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Full-Text Articles in Plant Sciences
The Use Of Long-Term Modelling In Analysing N2O Abatement Strategies In Dairy Pastures, Richard J. Eckard, I. R. Johnson, D. F. Chapman
The Use Of Long-Term Modelling In Analysing N2O Abatement Strategies In Dairy Pastures, Richard J. Eckard, I. R. Johnson, D. F. Chapman
IGC Proceedings (1997-2023)
Concerns about the environmental impact of nitrogen (N) losses in Australia, in particular, nitrous oxide emissions are related to the rapid increase in N application on dairy pastures. Computer modelling is the most suitable method available to assess the potential of best management practices (BMP) to reduce field losses, as direct field measurements are frequently limited by the short term nature of many field trials.
Influence Of Giving A Choice Of Grazing Or Maize Silage Offered In The Field Simultaneously On Diet Selection Of Lactating Dairy Cows, O. Hernández‐Mendo, J. D. Leaver
Influence Of Giving A Choice Of Grazing Or Maize Silage Offered In The Field Simultaneously On Diet Selection Of Lactating Dairy Cows, O. Hernández‐Mendo, J. D. Leaver
IGC Proceedings (1997-2023)
Changing the times of access to grazing and to maize silage (MS) offered indoors affects the relative intake of each feed, but has little effect on dairy cow performance (Hernandez-Mendo & Leaver, 2000). Offering the MS in the grazing paddock as an instantaneous alternative to grazing should give an insight into the factors influencing feed intake, and may provide a means of alleviating the high rate of decline in milk yield of grazing dairy cows. The objective of this study was to examine the response in diet preferences and performance of lactating dairy cows when grazing a perennial ryegrass sward …
Elasticity Of Ingestive Behaviour And Intake In Sheep Associated With Food Diversity On Plurispecific Swards, C. Cortes, J. C. Damasceno, G. Bechet, J. Jamot, S. Prache
Elasticity Of Ingestive Behaviour And Intake In Sheep Associated With Food Diversity On Plurispecific Swards, C. Cortes, J. C. Damasceno, G. Bechet, J. Jamot, S. Prache
IGC Proceedings (1997-2023)
Animals on heterogeneous swards generally opt for a varied diet. This may stimulate their intake, unless searching constraints limit intake rate (Champion et al., 1998). However the management of plurispecific swards presents a risk of overgrazing the preferred species and undergrazing the less-preferred species. This study aimed to test the effect of type of diversity and type of management on the elasticity of ingestive behaviour and intake in sheep.
An Evaluation Of The N-Alkane Technique For Determining Diet Composition In Animals Grazing Complex Swards, M. D. Fraser, J. M. Moorby, V. J. Theobald, R. Jones
An Evaluation Of The N-Alkane Technique For Determining Diet Composition In Animals Grazing Complex Swards, M. D. Fraser, J. M. Moorby, V. J. Theobald, R. Jones
IGC Proceedings (1997-2023)
The n-alkane profiles of epicuticular waxes derived from different plant species are sufficiently distinct to allow assessment of the proportions of different herbages in two-component mixtures including perennial ryegrass/white clover, heather/hill grass and rush/perennial ryegrass (Dove & Mayes, 1996). Evidence suggests the reliability of such estimates declines as the number of different dietary components increases. However, recent studies have shown analysis of additional compounds, including long-chain fatty alcohols, may improve discrimination between different dietary components. The aim of this experiment was to quantify the accuracy of such methods for determining the diet composition of animals grazing complex swards.
Rich Information In The Acoustic Signals From Feeding And Grazing In Ruminants, Montague W. Demment, J. R. Galli, Carlos A. Cangiano, Emilio A. Laca
Rich Information In The Acoustic Signals From Feeding And Grazing In Ruminants, Montague W. Demment, J. R. Galli, Carlos A. Cangiano, Emilio A. Laca
IGC Proceedings (1997-2023)
Because of their impact on productivity and the environment, feeding behaviour, ingestion and rumination are critical to understand intake in grazing ruminants. Many systems, mainly mechanical, have been developed to measure ingestive behaviour. However, these systems have problems, including mechanical failure and the inability to distinguish between the complex jaw movements of prehension and ingestion (Laca et al., 1994). The sounds generated by these behaviours are rich in information that holds potential not only to distinguish and count behaviours, but also identify aspects of the nature of the foods ingested.
The Sound Of Chewing, J. R. Galli, Carlos A. Cangiano, Emilio A. Laca, M. W. Demment
The Sound Of Chewing, J. R. Galli, Carlos A. Cangiano, Emilio A. Laca, M. W. Demment
IGC Proceedings (1997-2023)
Acoustic biotelemetry has been proposed as a way to count ingestive bites and chews of grazing animals. Recent work has indicated the possibility that detailed analysis of 'sounds of chewing' contains information about other characteristics of the ingestive process that can be used to study grazing behaviour of free ranging animals (Laca & Wallis DeVries, 2000), or to monitor stall-fed animals in more detail.
Development Of A 2-Dimensional Video-Acoustic Tool For Monitoring Bite Placement, Wendy Griffiths, V. Alchanatis, R. Nitzan, V. Ostrovsky, E. Ben-Moshe, R. Yonatan, S. Brenner, H. Baram, E. D. Ungar
Development Of A 2-Dimensional Video-Acoustic Tool For Monitoring Bite Placement, Wendy Griffiths, V. Alchanatis, R. Nitzan, V. Ostrovsky, E. Ben-Moshe, R. Yonatan, S. Brenner, H. Baram, E. D. Ungar
IGC Proceedings (1997-2023)
Studies of grazing behaviour conducted at the spatial scale of a feeding station demonstrate that intake rate declines with increasing depletion, a response attributed to an increase in bite overlap (Ginnett et al., 1999; Ungar et al., 2001). In order to understand the rules that govern bite placement, a methodology is required that can map the sequential placement of bites on the sward surface. We developed a video-acoustic tool to achieve this and report the findings of using the tool on small uniform patches of herbage.
Production Systems To Integrate Livestock Grazing And Grain Production In Southern Brazil And Midwestern Usa, R. Mark Sulc, A. Moraes, S. J. Alves, A. Pelissari, Paulo C. De F. Carvalho, C. R. Lang
Production Systems To Integrate Livestock Grazing And Grain Production In Southern Brazil And Midwestern Usa, R. Mark Sulc, A. Moraes, S. J. Alves, A. Pelissari, Paulo C. De F. Carvalho, C. R. Lang
IGC Proceedings (1997-2023)
Agriculture in the USA and Brazil has undergone similar and dramatic changes in the past 20 years. In both countries, production systems have become increasingly specialized. Large farms are characterized by single enterprises, simple crop rotations, and livestock production is segregated from grain production. The lack of diversification and high production costs expose producers to risk from economic swings of single enterprises and greater reliance on pesticides and synthetic fertilizers to maintain profitability, along with greater risk of soil erosion from continuous row crop production. Scientists in southern Brazil and Ohio are collaborating to develop no-tillage systems that integrate livestock …
Rangelands In The Mediterranean Zone Of Croatia, J. Rogosic
Rangelands In The Mediterranean Zone Of Croatia, J. Rogosic
IGC Proceedings (1997-2023)
Rangelands dominate the landscape of the Mediterranean part of Croatia along the Adriatic coastline, occupying 83% of the agricultural land (1.7 million ha) and 40% of the entire country. The proportion of rangelands is considerably higher in the Mediterranean littoral than in other ecological regions of Croatia. Sheep and goats are widespread in the region, comprising 76% of total sheep and goat numbers in Croatia. However, in comparison to other regions of Croatia, livestock production in the Mediterranean zone is not well developed. Continuous grazing begun too early in the growing season has caused substantial rangeland degradation and a decline …
Variation Within The Species Macroptilium Atropurpureum Regarding Adaptation To Grazing, Cam K. Mcdonald, R. J. Clements
Variation Within The Species Macroptilium Atropurpureum Regarding Adaptation To Grazing, Cam K. Mcdonald, R. J. Clements
IGC Proceedings (1997-2023)
The twining legume Macroptilium atropurpureum cv. Siratro was released around 1960 (Hutton 1962) and the rust resistant cultivar Aztec was released in 1994 (Bray & Woodroffe 1995). The species showed great potential for pastures in northern Australia and was planted over some 220 Kha in the 1960's and 70's. The species was high yielding and readily eaten by cattle. However, by the early 1980's the species had declined dramatically in grazed pastures. Clements (1989) showed that a major problem with Siratro was the frequency of removal of growing points. This leads to less regrowth after grazing, less seed set and …
A Grazing Method To Solve The Lack Of Pastures In The Dry Season Of Tropical Areas With Long Periods Of Drought, R. O. Martinez, R. Tuero, M. F. Díaz
A Grazing Method To Solve The Lack Of Pastures In The Dry Season Of Tropical Areas With Long Periods Of Drought, R. O. Martinez, R. Tuero, M. F. Díaz
IGC Proceedings (1997-2023)
Rotational grazing systems used in tropical areas in Latin America do not solve the great difference in pasture availability between the dry and the rainy season. The main studies on rational grazing (Voisin, 1963) were performed in temperate areas where the deficit of feeds in winter may only be solved with external feeds such as forages and silages produced out of the grazing system. The objective of this work was to demonstrate that it is possible to maintain pasture availability throughout the year with the use of a Pennisetum purpureum clone (Cuba CT-115) adapted to grazing (Martínez et al., …
Utilizing Forages To Program Steer Growth Patterns To Achieve Consistent Quality Beef, B. G. Warrington, J. W. Holloway, R. K. Miller, H. Lippke
Utilizing Forages To Program Steer Growth Patterns To Achieve Consistent Quality Beef, B. G. Warrington, J. W. Holloway, R. K. Miller, H. Lippke
IGC Proceedings (1997-2023)
Many options are available for programming stocker cattle growth patterns through forage selection. In semi-arid south Texas rapid growth rates can be achieved by grazing irrigated small grains (oats, wheat and ryegrass) and slow growth rates are possible grazing native range pastures. Ryegrass (RG) nutrient quality indicates potential gains greater than 1.0 kg/d for steers, while typical winter native range (NR) pasture indicates gains of 0.45 kg/d or less. The purpose of this experiment was to quantify the impact of different programmed growth patterns on beef retail product especially size, marbling and tenderness.
Effect Of Potato Pulp Silage Supplementation On Milk Production In Cows Grazing Temperate Pasture, Masaaki Hanada, Y. Aibibula, D. Okumura, Meiji Okamoto
Effect Of Potato Pulp Silage Supplementation On Milk Production In Cows Grazing Temperate Pasture, Masaaki Hanada, Y. Aibibula, D. Okumura, Meiji Okamoto
IGC Proceedings (1997-2023)
In a dairy farming system based on pasture in Japan, maize grain is generally used as an energy source for milking cows, with almost all grain been imported. Potato-pulp is one of the agricultural by-products derived from the starch industry in the northern island of Japan. In our previous study (Aibibula et al., 2004), it was demonstrated that potato pulp could be preserved for a long time by ensiling without additives, and that the digestible energy value of potato pulp silage (13 MJ/kg DM) was almost the same as beet pulp. From these results, it is possible that some …
Mortality Model For A Perennial Grass In Australian Semi-Arid Wooded Grasslands Grazed By Sheep, K. C. Hodgkinson, W. J. Muller
Mortality Model For A Perennial Grass In Australian Semi-Arid Wooded Grasslands Grazed By Sheep, K. C. Hodgkinson, W. J. Muller
IGC Proceedings (1997-2023)
Grazing of sheep in marginal semi-arid environments is risky because grazing appears to predispose grass plants, especially palatable species, to sudden death (Hodgkinson, 1994; 1995). These early observations were based on a preliminary analysis of perennial grass survival in a single drought and supported the concept of tactical grazing proposed by Westoby et al. (1989) as a preferred management. Later this idea was developed by suggesting the existence of critical thresholds for perennial grass survival, which when crossed, collapses grass populations (Hodgkinson, 1994). Here we examine the relationship between mortality of a palatable perennial grass, Thyridolepis mitchelliana, and a …
Managing Resources By Grazing In Grasslands Dominated By Dominant Shrub Species, D. Magda, Cyril Agreil, Michel Meuret, E. Chambon-Dubreuil, P. -L. Osty
Managing Resources By Grazing In Grasslands Dominated By Dominant Shrub Species, D. Magda, Cyril Agreil, Michel Meuret, E. Chambon-Dubreuil, P. -L. Osty
IGC Proceedings (1997-2023)
The European natural grasslands are attracting new attention because of their environmental value as habitats for threatened fauna and flora species and their contribution to the diversity of landscapes. Those responsible for the implementation of the European agri-environmental policy are hence encouraging livestock farmers to adopt grazing practices that contribute to the conservation of grassland biodiversity especially by limiting encroachment by dominant shrubs. However, current scientific knowledge and technical information are often insufficient to connect flock feeding and the impact of grazing on shrub dynamics and livestock farmers are not very enthusiastic about restoring or conserving “plant mosaics” including shrubs …
Effect On Sward Botanical Composition Of Mixed And Sequential Grazing By Cattle And Sheep Of Upland Permanent Pasture In The Uk, J. E. Vale, M. D. Fraser, J. G. Evans
Effect On Sward Botanical Composition Of Mixed And Sequential Grazing By Cattle And Sheep Of Upland Permanent Pasture In The Uk, J. E. Vale, M. D. Fraser, J. G. Evans
IGC Proceedings (1997-2023)
Previous work has shown benefits of sequential grazing by cattle and sheep, with superior liveweight gains being recorded for lambs grazing swards previously grazed by cattle. A preliminary study of the effects of mixed sheep and cattle grazing also suggested that more extensively grazed swards offer scope for complementary grazing between sheep and cattle. The aim of this experiment was to directly compare these two approaches of integrating the grazing of cattle and sheep.
Effect Of Mixed And Sequential Grazing By Cattle And Sheep Of Upland Permanent Pasture On Liveweight Gain, M. D. Fraser, J. E. Vale, J. G. Evans
Effect Of Mixed And Sequential Grazing By Cattle And Sheep Of Upland Permanent Pasture On Liveweight Gain, M. D. Fraser, J. E. Vale, J. G. Evans
IGC Proceedings (1997-2023)
Previous work has shown benefits of sequential grazing by cattle and sheep, with superior liveweight gains being recorded for lambs grazing swards previously grazed by cattle. A preliminary study of the effects of mixed sheep and cattle grazing also suggested that more extensively grazed swards offer scope for complementary grazing between sheep and cattle. The aim of this experiment was to directly compare these two approaches of integrating the grazing of cattle and sheep.
Nutritional Value Of Pasture Forage For Sheep In Krkonoše National Park, P. Homolka
Nutritional Value Of Pasture Forage For Sheep In Krkonoše National Park, P. Homolka
IGC Proceedings (1997-2023)
This study describes the nutritional value of pastures in extreme mountain conditions in Krkonoše Mountains National Park. The Park performs important ecological and environmental functions. Extensive sheep grazing serves in the preservation of rare, protected and endangered species of plants (including endemics) and in the restoration of the biodiversity of meadows. The objective of this experiment was to estimate the production of plant biomass in these pastures and its digestibility by sheep.
Genetic Alternatives For Dairy Producers Who Practise Grazing, H. D. Norman, J. R. Wright, R. L. Powell
Genetic Alternatives For Dairy Producers Who Practise Grazing, H. D. Norman, J. R. Wright, R. L. Powell
IGC Proceedings (1997-2023)
The decline in cow fertility has had a negative impact on all dairy producers, especially those that practise seasonal calving with pasture-based dairying. One alternative that is being tried in the United States (US) by a few graziers is to use bulls from New Zealand (NZ) because NZ producers have practised seasonal calving for some time. However, genotype-environment interaction is a concern; genetic correlations that were derived by the International Bull Evaluation Service (2004) between bull rankings from different countries were often lower for NZ than for other countries. The objective of this study was to compare the performance of …
Variation Between Individuals In Voluntary Intake And Herbage Intake Of Grazing Dairy Cows, H. M. N. Ribeiro Filho, R. Delagarde, L. Delaby, J. L. Peyraud
Variation Between Individuals In Voluntary Intake And Herbage Intake Of Grazing Dairy Cows, H. M. N. Ribeiro Filho, R. Delagarde, L. Delaby, J. L. Peyraud
IGC Proceedings (1997-2023)
Herbage intake and milk yield of unsupplemented grazing dairy cows are highly variable between animals within a herd (Delaby et al., 2001). The objective of this experiment was to describe the relationship between the individual voluntary intake (VI) of dairy cows measured before turnout and their herbage intake at grazing, at two herbage allowances.
Visual Modelling Of Alfalfa Growth And Persistence Under Grazing, S. R. Smith Jr., L. Muendermann, A. Singh
Visual Modelling Of Alfalfa Growth And Persistence Under Grazing, S. R. Smith Jr., L. Muendermann, A. Singh
IGC Proceedings (1997-2023)
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 Farmer Friendly Feed Budget Calculator For Grazing Management Decisions In Winter And Spring, M. Curnow, M. W. Hyder
A Farmer Friendly Feed Budget Calculator For Grazing Management Decisions In Winter And Spring, M. Curnow, M. W. Hyder
IGC Proceedings (1997-2023)
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 …
Pasture Land Management System Decision Support Software, G. E. Groover, S. R. Smith, N. D. Stone, J. J. Venuto, J. M. Galbraith
Pasture Land Management System Decision Support Software, G. E. Groover, S. R. Smith, N. D. Stone, J. J. Venuto, J. M. Galbraith
IGC Proceedings (1997-2023)
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, K. Søegaard, J. Berntsen, K. A. Nielsen, I. Thysen
Forecast Of Herbage Production Under Continuous Grazing, K. Søegaard, J. Berntsen, K. A. Nielsen, I. Thysen
IGC Proceedings (1997-2023)
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 …
Milk Production Performance Based On Grazed Grassland In Switzerland, P. Thomet, H. Menzi
Milk Production Performance Based On Grazed Grassland In Switzerland, P. Thomet, H. Menzi
IGC Proceedings (1997-2023)
A common feature of profitable dairy systems is the use of large amounts of low cost feed. One approach to improve the competitive ability of the dairy production therefore is to promote grazing (Dillon et al., 1995). A comparison of the actual feeding costs on typical Swiss dairy farms showed that hay and grass silage were four times and concentrates seven times more expensive than grazed grass. A maximum utilisation of grazed grass can be achieved with a seasonal production system, which synchronises the cow’s feed requirements with pasture growth. This strategy was implemented and consistently optimised on an …
The Effect Of Inclusion Of A Range Of Supplementary Feeds On Herbage Intake, Total Dry Matter Intake And Substitution Rate In Grazing Dairy Cows, S. J. Morrison, D. C. Patterson, S. Dawson, C. P. Ferris
The Effect Of Inclusion Of A Range Of Supplementary Feeds On Herbage Intake, Total Dry Matter Intake And Substitution Rate In Grazing Dairy Cows, S. J. Morrison, D. C. Patterson, S. Dawson, C. P. Ferris
IGC Proceedings (1997-2023)
The milk production potential of dairy cows has increased substantially over the past two decades. This development presents new challenges for managing dairy cows during grazing, particularly where the objective is to maximise the proportion of energy in the diet derived from forage. The objective of the current study was to explore supplementation strategies to maintain high total forage intakes from grazed grass supplemented with alternative forage supplements in dairy cows during the grazing season. A second objective of the study was to examine the effect of supplement on substitution rate (SR) and milk yield response.
Manipulation Of Grass Growth Through Strategic Distribution Of Nitrogen Fertilisation, M. Stettler, P. Thomet
Manipulation Of Grass Growth Through Strategic Distribution Of Nitrogen Fertilisation, M. Stettler, P. Thomet
IGC Proceedings (1997-2023)
The objective of this study was to evaluate possibilities and limits of manipulating the grass growth of pastures by different nitrogen (N) application strategies with the aim to better synchronise grass supply and feed demand. In Switzerland, the use of N is strongly restricted by legislation. An efficient and well allocated N fertilisation is therefore important.
The Effect Of Closing Date And Type Of Utilisation In Autumn On Grass Yield In Spring, E. Mosimann, M. Lobsiger, C. Hofer, B. Jeangros, A. Lüscher
The Effect Of Closing Date And Type Of Utilisation In Autumn On Grass Yield In Spring, E. Mosimann, M. Lobsiger, C. Hofer, B. Jeangros, A. Lüscher
IGC Proceedings (1997-2023)
Due to the low cost of grazed grass, most dairy farmers extend the grazing period in autumn. However, delaying the closing date may reduce the grass yield in the following spring (Roche et al., 1996; O’Donovan et al., 2002). The objective of this experiment, conducted in the Swiss lowlands, was to quantify the effects of closing date and type of utilisation in autumn on grass yield in the following spring.
Supplementation Under Intensive Grazing, Silage- Or Grain-Based Diets For Beef Production On Steer Performance And Meat Fatty Acid Composition, J. Martínez Ferrer, E. Ustarroz, C. G. Ferrayoli, A. R. Castillo, D. Alomar
Supplementation Under Intensive Grazing, Silage- Or Grain-Based Diets For Beef Production On Steer Performance And Meat Fatty Acid Composition, J. Martínez Ferrer, E. Ustarroz, C. G. Ferrayoli, A. R. Castillo, D. Alomar
IGC Proceedings (1997-2023)
Alfalfa (Medicago sativa L.) is the main cultivated pasture in Argentina. In beef production enhanced productivity and profit depend on high stocking rates and pasture utilisation, with grain supplementation necessary to maintain high individual live weight gains (LWG) and to increase production per ha (Ustarroz, 1999). Substitution of grazed grass by concentrate can affect meat fatty acid (FA) composition (French et al., 2000). The objective of this study was to evaluate the effects of intensifying an alfalfa-based grazing system and two confinement dietary regimens for beef steer finishing on animal performance and meat FA composition.
Farming For Fun & Profit, M. Murphy
Farming For Fun & Profit, M. Murphy
IGC Proceedings (1997-2023)
We live in a competitive capitalist economy. Farming is rapidly moving from a highly subsidised sheltered existence into a more competitive future. Milk is a commodity. In commodity production the low cost producer survives and prospers. High cost farmers go out of business. So farmers, researchers and advisors need to maintain a relentless focus on low cost. We need durable, simple systems that exploit low feed cost based on grazed grass where temperate climate allows e.g. Ireland and New Zealand.