Physical Sciences and Mathematics Commons^™

Influence Of Grazing On Soil Microbial Communities On A Mixed Grass Prairie Ecosystem, L. J. Ingram, G. E. Schuman, P. D. Stahl, J. Buyer

IGC Proceedings (1997-2023)

The grazing of ungulates is the predominant use for much of the world's semiarid rangelands. Grazing these lands can result in significant changes not only in the vegetation community but also in the soil physical, chemical and biological properties. Changes in soil physical and chemical properties and the plant community can potentially lead to changes in soil microbial communities which may have long-term ramifications for nutrient cycling and carbon (C) sequestration. The objective of this research was to ascertain the influence of three long-term grazing treatments on soil microbial communities.

Pâtur’In: A User-Friendly Software Tool To Assist Dairy Cow Grazing Management, Luc Delaby, J. L. Peyraud, P. Faverdin

IGC Proceedings (1997-2023)

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 …

External Validation In Northwest Spain Of A Decision Support System For Grazing Dairy Cows (Grazemore), Antonio González-Rodríguez, J. López Díaz, O. P. Vázquez Yáñez

IGC Proceedings (1997-2023)

A model to predict intake and milk production of cows on grazed grass (Grazemore) was developed (Mayne et al., 2004) for farmers to increase reliance on the grassland resources of the farm and reduce the tendency towards intensive dairy production in most countries of the Atlantic Arc of Europe (González, 2003). Climatic conditions and fertiliser use is the basis of the herbage growth model, but under practical conditions the estimation of the nutrient supply to cows is much affected by management, number of cows and the area of each paddock grazed. The intake capacity of the animal and the …

Determination Of Optimal Grazing Management For Dairy Cows In Galicia (Spain) Using A Decision Support System, O. P. Vázquez Yáñez, A. González Rodríguez, J. López Díaz

IGC Proceedings (1997-2023)

GRAZEMORE is a decision support system (DSS) oriented to evaluate dairy grazing management decisions on pasture growth and milk production. The system integrates a herbage growth model (Barrett et al., 2003) and a herbage intake model (Delagarde et al., 2004) and has been validated in several EU countries. The objective of this work was to use this DSS to determine optimal grazing management of dairy cows at three supplementation levels and three grazing management strategies under Galician conditions.

Grassland Technology Interaction And Policy Evolution In Canada, Duane H. Mccartney, P. Jefferson

IGC Proceedings (1997-2023)

Canada is the world's second largest country covering approximately 10 million km² (McCartney & Horton, 1997). About 90% of Canada is uninhabited with 90 percent of Canadians living within 500 km of the American border. The forage resources used by livestock grazing and the production of forage crops covers over 36 million ha of Canada's land base (3.6%) and is divided into 72% native range (26 million ha), 11% cultivated pastures (4 million ha) and 17% forage crops (6 million ha) There are 25 million ha in grain and oilseed crops (McCartney & Horton, 1997).

Dynamics Of Long-Term Carbon Sequestration On Rangelands In The Western Usa, G. E. Schuman, L. J. Ingram, P. D. Stahl, G. F. Vance

IGC Proceedings (1997-2023)

Rangelands in the USA occupy 161 million hectares of land. Worldwide, rangelands occupy about half of the land area and account for more than 1/3 of the world's terrestrial carbon (C) reserves. Because of their large land area, rangelands have the potential to sequester a significant amount of additional atmospheric C. Schuman et al. (2001) estimate that rangelands and marginal croplands restored to grasslands in the USA can sequester 64 million metric tonnes C/ha/yr if properly managed. The objective of this research was to evaluate the long-term effects of grazing on soil C storage in a northern mixed-grass prairie (NMP).

Cattle Grazing Management Effects On Pasture Composition In Semi-Arid Woodlands, Trevor J. Hall, J. R. Douglas

IGC Proceedings (1997-2023)

Manipulating grazing pressure, controlling tree competition and burning are the main options for cattle farmers to manage land in subtropical Australian Eucalypt woodlands. These can contain >175 herbaceous and 60 woody species, but only 5 are desirable perennial and productive grass (Silcock et al., 1996). Here we describe the responses of some perennial grasses to cattle grazing pressure, tree competition and spring burning.

Sustainable Semi-Arid Grazing Management Based On Indigenous Shona Practices Prior To Introduction Of Western Ideas In Zimbabwe, O. Mugweni, R. Mugweni

IGC Proceedings (1997-2023)

In the Shona culture the land, i.e. the plants, animals, soil, water, air and others, evolved with herding animals. Hence, the absence of one results in the destruction of the other. It is argued that the conventional grazing management belief that too many animals cause overgrazing is a misconception of the semi-arid savanna environments of Southern Africa where these environments evolved with thousands of herding grazers and mega-faunas such as elephants, wildebeests and buffalo. The objective of the research is to establish that grazing with an adequate recovery period for grazed plants, as a result of domesticated animals being managed …

Herbage Production Of Tanzania Grass (Panicum Maximum Cv. Tanzania) Submitted To Combinations Of Frequencies And Intensities Of Grazing By Cattle, Domicio Nascimento Jr., Rodrigo A. Barbosa, Valéria P. B. Euclides, S. C. Da Silva, R. A. Torres

IGC Proceedings (1997-2023)

Animal production from pastures is a complex process comprising three main stages: herbage growth, consumption by grazing animals and conversion into animal products (Hodgson, 1990). Utilisation is the stage where the grazier finds greater flexibility for management, probably because most processes related to harvest of the produced herbage by the grazing animals are very responsive to manipulation and control of defoliation practices. The objective of this study was to evaluate herbage production of a Panicum maximum cv. Tanzania pasture submitted to combinations of frequencies and intensities of grazing.

Herbage Intake And Animal Performance Of Cattle Grazing Brachiaria Brizantha Cv. Marandu Under Continuous Stocking, S. C. Da Silva, P. Sarmento, L. K. Molan, F. M. E. Andrade, André F. Sbrissia, A. V. Lupinacci, A. C. Gonçalves, D. E. Oliveira

IGC Proceedings (1997-2023)

Grazing management affects sward structure, which in turn influences plant and animal responses. With the objective of understanding causal relationship between sward structure and animal responses, the present experiment evaluated the daily herbage intake and live weight gain of growing cattle on Brachiaria brizantha cv. Marandu pasture during summer (Dec. 2001 to Mar. 2002).

Sustainable Semi-Arid Grazing Management Based On Indigenous Shona Practices Prior To Introduction Of Western Ideas In Zimbabwe, O. Mugweni, R. Mugweni

IGC Proceedings (1997-2023)

In the Shona culture the land, i.e. the plants, animals, soil, water, air and others, evolved with herding animals. Hence, the absence of one results in the destruction of the other. It is argued that the conventional grazing management belief that too many animals cause overgrazing is a misconception of the semi-arid savanna environments of Southern Africa where these environments evolved with thousands of herding grazers and mega-faunas such as elephants, wildebeests and buffalo. The objective of the research is to establish that grazing with an adequate recovery period for grazed plants, as a result of domesticated animals being managed …

Rangeland As A Common Property Resource: Contrasting Insights From Communal Areas Of Central Eastern Cape Province, South Africa, J. E. Bennett, H. R. Barrett

IGC Proceedings (1997-2023)

In communal areas of South Africa, grazing systems are held under a variety of different common property regimes. However, the social and ecological realities of these communal grazing systems remain poorly understood, particularly with regard to the use of land allocated for crop production. Little is known about how these arable areas are utilised as a common grazing resource but the wide array of tenure arrangements under which they are held suggests that they facilitate some interesting departures from recognised common property systems. A clearer understanding of how common property regimes function at an integrated level in South Africa will …

Pâtur’In: A User-Friendly Software Tool To Assist Dairy Cow Grazing Management, L. Delaby, J. L. Peyraud, P. Faverdin

IGC Proceedings (1997-2023)

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, S. J. Barry, K. Guenther, G. Hayes, R. Larson, G. Nader, M. Doran

IGC Proceedings (1997-2023)

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, …

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 (1997-2023)

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, P. Defrance, J. M. Seuret, L. Delaby

IGC Proceedings (1997-2023)

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.

Both Grass Development Stage And Grazing Management Influence Milk Terpene Content, G. Tornambé, A. Cornu, N. Kondjoyan, P. Pradel, M. Petit, B. Martin

IGC Proceedings (1997-2023)

Terpenes are a wide group of molecules originating from plants’ secondary metabolism. Forage terpenes vary according to the botanical composition and in particular to the proportion of plants such as Apiaceae, Lamiaceae or Asteraceae. These molecules are considered effective milk markers for the presence of diversified forages in dairy cow diets. The variation in terpene content in the milk of grazing cows would depend on the period of development of terpene-rich plants and on the grazing management, whereby cows do or do not have the opportunity to choose and to modify the botanical composition of the ingested grass. The aim …

Foraging Behaviour And Herbage Intake In The Favourable Tropics/Sub-Tropics, S. C. Da Silva, Paulo C. De F. Carvalho

IGC Proceedings (1997-2023)

1. Herbage intake by animals grazing tropical/sub-tropical pastures is directly related to bite mass, as it is for those grazing temperate pastures.
2. Where these swards have low proportions of stem and dead material (controlled swards), herbage intake follows a similar pattern to that of temperate pasture species, but leaf characteristics, such as lamina length play an important role and influence the short-term rate of intake.
3. Sward structural characteristics and behavioural factors are relatively more important than nutritional factors in terms of herbage intake regulation. The feeding value of the herbage produced is potentially adequate to sustain high levels of beef cattle …

Challenges And Opportunities For Sustainable Rangeland Pastoral Systems In The Edwards Plateau Of Texas, J. W. Walker, J. L. Johnson, C. A. Taylor Jr.

IGC Proceedings (1997-2023)

This paper focuses on pastoral systems in an area of west-central Texas known as the Edwards Plateau. These rangelands have a combination of grass, forb and browse species and are used primarily for combinations of grazing by cattle, sheep, goats and wildlife. A major ecological challenge is woody plant encroachment. Stocking rate is the major factor affecting sustainability and historically this area was heavily grazed. Today the stocking rate is half or less of its historical peak. Species of livestock has shifted from predominantly small ruminant to cattle. About 70 % of pastoralists use some sort of rotational grazing system. …