scholarly journals Estimating the balance between pasture feed supply and demand of grazing livestock in a farmlet experiment

2013 ◽  
Vol 53 (8) ◽  
pp. 711 ◽  
Author(s):  
L. M. Shakhane ◽  
J. M. Scott ◽  
G. N. Hinch ◽  
D. F. Mackay ◽  
C. Lord
Keyword(s):  
Energy Balance ◽  
Soil Fertility ◽  
Energy Supply ◽  
Energy Demand ◽  
Supply And Demand ◽  
Grazing Management ◽  
Net Energy ◽  
Stocking Rate ◽  
Rates Of Change ◽  
Grazing Livestock

Data from the Cicerone farmlet study were used to quantify the balance between pasture feed supply and the demand from grazing livestock, in terms of metabolisable energy (ME), on three differently managed farmlets (each of 53 ha) on the Northern Tablelands of New South Wales, Australia. Farmlet A had a high level of pasture renovation and higher soil fertility than the other two farmlets and employed flexible grazing management over eight paddocks. Farmlet B was designed to represent management ‘typical’ of the region and had the same grazing management and number of paddocks as farmlet A but moderate levels of pasture renovation and soil fertility. The third farmlet (C) had the same level of inputs as farmlet B but practised intensive rotational grazing over 37 paddocks. Regular measurements of the feed supply, namely herbage mass and quality, pasture growth and supplement fed and of feed demand were assembled to provide monthly estimates of the balance between feed supply and animal demand of all classes of livestock run on the experiment over its duration of 6.5 years. The significantly greater stocking rate, liveweight and reproductive rate of sheep reached on the higher input system (farmlet A) meant higher levels of ME were required to satisfy the nutritional demands of these animals. As only limited measurements were taken of animal intake, it was assumed that the supply of ME was derived from pasture growth and supplement fed. Using key livestock management dates and measurements of liveweights, the changes in the energy requirements of each class of animal were calculated and aggregated to provide an estimate of overall livestock energy demand over time. Subtracting the energy demand from the estimated energy supply provided a partial net energy balance. Measurements of the rates of change of green herbage during grazing events were found to be highly dependent on stock density with farmlets A, B and C recording rates of change of up to –50, –30 and –200 green DM/ha.day, respectively. Over a series of generally drier-than-average years, the ME supplied in pasture growth and through supplementation was at times inadequate to meet the energy demands of the livestock, resulting in periods during winter when the partial energy balance became negative. Similar feed deficits were observed for all three farmlets, suggesting that they were over-stocked to a similar extent. In spite of the divergence in the stocking rate supported by each farmlet, the similarity of the ME balances between farmlets suggests that no farmlet was subjected to bias because of decisions relating to feed supply and demand. The analyses presented suggest there is considerable potential for practical paddock and grazing management to be improved if more timely and regular assessments can be made of changes in the feed energy supply using satellite images of normalised difference vegetation indices and feed energy demand using calculations of the ME required by grazing livestock.

The dynamics of energy supply and demand of foaling mares managed at pasture: a deterministic modelling approach

2020 ◽  
Vol 60 (18) ◽  
pp. 2122
Author(s):  
Y. Y. Chin ◽  
F. J. Roca Fraga ◽  
P. J. Back ◽  
E. K. Gee ◽  
C. W. Rogers
Keyword(s):  
New Zealand ◽  
Energy Balance ◽  
Nutritional Status ◽  
Reproductive Performance ◽  
Energy Supply ◽  
Energy Requirement ◽  
Supply And Demand ◽  
Energy Deficit ◽  
Positive Energy ◽  
Deterministic Modelling

Context. At pasture, the nutritional status of mares will change due to a dynamic association between their energy requirements and the energy supply. Change in the plane of nutrition can influence reproductive performance measures in the mares. To help optimise nutritional and operational management of mares on stud farms, the nutritional status of Thoroughbred broodmares and the factors influencing the energy supply and demand were investigated. Aims. To assess nutritional status of the Thoroughbred broodmare herds under ‘normal’ New Zealand commercial stud-farm conditions. Methods. The energy intake, energy requirement and energy balance during the last 3 months of pregnancy and the first 5 months of lactation were modelled for mares with an initial bodyweight of 450 kg, 500 kg, 550 kg and 600 kg, and foaled at 0, 15, 50, and 90 days after 1 September. Key results. For all foaling dates and bodyweights, mares were in positive energy balance during the last 3 months of pregnancy (6.1–8.5%). Energy balance decreased as pregnancy progressed, followed by a large and acute energy deficit that was initiated soon after foaling and continued during lactation. The energy deficit during lactation varied between –8.6% and –12.4%, depending on the foaling date modelled. Mares foaling later in the season (50–90 days after 1 September) had greater and longer (30–50 days) postpartum energy deficit than did mares that foaled earlier in the season, who recovered within 20 days postpartum. The modelled changes in the energy balance would be large enough to initiate mobilisation of the fat reserve (body condition), and could, therefore, explain the observation of delayed postpartum to conception interval observed with later-foaling mares on commercial farms. Conclusions. There is a large and prolonged energy deficit soon after foaling and throughout 150 days of lactation in Thoroughbred mares managed under New Zealand commercial grazing conditions. Foaling later in the season can cause a mismatch in energy supply and demand that would increase and prolong the energy deficit. Implications. These findings suggest a need for stud farms to actively manage the pasture supply and monitor the mare’s BWT and BCS changes in an attempt to optimise the mare’s nutritional status and reproductive performance.

scholarly journals Reflections on the concept, conduct and findings of the producer-led Cicerone Project

2013 ◽  
Vol 53 (8) ◽  
pp. 856 ◽  
Author(s):  
T. Coventry ◽  
H. Sutherland ◽  
M. Waters ◽  
P. Dutton ◽  
B. Gream ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Field Investigation ◽  
Leadership Role ◽  
Grazing Management ◽  
Successful Outcome ◽  
Integrated Analysis ◽  
Stocking Rate ◽  
Agricultural Ecosystem ◽  
Ecosystem Research ◽  
The Impact

The Cicerone Project began as a producer-led partnership that sought, over a period of 8 years, to enhance the profitability and sustainability of livestock enterprises by improving the connection between those producers, research and extension. Following a detailed survey, the research and extension needs of livestock producers were identified and several applied investigations were conducted to meet those needs and delivered through a range of extension activities. This final paper of the Cicerone Special Issue reflects on the entire Project from a wide array of perspectives, including livestock producers, researchers, extension specialists and staff employed by the Project, all of whom are authors of this paper. A notable early successful outcome of the Project was the improved precision of footrot diagnosis, which has been of value to the entire sheep industry, and that flowed from a field investigation of benign and virulent footrot combined with detailed genetic investigations, which led to an improved testing regime. This paper also reflects on the findings of an unreplicated agricultural ecosystem research trial, which measured the impact of pasture renovation, increased soil fertility and grazing management on the profitability and sustainability of three different 53-ha farmlets. Valuable findings from this whole-farmlet trial included the need for a high quality feed supply for increasing stocking rate and animal liveweights; the ability and utility of satellite imagery to detect changes in pasture growth, composition and recent grazing pressure; the value of short grazing and long rest periods for controlling Barber’s pole worms of sheep; the impact of increased stocking rates on whole-farm profitability and risk; methods of optimising decisions relating to pasture renovation, fertiliser applications and grazing management; and an integrated analysis of all key measured components of the farmlet management systems. Collectively, these findings were powerful as they were demonstrated at a scale credible to livestock producers using the ‘compare – measure – learn – adopt’ approach, which was the key philosophy adopted by the Cicerone Project. By comparing and measuring different whole-farm systems, and by ensuring that producers had ownership of the trial process, the Project successfully delivered objective findings that producers trusted and which increased our understanding of important drivers of complex grazing enterprises under variable climatic conditions. Some of these drivers included: the influence of soil phosphorus on botanical composition and subsequent livestock production, the role of pasture renovation and soil fertility on herbage supply, herbage quality and stocking rate, and the improved gastrointestinal nematode control delivered by intensive rotational grazing. The beneficiaries of the Project included the 180 farmer members who participated in some 61 field days and workshops; the research and extension collaborators including four postgraduates who completed their research investigations in conjunction with the Project; and some 500 undergraduate and 300 technical students who benefited from coming to understand the applied field comparisons of the three whole-farmlet systems. Having livestock producers play a significant leadership role led to valuable outcomes achieved with research collaborators; this should encourage the development of other learning partnerships which aim to explore complex farming system issues.

Russian Energy Sector: Inertia Strategy or Efficiency Strategy?

2007 ◽  
pp. 104-122 ◽  
Author(s):  
I. Bashmakov
Keyword(s):  
Economic Growth ◽  
Energy Supply ◽  
Energy Demand ◽  
Supply And Demand ◽  
Energy System ◽  
Or Efficiency ◽  
Russian Economy ◽  
Oriented Energy ◽  
The Given ◽  
Scenario Approach

The paper presents a vision of Russian energy future before 2020. The scenario approach is required to identify potential energy supply and demand future trajectories for Russia facing uncertainties of both global energy system evolution and domestic demographic and economic development in 2007-2020. It allows for assessing energy demand by sectors under different investment, technological and energy pricing policies favoring the least cost balancing of energy supply options and energy efficiency improvements to sustain dynamic economic growth. The given approach provides grounds for evaluation of different energy policies effectiveness. Three scenarios - "Inertia Strategy", "Energy Centrism", and "Efficiency Strategy - Four I" - integral-innovative-intellectual-individual oriented energy systems - are considered in the paper. It shows that ignorance of the last scenario escalates either energy shortages in the country or Russian economy overloading with energy supply investments both preventing from sustaining rates of economic growth which have recently been demonstrated by Russia.

Study on Region Energy Allocation under Carbon Emission Constraints: Base on Analysis of Carbon Pinch

2014 ◽  
Vol 977 ◽  
pp. 149-154
Author(s):  
Hong Yu ◽  
Jun Feng Wang ◽  
Lei Hu
Keyword(s):  
Energy Supply ◽  
Energy Demand ◽  
Carbon Emission ◽  
Supply And Demand ◽  
Clean Energy ◽  
Energy Allocation ◽  
Energy Utilization ◽  
Practical Significance ◽  
Energy Structure ◽  
Regional Energy

Energy Supply and demand, and carbon emission constraints are the problems that must be considered in the process of rapid economic development by national and every province. Under the constraints of energy supply and demand, and carbon emissions, there has practical significance to rational allocate regional energy utilization. With carbon pinch method, this paper research the energy allocation of Tianjin, establish analysis model. Considering the overall and regional energy demand and carbon emission constraints, to determine the usage amount of every kind of fossil energy and clean energy, in order to achieve the best energy structure and optimal balance between energy supply and demand. To provide scientific evidence for local government to make reasonable energy supply and carbon emission constraint index.

Heterogeneous Communication Architecture to Enable Demand Response Management for the Smart Grid

2013 ◽  
Vol 760-762 ◽  
pp. 652-655
Author(s):  
Zhong Wei Sun
Keyword(s):  
Optical Networks ◽  
Demand Response ◽  
Energy Supply ◽  
Energy Demand ◽  
Supply And Demand ◽  
Electrical Energy ◽  
Communication Technologies ◽  
Wireless Sensor ◽  
Communication Architecture ◽  
Home Area

Demand response entails the control of the energy demand and loads during critical peak situations to achieve a balance between electrical energy supply and demand. A robust communication infrastructure, which consists of network components of Home Area Networks (HANs) and Neighborhood Area Networks (NANs) is the touchstone to achieve the demand response goals. This paper surveys existing communication technologies that can be adopted for demand response applications. A heterogeneous communication architecture based on Wireless Sensor Networks (WSNs) and Ethernet Passive Optical Networks (EPONs) is presented, and the reliability and scalability requirements of communication system is satisfied.

scholarly journals Livestock weights in response to three whole-farmlet management systems

2013 ◽  
Vol 53 (8) ◽  
pp. 727 ◽  
Author(s):  
G. N. Hinch ◽  
J. Hoad ◽  
M. Lollback ◽  
S. Hatcher ◽  
R. Marchant ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Management Strategies ◽  
Experimental Period ◽  
Supplementary Feeding ◽  
Grazing Management ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Average Value ◽  
Management Regime ◽  
Similar Range

This paper reports changes in livestock weights recorded in a whole-farmlet experiment, which aimed to examine the profitability and sustainability of three different pasture and grazing management strategies. The assessment of liveweights was considered a key component of measuring the integrated effects of the farmlet-scale treatments. The three farmlets comprised a typical management regime, which employed flexible rotational grazing over eight paddocks with moderate soil fertility (farmlet B), a system based on the same grazing management and paddock number but with higher levels of sown pasture and soil fertility (farmlet A) and a farmlet with moderate soil fertility and intensive rotational grazing over 37 paddocks (farmlet C). Early in the experimental period, there were no significant differences between farmlets in the liveweight of any class of livestock. However, from the second year onwards, as the pasture renovation, soil fertility and grazing management treatments took effect, differences in liveweight between farmlets became more apparent and significant. The stocking rate, which was treated as an emergent property of each farmlet, reached a maximum annual average value after 5 years of 12.6, 8.5 and 7.7 dry sheep equivalents (dse)/ha on farmlets A, B and C representing 84, 113 and 51% of their respective target stocking rates which were 15, 7.5 and 15 dse/ha. The liveweights of ewes, both before joining and during pregnancy, varied with year and farmlet with those on farmlets A and B tending to be significantly heavier than those on farmlet C. From 2003 to 2006, liveweights were significantly (P < 0.001) affected by a wide array of factors and their interactions including: date, ewe age, green digestible herbage, legume herbage mass, proportion of farmlet grazed, stocking rate and level of supplementary feeding. The weights of lambs/weaners/hoggets, both pre- and post-weaning, were at times also higher on farmlets A and B compared with those on farmlet C and were affected by a similar range of factors to those which affected ewe weights. Similar relative differences also applied to the liveweights of the other livestock run on the farmlets, namely wethers and non-reproductive cattle. The results suggest that stocking rate was able to be increased towards the higher target of farmlet A due to the higher level of pasture renovation and soil fertility on that farmlet, which led to high liveweights per head as well as the higher stocking rate. However, as the stocking rate increased on farmlet A, the differences between farmlets in liveweight per head diminished and the need for supplementary feeding increased. In contrast, the intensive rotational grazing practised on farmlet C did not allow the farmlet to increase its stocking rate towards its higher target. It appears that the higher proportion of each of farmlets A and B grazed at any one time allowed all classes of livestock to reach higher liveweights per head than on farmlet C, due presumably to the greater proportion of those two farmlets grazed at any one time.

scholarly journals Energy Development: A Need for Vision and Statesmanship

1974 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
George A. Bevan
Keyword(s):  
Policy Development ◽  
Energy Supply ◽  
Energy Demand ◽  
Supply And Demand ◽  
The United States ◽  
Petroleum Products ◽  
Energy Development ◽  
Energy Resources ◽  
The World ◽  
Resource Policy

Energy demand the world over is increasing, and one of the consequences of this increased demand is raging debate on energy resources, development, and usage. This article examines the various sources of energy supply (such as coal, hydro-electric power, petroleum products, etcj and the energy demand requirements in (I) the world, (2) the United States, and (3) Canada, and then discusses the long-range implications of such supply and demand requirements against energy—proven and potential. The author then discusses the problem of resource policy development in Canada today, and in so doing, covers such issues as resource availability; capital requirement; pricing; exporting of energy; etc. Finally, the author proposes framework for the achievement of national consensus on energy development and usage for Canada.

scholarly journals 100% Renewable Energy Scenarios for North America—Spatial Distribution and Network Constraints

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 658
Author(s):  
Elmar Zozmann ◽  
Leonard Göke ◽  
Mario Kendziorski ◽  
Citlali Rodriguez del Angel ◽  
Christian von Hirschhausen ◽  
...  
Keyword(s):  
Renewable Energy ◽  
North America ◽  
Energy Supply ◽  
Energy Demand ◽  
Power Plants ◽  
Supply And Demand ◽  
State Level ◽  
Renewable Resource ◽  
Energy System ◽  
Energy System Model

The urgency to combat climate change and the widely distributed, increasingly competitive renewable resources in North America are strong arguments to explore scenarios for a renewable energy supply in the region. While the current power system of North America is heavily dependent on fossil fuels, namely natural gas, coal and oil, and some nuclear power plants, some current policies at the state level, and future federal policies are likely to push the share of different renewable sources available in Mexico, the U.S., and Canada. This paper explores three scenarios for a renewable energy supply, using a bottom-up energy system model with a high level of spatial and time granularity. The scenarios span the extremes with respect to connecting infrastructure: while one scenario only looks at state-level supply and demand, without interconnections, the other extreme scenario allows cross-continental network investments. The model results indicate that the North American continent (a) has sufficient renewable potential to satisfy its energy demand with renewables, independent of the underlying grid assumption, (b) solar generation dominates the generation mix as the least-cost option under given renewable resource availability and (c) simultaneous planning of generation and transmission capacity expansion does not result in high grid investments, but the necessary flexibility to integrate intermittent renewable generation is rather provided by the existing grid in combination with short-term and seasonal storages.

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