Physical Sciences and Mathematics Commons^™

Interpreting Indicators Of A Transfer Of N From Legume To Grass In Competition Studies, P G. Tow

IGC Proceedings (1997-2023)

The transfer of N from legume to grass in mixtures is important for regulating competition. In competition studies which include both monocultures and mixtures, N transfer should be detectable by grass N measurements but may be masked by competitive reductions in grass growth. In the study reported here, whole plant DM and N were measured in Panicum maximum var trichoglume and Neonotonia wightii grown in monocultures and additively in mixtures. While competition reduced whole grass plant DM and N in mixture relative to monoculture, higher grass shoot % N and N yield in the mixture at early harvests appeared reliable …

Relationship Of Visual And Quantitative Methods Of Grass Sward Development, R B. Mitchell, L E. Moser, K J. Moore

IGC Proceedings (1997-2023)

The objective of this study was to determine the relationship between visual and quantitative estimates of the morphological development of perennial grass swards. Pure stands of intermediate wheatgrass [Thinopyrum intermedium (Host) Barkw. & D.R. Dewey] and switchgrass (Panicum virgatum L.) were hand-clipped to ground level at 2-wk intervals in 1991 at Mead, NE, morphologically classified as mean stage count (MSC), and visually estimated for sward development. Visual estimations of sward development for both species were representative of quantitative measurements during vegetative growth. However, as sward development advanced to the elongation and heading stages, visual methods over-estimated the population …

Intake And Diet Selection By Sheep Grazing Grass/Clover Patches, I J. Gordon, A W. Illius

IGC Proceedings (1997-2023)

The effects of the spatial dispersion of ryegrass (Lolium perenne L) and clover (Trifolium repens L), at the feeding station scale, on diet composition and feeding behaviour were studied for sheep. There were no significant changes in diet composition with changes in the spatial dispersion of sward components. Bite size, bite rate and intake rate did increase as the species became more aggregated.

Monitoring Productivity And Quality Of Grass-Legume Pastures Under Irrigated Condition, L Tahtacioglu, A Mermer, M Avcy

IGC Proceedings (1997-2023)

The performance of six grass-white clover mixtures were evaluated in winter cold zone of Eastern Anatolia. In combination with white clover, ryegrass (Lolium perenne L) cocksfoot, (Dactylis glomerata L) and smooth brome (Bromus inermis Leyss) were used in double and triple plant mixtures. Average DM production ranged from 7.5 to 10 t/ha , with no significant differences observed among the mixed swards. DM production of all mixed swards significantly varied between cutting periods and years. A gradual decrease in DM production was observed both from the first to forth cut and from the first to third year. …

Conservation Of Grass Collections At The Western Regional Plant Introduction Station, V L. Bradley, R C. Johnson

IGC Proceedings (1997-2023)

Germplasm managers at the Western Regional Plant Introduction Station (WRPIS) have focused on improving seed regeneration in forage and turf grass species through studies of diversity maintenance, using isozyme markers in annual ryegrass (Lolium multiflorum Lam.) and through studies of pollen isolation, using strains of dominant pubescent and recessive glabrous smooth bromegrass (Bromus inermis Leyss.). Balanced samples of annual ryegrass (an equal number of seeds per plant) from field plots were best for maintaining allelic frequencies, but genetic diversity (heterozygosity and allelic richness) was maintained nearly as well in bulk samples (seeds proportionally assembled according to seeds per …

Development Of Megathyrsus Maximus Genotypes For Intensification Of Cattle Rearing In Brazil, Liana Jank, M. F. Santos, Sanzio Carvalho Barrios, Cacilda Borges Do Valle, Rosangela Maria Simeão

IGC Proceedings (1997-2023)

Megathyrsus maximus is a forage species used over 30 million hectares in Brazil and in the surrounding countries for intensification of the cattle production systems. Due to the large area and distinct biomes in which it is used, there is a need to continuously develop more productive and adapted cultivars to each biome and use. Three apomictic accessions were crossed with five sexual plants at Embrapa Beef Cattle in Campo Grande, MS, Brazil in 2014. More than 1100 hybrids were planted in a spaced-plant field and evaluated visually for regrowth after cuts and for disease and pest damage. In 2016, …

Herbage Accumulation And Mass In Massai Grass Plots Mixed With Forage Peanut And Fertilized With Nitrogen, Carlos A. B. Carvalho, M. O. Leal Junior, P. P. Carneiro, J. V. B. Ramos, N. Schultz, J. C. C. Almeida, A. J. Paiva

IGC Proceedings (1997-2023)

The objective of this work was to evaluate herbage accumulation and mass during the growing season of Massai grass mixed with peanut forage and fertilized with nitrogen. The work was carried out at Federal Rural University of Rio de Janeiro, Brazil, from 11/2021 to 03/2022. A randomized block experimental design was used, in plots of Massai grass Megathyrsus maximus, in a factorial arrangement, with seven replications. Four treatments formed by the combination of the presence or absence of Archis pintoi and nitrogen fertilization (0 and 50 kg ha^-1 of N). Canopy heights of the plots were evaluated weekly …

A Novel Tractor Operated Grass Seed Harvester Developed In India, Chandra Shekhar Sahay, D. S. Thorat, P. S. Pathak

IGC Proceedings (1997-2023)

The demand of green and dry fodder in India is estimated to increase to 1170 and 650 m tonne whereas availability is expected to be at 411.3 and 488 m tonne in 2025, respectively, depicting deficit of about 64.9% green fodder and 24.9% dry fodder (Vision 2030, ICAR - IGFRI, Jhansi, 2011). In forages, availability of quality seed is only 25-30% in cultivated fodder and less than 10 % in range grasses and legumes (Vision 2050, IGFRI). Prices paid for grass seeds of native species vary from Rs.5,000 to 6,500 per kg for clean, un-haired seeds due to excessive use …

Tiller Demography Within Synthetic Grass Populations, K. J. Moore, C. Córdova

IGC Proceedings (1997-2023)

Like other populations of biological organisms, the collective aging structure of a population of grass tillers has meaning and consequences far beyond the development of an individual within it. Using various methods, it is possible to assign numerical indices to tiller development so that it can be described numerically. By sampling a population of tillers and assigning a numerical index to each, the average stage of tillers within a population can be calculated and a repeatable assessment of its development determined. The average or mean stage count (MSC) of tiller development is commonly calculated and used to compare the development …

Sustainable Pastures For The High Altitude Andean Tropics Of Colombia, E. Cárdenas, L. Panizzo

IGC Proceedings (1997-2023)

Dairy production systems in the high altitude Andean region of Colombia (>2.600 m.a.s.l.) use large amounts of nitrogen (N) fertilisation. Due to the inefficient use of N by the grass, it contaminates surface and ground water resulting in the eutrophication of lakes and rivers. It contributes to increased atmospheric NOx, greenhouse gas and acid rain. Therefore, the effect of different species of grasses mixed with Lotus corniculatuson N soil balance was evaluated.

The Effects Of Offering Hay, Pit-Stored Grass Silage Or Big-Bale Silage To Pregnant Ewes On Ewe And Lamb Performance, T. F. Crosby, P. J. Quinn, J. J. Callan, T. Mcgrane

IGC Proceedings (1997-2023)

Hay and pit silage have been used extensively for feeding sheep over the winter period, but in recent years, especially on smaller farms, big-bale silage has become increasingly popular. However, there is limited comparative information on the use of big-bale silage for sheep, especially in relation to the effects of chopping and growth stage at harvest. This study compared the performance of ewes offered hay, pit silage, or big-bale grass silage made from either chopped or unchopped grass and cut from the same field at the same time.

The Effects Of Offering Grass Or Maize Silages To In-Lamb Ewes On Body Weight And Condition Changes, Colostrum Yield And Quality, T. F. Crosby, P. J. Quinn, J. J. Callan, P. Reilly, B. Flynn, D. Cunningham, T. Massey

IGC Proceedings (1997-2023)

Hay and more recently grass silage (GS) have been the traditional feeds for sheep in Ireland over the winter period. Alternatives such as maize silage (MS) are becoming increasingly important as winter forage sources especially for cattle. This study sought to evaluate grass silage and maize silage when offered to pregnant ewes.

Grass Pellet Bioenergy In The Northeastern Usa, J. H. Cherney, D. J. R. Cherney

IGC Proceedings (1997-2023)

Grass pellets are a renewable energy supply that combines low technology/small-scale with local production/consumption for a cost effective energy system. There have been significant recent advances in pellet furnace technology and some pellet stove manufacturers now claim their stoves are capable of burning biomass with 5-6% ash content. Cool-season grasses have not been considered acceptable for pelleting and direct combustion in the past due to high ash content. Rain after harvest, however, has been shown to leach significant amounts of potassium and chlorine from grass (Sander, 1997). High yields are possible under lax harvest management (Cherney et al., 2003), producing …

Water-Soluble Carbohydrate (Wsc) Concentrations In Ireland And Norway Of Lolium Perenne Differing In Wsc Genotype And Receiving Varying Rates Of N Fertiliser, P. O'Kiely, L. Nesheim, P. Conaghan, F. P. O'Mara

IGC Proceedings (1997-2023)

Cultivars bred for elevated water-soluble carbohydrate (WSC) concentration may have improved grass ensilability and nutritive value. Increasing rates of application of N fertiliser generally reduce grass WSC concentration, although it is unknown if the response is similar for normal and elevated WSC genotypes or if these factors interact with growing conditions. This experiment evaluated the effects on grass WSC concentration of varying N fertiliser application rates to perennial ryegrass cultivars of high or normal WSC genotype grown in Ireland and Norway.

Lipid Oxidation And Sensory Characteristics Of Grass-Fed Beef: Effect Of Duration Of Grazing Prior To Slaughter, A. P. Moloney, F. Noci, F. J. Monahan, G. E. Nute, R. I. Richardson

IGC Proceedings (1997-2023)

Beef from cattle produced from grass has a higher concentration of fatty acids considered to be beneficial to human health than beef produced from more intensive production systems and this increase in fatty acid concentration is dependant on the duration at pasture prior to slaughter (Noci et al., 2003). Improvements in the fatty acid composition of beef must not impair other quality characteristics of beef. Little information is available on the pattern of change of quality characteristics in grazing animals. The objective of this study was to determine the shelf-life and eating quality of beef from cattle produced from …

Constraints On Dairy Cattle Production From Locally Available Forages In Bangladesh, M. A. S. Khan

IGC Proceedings (1997-2023)

The productivity of milk producing animals in Bangladesh is low because of low individual yield and poor fertility. The reasons for the low productivity are complex but, in order of priority, appear to be (a) the imbalanced nature of the nutrients that arise from the digestion of the forage resources, (b) the incidence of disease/parasitism, and (c) the often harsh climatic circumstances. Thus, the purpose of this study was to find out the practical constraints on dairy cattle production from locally available forages under small holding village conditions of Bangladesh.

Analysis Of Bromus Inermis Populations Using Amplified Fragment Length Polymorphism Markers To Identify Duplicate Accessions, V. L. Bradley, T. J. Kisha

IGC Proceedings (1997-2023)

The temperate grass germplasm collection maintained at the USDA, ARS Western Regional Plant Introduction Station (WRPIS) in Pullman, Washington, consists of more than 18,000 accessions. Passport and collection data suggest that some of these accessions are duplicates, and their maintenance unnecessarily drains limited resources. The objective of this study was to use Amplified Fragment Length Polymorphism (AFLP) marker analysis on 4 populations of smooth bromegrass, Bromus inermis Leyss. subsp. inermis `Manchar ́, a cross-pollinated perennial grass, to determine if the genetic variation among them was significant. If not, then maintaining separate populations would be unnecessary.

Improving Forage Quality Of Tall Fescue (Festuca Arundinacea) By Genetic Manipulation Of Lignin Biosynthesis, Z. -Y. Wang, L. Chen, C. -K. Auh, A. Hopkins, P. Dowling

IGC Proceedings (1997-2023)

Lignification of plant cell walls is a major factor limiting forage digestibility and concomitantly animal productivity. Improvement in forage grass cell wall digestibility has become an important goal of many plant-ruminant animal research programs. Lignins are complex phenolic heteropolymers associated with the polysaccharidic components of the wall in specific plant cells. Lignin in forage grasses comprises guaiacyl (G) units derived from coniferyl alcohol, syringyl (S) units derived from sinapyl alcohol, and p-hydroxyphenyl (H) units derived from p-coumaryl alcohol. Cinnamyl alcohol dehydrogenase (CAD) and caffeic acid O- methyltransferase (COMT) are key enzymes involved in lignin biosynthesis. Tall fescue …

Constraints On Dairy Cattle Production From Locally Available Forages In Bangladesh, M. A. S. Khan

IGC Proceedings (1997-2023)

The productivity of milk producing animals in Bangladesh is low because of low individual yield and poor fertility. The reasons for the low productivity are complex but, in order of priority, appear to be (a) the imbalanced nature of the nutrients that arise from the digestion of the forage resources, (b) the incidence of disease/parasitism, and (c) the often harsh climatic circumstances. Thus, the purpose of this study was to find out the practical constraints on dairy cattle production from locally available forages under small holding village conditions of Bangladesh.

Non-Destructive Assessment Of Quality And Yield For Grass-Breeding, A. G. T. Schut, M. J. J. Pustjens, P. W. Wilkins, J. Meuleman, P. Reyns, A. Lovatt, G. W. A. M. Van Der Heijden

IGC Proceedings (1997-2023)

Selection of cultivars has, until now, been based mainly on dry matter (DM) yields because of the high costs of sampling and chemical analysis. Imaging spectroscopy could reduce costs by limiting sampling and harvesting of individual plots to reference samples (Schut et al., accepted). In this study, the prediction accuracy of DM yields and chemical composition with imaging spectroscopy is evaluated for cultivar selection purposes.

Does The Feeding Behaviour Of Dairy Cows Differ When Fed Ryegrass Indoors Vs. Grazing?, A. V. Chaves, A. Boudon, J. L. Peyraud, R. Delagarde

IGC Proceedings (1997-2023)

Dairy cows eating ryegrass ingest smaller boli when grazing than when fed indoors (93 vs. 142 g; Boudon et al., 2004). To investigate whether this difference in bolus affects feeding behaviour of the cows, an automated system (chewing halters) was used to monitor feeding behaviour of cows given ad libitum access to perennial ryegrass in individual feed troughs (indoor feeding, IF) or at pasture (grazing, GR).

A New Agro-Meteorological Simulation Model For Predicting Daily Grass Growth Rates Across Ireland, R. P. O. Schulte

IGC Proceedings (1997-2023)

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.

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 (1997-2023)

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.

What Supplementation Type For Spring Calving Dairy Cows At Grass In Autumn?, M. O'Donovan, E. Kennedy, T. Guinee, J. J. Murphy

IGC Proceedings (1997-2023)

In spring-calving herds the requirement for conserved forages for indoor feeding is very limited but these feeds may have a role to play as buffer feeds in the spring and autumn periods when grass supply is less than required or as alternatives to concentrates on pasture for cows in early lactation. The objective of this experiment was to compare alternative forages and concentrates as buffer feeds on pasture with spring-calving cows in the autumn.

A Comparison Of Three Systems Of Milk Production With Different Land Use Strategies, L. Shalloo, P. Dillon, J. J. Murphy

IGC Proceedings (1997-2023)

Under the Luxemburg agreement FAPRI-Ireland (Breen & Hennessey 2003) projects that milk price will decrease by 5.0 to 5.5 c/l because of reductions in support for butter and skimmed milk powder. These changes mean that many dairy farmers need to reappraise their systems of milk production and consider necessary adjustments that will ensure viability in the longer term. The objective of this study was to model three different systems of milk production in scenarios where quota, cow numbers or land was restricted.

Feeding Mixed Grass-Clover Silages With Elevated Sugar Contents To Dairy Cows, J. Bertilsson

IGC Proceedings (1997-2023)

Grasses with high sugar content (WSC) have been claimed to increase feed intake and milk production and at the same time give more efficient N utilisation and thus reduce pollution (e.g. Miller et al., 2001). In an ongoing EU-supported project (“Sweetgrass”), we have grown the new varieties of perennial ryegrasses and fed them to dairy cows. Results from the first year’s experiment when pure ryegrass silages made from standard or high-sugar varieties were fed, showed small differences in feed intake, milk production and N partitioning. In order to test the principle, it was therefore decided to increase the difference …

Improving The Quality Of Products From Grassland, Nigel D. Scollan, R. J. Dewhurst, A. P. Moloney, J. J. Murphy

IGC Proceedings (1997-2023)

1. Consumers are increasingly aware of the links between diet and health, and place increasing emphasis on nutritional quality as a component of product quality.
2. Meat and milk products are rich sources of nutrients such as omega-3 (n-3) fatty acids and conjugated linoleic acid, which offer health benefits to consumers.
3. Green plants are the primary source of n-3 fatty acids in the food chain.
4. Grassland production systems have the potential to enhance the content of beneficial fatty acids, improve stability (from higher antioxidant content) and alter sensory attributes of meat and milk.
5. Grassland offers considerable scope to help …

Improving The Quality Of Products From Grassland, Nigel D. Scollan, R. J. Dewhurst, A. P. Moloney, J. J. Murphy

IGC Proceedings (1997-2023)

Key points

1. Consumers are increasingly aware of the links between diet and health, and place increasing emphasis on nutritional quality as a component of product quality.

2. Meat and milk products are rich sources of nutrients such as omega-3 (n-3) fatty acids and conjugated linoleic acid, which offer health benefits to consumers.

3. Green plants are the primary source of n-3 fatty acids in the food chain.

4. Grassland production systems have the potential to enhance the content of beneficial fatty acids, improve stability (from higher antioxidant content) and alter sensory attributes of meat and milk.

5. Grassland offers …

Digestibility Estimates Based On A Grass Growth Model Are Distributed Via Internet To Finnish Farmers, Marketta Rinne, J. Nousiainen, I. Mattila, H. Nikander, P. Huhtanen

IGC Proceedings (1997-2023)

Optimising the harvesting time of grass in primary growth is difficult under Finnish climatic conditions, because the digestibility of grass decreases on average by 0.5 percentage units daily. We constructed a model based on cumulative temperature and geographical location which estimates the digestibility of grass. This model is used to produce estimates utilising real time weather information. The estimates are presented as a map, which is revised daily. Farmers have free access to the maps via Internet.

Survival Of Escherichia Coli 0157:H7 Added To Grass At Ensiling And Its Influence On Silage Fermentation, P. O’Kiely, C. Byrne, D. Bolton

IGC Proceedings (1997-2023)

Escherichia coli can cause health problems in humans and livestock. It is frequently found in faeces and soil, both of which can contaminate grass harvested for silage-making. To determine the survival of E. coli 0157:H7 during ensilage, and its influence on ensilage, unwilted precision-chop grass was ensiled in laboratory silos with the following additive treatments: (a) no additive, (b) E. coli 0157:H7 (Ec - non-infectious strain, at log₁₀ 4.5 colony forming units (cfu) g^-1), formic acid (FA), and (d) Ec + FA. Silos were stored at 15^oC. Three silos per treatment were opened on days …