Digital Commons Network^™

A Survey Of European Regional Adaptation In Italian Ryegrass Varieties, T. J. Gilliland, A. J. P. Wijk

IGC Proceedings (1977-2023)

Ryegrass is widely adapted to cool temperate eco-zones and breeders often submit individual varieties for testing in a number of EU countries. National testing programmes often combine data from several trial sites that may differ climatically, but not from sites in other member states, despite the possibility of high ecological similarity. Given increasing interest in ‘animal value’ characters (soluble sugars, lipids, sward geometry), additional testing for these would be valuable but is prohibited by capped or declining funding. Data sharing between EU national authorities could be advantageous but is inhibited by the lack of statistically valid data on the sensitivity …

Perennial Ryegrass Variety Differences In Nutritive Value Characteristics, T. J. Gilliland, R. E. Agnew, A. M. Fearson, F. E. A. Wilson

IGC Proceedings (1977-2023)

Animal grazing performance at grass is predominately determined by herbage intake rates, with high yielding dairy cows requiring up to 20 kg/d DM within a limited grazing time (Gibb, 1998). Grass nutritional factors such as seasonal patterns in digestibility and water-soluble carbohydrate levels have been linked to animal productivity (Davies et al., 1991), while sward surface height, herbage mass, bulk density and green leaf mass have been shown to promote high grazing intake (Barrett et al., 2001). Furthermore, fatty acid profiles have been shown to improve the unsaturated fatty acid composition of milk, with potential human health benefits …

Management Of Pasture Quality For Sheep On New Zealand Hill Country, D. I. Gray, J. I. Reid, P. D. Kemp, I. M. Brookes, D. Horne, P. R. Kenyon, C. Matthew, S. T. Morris, I. Valentine

IGC Proceedings (1977-2023)

The control of pasture quality over spring is central to the achievement of high levels of sheep performance on hill country. Despite this, with the exception of the work of Lambert et al. (2000), little is known about how farmers actually manage pasture quality. The purpose of this research was to describe how a high performing hill country farmer manages pasture quality on their sheep area over spring and from this develop a framework that will assist other farmers improve their pasture management.

Production And Plant Density Of Sulla Grazed By Sheep At Three Growth Stages, H. Krishna, P. D. Kemp

IGC Proceedings (1977-2023)

Sulla is one of the few temperate forage legumes that contain enough condensed tannins to improve the efficiency with which livestock use protein (Marshall et al., 1979). However, it usually is productive only for approximately 14 months in New Zealand, and little is known of its response to grazing. This paper reports on the production and persistence of Sulla cv. Necton, when using growth stage as the criterion for time of grazing by sheep in a maritime, temperate environment.

Spring Calving Suckler Beef Systems: Influence Of Grassland Management System On Herbage Availability, Utilisation, Quality And Cow And Calf Performance To Weaning, M. J. Drennan, M. Mcgee, S. Kyne, B. O'Neill

IGC Proceedings (1977-2023)

Suckler beef systems in Ireland are primarily based on grass. Suckler systems vary in intensity but many operate low input systems and participate in REPS (Rural Environmental Protection Scheme). As there is a considerable cost associated with second-cut silage this research compared a two-cut system with a simplified low input one-cut system.

The Importance Of Patch Size In Estimating Steady-State Bite Rate In Grazing Cattle, E. D. Ungar, N. Ravid, T. Zada, E. Ben-Moshe, R. Yonatan, S. Brenner, H. Baram, A. Genizi

IGC Proceedings (1977-2023)

Since the pioneering work of Black and Kenney (1984), various intake studies have been conducted at the spatial scale of a single feeding station ("patch") to elucidate the processes that determine instantaneous intake rate (e.g. Laca et al., 1994). While these are well-suited for patch depletion studies, it is less clear how well they represent non-patchy and relatively homogeneous environments (Ungar & Griffiths, 2002). Clearly, grazing should be restricted to the upper grazing horizon (i.e. layer of bites), but sample duration may be insufficient to characterize steady-state behaviour, especially when grazing commences on an empty mouth. We examined the …

Performance Of Meat Goats Grazing Winter Annual Grasses In The Piedmont Of The Southeastern Usa, J-M. Luginbuhl, J. P. Mueller

IGC Proceedings (1977-2023)

In the Southeastern United States, meat goats (Capra hircus hircus) are becoming increasingly important contributors to the income of many small producers. Meat goats perform well in grazing situations if grazing management practices match their grazing behavior. Nevertheless, little research data are available from the region specifically directed toward forage feeding programs for goats reared for meat production. Hart et al. (1993) reported that growing Alpine, Angora and Nubian kids grazed on high quality Triticum aestivum forage gained 50 g/d, whereas Kiesling et al. (1994) reported gains ranging from 65 to 141 g/d in growing Angora …

The Effect Of Early And Delayed Spring Grazing On The Milk Production, Grazing Management And Grass Intake Of Dairy Cows, E. Kennedy, M. O'Donovan, J. P. Murphy, L. Delaby, F. P. O'Mara

IGC Proceedings (1977-2023)

Earlier access to pasture can increase the overall proportion of grazed grass in the diet of the spring calving dairy cow. Further benefits can also be achieved from early turnout, including improved animal production, increased sward utilisation and enhanced sward quality (O’Donovan et al., 2004). The objective of this study was to compare the effect of initial spring grazing date and stocking rate on the performance of spring calving dairy cows.

Intake Characteristics Of Diploid And Tetraploid Perennial Ryegrass Varieties When Grazed By Simmental X Holstein Yearling Heifers Under Rotational Stocking Management, R. J. Orr, J. E. Cook, K. L. Young, R. A. Champion, A. J. Rook

IGC Proceedings (1977-2023)

Orr et al. (2003) measured large differences in dry matter (DM) intake rate between 15 intermediate-heading perennial ryegrass varieties when they were continuously stocked with sheep and subsequently explored the extent to which, for 5 of these varieties, these differences could be explained by chemical and morphological traits (Orr et al., 2004a) which could be targeted in grass breeding programmes. Here, four of the 15 varieties, which within ploidy had low or high intake characteristics when grazed by sheep, were rotationally stocked with cattle and intake and sward factors were measured.

Optimising Financial Return From Grazing In Temperate Pastures, P. Dillon, J. R. Roche, L. Shalloo, B. Horan

IGC Proceedings (1977-2023)

Key Points

1. The increased interest in pasture-based systems of milk production in recent years has been largely generated through lower product prices and rising costs of production.

2. Pasture based systems of milk production decrease unit production costs, through lower feed and labour expenses, and reduced capital investment.

3. Systems utilising grazed pasture will be optimised in regions where pasture production potential is high, variability in seasonal pasture supply and quality is low, manufacturing milk accounts for a large proportion of total production, and where large areas of land are available at relatively low cost.

4. Pasture based systems may allow greater global …

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Challenges And Opportunities For Animal Production From Temperate Pastures, D. A. Clark

IGC Proceedings (1977-2023)

Key points

1. Temperate pastures offer a major opportunity to reduce the feed costs associated with ruminant production.

2. Pastures offer unique opportunities for producing high value components in feedstuffs that are beneficial to human health.

3. The increased use of pasture will not automatically lead to improved environmental outcomes – difficult challenges exist in reducing nitrogen and greenhouse gas pollution.

4. Grazed pasture systems offer advantages in animal welfare, provided management avoids the problems associated with climatic extremes, and the toxins associated with some pastures.

5. To remain competitive with total mixed ration systems, and environmentally acceptable, pastures with higher intake characteristics that allow …

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Decision Support For Temperate Grasslands: Challenges And Pitfalls, J. R. Donnelly, L. Salmon, R. D. H. Cohen, Zl. Liu, Xp. Xin

IGC Proceedings (1977-2023)

Key points

1. Successful adoption of decision support tools (DS tools) to address grassland management issues requires careful attention in design to ensure ease-of-use, accuracy in prediction and the flexibility to simulate actual practices.

2. DS tools must handle spatial variability and where possible include facilities for automatic sourcing of essential information for initialisation.

3. Advances in the development of DS tools will depend on resolution of scientific issues in grassland biology including investment in dedicated experiments to determine parameter values for model equations.

4. The use of mechanistic models, the integration of remote sensing technology and cooperation between research groups to develop modular …

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Modelling Of Herbage Intake And Milk Production By Grazing Dairy Cows, Rémy Delagarde, M. O'Donovan

IGC Proceedings (1977-2023)

Key-points

1. Models predicting intake and performance of grazing ruminants from animal, sward, grazing and supplements characteristics are rare, but they are now included in several decision support systems (DSS).

2. An evaluation of the performance and accuracy of published models are rarely undertaken by their authors, but this is proposed in this paper.

3. There is still a need for experimental research but also for the development of generic and dynamic models to predict intake and performance over a wide range of grazing conditions.

Grass Growth Modelling: To Increase Understanding And Aid Decision Making On-Farm, P. D. Barrett, A. S. Laidlaw

IGC Proceedings (1977-2023)

Key points

1. Crop and grass growth models have been developed over the last 50 years, or so, but general appreciation of their benefits and potential has been recognised only relatively recently. The most popular application of grass growth models has traditionally been for knowledge understanding.

2. There is growing awareness of the potential of models in decision support systems (DSS) applications to aid pasture management and grassland budgeting on dairy farms.

3. Although some models have been developed for DSS, their widespread uptake in industry has been slow; challenges still exist which need to be addressed in order to improve their precision …

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Genetic Characteristics Required In Dairy And Beef Cattle For Temperate Grazing Systems, F. Buckley, C. Holmes, M. G. Keane

IGC Proceedings (1977-2023)

Key points

1. Only about 10% of the world’s milk is produced from grazing systems. Consequently the majority of dairy cattle have not been selected under grazing, nor on seasonal systems. This is not true for beef cattle, for which the majority, especially the dams, are managed under seasonal grazing systems.

2. In grazing systems daily feed intake is limited to lower levels than are achievable on concentrate plus conserved forage rations. Consequently, cows most suited to grazing environments are likely to have a lower genetic potential for milk production than cows selected in high concentrate systems, to minimise their relative energy …

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New Insights Into The Nutritional Value Of Grass, D. H. Rearte

IGC Proceedings (1977-2023)

Key points

1. The rumen environment in cattle grazing high quality forage is different to that reported for cattle fed indoors with diets based on processed feedstuffs.
2. Temperate pasture is an excellent source of nutrients for ruminants but a high energy:protein imbalance can occur when it is offered at the stage of optimal digestion.
3. Beef and milk produced on grass in temperate regions have a composition with nutritional advantages over beef or milk produced in indoor systems based on concentrate.
4. Increasing water soluble carbohydrate content of grasses would diminish environmental contamination by reducing the excretion of urea through the urine.
5. Increasing …

Plant And Sward Characteristics To Achieve High Intake In Ruminants, W. J. Wales, C. R. Stockdale, P. T. Doyle

IGC Proceedings (1977-2023)

Key points

1. Intake is affected by complex interactions between signals from the digestive tract, intermediary metabolism and energy supply, and behavioural signals associated with learned behaviours or sensory signals.
2. The ideal sward needs to have characteristics that are similar to total mixed rations to achieve high intake and animal performance.
3. Genetic manipulation of plants may offer an accelerated rate of plant improvement, but benefits need to be demonstrated in a systems context.

Overview Of Animal Production From Pastures In Ireland, M. J. Drennan, A. F. Carson, S. Crosse

IGC Proceedings (1977-2023)

Key points

The importance of grassland to agriculture in Ireland is indicated by the fact that:

1. Sixty percent of agricultural output is from grassland as cattle, milk and sheep products.
2. Over 90% of the total farmed area is in grass.
3. Livestock are almost entirely dependent on grazed grass for 200 to 235 days of the year.
4. Grass conserved as silage is the main source of fodder in winter.
5. To improve competitiveness changes are continuously taking place, which include:

• increased suckler herd size and a movement to late maturing continental cattle breeds;
• movement in the dairy herd towards Holstein with increased …

A Diagnostic Framework For Reengineering Soil: Potential Strategies To Manage Combinations Of Soil Constraints For Sands And Texture Contrast Soils, Gaus Azam, Stephen Davies

Natural resources published reports

This report is an output of project DAW1902-003RTX ‘Reengineering soils to improve the access of crop root systems to water and nutrients stored in the subsoil’, supported by a co-investment between the Department of Primary Industries and Regional Development (DPIRD) and the Grains Research and Development Corporation (GRDC).

Key messages:

• Existing soil amelioration options can generate substantial yield responses. However, further yield gain is possible with further improvement in soil amelioration strategies.

• Mapping of soil constraints and potential yield gaps using the water use efficiency achieved from a pilot reengineering experiment has identified a significant yield gap attributed …

College Of Natural Sciences Newsletter, November 2022 - January 2023, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volme 3, Issue 7

Page 1 Dean's Message
Page 2 Awards & Recognition
Page 3 Sioux Falls Middle School Visit
Page 4 Bio-Micro Day of Scholars
Page 5 GIS Day at USGS EROS
Page 6 Indigenous People's Festival, & Visiting Jack's Imagination Lab
Page 7 Media Coverage of CNS, & Research Highlights from Geography & Geospatial Sciences
Page 8 Media Coverage of CNS. cont.
Page 9 Open PRAIRIE Data
Page 10 Recent Publications from CNS
Page 11 Recent Publications from CNS. cont.
Page 12 CNS Holiday Snapshots
Page 13 & 14 Fall 2022 Dean's List
Page 12-14 Fall 2022 Outreach …

Metal Contents In House Geckos (Squamata: Gekkonidae) From Industrial And Urban Areas Of Southern Tamaulipas, Mexico And Western Andalucía, Spain, May Reflect Airborne Metal Pollution, Luisiana Morales-Zamudio, Alejandro Fierro-Cabo, Md. Saydur Rahman, Miguel Antonio Dominguez-Crespo

School of Earth, Environmental, & Marine Sciences Faculty Publications

House geckos share living quarters with humans in the tropical and subtropical regions inhabited by these reptiles. Gecko behavior, biological traits, continuous exposure to suspended particulate matter 0 µm in diameter (PM10) and dust, as well as status as exotic species, motivated the choice of these species to examine environmental exposure to ambient air pollutants, in particular metals, and subsequent accumulation in these organisms. One part of the study was conducted in Tamaulipas (Mexico) where Hemydactylus frenatus is abundant in urban and industrial environments, the other part was conducted in Andalucia (Spain) where Tarentola mauritanica is found in similar environments. …

Higher Concentrations Of Microplastics In Runoff From Biosolid-Amended Croplands Than Manure-Amended Croplands, Nasrin Naderi Beni, Shahab Karimifard, John Gilley, Tiffany L. Messer, Amy Schmidt, Shannon Bartelt-Hunt

UK CARES Faculty Publications

Land-applied municipal biosolids, produced from municipal wastewater treatment sludge, contributes to microplastics contamination in agroecosystems. The impacts of biosolids on microplastic concentrations in agricultural soil have been previously investigated, however, the potential for microplastics transport from biosolid-amended croplands has not been previously quantified. In this study, manure and biosolids were applied to field plots, runoff was collected following natural precipitation events and the potential of bacterial biofilm to grow on different microplastic morphologies was investigated. Higher concentrations of microplastics were detected in runoff from plots with land-applied biosolid in comparison with manure-amended and control plots. Fibers and fragments were the …

The Use And Challenges Of Spatial Data In Archaeology, Carla Klehm

Anthropology Faculty Publications and Presentations

Spatial data, under the broader umbrella of digital data, is becoming increasingly integral to all stages of archaeological research design and dissemination. As archaeologists lean toward reuse and interoperability, with ethics on their minds, how to treat spatial data is of particular importance. This is because of the complexities involved at every life-cycle stage, from collection to publication, including black box issues that may be taken for granted, and because the size of spatial data can lead to archiving difficulties. Here, the “DIY” momentum of increasingly accessible spatial methods such as photogrammetry and handheld lidar is examined alongside forthcoming changes …

Grassland Productivity And Water Quality: A 21st Century Issue, David M. Nash, P. M. Haygarth

IGC Proceedings (1977-2023)

1. Irrigation and other changes to the hydrological cycle can increase soil and water salinity.
2. Primary salinisation is a natural process that affects much of Europe, Asia, Africa, the Americas and Australia. Secondary salinisation is caused by human activities such as irrigation and land clearing that mobilise salt stored in the soil.
3. The critical water contaminants exported from grasslands are nitrogen, phosphorus, potential pathogens and sediment.
4. The mechanisms responsible for diffuse pollution from grasslands and mitigation strategies are most effectively investigated using a ‘source-mobilisation-transport’ framework.
5. There is a lack of coherent interaction across discipline boundaries that links pollutant sources to impact. …

Water Resources, Agriculture And Pasture: Implications Of Growing Demand And Increasing Scarcity, M. W. Rosegrant, R. A. Valmonte-Santos, S. A. Cline, C. Ringler, W. Li

IGC Proceedings (1977-2023)

1. Water availability for irrigation is threatened in many regions by rapidly increasing demand for nonagricultural water uses in industry, households, and the environment. The scarcity of irrigation water will not only impact crop production, but also meat production, as much of the pasture used to feed livestock is irrigated.
2. Grassland is caught between two countervailing forces: a requirement for increasing meat demand that boosts the need for additional pasture to support livestock production, and rapidly increasing water scarcity that makes pasture irrigation uneconomical.
3. The most effective means of dealing with water scarcity is likely to be conserving water in existing …

Soil Quality Assessment And Management, M. G. Kibblewhite

IGC Proceedings (1977-2023)

1. Soil quality is related to the capacity of soil to deliver ecosystem services on a sustainable basis.
2. Effective management of soil within grasslands can deliver many benefits to mankind but poor management may cause loss of soil quality from erosion, loss of organic matter, physical deterioration etc.
3. Services are delivered from soil by biological processes. Soil quality depends on the form and condition of the soil habitat. Fixed factors (e.g. texture) are useful for assigning soil to types. Variable factors (e.g. organic carbon) can then be used to assess quality within soil types, by reference to percentiles of the distribution …

Soil Microbial Community: Understanding The Belowground Network For Sustainable Grassland Management, Y. G. Zhu, W. D. Kong, B. D. Chen, Z. B. Nan, P. Christie

IGC Proceedings (1977-2023)

1. In addition to the use of conventional methodologies in soil microbial research, molecular techniques are now being applied to gain insights into the soil microbial community;
2. Plant diversity can exert impacts on soil microbial diversity (through root activities and plant litter etc.), but may in itself be significantly altered by soil properties;
3. Soil microbial diversity largely determines the stability of soil ecosystems under biotic and abiotic perturbations.
4. Management of soil microbial diversity can only be achieved through better understanding their structures and functions.

Grasslands1 For Production And The Environment, David R. Kemp, David L. Michalk

IGC Proceedings (1977-2023)

1. To manage grasslands for production and enhanced environmental values requires a redefinition of the frameworks within which management decisions are made, and a tailoring of practices to suit the ways that farmers operate.
2. Improving the perenniality and permanence of grasslands usually leads to better environmental and production outcomes.
3. There is a case for a more conservative approach to utilising grasslands in order to sustain the functioning of local ecosystems and to improve water quality, nutrient and energy cycling and biodiversity.
4. A landscape rather than paddock focus is more appropriate for meeting current grassland management objectives. Grasslands can be triaged to …

The Potential Of Grassland And Associated Forages To Produce Fibre, Biomass, Energy Or Other Feedstocks For Non-Food And Other Sectors: New Uses For A Global Resource, M. F. Askew

IGC Proceedings (1977-2023)

1. In developed countries increased areas of land will become available for non-food production. Recent reforms of the Common Agricultural Policy will further intensify this trend in Europe.
2. There is potential for grassland and associated species to contribute to large tonnage markets of energy and bulk fibres, to the supply of fermentation products and to speciality markets, but processes and approaches to the market are not as yet developed.
3. There is potential for the establishment of Graminaceous species - specifically for non- food use. For European conditions particular attention is being given to Miscanthus sinensis (Miscanthus), Arundo donax (Giant Reed), Phalaris …

Grasses As Biofactories: Scoping Out The Opportunities, Nick Roberts, K. Richardson, G. Bryan, Christine R. Voisey, W. Mcnabb, T. Conner, M. Christey, R. Johnson

IGC Proceedings (1977-2023)

1. Plant biopharming is set to dominate commercial recombinant protein expression for specific proteins.
2. The choice of plant species depends on a multitude of factors and is determined on a case- by-case basis.
3. As a leaf based expression system grasses would have to compete predominantly with tobacco and alfalfa.
4. The grass-endophyte symbiosis offers a number of unique possibilities for biopharming.