeweed compensated for the absence of the grasses. The higher stocking rate reduced available clover, capeweed and total dry matter (P = 0.05) throughout both years. Sheep grazing grass-free pastures had lower liveweights during winter in both years, but made compensatory gains during late spring and summer consistent with the higher quality (1.6 v. 1.07% nitrogen when sampled in January) of propyzamide treated pastures. In 198 1, wool growth rates were reduced at the higher stocking rate and total clean wool production was reduced from 4.55 kg/sheep at 4/ha to 3.65 kg/sheep at 8/ha. Pasture treatment had no effect on wool production in either year. The implications of using selective herbicides to remove the annual grass component of legume-based annual pastures in south-western Australia are dis cussed in relation to pasture and sheep production.
9
Edwards, J. E. Hocking, K. J. Copping e A. N. Thompson. "Managing the nutrition of twin-bearing ewes during pregnancy using Lifetimewool recommendations increases production of twin lambs". Animal Production Science 51, n. 9 (2011): 813. http://dx.doi.org/10.1071/an09158.
Testo completoAbstract (sommario):
The effect on ewe and lamb production by differential management of single- and twin-bearing Merino ewes during pregnancy and lactation was examined. The hypothesis that the survival and productivity of single- and twin-born progeny is not affected by differential management of single- and twin-bearing ewes was tested. To test this hypothesis, two ewe flocks were monitored on a commercial property in the south-east of South Australia. The body condition score of one flock of ewes was managed according to Lifetimewool recommendations for southern Australian (Lifetimewool flock; n = 464). Lifetimewool recommendations are that body condition score should be 3.0 at mating and then allowed to decline to an average of 2.7, which is maintained until lambing. Twin- and single-bearing ewes were managed as separate mobs after pregnancy scanning to meet their energy requirements. The second flock was managed similarly to the commercial ewe flock and was representative of ewe management practices in the region (normal-practice flock; n = 464). At lambing, the condition score of the Lifetimewool flock was 0.7 condition scores units greater than the normal-practice flock. Ewe clean fleece weight and fibre diameter were greater in the Lifetimewool flock and their lambs had higher survival rates to weaning. Over three shearings, progeny from Lifetimewool ewe flocks produced more clean wool (P < 0.0001) but there was no consistent effect on fibre diameter, staple length or staple strength. Twin-born lambs from ewes managed to Lifetimewool guidelines had a similar liveweight and produced similar quantity and quality of wool to single-born lambs managed to Lifetimewool guidelines, but still suffered higher rates of mortality to weaning. This suggests that it is possible to manage ewes pregnant with twins to ensure that their surviving progeny perform at a level similar to single-born progeny managed under similar targets.
10
Raymond, Carolyn A. "Influence of prior land use on wood quality of Pinus radiata in New South Wales, Australia". Forest Ecology and Management 255, n. 7 (aprile 2008): 2626–33. http://dx.doi.org/10.1016/j.foreco.2008.01.020.
Testo completo
11
Scott, B. J., A. M. Ridley e M. K. Conyers. "Management of soil acidity in long-term pastures of south-eastern Australia: a review". Australian Journal of Experimental Agriculture 40, n. 8 (2000): 1173. http://dx.doi.org/10.1071/ea00014.
Testo completoAbstract (sommario):
Acidification of non arable soils under long-term pasture presents a major agricultural problem in the high rainfall areas (≥600 mm/year) of central and southern New South Wales and north-eastern Victoria. Some of these soils were already strongly acid to depth before agriculture. Evidence suggests that persistence of pasture species tolerant of acidic soils is being affected adversely on a number of severely acidic soils. Acidification processes are well understood but the capacity for grazing enterprises to pay for amendment by lime application is a major constraint in long-term pasture areas. In addition, soil acidification is likely to have substantial off-site effects on water quantity and quality and as a result, on dryland salinity. However, there is a paucity of scientific evidence to link soil acidity and dryland salinity in this way. Production from a grazing enterprise can be maintained by selecting plants for tolerance of acidity, surface application of lime or a combination of both. Responses by subterranean clover, lucerne and perennial grass (mainly phalaris and cocksfoot)-based pastures to incorporated lime are reported, but there is limited evidence of responses to surface applied lime. The movement of the lime effect into the soil from surface application is suggested as a major factor in controlling lime responses by plants. There is a need for more confidence in the benefits of topdressed lime in non arable soils before producers are likely to adopt the practice. High subsurface acidity in many soils is a major limitation to the range of species that can be grown. In the longer term, the use of lime may remove constraints on the use of productive species such as lucerne. Other options for acidic soils where slope is less than 10% are for the grazing system to be modified or intensified, or for crop or horticultural production. Costs of lime could be justified through more profitable enterprises than traditional grazing operations. Low input systems based on native grasses are intrinsically appealing, however, this is only possible where a premium is paid for such produce (such as super fine wool). Forestry is an option where suitable land and infrastructure are present and should slow soil acidification and minimise off-site impacts. Land retirement may be a useful option for some parts of the landscape that contribute disproportionately to environmental problems. Private and government funded land retirement may have a role to play.
12
Hung, Tran D., Jermey T. Brawner, David J. Lee, Roger Meder e Mark J. Dieters. "Genetic variation in growth and wood-quality traits ofCorymbia citriodorasubsp.variegataacross three sites in south-east Queensland, Australia". Southern Forests: a Journal of Forest Science 78, n. 3 (30 maggio 2016): 225–39. http://dx.doi.org/10.2989/20702620.2016.1183095.
Testo completo
13
Lakota, E. А. "PRESERVATION OF GENETIC POTENTIAL OF STAVROPOL SHEEP BREED FOR POVOLZHYE DREY STEPPE ZONE". Vestnik of Ulyanovsk state agricultural academy, n. 3(50) (8 settembre 2020): 179–84. http://dx.doi.org/10.18286/1816-4501-2020-3-179-184.
Testo completoAbstract (sommario):
In conditions of Povolzhye steppe zone development of productive qualities of Stavropol breed sheep was conducted by meat merino sheep. Experimental research was carried out in ZAO «Novaya Zhizn» in Novouzensky district of Saratov region, located in semi desert zone, bordering upon South-West Khazakhstan. The research aim was the increase and maintenance of genetic potential of Stavropol breed sheep of Povolzhye population. Working procedure is based on guidelines of the All-Union Academy of Agricultural sciences, All Union research institute of sheep and goat breeding. The study materials were Stavropol pure breed sheep and 1/8 –thoroughbred cross breed with Australian meat merino herdmates. As the result of stepped breeding of local Stavropol ewe with half bred by Australian meat merino ram- breeder of Stavropol breed animals of 1/2 ,1/4, 1/8 –blood were obtained, which then one- shear tupped by breeding «inter se». It is proved that in applying such selective method 1/8-blood by Australian meat merino sheep were characterized with higher body weight, better wool quality in contrast to Stavropol pure –breed herdmates. So, in 1/8-blood by Australian meat merino of hybrid ewe during breeding «inter se» live body at birth was higher than at pure breed herdmates for 5,56 %, during ablactation –at the age of 4 months - for 6,38 % (difference isn’t accurate). According to sharing of wool in grease, superiority of ewe of hybrid origin over pure breed was 5,6 % (Р≥0,99), but in terms of washed fiber it increases to 8,3 % (Р≥0,999). So, in dry steppe zone of Povolzhye new improved, according to its productive qualities, genotype of Stavropol breed sheep is created with retention of genetic resource that is essential economic factor for the modern maintenance of fine-wool sheep breeding field.
14
McGrath, S. R., R. Behrendt, M. A. Friend e A. D. Moore. "Utilising dual-purpose crops effectively to increase profit and manage risk in meat production systems". Animal Production Science 61, n. 11 (2021): 1049. http://dx.doi.org/10.1071/an20495.
Testo completoAbstract (sommario):
Dual-purpose cropping (sowing crops with the intention of both grazing them during vegetative growth and harvesting grain thereafter) has become a widespread farming practice in southern Australia. This synopsis paper integrates research from a multi-institutional research project conducted at three nodes located near Hamilton (south-western Victoria), Wagga Wagga (southern NSW) and Canberra (ACT), and sets out 11 principles for the effective utilisation of dual-purpose crops in meat production systems to increase profit and manage risk. Dual-purpose crops can be used to overcome feed quality gaps in late summer–autumn or feed quantity gaps in late autumn/winter. They provide large quantities of high-quality forages for grazing in summer, autumn and winter and can provide a substantial contribution to the annual number of grazing days on a farm. Utilisation of the high-quality dry matter provided by dual-purpose crops is most effective when directed at young growing stock for sale or future reproduction rather than reproducing adult ewes. For example, sale weight of yearlings per ewe was increased by 16% in systems at the Canberra node when dual-purpose crops were prioritised for grazing by weaners. Wool production was also increased in systems that included grazing of dual-purpose crops. Grazing crops in winter does not necessarily reduce supplementary feeding costs for winter or spring lambing. Modelling suggests that inclusion of dual-purpose crops does not substantially change the optimum time of lambing for sheep meat systems. Financial analysis of the experimental data from the Canberra node showed that although cash expenses per hectare were increased in the crop-grazing systems, the overall profitability of those systems over the life of the experiment was greater by AU$207/ha.year than that of the pasture-only system. Factors driving improved profitability included income from grain, higher income from meat and wool, and lower supplementary feeding costs. However, increasing the area sown to crop from 10% to 30% of the farm area in this Southern Tablelands system appeared to increase risk. In south-western Victoria, spring-sown canola carried risk similar to or less than other options assessed to achieve ewe-lamb mating weight. It is likely that at least part of the reduction in risk occurs through the diversification in income from the canola produced as part of the system. It was concluded that the grazing of cereal and canola crops for livestock production can be profitable and assist in managing risk.
15
Midgley, S. J., e J. W. Turnbull. "Domestication and use of Australian acacias: case studies of five important species". Australian Systematic Botany 16, n. 1 (2003): 89. http://dx.doi.org/10.1071/sb01038.
Testo completoAbstract (sommario):
Some Acacia species native to Australia and neighbouring countries are significant in the rural economy of many countries. Aspects of the domestication process and uses of A. mangium, A. crassicarpa, A. mearnsii, A.�saligna and A. colei are reviewed. Commercial plantations of A. mearnsii in tropical highlands and temperate areas provide high quality tannins for adhesives and leather making and wood for paper pulp, rayon, charcoal and small-utility timbers. Plantations of A. saligna in warm-temperate and semi-arid areas provide stock fodder, soil stabilisation, fuelwood and charcoal. In the humid tropical lowlands of South-east Asia, pulpwood is produced in extensive plantings of A. mangium and in smaller-scale plantations of A. crassicarpa in Indonesia. The human food value of seeds of some dry-zone Australian acacias, such as A. colei, is recognised. Domestication of these and other Australian acacias is at various stages and is influenced by the characteristics of the species, extent of planting and the commercial value of the products. The potential for many acacias to become weeds is recognised. The case studies highlight a number of important aspects in domesticating acacias.
16
Scott, J. M., K. Behrendt, A. Colvin, F. Scott, L. M. Shakhane, C. Guppy, J. Hoad et al. "Integrated overview of results from a farmlet experiment which compared the effects of pasture inputs and grazing management on profitability and sustainability". Animal Production Science 53, n. 8 (2013): 841. http://dx.doi.org/10.1071/an12284.
Testo completoAbstract (sommario):
The Cicerone Project conducted a grazed farmlet experiment on the Northern Tablelands of New South Wales, Australia, from July 2000 to December 2006, to address questions raised by local graziers concerning how they might improve the profitability and sustainability of their grazing enterprises. This unreplicated experiment examined three management systems at a whole-farmlet scale. The control farmlet (farmlet B) represented typical management for the region, with flexible rotational grazing and moderate inputs. A second farmlet (farmlet A) also used flexible rotational grazing but had a higher level of pasture renovation and soil fertility, while the third farmlet (farmlet C) had the same moderate inputs as farmlet B but employed intensive rotational grazing. The present paper provides an integrated overview of the results collated from component papers and discusses the inferences that can be drawn from what was a complex, agroecosystem experiment. The measurements recorded both early and late in the experiment were tabulated for each of the farmlets and compared with each other as relative proportions, allowing visual presentation on a common, indexed scale. Because of equivalent starting conditions, there was little difference between farmlets early in the experimental period (2000–01) across a wide array of measured parameters, including herbage mass, potential pasture growth rate, liveweight, wool production per head, stocking rate, gross margin and equity. Although the experiment experienced drier-than-average conditions, marked differences emerged among farmlets over time, due to the effects of treatments. During the latter half of the experimental period (2003–06), farmlet A showed numerous positive and a few negative consequences of the higher rate of pasture renovation and increased soil fertility compared with the other two farmlets. While intensive rotational grazing resulted in superior control of gastrointestinal nematodes and slightly finer wool, this system had few effects on pastures and no positive effects on sheep liveweights, wool production or stocking rate. Whereas farmlet A showed higher gross margins, it had a negative and lower short-term cash position than did farmlets B and C, due largely to the artificially high rate of pasture renovation undertaken on this farmlet during the experiment. Although farmlet B had the highest cash position at the end of the experiment, this came at a cost of the declining quality of its pastures. Modelling of the farmlet systems allowed the results to be considered over the longer timeframes needed to assess sustainability. Thus, returns on investment were compared over realistic amortisation periods and produced outcomes based on long-term climatic expectations which were compared with those that arose under the drier-than-average conditions experienced during the experimental period. The main factors responsible for lifting the productivity of farmlet A were the sowing of temperate species and increased soil fertility, which enhanced the amount of legume and increased pasture quality and potential pasture growth. The factor that affected farmlet C most was the low proportion of the farmlet grazed at any one time, with high stock density imposed during grazing, which decreased feed intake quality. The paper concludes that more profitable and sustainable outcomes are most likely to arise from grazing enterprises that are proactively managed towards optimal outcomes by maintaining sufficient desirable perennial grasses with adequate legume content, enhancing soil fertility and employing flexible rotational grazing.
17
Robinson, Dorothy L. "Accurate, Low Cost PM2.5 Measurements Demonstrate the Large Spatial Variation in Wood Smoke Pollution in Regional Australia and Improve Modeling and Estimates of Health Costs". Atmosphere 11, n. 8 (13 agosto 2020): 856. http://dx.doi.org/10.3390/atmos11080856.
Testo completoAbstract (sommario):
The accuracy and utility of low-cost PM2.5 sensors was evaluated for measuring spatial variation and modeling population exposure to PM2.5 pollution from domestic wood-heating (DWH) in Armidale, a regional town in New South Wales (NSW), Australia, to obtain estimates of health costs and mortality. Eleven ‘PurpleAir’ (PA) monitors were deployed, including five located part of the time at the NSW government station (NSWGov) to derive calibration equations. Calibrated PA PM2.5 were almost identical to the NSWGov tapered element oscillating microbalance (TEOM) and Armidale Regional Council’s 2017 DustTrak measurements. Spatial variation was substantial. National air quality standards were exceeded 32 times from May–August 2018 at NSWGov and 63 times in one residential area. Wood heater use by about 50% of households increased estimated annual PM2.5 exposure by over eight micrograms per cubic meter, suggesting increased mortality of about 10% and health costs of thousands of dollars per wood heater per year. Accurate real-time community-based monitoring can improve estimates of exposure and avoid bias in estimating dose-response relationships. Efforts over the past decade to reduce wood smoke pollution proved ineffective, perhaps partly because some residents do not understand the health impacts or costs of wood-heating. Real-time Internet displays can increase awareness of DWH and bushfire pollution and encourage governments to develop effective policies to protect public health, as recommended by several recent studies in which wood smoke was identified as a major source of health-hazardous air pollution.
18
Badgery, W. B., G. D. Millar, D. L. Michalk, P. Cranney e K. Broadfoot. "The intensity of grazing management influences lamb production from native grassland". Animal Production Science 57, n. 9 (2017): 1837. http://dx.doi.org/10.1071/an15866.
Testo completoAbstract (sommario):
The intensity of grazing management required for optimal pasture and animal production from heterogeneous native grasslands has received little research in the high-rainfall zone of south-eastern Australia. The aim of this experiment was to determine how the intensity of grazing management, from continuous grazing (P01) to flexible 4- and 20-paddock rotational systems (P04 and P20), influenced the productivity and sustainability of a Merino ewe, terminal sire lamb production system run on a native grassland dominated by Microlaena stipoides and Rytidosperma spp. The present paper focuses on the animal production and feed-quality results from this experiment. There was a higher per head animal production for the P01 than the P20, with the P04 being intermediate. The differences were found for ewe liveweight and fat score, lamb growth rates and lamb liveweight at weaning. The P20 was able to run higher ewe numbers, in response to greater feed on offer than for P04 and P01, which enabled lamb production per hectare at weaning to be similar and greasy wool production per hectare to be greater than for P01. The organic matter digestibility of the ewe diet estimated from faecal analysis was lower for P20 and P04 systems than for P01 over a 7-month period and explained differences measured in sheep performance at that time. When lambs were retained after weaning, they could be kept for longer on the P20 and grown to a greater weight than for the P01 and P04, but the criteria for setting stocking rates and selling lambs from systems influenced the production from the systems. Further work is needed to investigate the interaction between stocking rate (ewe numbers and lamb sale time) and grazing management and examine different options for managing rotational grazing systems.
19
Duc, Hiep Nguyen, Kristina Shingles, Stephen White, David Salter, Lisa Tzu-Chi Chang, Gunaratnam Gunashanhar, Matthew Riley et al. "Spatial-Temporal Pattern of Black Carbon (BC) Emission from Biomass Burning and Anthropogenic Sources in New South Wales and the Greater Metropolitan Region of Sydney, Australia". Atmosphere 11, n. 6 (31 maggio 2020): 570. http://dx.doi.org/10.3390/atmos11060570.
Testo completoAbstract (sommario):
Biomass burnings either due to Hazards Reduction Burnings (HRBs) in late autumn and early winter or bushfires during summer periods in various part of the world (e.g., CA, USA or New South Wales, Australia) emit large amount of gaseous pollutants and aerosols. The emissions, under favourable meteorological conditions, can cause elevated atmospheric particulate concentrations in metropolitan areas and beyond. One of the pollutants of concern is black carbon (BC), which is a component of aerosol particles. BC is harmful to health and acts as a radiative forcing agent in increasing the global warming due to its light absorption properties. Remote sensing data from satellites have becoming increasingly available for research, and these provide rich datasets available on global and local scale as well as in situ aethalometer measurements allow researchers to study the emission and dispersion pattern of BC from anthropogenic and natural sources. The Department of Planning, Industry and Environment (DPIE) in New South Wales (NSW) has installed recently from 2014 to 2019 a total of nine aethalometers to measure BC in its state-wide air quality network to determine the source contribution of BC and PM2.5 (particulate Matter less than 2.5 μm in diameter) in ambient air from biomass burning and anthropogenic combustion sources. This study analysed the characteristics of spatial and temporal patterns of black carbon (BC) in New South Wales and in the Greater Metropolitan Region (GMR) of Sydney, Australia, by using these data sources as well as the trajectory HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) modelling tool to determine the source of high BC concentration detected at these sites. The emission characteristics of BC in relation to PM2.5 is dependent on the emission source and is analysed using regression analysis of BC with PM2.5 time series at the receptor site for winter and summer periods. The results show that, during the winter, correlation between BC and PM2.5 is found at nearly all sites while little or no correlation is detected during the summer period. Traffic vehicle emission is the main BC emission source identified in the urban areas but was less so in the regional sites where biomass burnings/wood heating is the dominant source in winter. The BC diurnal patterns at all sites were strongly influenced by meteorology.
20
Raymond, Carolyn A., Bill Joe, Dean W. Anderson e Duncan J. Watt. "Effect of thinning on relationships between three measures of wood stiffness in Pinus radiata: standing trees vs. logs vs. short clear specimens". Canadian Journal of Forest Research 38, n. 11 (novembre 2008): 2870–79. http://dx.doi.org/10.1139/x08-124.
Testo completoAbstract (sommario):
The effect of thinning on the relationship of wood quality traits measured on standing trees (dynamic modulus of elasticity (MOE) and outerwood density) and traits measured on logs or short clear specimens was determined using data collected from radiata pine ( Pinus radiata D. Don) trees growing in 22 unthinned and 16 thinned plots of harvest age trees in New South Wales, Australia. Stiffness showed a linear decrease along the stem. Trees growing on thinned sites were, on average, 3% lower in stiffness at each height in the stem. MOE measured on short clear specimens was moderately related to standing tree MOE (R2 = 0.62) and outerwood density (R2 = 0.56) but less well related to MOE of the adjacent log (R2 = 0.30). Standing tree MOE was a better predictor of whole stem MOE for the thinned sites (R2 = 0.60) than for the unthinned sites (R2 = 0.31). Stiffness and density appear to follow different patterns of variation and results for density may not be extrapolated to stiffness. Outerwood density was a very poor predictor of mean whole stem stiffness (R2 = 0.14). Overall, the acoustic tool, TreeTap, was a better predictor of whole stem stiffness than outerwood density, particularly for the thinned sites.
21
Doran-Browne, Natalie A., John Ive, Phillip Graham e Richard J. Eckard. "Carbon-neutral wool farming in south-eastern Australia". Animal Production Science 56, n. 3 (2016): 417. http://dx.doi.org/10.1071/an15541.
Testo completoAbstract (sommario):
Ruminant livestock production generates higher levels of greenhouse gas emissions (GHGE) compared with other types of farming. Therefore, it is desirable to reduce or offset those emissions where possible. Although mitigation options exist that reduce ruminant GHGE through the use of feed management, flock structure or breeding management, these options only reduce the existing emissions by up to 30% whereas planting trees and subsequent carbon sequestration in trees and soil has the potential for livestock emissions to be offset in their entirety. Trees can introduce additional co-benefits that may increase production such as reduced salinity and therefore increased pasture production, shelter for animals or reduced erosion. Trees will also use more water and compete with pastures for water and light. Therefore, careful planning is required to locate trees where the co-benefits can be maximised instead of any negative trade-offs. This study analysed the carbon balance of a wool case study farm, Talaheni, in south-eastern Australia to determine if the farm was carbon neutral. The Australian National Greenhouse Gas Inventory was used to calculate GHGE and carbon stocks, with national emissions factors used where available, and otherwise figures from the IPCC methodology being used. Sources of GHGE were from livestock, energy and fuel, and carbon stocks were present in the trees and soil. The results showed that from when the farm was purchased in 1980–2012 the farm had sequestered 11 times more carbon dioxide equivalents (CO2e) in trees and soil than was produced by livestock and energy. Between 1980 and 2012 a total of 31 100 t CO2e were sequestered with 19 300 and 11 800 t CO2e in trees and soil, respectively, whereas farm emissions totalled 2800 t CO2e. There was a sufficient increase in soil carbon stocks alone to offset all GHGE at the study site. This study demonstrated that there are substantial gains to be made in soil carbon stocks where initial soils are eroded and degraded and there is the opportunity to increase soil carbon either through planting trees or introducing perennial pastures to store more carbon under pastures. Further research would be beneficial on the carbon-neutral potential of farms in more fertile, high-rainfall areas. These areas typically have higher stocking rates than the present study and would require higher levels of carbon stocks for the farm to be carbon neutral.
22
Pilbeam, Roslyn A., Kay Howard, Bryan L. Shearer e Giles E. St J. Hardy. "Phosphite does not stimulate a wounding response in Eucalyptus marginata seedlings". Australian Journal of Botany 59, n. 4 (2011): 393. http://dx.doi.org/10.1071/bt10252.
Testo completoAbstract (sommario):
Phosphite is used to protect plants from the soilborne plant pathogen, Phytophthora cinnamomi. While several studies have reported a stimulation of defence mechanisms in response to the infection of plants treated with phosphite, the effect of phosphite on abiotic wound repair is unknown. The aim of this histological study was to detail the effects of phosphite on previously undescribed wound repair in Eucalyptus marginata, an important forest tree of south-western Australia, which responds to phosphite treatment. Clonal lines of young plants of E. marginata without a periderm, considered resistant and susceptible to P. cinnamomi, were sprayed with phosphite and the green stems were wounded with liquid nitrogen, where a small area of the vascular cambium was damaged. Transverse hand sections showed phosphite had no effect and there was no genotypic difference on wound responses in E. marginata. Wound periderm and a ligno-suberised boundary zone formed within 7 days. The generation of new phellogen derivatives occurred and by 14 days the vascular cambium was almost fully restored with wound wood formed by 21 days. In the absence of a pathogen, phosphite did not interfere with the quality and speed of wound repair in the E. marginata clones suggesting that wound repair will not be affected when phosphite is used as a prophylactic treatment.
23
Yazaki, Yoshikazu. "Utilization of Flavonoid Compounds from Bark and Wood: A Review". Natural Product Communications 10, n. 3 (marzo 2015): 1934578X1501000. http://dx.doi.org/10.1177/1934578x1501000333.
Testo completoAbstract (sommario):
Flavonoid compounds, which are extracted from bark and wood and used commercially, are flavan 3-ols as monomers and their polymers, which are called “condensed tannins”. Reactions of the condensed tannins with formaldehyde are the basis for wood adhesives. In the late 1940s, tannin research for wood adhesives was begun and the world-first commercial use of wattle tannin from black wattle ( Acacia mearnsii) bark as wood adhesives occurred in Australia in the 1960s. In addition, wattle tannin-based adhesives were further developed in South Africa and the uses of these adhesives have been continuing to date. The success of wattle tannin in wood adhesives is demonstrated by the collaboration of the ACIAR with the CAF in the early 1990s. Although radiata pine bark ( Pinus radiata) could be a useful resource for the production of wood adhesives, three problems prevented its use in this application: low extractive yields from the bark, variable quality of the tannin extracts and excessive viscosity of the formulated tannin adhesives. In order to overcome these problems, various extraction methods have been proposed. Studies on tannin adhesives from bark of other pine species are also described. Furthermore, the use of the tannin in the bark without extraction is described as “bark adhesives” from radiata pine and black wattle. The use of radiata tannin without formaldehyde for moulded wood products is also described. Owing to the strong antioxidant activity of flavonoid compounds, bark extracts from French maritime pine ( Pinus pinaster, synonym P. maritima) and radiata pine have been commercialized as nutritional supplements: Pycnogenol and Enzogenol, respectively. The background and the development of Pycnogenol and the basic difference in the preparation processes between Pycnogenol and Enzogenol are described. On the basis of the discovery that the SOSA value for wattle tannin is approximately 10 times that of extracts from pine bark supplements (Pycnogenol and Enzogenol), chemical, biochemical and clinical studies on wattle tannin were conducted. Results from these studies are outlined. Wattle tannin has been developed as a nutritional supplement and marketed as Acapolia in Japan.
24
Solano, Jaime, Leonardo Anabalón, Francisco Encina, Carlos Esse e Diego Penneckamp. "Hybrid identification in Nothofagus subgenus using high resolution melting with ITS and trnL approach". PeerJ 7 (9 maggio 2019): e6779. http://dx.doi.org/10.7717/peerj.6779.
Testo completoAbstract (sommario):
The genus Nothofagus is the main component of southern South American temperate forests. The 40 Nothofagus species, evergreen and deciduous, and some natural hybrids are spread among Central and Southern Chile, Argentina, New Zealand, Australia, New Guinea and New Caledonia. Nothofagus nervosa, Nothofagus obliqua and Nothofagus dombeyi are potentially very important timber producers due to their high wood quality and relative fast growth; however, indiscriminate logging has degraded vast areas the Chilean forest causing a serious state of deterioration of their genetic resource. The South of Chile has a large area covered by secondary forests of Nothofagus dombeyi. These forests have a high diversity of species, large amount of biomass and high silvicultural potential. This work shows a case of hybrid identification in Nothofagus subgenus in different secondary forests of Chile, using high resolution melting. Unknown samples of Nothofagus subgenus are genetically distinguishable with the ITS region of Nothofagus antarctica, Nothofagus nitida and N. obliqua species. It was not possible to distinguish between unknown samples of Andean versus coastal origin. Melting curves with ITS approach of unknown material are genetically similar, positioned between N. dombeyi and N. antarctica and distant from N. nitida. The unknown samples are genetically very close to Nothofagus dombeyi. This suggests the presence of hybrid individuality between species (N. dombeyi × N. antarctica) with the possibility of introgression towards the gene pool of N. antarctica, producing the deciduous foliage that is both present. The trnL locus has no distinction between the N. dombeyi and N. antarctica species, since a similar melting curve is present and equal Tm (80.00 °C). The trnL locus cannot be genetically distinguished from one unknown sample of Nothofagus to another, as highlighted in this study.
25
Jordan, Matthew. "Quality control in South Australia". Journal of Australian Studies 16, n. 34 (settembre 1992): 53–68. http://dx.doi.org/10.1080/14443059209387108.
Testo completo
26
Norton, Mark R., Denys L. Garden, Beverley A. Orchard, Philip Armstrong e Trent Brassil. "Effects of lime, phosphorus and stocking rate on an extensively managed permanent pasture: botanical composition and groundcover". Crop and Pasture Science 71, n. 7 (2020): 700. http://dx.doi.org/10.1071/cp20135.
Testo completoAbstract (sommario):
Low phosphorus (P) constrains productivity of many of the permanent pastures of south-eastern Australia where wool and meat production are important. Whereas the need for fertilisation with P is indisputable for many soils, the benefits of liming to ameliorate soil acidification are not always clear in terms of forage production or quality. This experiment, by measuring botanical composition and groundcover over 10 years, aimed to address the issue of forage composition and groundcover. Merino wethers were continuously grazed on a permanent pasture under two stocking rates (low and high) following treatments with three rates of surface-applied lime and two rates of P. The lime rates were: nil, and sufficient to raise the pHCaCl2 of the 0–10 cm soil layer to 5.0 and to 5.5. Phosphorus was added as two rates of single superphosphate: 125 kg ha–1 every 2–3 years, and 250 kg ha–1 every year. Two hypotheses were proposed: (i) as lime application rate increased, it would lead to the pasture swards having a higher percentage of species favourable for grazing animal production, and a higher level of sward groundcover would be maintained; and (ii) legume presence would be favoured by a higher level of applied P over the long term. The Millennium Drought (1997–2008), which coincided with this experiment (1998–2008), tended to mask or reduce lime effects; nevertheless, the higher legume content in the sward, as well as the superior groundcover found in the high lime–high P treatments at various times throughout the experiment and at its completion compared with the nil-lime control, indicated positive forage effects of lime application. Moreover, by the termination of the experiment in 2008, groundcover generally tended to be lower under nil lime than in treatments that had received lime. The higher proportion of legume in the sward was closely linked to greater applied P, although this did not occur at the low stocking rate in the absence of lime. By contrast, similar high P–low stocking rate treatments but with applied lime had the highest clover contents. It is proposed that the poor persistence of the treatment without lime may be due to a combination of poor legume seedset, because of excessive competition from accompanying grasses, and aluminium toxicity adversely affecting legume growth.
27
Doyle, PT, RA Love e TW Plaisted. "Mineral supplementation and wool production of young Merino sheep on the south coast of Western Australia". Australian Journal of Experimental Agriculture 35, n. 4 (1995): 437. http://dx.doi.org/10.1071/ea9950437.
Testo completoAbstract (sommario):
Wool-free liveweight change (LWC), wool growth rate, annual wool production, and wool characteristics of young Merino wethers fed supplements of lupins with gypsum or a multi-element mineral lick were examined in 12 experiments at 5 farms between 1989 and 1992. The source of sheep varied between experiments; age was 4.5-6.5 months and liveweight 28-37 kg at the beginning of supplementation. Sheep were fed lupins, lupins coated with gypsum (15-20 g/kg lupins), or lupins along with access to the mineral lick (offered at 140 g/sheep.week). The amount of lupins offered in all treatments within any experiment was the same. Supplementary feeding varied between experiments from 150 to 240 days. The sheep grazed annual pastures at stocking rates of 8-1 6.7ha. Average lick intake was 12-18 g/sheep. day. During supplementary feeding, there was considerable variation in LWC (-80 to +110 g/day) and clean wool growth rates (3.8-15.1 g/day) within and between experiments. However, there was no significant positive effect of gypsum or mineral lick supplementation on LWC or clean wool growth rates during or after supplementary feeding in any experiment. There were positive (P<0.01) relationships between LWC and clean wool growth rates during supplementation. Also, for some spring-shorn sheep types, staple strength of wool was linearly related (P<0.01) to LWC in the period before the position of break in the wool staple. Annual wool production, average fibre diameter, and staple strength of midside wool were not significantly increased by supplements of gypsum or mineral lick in any experiment.
28
Vere, D. T., P. M. Dowling, R. E. Jones e D. R. Kemp. "Economic impact of Vulpia in temperate pasture systems in south-eastern Australia". Australian Journal of Experimental Agriculture 42, n. 4 (2002): 465. http://dx.doi.org/10.1071/ea01100.
Testo completoAbstract (sommario):
An increasing incidence of annual grasses is considered to be a primary cause of decline in the productivity of Australia's temperate pasture systems. In particular, Vulpia (silver grass) comprises a significant proportion of the biomass of many temperate pastures and can seriously affect livestock productivity. The main economic effects of Vulpia include reducing pasture carrying capacities, contaminating produce and competing with more desirable pasture species. This paper presents the results of an economic evaluation of the costs of Vulpia and the long-term benefits of improving Vulpia management in the high-rainfall areas of south-eastern Australia. The evaluation used an integrated economic modelling system that determined the grazing system and livestock industry impacts of Vulpia and translated these into measures of economic welfare change that enabled the benefit-cost analysis of various levels of Vulpia management to be undertaken. With a focus on wool, the analysis established the high annual costs of Vulpia to wool producers and consumers, together with substantial long-term economic benefits that could potentially result from reducing the incidence of Vulpia in pastures. Total annual costs to the wool industry in the temperate pasture zone of New South Wales and Victoria ranged between A$7 and $30 million, while the potential discounted net benefits to the Australian and international wool industries were between $32 and $287�million over a 15-year period at a real discount rate of 5%. These estimates provide a strong economic basis for promoting improved management strategies for reducing Vulpia incidence in pastures.
29
Campbell, A. J. D., J. W. A. Larsen e A. L. Vizard. "The effect of annual shearing time on wool production by a spring-lambing Merino flock in south-eastern Australia". Animal Production Science 51, n. 10 (2011): 939. http://dx.doi.org/10.1071/an10270.
Testo completoAbstract (sommario):
Time of shearing affects many aspects of wool production and sheep health but no study has examined these factors concurrently in a spring-lambing, self-replacing Merino flock in southern Australia. A 5-year field experiment compared wool production in spring-lambing Merino ewes and their progeny shorn at different times and managed under commercial conditions in south-eastern Australia. Groups of 200 adult ewes were shorn in December, March or May, and their progeny were shorn in December or October, March or June, or May or July, respectively. There was no consistent association between time of shearing and the staple strength of wool (P = 0.73). December-shorn ewes produced significantly lighter and finer fleeces (average 19.1 μm, 3.0 kg clean weight) than did March-shorn ewes (19.4 μm, 3.1 kg). Fleeces from ewes shorn in May were of similar weight to those from March-shorn ewes (3.1 kg), but they were of significantly broader diameter (19.7 μm). In young sheep, desirable changes in some wool characteristics for each shearing group were offset by undesirable changes in others. On the basis of median historical (1991–2006) wool prices, shearing ewes in March and their progeny first in June produced the greatest total value of wool over a sheep’s lifetime ($161/head). The wool values per head for other shearing times were as follows: March (weaners)–March (ewes): $158; October–December: $157; December–December: $153; July–May: $151; and May–May: $148. Thus, December and March shearing were appropriate alternatives for maximising wool value produced from a self-replacing Merino flock in south-eastern Australia, whereas May was a less preferable shearing time because it always produced wool of lesser value.
30
Albertsen, TO, RH Casey e KP Croker. "Accumulation and dissipation of dieldrin in mature wethers in the south-west of Western Australia". Australian Journal of Experimental Agriculture 35, n. 3 (1995): 331. http://dx.doi.org/10.1071/ea9950331.
Testo completoAbstract (sommario):
The concentrations of dieldrin in body and wool fats of wethers grazed on 6 dieldrin-contaminated sites in the south-west of Western Australia were monitored over 2.5 years. Soil and pasture concentrations of dieldrin, a legacy of previous horticultural activities at these sites, were also measured. The concentrations of dieldrin in the soils varied from about 0.2 to 1.7 m a g . The production of the pastures at all sites showed a typical Mediterranean pattern with peak production in spring. The quantity of dry matter available ranged from <1000 kg/ha during summer-autumn to 10000 kg/ha in spring. In some samples the concentration of dieldrin in the dried plant material was above the accepted limit of 0.01 m a g for fresh material, but there were decreases over spring because of the substantial increase in the amount of dry matter available. The concentrations of dieldrin in the body and wool fats of the wethers increased during the winter and peaked at the start of spring, with the highest mean concentrations (mg/kg) in 1989 of 0.09-1.10 in body fats and 0.07-0.63 in wool fats. During spring the concentrations decreased and were at relatively low levels at the start of summer, with mean concentrations (mg/kg) of 0.02-0.72 in body fats and 0.01-0.18 in wool fats. Detailed results from 2 sites are discussed: Carbunup, with poorly structured loam soil; and Donnybrook, with good loam soil. On paddocks contaminated with dieldrin, production of wool with low concentrations of dieldrin is possible. If sheep grazed on contaminated paddocks are to be slaughtered, they should be sold in late spring, when concentrations of organochlorines in body fat should be low, or they should be run on uncontaminated land for about 2 months before their sale for slaughter.
31
Bird, PR, PR Bird, JD Kellas, JD Kellas, GA Kearney, GA Kearney, KN Cumming e KN Cumming. "Animal production under a series of Pinus radiata-pasture agroforestry systems in South-West Victoria, Australia". Australian Journal of Agricultural Research 46, n. 6 (1995): 1299. http://dx.doi.org/10.1071/ar9951299.
Testo completoAbstract (sommario):
Liveweight and greasy wool production data from young wethers were collected for the period autumn to early summer for the years 1986 to 1994 from an on-going Pinus radiata-pasture project at Carngham, Victoria. A plantation established in 1981 on a grazing property was thinned in 1983 to give trees spaced at: (i) no trees (a grazing control), (ii) 8 mx 12 m, (iii) 4 mx9 m, (iv) 4 mx3 m in a 5-row belt then a 10-row pasture gap, and (v) 2 mx3 m (original spacing). By 1989 the density of trees in these systems was slightly reduced by windthrow, animal damage and thinning to (ii) 60 trees/ha, (iii) 200 trees/ha wide-spaced, (iv) 200 trees/ha 5-row belt and (v) 1360 trees/ha. All trees in systems (ii), (iii) and (iv) had been pruned to 6 m by late 1992. The sheep stocking policy was initially based on a set 10 sheep ha-1. Since 1991 the stocking rate has been varied yearly in an attempt to maintain similar production per sheep. The pastures were re-sown in 1989 with perennial rye-grass and subterranean clover cultivars. Since 1991, wool production per ha from the 200 trees/ha wide-spaced system has been consistently less than in systems (i), (ii) and (iv). Wool production among systems differed significantly since 1992. Expressed as a percentage of wool production achieved on open pasture, the relative values for the agroforestry systems from 1990 to 1994 as follows.
32
Henry, B. K., D. Butler e S. G. Wiedemann. "Quantifying carbon sequestration on sheep grazing land in Australia for life cycle assessment studies". Rangeland Journal 37, n. 4 (2015): 379. http://dx.doi.org/10.1071/rj14109.
Testo completoAbstract (sommario):
The sheep industry has played an important role in Australia’s development and economy over the 220 years since European settlement and remains an important land use in Australia, occupying an estimated 85 million ha of continental land mass. Historically, deforestation was carried out in many sheep-rearing regions to promote pasture growth but this has not occurred within recent decades and many wool producers have invested in planting trees as well as preserving patches of remnant vegetation. Although the limitations of single environmental impact studies are recognised, this paper focuses on the contribution of carbon sequestration in trees and shrubs on sheep farms to the global warming potential impact category in life cycle assessment of wool. The analysis represents three major wool-producing zones of Australia. Based on default regional yields as applied in Australia’s National Inventory model, FullCAM, CO2 removals in planted exotic pines and mixed native species were estimated to be 5.0 and 3.0 t CO2 ha–1 year–1, respectively, for the Northern Tablelands of New South Wales in the ‘high-rainfall zone’ and 1.4 t CO2 ha–1 year–1 for mixed native species in the ‘sheep-wheat zone’ of Western Australia. Applying modified factors allowing for the higher measured growth rates in regions with rainfall >300 mm, gave values for native species reforestation of 4.4 and 2.0 t CO2 ha–1 year–1 for New South Wales and Western Australia, respectively. Sequestration was estimated to be 0.07 t CO2 ha–1 year–1 over 100 years for chenopod shrublands of the ‘pastoral zone’ of South Australia but this low rate is significant because of the extent of regeneration. Sequestration of soil organic carbon in improved permanent pastures in the New South Wales Northern Tablelands was evaluated to be highly uncertain but potentially significant over large areas of management. Improved data and consistent methodologies are needed for quantification of these benefits in life cycle assessment studies for wool and sheep meat, and additional impact categories, such as biodiversity, need to be included if the public and private benefits provided by good management of vegetation resources on farms are to be more fully recognised.
33
Hatton MacDonald, Darla, Ali Ardeshiri, John M. Rose, Bayden D. Russell e Sean D. Connell. "Valuing coastal water quality: Adelaide, South Australia metropolitan area". Marine Policy 52 (febbraio 2015): 116–24. http://dx.doi.org/10.1016/j.marpol.2014.11.003.
Testo completo
34
Craig, AD. "The performance of Merino ewes and lambs grazing two cultivars of Trifolium subterraneum at Kybybolite, South Australia". Australian Journal of Experimental Agriculture 32, n. 5 (1992): 605. http://dx.doi.org/10.1071/ea9920605.
Testo completoAbstract (sommario):
Two cultivars of subterranean clover, Trikkala and Mt Barker, were continuously grazed by Merino ewes and lambs at 3 stocking rates (8, 13, 18 ewes/ha) from 1976 to 1981. The sheep were assessed for liveweight, fleeceweight, fibre diameter, staple length, wool yield and lambing performance including lambing, marking and weaning percentage. From September 1978 onward, ewes grazing Trikkala pastures were consistently heavier than those grazing Mt Barker pastures, and they produced heavier fleeces in 1978 and 1980, with a 3 and 9% greater total wool production. The heavier fleeces of 1980 were associated with a larger fibre diameter. There were no cultivar differences in lambing performance. Cultivar treatment had no effect on lamb birthweight, but in 1980 the Trikkala lambs were, on average, 3.5 kg heavier at weaning. These lambs also produced heavier fleeces than lambs on the Mt Barker pastures. Higher stocking rates produced decreases in all of the animal performance variables measured. The results of this study suggest that improved livestock performance may only occur if animals are grazed on higher performing cultivars for at least 3 years.
35
Butler, LG, e GM Head. "Photoperiodic rhythm of wool growth and its contribution to seasonal wool production by the Merino, Polwarth, and their reciprocal crosses in southern Australia". Australian Journal of Experimental Agriculture 34, n. 3 (1994): 311. http://dx.doi.org/10.1071/ea9940311.
Testo completoAbstract (sommario):
Twelve wethers of each of the Merino and Polwarth breeds and their reciprocal crosses were fed at1 of 2 levels in individual pens for 14 months. Periodic clean wool weight, yield, fibre diameter, and the coefficient of variation (CV%) for fibre diameter were measured from midside patches harvested every6 weeks.There was a significant effect of time of wool harvest on clean wool weight per cm2, yield, fibre diameter(all P<0.01), and its CV% (P<0.05). A trough in wool production occurred about August-September and a peak in January. The amplitude of the photoperiodic rhythm of wool growth (difference between maximum and minimum wool growth per cm2 per 42 days as a percentage of the average) was 40%. Yield also displayed a substantial photoperiodic rhythm, but that of fibre diameter was less pronounced. Mean staple strength was 32.3 N/ktex, the mean break occurring at a distance of 60% of the staple length from the tip; there was no effect of genotype or level of feeding. From comparison with published Tasmanian field data, the seasonal wool growth pattern of sheep at pasture appears similar to the photoperiodic rhythm but occurs about a month earlier. It was concluded that the photoperiodic rhythm of wool production of Tasmanian Merino-based breeds should not be a barrier to manipulation of wool quality (staple strength and fibre diameter) by nutritional management.
36
Fleming, P. J. S., J. D. Croft e H. I. Nicol. "The impact of rabbits on a grazing system in eastern New South Wales. 2. Sheep production". Australian Journal of Experimental Agriculture 42, n. 7 (2002): 917. http://dx.doi.org/10.1071/ea01107.
Testo completoAbstract (sommario):
Much research, time and money have been invested in the control of rabbits in Australia, yet the relationship between rabbit density and livestock production losses has not been quantified. We experimentally investigated the variations in sheep production parameters caused by 4 densities of rabbits, 0, 24, 48 and 72 rabbits/ha. Medium to strong wool merino wethers were run at a constant stocking rate in replicated plots with rabbits at 4� different densities. Sheep liveweight and body condition and wool production variables were measured over 3�years. Low to medium densities of rabbits were not found to reduce liveweights of wethers, whereas wethers run with the high density of rabbits were significantly lighter. The presence of rabbits reduced the body condition of sympatric sheep with the lowest body condition recorded at the high rabbit density. Mean greasy fleece weights, wool yields and clean-fleece weights were significantly different between densities of rabbits. Wethers run with the high rabbit density grew less wool than the wethers run with the other 3 densities of rabbits. The cumulative gross return per ha from wool production was highest for the medium rabbit density and lowest at high rabbit density. At the conclusion of this short-term experiment, the presence of some rabbits enhanced returns from wool production because of lower fibre diameter and comparable clean-fleece weights of fleeces grown at low and medium rabbit densities. These production characteristics might have been caused by synergistic effects on pasture growth or a sheep stocking rate that was too conservative for the prevailing seasonal conditions. At high rabbit density, competition for pasture between rabbits and sheep overrode possible synergistic and understocking effects. The economic implications of the presence of rabbits on merino sheep production are discussed.
37
Niven, DR, e DA Pritchard. "Effects of control of the sheep body louse (Damalinia ovis) on wool production and quality". Australian Journal of Experimental Agriculture 25, n. 1 (1985): 27. http://dx.doi.org/10.1071/ea9850027.
Testo completoAbstract (sommario):
Groups of 35 Merino wethers under natural challenge by sheep body lice, Damalinia ovis, in south-western Queensland were subjected to four different chemical lice control treatments (arsenic, diazinon, cypermethrin and deltamethrin) over a 12-month period. Shearing took place in June. Louse populations were reduced by repeated treatments with cypermethrin. Despite high temperatures and some rainfall, populations in controls peaked at the end of summer, indicating that wool length influenced population growth. Greasy and clean fleece weights of treated sheep were higher (P<0.05) than those of controls by 0.4-1.1 kg/sheep and 0.3-0.9 kg/sheep, respectively, depending on treatment. Wool base yield was 2-45.5% higher. Sheep that were repeatedly treated with cypermethrin produced more (P<0.05) sound fleece wool (3.0 vs 1.7 kg/head greasy) and less cast fleece wool (0.1 vs 0.4 kg/head greasy) than controls. The differences in wool value between treated groups and controls ranged from $A0.45 to $A3.19 per sheep. No effect on liveweight could be attributed to treatment.
38
Doyle, PT, TW Plaisted e RA Love. "Supplementary feeding pattern and rate of liveweight gain in winter-spring affect wool production of young Merino sheep on the south coast of Western Australia". Australian Journal of Experimental Agriculture 35, n. 8 (1995): 1093. http://dx.doi.org/10.1071/ea9951093.
Testo completoAbstract (sommario):
The effects of different supplementary feeding practices in summer-autumn and management strategies on green pasture on liveweight change, wool growth rate, annual wool production and wool characteristics of young Merino wethers were examined at 2 farms. The grain feeding treatments were lupins (L) or lupins and oats (LO) fed in amounts that were adjusted to try and maintain liveweight, or lupins and oats (LOG) fed at a higher rate. The objectives of liveweight maintenance or gain were not always achieved, but liveweight patterns differed between LOG compared with L or LO during summer-autumn. The sheep used at farm 1 were aged 4.5 months and liveweight 32 kg at the start of the experiment, while those at farm 2 were 6.5 months and liveweight 39 kg. The stocking rate in summer-autumn was 8 wethers/ha at both farms. During supplementation, sheep on LOG had a higher (P<0.05) liveweight change compared with those on L or LO (farm 1, 15 v. -8 g/sheep. day; farm 2, -35 v. -51 g/sheep. day) and clean wool growth rates (farm 1, 7.1 v. 6.4 g/sheep. day; farm 2, 5.1 v. 4.8 g/sheep.day). The sheep on LOG grew broader (P<0.05) wool than those on L or LO (farm 1, 19.0 v. 18.5 �m; farm 2, 21.7 v. 20.8 �m), and at farm 1 length was also greater (P<0.05) (114 v. 111 mm), while at farm 2 staple strength was greater (P<0.01) (22.9 v. 16.4 N/ktex). There were no significant differences in annual clean wool production. There were positive (P<0.01) relationships between staple strength and liveweight change to the time of minimum liveweight in summer-autumn. After green pasture on offer reached 500 kg DM/ha in autumn, different liveweight change patterns were achieved in 2 groups (LS, lower stocking rates; HS, higher stocking rates) of sheep at each farm by adjusting stocking rates. Within a farm, the LS and HS groups were comprised of equal numbers of sheep from each replicate of the supplementary feeding treatments. There were differences (P<0.05 to 0.01) in liveweight change between LS and HS (farm 1, 93 v. 72 g/day; farm 2, 127 v. 60 g/day), the differences being more pronounced at farm 2. The differential stocking rates at farm 2 resulted in differences in clean wool growth rates (P<0.01), in clean wool production (4.22 v. 4.53 kg, P<0.05), and fibre diameter (20.8 v. 21.4 �m, P<0.01), but there were no significant effects on staple length or strength. There were no significant effects of the supplementary feeding treatments imposed in summer-autumn on the responses to the stocking rate treatments on green pasture.
39
Merrett, David Tolmie, e Simon Ville. "Accounting for Nonconvergence in Global Wool Marketing before 1939". Business History Review 89, n. 2 (2015): 229–53. http://dx.doi.org/10.1017/s0007680515000641.
Testo completoAbstract (sommario):
From the mid-nineteenth century, raw wool became a global commodity as new producing countries in the Southern Hemisphere supplied the world's growing textile industries in the North. The selling practices of these big-five exporters—Australia, New Zealand, South Africa, Argentina, and Uruguay—ranged from auction through a hybrid of auction and private sale to exclusively private sale. We explore why these countries persisted with different marketing arrangements, contradicting two streams of literature on institutions: isomorphism and the new institutional economics. The article makes several important contributions through blending distinct branches of theory and by focusing on the international constraints to convergence in an earlier period of globalization.
40
Gardener, M. R., R. D. B. Whalley e B. M. Sindel. "Ecology of Nassella neesiana, Chilean needle grass, in pastures on the Northern Tablelands of New South Wales. I. Seed production and dispersal". Australian Journal of Agricultural Research 54, n. 6 (2003): 613. http://dx.doi.org/10.1071/ar01075.
Testo completoAbstract (sommario):
Nassella neesiana (Trin. & Rupr.) Barkworth (Chilean needle grass) originated in South America and is now a widespread weed in pastures in south-eastern Australia. To date, little research on the biology of N.�neesiana has been undertaken in Australia. This study investigated several aspects of the biology of N. neesiana in pastures on the Northern Tablelands of New South Wales. The main flowering period for N. neesiana in Australia was shown to extend from November to February and is similar to that in South America. Potential for production of panicle seeds was large and varied from 1584 seeds/m2 in 1995 to 22 203 seeds/m2 in 1996 as a result of changes in the density of flowering tillers per unit area. Nassella neesiana produced a further 7.2 cleistogenes (hidden seeds in the flower stem) on average per tiller. Hence, total potential seed production (panicle seeds and cleistogenes) was 28 282 and 8036 seeds/m2 in 1996 and 1997, with the cleistogenes accounting for 21.5 and 26.1% of the total respectively. Furthermore, the production of cleistogenes was not affected by clipping flowering tillers at 3 different heights. Three possible dispersal mechanisms of N. neesiana seeds were investigated. Adherence of seeds to the wool appeared to be the most effective. Twenty-five per cent of seeds that were picked up naturally in the wool of sheep after grazing in a paddock of N. neesiana, remained after 5 months. Shearing just before seed set reduced the number of seeds adhering to the wool. An average of 1.7% of panicle seeds and 5.3% of cleistogenes fed to Angus steers passed through the animal intact within 4 days, but <50% of these seeds were viable. The majority of seeds recovered from a wind dispersal experiment were within 1 m of the parent plant and the furthermost seed was 2.8 m away. The implications of these results for management are discussed.
41
Snyder, Richard G. "PINE BARK, RICE HULLS, AND OTHER INEXPENSIVE MEDIA FOR GREENHOUSE TOMATO PRODUCTION IN THE SOUTH". HortScience 29, n. 7 (luglio 1994): 733d—733. http://dx.doi.org/10.21273/hortsci.29.7.733d.
Testo completoAbstract (sommario):
Successful greenhouse tomato businesses are able to keep production and quality high while maintaining reasonable cost controls. One way of controlling costs is to use growing media that are locally available in good supply, and therefore of low cost. In Mississippi. as in other states in the southeast, pine bark is an available byproduct resource from the forestry industry; fines (<=95mm diameter) can be used as a growing medium following composting. Rice hulls are a readily available waste product from rice mills, especially in the Mississippi Delta region; these are suitable after being crushed and composted. In comparison to plants grown in rock wool, yield from plants in pine bark fines, rice hulls, or sand were higher, while quality was not significantly different in the l-crop/year system. In a spring crop, yield and quality were higher from plants in pine bark, rice hulls, and rock wool than from those grown in sand. On a per plant basis, cost for the rock wool system, perlite system (pre-bagged), perlite (bulk), peat moss, sand, composted rice hulls, and pine bark lines are $1.50, $1.00, $0.35, $0.60, $0.24, $0.22 and $0.17, respectively. Pine bark and rice hulls are good choices for growing media for greenhouse tomatoes in areas where they are available.
42
Kleemann, DO, RW Ponzoni, JE Stafford e RJ Grimson. "Carcass composition of the South Australian Merino and its crosses with the Booroola and Trangie Fertility Merino". Australian Journal of Experimental Agriculture 28, n. 2 (1988): 167. http://dx.doi.org/10.1071/ea9880167.
Testo completoAbstract (sommario):
South Australian medium-wool (M), non- Peppin medium-wool Booroola (B) and Peppin medium-wool Trangie Fertility (TF) Merino rams were joined to M ewes at Turretfield Research Centre, South Australia, in 2 years. Carcass composition was assessed in the ewe and wether progeny at 2 mean slaughter liveweights, viz. 24 and 38 kg. When adjusted to the same carcass weight, B x M had 13% more carcass chemical fat, 15% more subcutaneous fat, 6% less bone and the same lean tissue as M. The same result was observed for TF x M in relation to M in year 2. However, TF x M had more lean and the same amount of subcutaneous and chemical fat as M in year 1. Within the Booroola strain, there were no differences between offspring from 3 sires with genotype FF and the 1 sire with + + for any of 5 variables analysed. We conclude that crossing the Booroola with the South Australian Merino produces carcasses with the same amount of lean tissue, less bone and more fat when compared at the same carcass weight. The rank of TF x M with the other strains for the major carcass components remains obscure owing to a strain x year interaction.
43
Charlick, AJ, e GW Arnold. "Effect of bearing and rearing lambs on Merino wool production". Australian Journal of Experimental Agriculture 30, n. 5 (1990): 591. http://dx.doi.org/10.1071/ea9900591.
Testo completoAbstract (sommario):
Over a 15-year period, the greasy fleece weights of medium-wooled Merino ewes lambing in June in a 625 mm winter rainfall area in south-western Australia were examined in relation to the numbers of lambs born and reared. The ewes were set stocked at 6.7 ewes/ha on annual pasture. During this period selection for increased wool production was undertaken. A generalised linear model was used to assess the effects of bearing and rearing lambs. There was a significant (P<0.05) year x lambing interaction because of a different response over years 1-7 from that over years 8-15. Over years 1-7 when dry ewes cut an average of 4250 g greasy wool, ewes raising single lambs cut 185 g less wool (P<0.001); the few that raised twins cut a similar amount of wool to dry ewes. In years 8-15, wool production of dry ewes increased to an average of 5524 g. Ewes that lambed but lost their lambs cut 386 g less wool, those raising single lambs 652 g less wool, and those raising twins 846 g less wool. Over years 8-15, a second flock in which some ewes lambed twice a year was examined. These ewes received supplementary feed for out of season lambing. Those that raised 2 single lambs in a year cut 1120 g less wool than dry ewes.
44
Dlodlo, Nomusa, Lawrance Hunter, Anton Botha e Roger Metelerkamp. "A distributed knowledge-based system for the optimum utilisation of South African wool". Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 28, n. 3 (6 settembre 2009): 187–204. http://dx.doi.org/10.4102/satnt.v28i3.57.
Testo completoAbstract (sommario):
This article describes the concept and development of a knowledge-based advisory system for the optimum utilisation of South African wool for the benefit of present and potential investors and other interested parties. Wool is a natural animal fibre produced in varying quantities around the world. The wool fibre is far from homogenous; its type and quality, such as fineness and length, depending on the breed of sheep and the environmental conditions prevailing during its growth. Wool is used in a variety of end uses, ranging from fi ne worsted suiting, to hand knitting yarn, carpets, blankets and aircraft upholstery, its use depending largely on its fibre fineness and length. The wool industry is one of the oldest agricultural industries in South Africa, playing an important economic role as an earner of foreign exchange, and providing a living to many people. Wool is produced in many parts of South Africa under extensive, semi-extensive or intensive conditions, and is largely an export commodity. It is produced and traded in a sophisticated free market business environment into the international market place, where supply and demand forces determine price levels. More than 90% of locally produced wool is exported in an unprocessed or semi-processed form which detrimentally affects employment, foreign exchange and income-generating opportunities associated with value-addition prior to export. To reduce the amount of wool exported in unprocessed or semi-processed form, wool-processing enterprises need to be established to produce internationally marketable end products. Therefore, South Africa needs to attract investors into the wool sector, who will set up manufacturing mills in an economically sustainable manner. Potential and present investors in the South African (S.A.) wool industry need easily accessible and up-to-date information on the production statistics, processing properties and end-use pplications of the wool they need for the particular end-products they manufacture or could manufacture. To achieve this and ensure accessibility to such continuously updated information, it is essential to develop an integrated computer-based system. It is with the above in mind that a knowledge-based system for the optimum utilisation of South African wool has been developed, which is described here. This paper reviews relevant work in this fi eld and covers wool production statistics in South Africa, the end uses of the wool fibre versus the diameter of the fibre, the advantages of distributed architectures, and the flow of processes in a wool utilization system. It then sets out the concept and development of the proposed system, including the architecture of the proposed expert system, the associated analysis and finally the conclusions. The components of the expert system, namely the knowledge base, inference engine, knowledge acquisition component, and explanation system are described. The architecture of the system incorporates the concept of distributed systems and the related advantages incorporated in its general architecture and within its internal components. It marries both expert and general knowledge-based systems, consisting of a combination of an ordinary knowledge-based system (KBS) that can be queried for information and an expert system that provides advice to users. The distributed system developed involves collection of autonomous components that are interconnected, which enables these components to coordinate their activities and share resources of the system, so that users perceive the system as a single integrated facility. There are a number of advantages of such a distributed system and these are articulated in the paper. This approach allows not only incremental development of the system, but also facilitates sharing of data and information. The distributed nature of the architecture of the system developed, consists of three main elements: The expert system to advise on the characteristics of the wool that is required for a particular end use A knowledge-based system for querying on the distribution of wool of the various characteristics in South Africa An expert system for the selection of the best alternative area for investment for the particular product end use.The knowledge base consists of a number of databases, each representing the various wool characteristics. This represents a distributed architecture of the knowledge base. Therefore, this architecture inherits all the advantages of distributed processing systems as described in the paper. These knowledge bases can be queried by the user via a database management system (DBMS), a software that manages the creation, updating, maintenance and querying of the database. In terms of wool utilization, the system involves capturing the end-use and requirements of a product and from it, retrieving the characteristics of the wool that will meet the particular end-use. The availability of the wool is then checked by region and province for each style, type, clip type, yield, colour, vegetable matter fault and micron range, in line with the latest statistics available.The system developed enables questions such as the following to be asked at the user interface: What is the anticipated end use of the wool? What criteria must the wool satisfy for the selected end-use? What quantities of wool are required?The outputs at the user interface of the system are the quantities of wool per province and region in terms of micron, style, yield, colour, type, clip type as available on the web-site of Cape Wools SA. At the very end of the system, the best alternative site for siting the manufacturing base can also be indicated.
45
Croker, KP, MA Johns, SH Bell, GA Brown e JF Wallace. "The influence of vaccination with Fecundin and supplementation with lupin grain on the reproductive performance of Merino ewes in Western Australia". Australian Journal of Experimental Agriculture 30, n. 4 (1990): 469. http://dx.doi.org/10.1071/ea9900469.
Testo completoAbstract (sommario):
The reproductive performances of groups of 4-6-year-old medium wool Merino ewes that were vaccinated with Fecundin and/or fed sweet lupin grain prior to and during the early part of the joining period were compared with untreated ewes over 2 years. The rams were joined with the ewes in early January of each year. In both years the Fecundin and lupin treatments increased ovulation rates (between 0.13 and 0.56) and the incidence of multiple pregnancies (between 1 and 36%). The proportions of lambs born following treatment with Fecundin were larger than those from the ewes fed only lupins. When the treatments were combined, there were no increases in lambs born above that of Fecundin alone. Pregnancy significantly depressed wool production from individual ewes, while those with more than 1 lamb produced less wool than those with only 1 lamb. However, the average quantity (4.6 kg greasy) and quality of wool produced by the ewes each year was similar for all groups, indicating that the variation in the incidence of multiple pregnancies had not affected flock wool production. The average rate of growth of the progeny from marking to weaning was also similar for each group (191 and 238 g/head.day for years 1 and 2, respectively) even though there were more multiple-born lambs in the Fecundin-treated groups. On a flock basis, it would appear that the nutritional conditions experienced during this study were adequate to avoid significant penalties associated with multiple pregnancies.
46
Behrendt, R., A. J. van Burgel, A. Bailey, P. Barber, M. Curnow, D. J. Gordon, J. E. Hocking Edwards, C. M. Oldham e A. N. Thompson. "On-farm paddock-scale comparisons across southern Australia confirm that increasing the nutrition of Merino ewes improves their production and the lifetime performance of their progeny". Animal Production Science 51, n. 9 (2011): 805. http://dx.doi.org/10.1071/an10183.
Testo completoAbstract (sommario):
Experiments conducted by Lifetimewool at plot-scale have shown that differences in the maternal liveweight during pregnancy and lactation (liveweight profiles) of individual Merino ewes influences their wool production and reproductive rate as well as the birthweight, survival, weaning weight and lifetime wool production of their lambs in a predictable manner. This study determined whether these impacts of nutrition of the ewe on ewe and progeny performance are measurable on commercial properties across southern Australia at a paddock-scale where ewes were aggregated into flocks with a greater spread of the date of conception and where the liveweight profile of the flocks were managed based on random samples of 100 ewes and liveweight was uncorrected for fleece weight or conceptus. Eighteen paddock-scale experiments at 15 sites were conducted in cooperation with wool producers across Victoria, Western Australia, New South Wales, South Australia, and Tasmania. Each co-operator joined up to 1000 mixed aged adult Merino ewes. The flock was scanned using ultrasound at Day 50 from the start of joining to identify those ewes that conceived during the first 21 days of joining. These ewes were then split at random into two treatments and fed to achieve a target difference in liveweight of 10 kg or ~1 condition score/fat score at lambing. The production of ewes during their year of pregnancy and following their next joining was measured as was the performance of their progeny up to their third shearing. Only the 13 paddock-scale experiments that achieved a difference in liveweight profile at lambing of at least 4 kg were included in the final analysis. In these 13 experiments, increasing the nutrition of Merino ewes during pregnancy clearly increased the clean fleece weight and fibre diameter in ewes and the survival and lifetime wool production of their lambs. In most cases the size of the effect was not significantly different to that predicted by the relationship derived using individual liveweight profiles in the plot-scale experiments. This confirms that managing average ewe liveweight or condition score/fat score profile through better nutrition will lead to predictable increases in the performance of ewes and their progeny performance under commercial conditions and validates the use of the plot-scale relationships in economic analyses.
47
Senevirathna, S. T. M. L. D., Andrea M. Goncher e Aaron Hollier. "Assessment of drinking water quality in regional New South Wales, Australia". Journal of Water Supply: Research and Technology-Aqua 68, n. 8 (13 novembre 2019): 708–17. http://dx.doi.org/10.2166/aqua.2019.103.
Testo completoAbstract (sommario):
Abstract There is a substantial research gap relating to the quality of drinking water in regional Australia and identifying possible improvements. In particular, the quality of water available in public places (washing and drinking), such as water bubblers installed in regional parks, schools, rest areas and railway stations, is poorly investigated. This paper discusses the primary and secondary water quality of eight water distribution networks in New South Wales (NSW) regional towns. An analysis of a large number of drinking water samples (more than 11,000) identified that maintaining microbial water quality and the required free chlorine level (>0.2 mg/L) are challenging issues for regional water distribution networks. Sixty-three per cent of the samples collected from the water outlets available in public places of a regional town showed free chlorine levels of <0.2 mg/L, and 30% of samples showed positive results for total coliform. All heavy metal levels of the samples were within the safe level. Water temperature was identified as the most problematic secondary water quality parameter in public water bubblers. Stainless steel was the common material used in bubblers where surface temperatures exceeded 50 °C during summer. This study identifies possible design and operational modifications to improve regional drinking water quality and make public water bubblers more usable.
48
McGregor, B. A. "Influence of stocking rate and mixed grazing of Angora goats and Merino sheep on animal and pasture production in southern Australia. 3. Mohair and wool production and quality". Animal Production Science 50, n. 3 (2010): 168. http://dx.doi.org/10.1071/an09186.
Testo completoAbstract (sommario):
The effects of animal species (AS; Angora goats, Merino sheep, mixed-grazed goats and sheep at the ratio of 1 : 1) and stocking rate (SR; 7.5, 10 and 12.5 animals/ha) on fibre production and quality were determined in a replicated experiment on improved annual temperate pastures in southern Australia from 1981 to 1984. Separately grazed sheep produced the most total clean fibre/ha at each SR. Mixed-grazed treatments produced amounts of clean fibre/ha similar to the arithmetic mean of sheep and goat treatments at 7.5/ha (21.9 versus 21.3 kg/ha), 10% more at 10/ha (28.3 versus 25.3 kg/ha, P < 0.05) and 7% more at 12.5/ha (31.6 versus 29.6 kg/ha, P < 0.10). Clean wool production/head was affected by AS and SR but not year. Clean mohair production was affected by SR and year but not AS. Variation in mean fibre diameter (MFD) accounted for 67 and 71%, respectively, of the variation in clean wool and clean mohair production/head. There was an AS × SR interaction for clean fibre production/t pasture. Growth rate of mohair was highest in autumn and least in summer. In each season, an increase in the SR reduced the clean mohair growth rate. Growth rate of wool was highest in spring and least in summer. Wool and mohair MFD were affected by an AS × SR interaction. Mohair MFD was also affected by year and season. At 10/ha, wool from mixed-grazed sheep had a greater MFD than wool from separately grazed sheep (20.2 versus 18.9 μm) and mixed-grazed goats grew mohair 1 μm coarser than separately grazed goats. At 12.5/ha mixed-grazed goats grew mohair 1.9 μm finer than separately grazed goats. Mohair MFD was predicted by a multiple regression that included average liveweight for the period of fleece growth, season of growth (summer 1 µm finer than winter) and year (range 1.27 µm). Mohair MFD increased 4.7 µm/10 kg increase in average fleece-free liveweight (P = 6.4 × 10–14). Fleece-free liveweight alone accounted for 76.4% of the variation in mohair MFD. There was an AS × SR interaction for the incidence of kemp and medullated fibres; under severe grazing pressure their incidence was suppressed. This experiment indicated that the principles associated with the effects of SR on wool production on annual temperate pastures apply to mohair production. Mixed grazing of Merino sheep and Angora goats produced complementary and competitive effects depending on the SR. Angora goats should not be grazed alone or mixed-grazed with sheep on annual temperate pastures at SR greater than that recommended for Merino sheep.
49
Naidu, R., RH Merry, GJ Churchman, MJ Wright, RS Murray, RW Fitzpatrick e BA Zarcinas. "Sodicity in South Australia - a review". Soil Research 31, n. 6 (1993): 911. http://dx.doi.org/10.1071/sr9930911.
Testo completoAbstract (sommario):
The current knowledge of the nature and distribution of sodic soils in South Australia is reviewed. The agriculturally developed area of South Australia lies south of latitude 32-degrees-S. and is mainly used for low intensity grazing and dry land cereal/sheep production. A high proportion of the State, including much of the high rainfall area, has soils which are sodic (>6% ESP) through a significant proportion of the profile but information on the precise nature of sodicity in these soils is limited. Where exchangeable cation data axe available, the analytical techniques used often did not precisely delineate between soluble salts in the soil and ions on exchange sites. Therefore, many of the datasets have major weaknesses and may be unreliable. Since many soils with ESP <6 also show dispersive characteristics typical of sodic soils, there is an urgent need for new sodicity studies relating to distribution and the criteria (ESP) used to identify dispersive soils. Information on the effect of sodicity on nutrient requirements of plants, especially the modern varieties, is scarce both locally and internationally, making development of management strategies for economically sustainable crop production difficult. Further, many different grades of gypsum are available in South Australia. Preliminary studies show the presence of impurities drastically influences gypsum dissolution characteristics. More effort is needed to assess the quality and reactivity of South Australian gypsum. Some effort has been directed by land managers towards reclamation and management of sodic soils by using both gypsum and lime either separately or as mixtures. However, there is neither a scientific basis for the application of gypsum-lime mixtures nor crop production data to support such management strategies.
50
Hall, DG, EC Wolfe e BR Cullis. "Performance of breeding ewes on lucerne-subterranean clover pastures". Australian Journal of Experimental Agriculture 25, n. 4 (1985): 758. http://dx.doi.org/10.1071/ea9850758.
Testo completoAbstract (sommario):
Pasture production, ewe and lamb growth, ewe wool production and diet quality were studied on lucerne-subterranean clover pastures at Wagga Wagga, New South Wales. Lucerne was sown at rates of 0.75 to 3.0 kg/ha, and the pastures were rotationally grazed with Border Leicester x Merino ewes at 9.6 or 12.7 sheep/ha, the ewes lambing in August- September. Lucerne density declined by 45% over the 3 years on all treatments. The clover cultivar sown, Woogenellup, had low persistence, particularly at 12.7 sheep/ha. The density of lucerne had little effect on annual wool and lamb production, although the ewes grew faster on the denser lucerne in summer and the sparser lucerne in winter. At 12- 7 sheep/ha, there was an extra 19% total lamb weight by the end of November and an extra 22% of finer wool (1 �m) annually, but the fleeces had a higher proportion of wool tenderness. The major limitations of the lucerne-subterranean clover pastures to sheep production were the low quality of the diet in early summer, and low pasture production in late winter. In early summer the lucerne was rapidly consumed, leaving only moderate quality clover and grass residues, which limited lamb growth, while in winter pregnancy toxaemia occurred, fleeces were tender and wool growth was low, particularly during a drought in 1976.