Plant Pathology Commons^™

Herbage Quality Of Dwarf Napier Grass Under A Rotational Cattle Grazing System Two Years After Establishment, Yasuyuki Ishii, A. A. Sunusi, M. M. Mukhtar, Sachiko Idota, Kiichi Fukuyama

IGC Proceedings (1977-2023)

Dwarf Napier grass (Pennisetum purpureum Schumach) of a late-heading type (dwarf-late, DL), introduced by the Dairy Promotion Organization, Thailand, has a high over-wintering ability and is suitable for grazing. The objective of this study was to examine the digestibility and crude protein (CP) concentration of DL Napier grass both before and after rotational grazing in relation to the daily liveweight gain of cattle 2 years after establishment in the lowland area of Kyushu, Japan.

Grazing Suitability Of Various Napier Grass Varieties In Paddocks Of Different Ages, Yasuyuki Ishii, M. M. Mukhtar, Sayan Tudsri, Sachiko Idota, Y. Nakamura, Kiichi Fukuyama

IGC Proceedings (1977-2023)

Previous studies have demonstrated that late-heading type dwarf (DL) Napier grass (Pennisetum purpureum Schumach) introduced to Japan from Thailand by the Dairy Promotion Organization of Thailand was able to overwinter in the lowland areas of southern Kyushu (Mukhtar et al., 2003). The species has a higher proportion of leaf blade than other normal and dwarf varieties. These studies were conducted to assess the suitability of the various Napier grass varieties for grazing (Mukhtar et al., 2004). The objective of this study was to examine the grazing suitability, herbage quality and wintering ability of three Napier grass varieties …

Gene-Associated Single Nucleotide Polymorphism Discovery In White Clover (T. Repens L.), M. C. Drayton, R. C. Ponting, A. C. Vecchies, T. C. Wilkinson, J. George, N. O. I. Cogan, N. R. Bannan, K. F. Smith, G. Spangenberg, J. W. Forster

IGC Proceedings (1977-2023)

Single nucleotide polymorphism (SNP) discovery permits the discovery of molecular marker variation associated with functionally-defined genes. SNP markers have been developed for the temperate pasture legume crop white clover (Trifolium repens) using public and proprietary genic sequences correlated with key agronomic traits of interest.

Qtl Analysis Of Mineral Content In Perennial Ryegrass (Lolium Perenne L.), N. O. I. Cogan, A. C. Vecchies, T. Yamada, K. F. Smith, J. W. Forster

IGC Proceedings (1977-2023)

Variation in mineral content of grasses can be strongly influenced by genetic factors. Grass tetany (hypomagnesemia) of cattle and sheep is due to disturbances in serum magnesium levels. In Southern Australia, resultant levels of mortality in cattle vary between 0.5-1.5% of total stock numbers. Serum magnesium variation may be due to feed deficits, or dietary imbalances that interfere with magnesium metabolism. High levels of potassium appear to exert negative effects on the levels of magnesium in the blood. Italian ryegrass genotypes with high levels of magnesium can alleviate the incidence of grass tetany. The genetic control of mineral content, including …

A Molecular Study Of Alfalfa Megasporogenesis, D. Rosellini, Stefano Capomaccio, F. Veronesi

IGC Proceedings (1977-2023)

Our ability to control plant reproduction impacts on both seed production and plant breeding. A female sterility mutation was previously described (Rosellini et al., 1998; 2003) revealing a female-specific arrest of sporogenesis associated with ectopic, massive callose deposition within the nucellus. The goal of this study is to isolate and characterize genes involved in megasporogenesis and female sterility in alfalfa.

Modelling Grazing Animal Distributional Patterns Using Multi-Criteria Decision Analysis Techniques, M. R. George, N. R. Harris, N. K. Mcdougald, M. Louhaichi, M. D. Johnson, D. E. Johnson, K. R. Smith

IGC Proceedings (1977-2023)

Predicting livestock distribution is crucial to reducing livestock impacts on environmentally critical areas. Attempts to model livestock distribution on rangelands have met with varying levels of success. Most of these models described conditions at specific sites and did not work well when they were applied to other sites. In part, the weakness of these models arises from a lack of connection to the spatial arrangement of the study area and the pattern shown by animal distributions. To model the influence of the factors on livestock distribution we developed the Kinetic Resource and Environmental Spatial Systems (KRESS) Modeller. The KRESS Modeler …

Species Richness, Species Identity And Ecosystem Function In Managed Temperate Grasslands, S. C. Goslee, M. A. Sanderson, K. Soder

IGC Proceedings (1977-2023)

Manipulation of plant species diversity may provide a way to improve the ecosystem functioning of managed systems by increasing productivity and suppressing weedy species. As yet, the functional role of species richness is not well-enough understood to enable practical application. We investigated the effects of differing species richness on community stability and invasion resistance in a grazed temperate grassland.

Preference Of Goats For Cool-Season Annual Clovers In The Southern United States, Thomas H. Terrill, W. F. Whitehead, G. Durham, Carl S. Hoveland, B. P. Singh, S. Gelaye

IGC Proceedings (1977-2023)

In the southern U.S.A., annual clovers provide high-quality winter and spring grazing for beef cattle and sheep. New Zealand data on white clover (Trifolium repens L.) suggests that goats do not prefer this plant as much as sheep (Clark et al., 1982) but little data are available on willingness of goats to consume different clover types in the USA.

Production Per Animal And Use Of Intake Estimatives To Predicted Animal Productivity In Pennisetum Purpureum Cv. Mott And Cynodon Spp Cv. Tifton 85 Pastures, Fernando L. F. De Quadros, A. R. Maixner, Gilberto V. Kozloski, D. P. Montardo, A. Noronha, D. G. Bandinelli, M. Da S. Brum, N. D. Aurélio

IGC Proceedings (1977-2023)

Dairy production is a very important activity in southern Brazil, being an essential source of income to small household farms. Milk production from pastures is an alternative to reduce costs in dairy systems. Some C4 grasses, such as dwarf elephant grass (DEG) and Tifton 85, have presented high animal production per animal and per area. Although studies evaluating milk production from these pastures are rare in south Brazil, in vitro studies have demonstrated that the nutritional value of these forages is higher than production registered in grazing. So, it is possible that, in spite of a high intrinsic nutritional value, …

Ingestive Behaviour Of Steers In Native Pastures In Southern Brazil, C. E. Pinto, Paulo C. De F. Carvalho, A. Frizzo, J. A.S.F. Júnior, T. M. S. Freitas, Carlos Nabinger

IGC Proceedings (1977-2023)

The Campos biome, particularly its native pastures, is the main resource for livestock production in southern Brazil (Boldrini, 1997). It has a huge floristic diversity in which more than 400 grass and 150 legume species are found. These pastures are very heterogeneous with horizontal as well as vertical structure. Hodgson (1985) stressed the importance of sward structure upon diet selection, emphasizing the difficulties animals could have to access all pasture layers in temperate pastures. This experiment investigates how variation in herbage allowance along the growing season influences the ingestive behaviour of steers.

The Efficacy Of Genethresher® Methylation Filtering Technology In The Plant Kingdom, U. Warek, J. A. Bedell, M. A. Budiman, A. N. Nunberg, R. W. Citek, D. Robbins, N. Lakey, P. D. Rabinowicz

IGC Proceedings (1977-2023)

The genomes of many plants are known to be composed of a large fraction of repetitive DNA, while a small portion is dedicated to genes. The bulk of the repetitive DNA constitutes transposable elements and is heavily methylated. GeneThresher technology has been developed to take advantage of these differential methylation patterns by filtering genomic shotgun libraries to exclude methylated sequences (Rabinowicz et al., 1999; Palmer et al., 2003; Martienssen et al., 2004). The result is a gene-enriched genomic shotgun library. Random shotgun sequencing of plant gene space, enabled by GeneThresher technology, is a rapid and cost-effective strategy …

Translational Genomics For Alfalfa Varietal Improvement, G. D. May

IGC Proceedings (1977-2023)

Key points

1. Medicago truncatula is a model legume with available mapping, genome, and RNA, protein and metabolite profiling databases and genetically diverse populations.
2. Genomics resources developed for M. truncatula have application in the study and improvement of alfalfa making it an excellent model for this forage legume.

Species Richness Affects Grassland Yield And Yield Stability Across Seasons, Sites And Years, David J. Barker, Reuben M. Sulc, M. R. Burgess, T. L. Bultemeier

IGC Proceedings (1977-2023)

The benefits of biodiversity (specifically species richness) are proposed to include both greater yield and greater stability of yield in a variable environment (Sanderson et al., 2004). Experimental evidence showing yield benefits is inconsistent (White et al., 2004). There is relatively little experimental data showing the effects of species richness on yield stability. The objective of this study was to measure the yield from mixtures with up to 12 species, and to measure the variability of yield between 2 sites, between spring and summer, and in 2 successive years.

Discovery And Functional Categorisation Of Expressed Sequence Tags From Flowers Of Eragrostis Curvula Genotypes Showing Different Ploidy Levels And Reproductive Modes, V. Echenique, S. Felitti, N. Paniego, L. Martelotto, S. C. Pessino, D. Zanazzi, P. Fernández, M. Díaz, P. Polci, G. C. Spangenberg

IGC Proceedings (1977-2023)

Two novel genotypes of weeping lovegrass (Eragrostis curvula) - a dihaploid strain obtained in vitro from an apomictic cultivar and a tetraploid plant derived from the dihaploid after chromosome duplication – have recently been developed. These materials represent an excellent system for the identification, through transcriptional profiling, of genes involved in diplospory and/or ploidy level gene regulation. The aim of this work was the discovery and functional classification of expressed sequence tags (ESTs) from immature inflorescences of the apomictic E. curvula cultivar Tanganyika (2n=4x=40), a dihaploid sexual strain derived from it (2n=2x=20) and a tetraploid sexual strain …

Protection Of Agrobiodiversity: Model Calculations In Rhineland-Palatia: Costs And Implications For Farmers, H. Bergmann

IGC Proceedings (1977-2023)

Biological conservation and production use the same areas of land in less favoured areas. Grassland in these areas makes an important contribution to the protection of agro-biodiversity. However, under existing market conditions and production needs, the use of low yielding grasslands is not economically efficient. The objective of this study was to analyze the economic consequences of different mowing strategies in a small region in Rhineland-Palatia (Germany) that served the protection of two butterfly species.

Stocking Rate Theory And Profit Drivers In North Australian Rangeland Grazing Enterprises, Neil D. Macleod, A. J. Ash, John G. Mcivor

IGC Proceedings (1977-2023)

Setting correct stock numbers is a key decision for successful pastoralism. In marginal environments, typified by northern Australia, this involves careful cattle herd management across landscapes and seasons characterised by heterogeneous land condition and extreme climatic uncertainty. Stocking rate theory which links animal production to stocking rates concentrates only on liveweight gain of sale animals and ignores complex herd (e.g. reproduction, mortality) and pasture dynamics (e.g. land condition) and costs of maintaining stock numbers (e.g. supplementary feeding). Related economic models are generally naïve and incomplete, being based on liveweight gain, meat prices and variable husbandry costs (e.g. Workman, 1986). Modelling …

An Ecological And Economic Risk Avoidance Drought Management Decision Support System, R. K. Heitschmidt, L. T. Vermeire

IGC Proceedings (1977-2023)

Ecologists have long recognized the fundamental impacts of drought on rangeland structure and function. Simulation models have been developed to increase our understanding of these impacts as they relate to forage production, particularly for predictive purposes. Although the capacity of these models to accurately predict quantity and quality of forage produced under varying climatic conditions is often quite good, their ability to serve as an effective and proactive drought management decision support system is often limited. This is in large part because their complexity impedes their use by on-the-ground managers. The objective of this research was to develop a very …

Predicting The Effects Of Management On Upland Birds, Economy And Employment, S. M. Gardner, G. M. Buchanan, J. W. Pearce-Higgins, M. C. Grant, A. Waterhouse

IGC Proceedings (1977-2023)

Livestock farming systems play a significant role in the economy and conservation of the UK uplands and rely heavily upon public financial support. Changes in that support could have far-reaching impacts on the wildlife interest and socio-economics of upland areas. Predicting the impacts of such changes is difficult, since they arise from responses to new economic circumstances. The effect of management change is also influenced by natural variation, such as the mosaic of plant communities, already present in the upland landscape. This paper sets out an approach that integrates theoretical models with field studies to investigate the effects of management …

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 (1977-2023)

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 …

Challenges In Modelling Live-Weight Change In Grazed Pastures In The Australian Subtropics, C. K. Mcdonald, A. J. Ash

IGC Proceedings (1977-2023)

In sub-tropical regions there is enormous seasonal, annual and spatial variation in pasture quality and considerable variation in quality between pasture species. The heterogeneous structure of sub-tropical pasture swards means that process based modelling of liveweight change (LWC) is particularly difficult. In response to this complexity LWC has been expressed as a function of the length of the growing season and/or pasture utilization (McKeon et al. 2000), green leaf availability, or pasture availability and climate (Hirata et al. 1993). However, these relationships vary from year to year, often fail when species composition changes, and generally explain