Can resilience thinking provide useful insights for those examining efforts to transform contemporary agriculture?     

Katrina Sinclair  Allan Curtis  Emily Mendham  Michael Mitchell 《Agriculture and Human Values》2014,31(3):371-384

Agricultural industries in developed countries may need to consider transformative change if they are to respond effectively to contemporary challenges, including a changing climate. In this paper we apply a resilience lens to analyze a deliberate attempt by Australian governments to restructure the dairy industry, and then utilize this analysis to assess the usefulness of resilience thinking for contemporary agricultural transformations. Our analysis draws on findings from a case study of market deregulation in the subtropical dairy industry. Semi-structured interviews were conducted with dairy producers, their service providers, and industry and government staff. We found the adaptive cycle concept contributed to understanding how deregulation changed industry structures and working practices, how those changes led to feedbacks within the production system and supply chain, and how the industry following deregulation has experienced periods of stability and instability. Regime shifts were associated with an increase in demand for human capital, a degradation of cognitive social capital and a reduction in farm income. Findings identified that were not readily explained by the resilience thinking conceptual framework include a producer’s ability to anticipate and make choices and the change in social and power relationships in the industry.  相似文献   

Effects of diets with different plant proteins on the performance of silver perch (Bidyanus bidyanus Mitchell) and on water quality in earthen ponds     

Stuart J Rowland  Geoff L Allan  Charles Mifsud  Philip A Read  David Glendenning  & Brett A Ingram 《Aquaculture Research》2007,38(7):748-756

As part of a project to develop least‐cost diets with low levels of fish meal, silver perch (Bidyanus bidyanus Mitchell) fingerlings (mean weight, 11.8 g) were stocked at a density of 7500 fish ha⁻¹ into 0.1‐ha earthen ponds and fed one of two diets containing 33% digestible protein, 13 MJ kg⁻¹ digestible energy, similar nutrient specifications, but with different levels of fish meal and plant proteins. The reference diet SP35 had 27% fish meal, 28% wheat, 20% soybean and 11% sorghum, while the diet silver perch least‐cost (SPLC) had 10% fish meal, 20% peanut meal, 19% wheat, 17% lupins, 16% canola, 8% soybean and 5% blood meal; there were three replicate ponds for each diet. Fish were fed a restricted ration up to 5% body weight day⁻¹ and cultured for 10 months. Survival ranged from 85.9% to 94.3% and was not affected by diet. The mean weight (550 g), specific growth rate (SGR; 1.28% day⁻¹), absolute growth rate (AGR; 1.9 g fish⁻¹ day⁻¹) and production rate (4.5 tonnes ha⁻¹ year⁻¹) were significantly higher (P<0.05) and feed conversion ratio (FCR=1.8) was significantly lower for fish fed SP35 compared with fish fed SPLC (413 g, 1.18% day⁻¹, 1.4 g fish⁻¹ day⁻¹, 3.3 tonnes ha⁻¹ year⁻¹, 2.4). From October (spring) to March (autumn), turbidity was significantly lower (P<0.05) in SPLC ponds than in SP35 ponds, and fish were observed avoiding or ingesting and then expelling SPLC pellets. In February and March, infestations of the ectoparasitic copepod Ergasilus sp. were found on silver perch fed SPLC, and there was 5% post‐harvest mortality of these fish. The high inclusion levels of plant proteins, particularly peanut meal and canola in SPLC, may have provided anti‐nutritional factors and/or reduced the palatability and intake of the diet, adversely affecting the performance and health of silver perch, and water quality in the ponds. Our study demonstrates the value of evaluating new aquaculture diets under practical conditions over a complete growing period.  相似文献   

Hormonal regulation of antifreeze protein gene expression in winter flounder     

Garth L. Fletcher  David R. Idler  Allan Vaisius  Choy L. Hew 《Fish physiology and biochemistry》1989,7(1-6):387-393

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Combined effects of salinity and potassium concentration on juvenile mulloway (Argyrosomus japonicus, Temminck and Schlegel) in inland saline groundwater     

Mehdi S Doroudi  D Stewart Fielder  Geoff L Allan  & Grant K Webster 《Aquaculture Research》2006,37(10):1034-1039

This paper reports on experiments conducted to examine the combined effects of salinity and potassium concentration on survival and growth of juvenile mulloway (Argyrosomus japonicus, Temminck and Schlegel) in inland saline groundwater. Three separate experiments were conducted in 20 (±1)°C water. In the first experiment, mulloway were held in 60 L aquaria (triplicate) with salinities of 5, 15, 25 or 35 g L^?1 and potassium concentrations of 20%, 40%, 60% or 80% of the concentration present in oceanic water of the equivalent salinity in a 4 × 4 factorial combination for 7 days. Response surface contour diagrams were generated from survival data to estimate optimal conditions. The results showed that maximum survival of juvenile mulloway occurred at salinities of >14 g L^?1 and potassium concentrations of >38%. Survival was lowest at salinities of <7 and >33 g L^?1 and potassium concentrations of <25%. The second experiment was conducted with mulloway held in 60 L aquaria at salinities of 15, 25 or 35 g L^?1 and potassium concentrations of 40%, 60%, 80% or 100% in a 3 × 4 factorial combination for 44 days. Optimal conditions for maximum survival and growth of mulloway were within a salinity range of 15–35 g L^?1 and potassium concentration above 40%. The third experiment was conducted in three 500 L tanks to record the survival and growth of mulloway fingerlings held at 20 (±1)°C, 23 g L^?1 salinity and potassium concentrations of 50% for 8 months. Survival and growth of mulloway fingerling in inland saline groundwater were similar to those reported from a semi‐intensive floating tank system in inland saline water and sea cage trials in oceanic water.  相似文献   

Production of the Australian freshwater silver perch, Bidyanus bidyanus (Mitchell), at two densities in earthen ponds     

Stuart J. Rowland  Geoff L. Allan  Matthew Hollis  Trevor Pontifex 《Aquaculture (Amsterdam, Netherlands)》1995,130(4):317-328

Silver perch fingerlings (mean weight 15.3 g) were stocked at densities of 21 000 and 7000 fish/ha in six 0.1-ha earthen ponds and cultured for 10 months. There were three replicate ponds for each density. Ponds were aerated for at least 11 h a day and water was added every 4 weeks to replace that lost by evaporation and seepage. Fish were fed a formulated diet containing 35% crude protein at 4% body weight per day for the first 4 weeks and at rates up to 3% thereafter. The mean annual production rate of 9819 kg/ha of fish stocked at 21 000/ha was significantly higher (P < 0.01) than the annual rate of 3699 kg/ha of fish stocked at 7000/ha. The maximum daily production and growth rates achieved in any pond over a 1-month period during summer were 97.7 kg/ha and 5.1 g/fish, respectively. Stocking density did not significantly (P > 0.05) affect survival rate (treatment means for 21 000 and 7000 fish/ha: 92.8 and 94.7%), daily growth rate (0.2–3.3 and 0.3–3.4 g/fish), weight at harvest (434.9 and 473.2 g), food conversion ratio (1.9:1 and 1.8:1) and cost of feeding ($A1.55 and $A1.47/kg), suggesting that higher stocking densities and production rates are possible. Water temperatures ranged from 11.1 to 30.0 °C. Significantly (P < 0.05) slower growth during December was associated with concentrations of NH₃-N up to 0.65 mg/l. The results demonstrate that silver perch is an excellent species for semi-intensive culture in static earthen ponds with the potential to form the basis of a large industry in Australia, based on high-volume, relatively low-cost production.  相似文献   

Development of a feeding strategy for silver perch, Bidyanus bidyanus (Mitchell), based on restricted rations   总被引：1，自引：0，他引：1  

Stuart J Rowland  Geoff L Allan  Charlie Mifsud  Mark Nixon  Peter Boyd  & David Glendenning 《Aquaculture Research》2005,36(14):1429-1441

To develop a feeding strategy for the Australian freshwater fish silver perch (Bidyanus bidyanus Mitchell), a series of eight experiments was done in 1 m³ cages in an aerated, earthen pond to determine the effects of feeding rate (% body weight) and feeding frequency (no. of feeds day^?1) on the growth and feed conversion ratio (FCR) of fingerlings and larger fish under ambient water temperatures over the range 13.8–30.6°C. Fish were fed extruded pellets of a silver perch diet containing 34% digestible protein and 14 MJ kg^?1 digestible energy. Commercial silver perch farmers were consulted about feeding practices for large fish (>500 g) and at water temperatures below 12°C, and winter feeding practices for other warmwater species were used to complete the strategy. In the feeding experiments, growth and FCR increased with increasing feeding rates to a level above which only FCR increased. Optimal feeding rates and frequencies were those which resulted in maximal growth, while minimizing effort (feeding frequency) and FCR. The highest feeding frequency required for maximal growth, including that of small fingerlings was twice (2 ×) daily, and the optimal feeding rates varied with water temperature and size of fish. The optimal daily regimes were: small fingerlings (initial mean weight, 2.0 g) 7.5% 2 × at a mean temperature of 23.3°C; fingerlings (14.9–27.7 g) 7.5% 2 × at 27.1°C, 5.0% 2 × at 23.7°C and 2.0% 1 × at 16.8°C; and large silver perch (162.5–510.6 g) 0.5% 1 × daily or 1.0% on alternate days at 15.6°C, 1.0% 1 × at 17.3°C, 3.0% 2 × at 24.1°C and 2.0% 2 × at 27.9°C. It is suggested that regimes of 0.5% 1 × daily for fingerlings (<50 g) and 0.5% 1 × on alternate days for larger fish are used at temperatures of 9–12°C, and 0.5% 3 days week^?1 and 0.5% 1 day week^?1 for fingerlings and larger fish, respectively, at 6–9°C. Feed inputs should not exceed 150 kg ha^?1 day^?1 in ponds less than 0.3 ha and 100 kg ha^?1 day^?1 in larger ponds. Our research has established a feeding strategy for silver perch based on restricted rations.  相似文献   

The bacteriology of power station effluent used to farm marine fish     

A. Gilmour  May F. McCallum  M.C. Allan 《Aquaculture (Amsterdam, Netherlands)》1976,7(4):357-362

Duplicate water samples from an unstocked tank and from each of four tanks stocked with starved “1-group” plaice were analysed both quantitatively and qualitatively. It was found that bacterial counts obtained from samples taken from stocked tanks were significantly higher than those taken from an unstocked tank. Allowing for limited sampling, the flora of the water circulating through an unstocked tank did not radically differ from the flora of the water following the addition of starved fish. The predominant group was the Pseudomonas Group IV/Achromobacter/Alcaligenes/Agrobacterium group.  相似文献   

Carbohydrate utilization by juvenile silver perch, Bidyanus bidyanus (Mitchell). II. Digestibility and utilization of starch and its breakdown products     

D A J Stone  G L Allan  & A J Anderson 《Aquaculture Research》2003,34(2):109-121

Abstract The ability of silver perch ( Bidyanus bidyanus ) to digest and utilize dietary starch or starch breakdown products was investigated. For experiment 1 the ability of silver perch (2.7 ± 0.01 g) to digest wheat starch at two dietary inclusion levels (30% or 60%), each at four levels of gelatinization (0%, 25%, 50% or 80%), was investigated over a 31-day period. For experiment 2, the ability of silver perch (15.9± 0.25 g) to digest wheat starch, dextrin (at three levels of dextrinization), maltose, glucose and pea starch, all at the 30% inclusion level, was investigated over a 41-day period. Water temperature for both experiments was 25 ± 1 °C. Apparent digestibility coefficients (ADCs) for starch, dry matter (DM) and energy were affected by both degree of gelatinization (80% > 50% > 25% = 0%) and inclusion level (30% > 60%). Specific growth rate (SGR) was unaffected by the inclusion of 30% starch; however, it was reduced at the 60% starch content level. Degree of gelatinization had no effect on SGR. For experiment 2, there were significant differences between carbohydrate and DM ADCs for the test ingredients. The carbohydrate, DM and energy ADCs were ranked as follows: dextrin (Fieldose 9) = dextrin (Fieldose 17) = dextrin (Fieldose 30) = gelatinized wheat starch = maltose = glucose > raw wheat starch > raw pea starch. The protein ADC of the diets, postprandial plasma glucose concentration and SGR were all unaffected by ingredient type. For both experiments, HSI tended to increase with carbohydrate inclusion. Liver glycogen concentrations were also elevated, but muscle glycogen and liver and muscle triacylglycerol concentrations were unaffected. Digestibility of starch by silver perch is clearly affected by inclusion content and processing.  相似文献   

Effects of steam pelleting or extrusion on digestibility and performance of silver perch Bidyanus bidyanus     

M A Booth  G L Allan  A J Evans  & V P Gleeson 《Aquaculture Research》2002,33(14):1163-1173

The effects of different processing techniques on apparent digestibility coefficients (ADCs) and performance of silver perch Bidyanus bidyanus were evaluated. Results of a factorial digestibility trial, in which three diets (SP35, 95LC1 and 95LC2) and three processing methods (cold pelleted, steam pelleted and extruded) were evaluated, indicated that extrusion, but not steam conditioning, significantly improved ADCs of dry matter (DM) and energy. ADCs of DM and energy of cold‐pelleted diets were statistically similar to steam‐pelleted diets, and ADCs of nitrogen were unaffected by processing method. No interaction was found between diet type and processing method for DM, energy or nitrogen ADCs. A performance trial indicated that feed intake, weight gain and specific growth rate of fish fed steam‐pelleted diets was greater than those of fish fed extruded diets. Feed conversion and digestible protein efficiency was better in fish fed extruded diets. The results indicated that extruded diets were better utilized than steam‐pelleted diets; however, voluntary intake of extruded diets may have been limited. Fish fed cold‐pelleted SP35 exhibited inferior performance compared with fish fed steam‐pelleted or extruded SP35. Reduced performance of fish fed this diet may relate to poor utilization of digestible protein or reduced palatability. Diets for silver perch with similar formulations to SP35 and 95LC2 should be steam pelleted.  相似文献   

Control of MicroRNA Expression as a New Way for Resveratrol To Deliver Its Beneficial Effects     

Lançon A  Kaminski J  Tili E  Michaille JJ  Latruffe N 《Journal of agricultural and food chemistry》2012,60(36):8783-8789

Grapes produce large amounts of polyphenols. Many of them accumulate in the skin, pulp, and seeds and are consequently found in wine. The health benefits of a moderate consumption of wine have been attributed at least in part to grape's polyphenols. Among them, resveratrol (3,5,4'-trihydroxystilbene) is a phytoalexin that stimulates plant cell defenses against infections and also plays protective roles in humans, where it delays cardiovascular alterations and exerts anticancer and anti-inflammatory effects. Despite numerous studies, the molecular mechanisms of resveratrol action are only partially understood. Given its pleiotropic effects, it was previously suggested that resveratrol protective properties may arise from its modulation of the expression of microRNAs. Therefore, this review will focus on the effects of resveratrol on microRNA populations in humans and human cell lines, especially emphasizing the microRNAs that have been implicated in resveratrol effects on inflammation, cancer, metabolism, and muscle differentiation.  相似文献