Radiation Use Efficiency Of Ryegrass: Determination With Non Cumulative Data,
2023
Catholic University of Louvain, Belgium
Radiation Use Efficiency Of Ryegrass: Determination With Non Cumulative Data, R. Lambert, A. Peeters
IGC Proceedings (1977-2023)
The growth of a crop is generally described as biomass accumulation per unit time. Monteith (1977) developed a model of growth where biomass accumulation is related to solar radiation intercepted by the crop. This model has been largely used for different crops. The conversion factor between radiation absorbed or intercepted by the crop and the biomass production is called “radiation use efficiency” or “dry matter radiation quotient”. Radiation use efficiency (RUE) is usually calculated as the regression coefficient of the linear relationship between crop biomass measured repeatedly during growth and cumulated intercepted or absorbed solar radiation. Demetriades-Shah et al. …
Modelling The Digestibility Decrease Of Three Grass Species During Spring Growth According To The Age Of The Grass, The Thermal Age And The Yield,
2023
Catholic University of Louvain, Belgium
Modelling The Digestibility Decrease Of Three Grass Species During Spring Growth According To The Age Of The Grass, The Thermal Age And The Yield, M. E. Salamanca, R. Lambert, M. Gomez, A. Peeters
IGC Proceedings (1977-2023)
The nutritive value of forage changes during growth. For the protein content, a general evolution curve was found with the yield increase (Salette & Lemaire, 1984). The digestibility of the organic matter decreases during growth as cellulose and lignin content increase. Regrowth age is the main factor, which explains the digestibility decrease (Demarquilly & Jarrige, 1981). The crop age can be expressed in number of growth days but also in thermal age (cumulated temperature). We compared the digestibility change of three grass species during spring growth for two years as a function of yield increase, thermal age or number of …
Visual Modelling Of Alfalfa Growth And Persistence Under Grazing,
2023
University of Kentucky
Visual Modelling Of Alfalfa Growth And Persistence Under Grazing, S. R. Smith Jr., L. Muendermann, A. Singh
IGC Proceedings (1977-2023)
A ‘virtual’ alfalfa plant model was developed at the University of Manitoba in Canada as part of a comprehensive grazing research project. This model shows an alfalfa plant ‘growing’ on a computer screen and the plant’s response to grazing (similar to time-lapse photography). The original model was constructed by Singh (2005) to show the research potential of visually modelling alfalfa plant growth. The ability to visually ‘grow’ a plant on a computer screen also offers tremendous opportunities for teaching and extension. Detailed morphological measurements were used in the construction of Singh’s model, based on single plants subjected to the following …
A New Agro-Meteorological Simulation Model For Predicting Daily Grass Growth Rates Across Ireland,
2023
Teagasc, Ireland
A New Agro-Meteorological Simulation Model For Predicting Daily Grass Growth Rates Across Ireland, R. P. O. Schulte
IGC Proceedings (1977-2023)
Grass growth rates and herbage yields depend on weather conditions, soil characteristics and grassland management and differ from year to year and from site to site. In the past, grass growth has been predicted using both mechanistic and statistical models. The accuracy of mechanistic models is commonly insufficient for practical application, while statistical models generally apply to one test site only (e.g. Han et al., 2003). In this paper a semi-empirical grass growth model is presented which is numerically accurate, but which can be applied to contrasting sites across Ireland at the same time.
A Farmer-Based Decision Support System For Managing Pasture Quality On Hill Country,
2023
Massey University, New Zealand
A Farmer-Based Decision Support System For Managing Pasture Quality On Hill Country, I. M. Brookes, D. I. Gray
IGC Proceedings (1977-2023)
Despite considerable effort to promote formal feed budgeting in New Zealand, survey data suggests it is only adopted by 20% of farmers (Nuthall & Bishop-Hurley, 1999). Recent work (Gray et al., 2003) has identified that farmers may use a different approach - micro-budgeting - to manage feed. Rather than operate at a whole farm level, micro-budgeting focuses at the paddock level. This paper describes micro-budgeting as used by a high performing hill country sheep and cattle farmer to manage pasture quality over spring and a decision support model developed to help other farmers undertake this process
Pâtur’In: A User-Friendly Software Tool To Assist Dairy Cow Grazing Management,
2023
INRA, France
Pâtur’In: A User-Friendly Software Tool To Assist Dairy Cow Grazing Management, L. Delaby, J. L. Peyraud, P. Faverdin
IGC Proceedings (1977-2023)
The feeding of dairy cows at pasture presents many technical, economic and environmental advantages, while benefiting from a very favourable image. However, the management of grazed land is a complex game of strategy in which the farmer applies decisions in order to manage two unstable and uncertain fluxes of change: growth of grass and intake of the herd. Many tools (platemeter, etc.) and overall methods (local stocking rate references, farm cover, etc.) have been developed as aids to grazing management. Nevertheless, few decision-support systems are currently available that make it possible to anticipate and assess the consequences of a given …
Understanding Livestock Grazing Impacts: A Decision Support Tool To Develop Goal-Oriented Grazing Management Strategies,
2023
University of California
Understanding Livestock Grazing Impacts: A Decision Support Tool To Develop Goal-Oriented Grazing Management Strategies, S. J. Barry, K. Guenther, G. Hayes, R. Larson, G. Nader, M. Doran
IGC Proceedings (1977-2023)
Managing grasslands in the western United States has become much more complex over the last few decades. A century ago the goal was to survive as a livestock producer, and grassland management involved using forage effectively and overcoming obstacles such as predators and shortages of water and feed. Today the successful grassland manager also needs to consider the diversity and health of the ecosystem as a whole. Livestock grazing can negatively and/or positively affect riparian areas, sensitive plants, and endangered wildlife. Since the impact on a specific factor will vary depending on the timing, intensity and class of livestock grazed, …
Enhancing Grasslands Education With Decision Support Tools,
2023
University of New England, Australia
Enhancing Grasslands Education With Decision Support Tools, H. G. Daily, J. M. Scott, J. M. Reid
IGC Proceedings (1977-2023)
We have successfully used Decision Support Tools (DST) relevant to the management of grazing enterprises to enhance problem solving skills of undergraduates in Australia. Tools such as GrassGro™ (Moore et al., 1997) and GrazFeed™ (Freer et al., 1997) are accessed from a central server by authorised users at many widely dispersed Universities across Australia using remote access to thin-client technology via an Internet portal. This has been supplemented with training for lecturers. Experience in developing appropriate teaching and learning materials and the reliable delivery of simulation software to many clients has enhanced learning outcomes at tertiary level. We …
A Farmer Friendly Feed Budget Calculator For Grazing Management Decisions In Winter And Spring,
2023
Department of Agriculture Western Australia
A Farmer Friendly Feed Budget Calculator For Grazing Management Decisions In Winter And Spring, M. Curnow, M. W. Hyder
IGC Proceedings (1977-2023)
The Western Australian (WA) environment is Mediterranean with annual legume/grass pastures and a 6 month growing season. In autumn where over grazing can impact pasture establishment and in spring, prior to senescence, when under grazing can mean significant losses of efficiency are crucial times for grazing management. Pasture utilisation is typically low (25-35%) due to conservative stocking regimes; key to increasing productivity is increasing pasture utilisation (Grimm, 1998). Increased levels of productivity require farmer sophistication in the way they feed budget. To this end, satellite technology is being used to provide farmers in southern Australia with weekly estimates of pasture …
Simulation Of Pasture Phase Options For Mixed Livestock And Cropping Enterprises,
2023
CSIRO Plant Industry, Australia
Simulation Of Pasture Phase Options For Mixed Livestock And Cropping Enterprises, L. Salmon, A. D. Moore, J. F. Angus
IGC Proceedings (1977-2023)
In southern Australia, 50% of grain-producing farms also run beef and/or sheep enterprises. Legume pasture leys are used to replace soil nitrogen and manage crop disease risks. Deep-rooted perennials, predominantly lucerne (Medicago sativa), are replacing annual Trifolium subterraneum-based leys to increase pasture production. They also have the environmental benefits of limiting soil acidity, rising water tables and dryland salinity. After recent droughts depletion of soil water by lucerne has penalised wheat yields. Decision support tools can help farmers evaluate the long-term effects of grazed annual and perennial leys on animal and crop production at the whole farm …
Grasscheck: Monitoring And Predicting Grass Production In Northern Ireland,
2023
Agricultural Research Institute of Northern Ireland, UK
Grasscheck: Monitoring And Predicting Grass Production In Northern Ireland, P. D. Barrett, A. S. Laidlaw
IGC Proceedings (1977-2023)
No abstract provided.
Effect Of Strategy Of Forage Supplementation And Of Turnout Date In A Medium Stocking Rate System On The Main Characteristics Of Dairy Cows Grazing,
2023
CRA de Bretagne, France
Effect Of Strategy Of Forage Supplementation And Of Turnout Date In A Medium Stocking Rate System On The Main Characteristics Of Dairy Cows Grazing, P. Defrance, L. Delaby, J. M. Seuret, M. O'Donovan
IGC Proceedings (1977-2023)
Having a stocking rate of 2.9 cows per hectare of grassland (35 ares/cow) in Brittany offers many options for turnout date and forage supplementation strategies. For a farmer, knowing the consequences of the different options during the course of the grazing season makes grazing management decisions easier. As experiments on grazing management require considerable resources and are hardly generalisable, various spring scenarios have been tested using a dynamic decision support system, Pâtur’IN (Delaby et al., this volume).
Grass Growth Profiles In Brittany,
2023
CRA de Bretagne, France
Grass Growth Profiles In Brittany, P. Defrance, J. M. Seuret, L. Delaby
IGC Proceedings (1977-2023)
For farmers, knowing the local grass growth profile and the possible variations between years is very helpful in managing grazing. Indeed, the comparison with herd needs and anticipated farm cover change allows decisions to be made that will maintain the cover at the desired level. This paper proposes a ten-days grass growth profile corresponding to Brittany’s different conditions of soil, climate and pasture management.
Using The Grassgro Decision Support Tool To Evaluate The Response In Grazing Systems To Pasture Legume Or A Grass Cultivar With Improved Nutritive Value,
2023
CSIRO, Australia
Using The Grassgro Decision Support Tool To Evaluate The Response In Grazing Systems To Pasture Legume Or A Grass Cultivar With Improved Nutritive Value, H. Dove, J. R. Donnelly
IGC Proceedings (1977-2023)
Decision support tools (DST) based on models of grazing systems allow the evaluation of changes in enterprise management on productivity and profitability. The Grassgro DST (Moore et al., 1997) uses historical weather data on a daily time step to simulate pasture growth and the resultant productivity of either grazing sheep or cattle. Different pasture species are represented within a parameter set that describes the response of pasture species to their environment. Manipulation of these parameters provides a means of evaluating, a priori, the likely responses of livestock production to ‘improved cultivars’. We report the results of simulations conducted …
Pasture Land Management System Decision Support Software,
2023
VA Tech
Pasture Land Management System Decision Support Software, G. E. Groover, S. R. Smith, N. D. Stone, J. J. Venuto, J. M. Galbraith
IGC Proceedings (1977-2023)
Controlled or rotational grazing provides benefits to producers and society through profitable and sound management of grazing land and livestock. Pasture land management system (PLMS) is a decision support system developed to help university, government, and professionals provide technical pasture management assistance to beef and dairy producers. The PLMS focuses on the balance between seasonal forage supply and nutrient demand in a dairy or beef cattle operation. It allows users to explore and compare alternatives (dividing fields into multiple paddocks, changing stocking rates, and forage species) through a visual display and embedded simulation. Users enter a description of the farm …
Forecast Of Herbage Production Under Continuous Grazing,
2023
Danish Institute of Agricultural Sciences, Denmark
Forecast Of Herbage Production Under Continuous Grazing, K. Søegaard, J. Berntsen, K. A. Nielsen, I. Thysen
IGC Proceedings (1977-2023)
The utilization of pasture is very sensitive to oscillations in herbage growth. The farmer’s daily planning involves decisions on pasture use as well as on the amount and composition of supplement feeding. In this planning, expected daily growth rate is an important factor. Often the knowledge and experience about the growth rate is first available after changes in management should have been made. A different growth rate than expected should lead to changes in the grazing area or in the supplement feeding. Therefore, a simple model of grass/clover growth under grazing and irrigated conditions was developed. From spring 2004, the …
A Decision Support Tool For Seed Mixture Calculations,
2023
Alberta Agriculture, Food and Rural Development, Canada
A Decision Support Tool For Seed Mixture Calculations, B. P. Berg, G. Hutton
IGC Proceedings (1977-2023)
Grassland species are normally seeded in mixtures rather than monocultures. In theory, seeding rates for mixtures are simply a sum of the amount of pure live seed (PLS) of each seed lot in the mix, an amount sufficient to ensure establishment and survival of each species. Mixtures can be complex because of the number of species used (especially in conservation and reclamation programs) and variations in seed purity and seed size. Soil limitations and seeding equipment settings need to be considered and in Canada, a metric conversion may be required. All these conditions make by-hand calculations of mixtures containing more …
Risk-Efficiency Assessment Of Haying,
2023
Massey University, New Zealand
Risk-Efficiency Assessment Of Haying, A. J. Romera, J. Hodgson, S. T. Morris, S. J. R. Woodward, W. D. Stirling
IGC Proceedings (1977-2023)
Pastoral livestock farms are complex, dynamic systems subject to many forms of external disturbance. Farm Management strategies are therefore typically designed to minimize system variation. The objective of this study was to explore the impacts of different haying policies, in terms of expected profit and risk, for cow-calf farms in the Salado Region of Argentina.
Environmental Clustering Of New Zealand Dairy Herds,
2023
Massey University, New Zealand
Environmental Clustering Of New Zealand Dairy Herds, J. R. Bryant, N. López-Villalobos, J. E. Pryce, C. W. Holmes
IGC Proceedings (1977-2023)
Previous studies have found that milk yield (a proxy for feeding level) and temperature-humidity index (THI) are important factors in explaining genotype x environment (G x E) interactions, indicating differences between the abilities of genotypes to forage or consume concentrates effectively or to cope with thermal stress (Ravagnolo and Misztal, 2000; Zwald et al., 2003). The objective of this study was to quantify and cluster (CL) herd environments within New Zealand (NZ) based on production levels, a summer heat load index (HLI) and geographical location.
Irish Dairy Farming: Effects Of Introducing A Maize Component On Grassland Management Over The Next 50 Years,
2023
University College Dublin, Ireland
Irish Dairy Farming: Effects Of Introducing A Maize Component On Grassland Management Over The Next 50 Years, A. J. Brereton, N. M. Holden
IGC Proceedings (1977-2023)
Typical management of Irish dairy units is based on a low-cost spring-calving strategy with 90% of annual feed derived from grass grown on the farm. Almost 70% of feed is from grazed grass managed by rotational grazing, the remainder is conserved forage and concentrates. The objectives of the work were to examine how the management system has to be modified when part of the dairy unit land is allocated to maize silage instead of grass silage production, and to examine how climate change over the next 50 years will impact on grass and maize management within the production system.
