Plant Biology Commons^™

Divergent Metabolic Changes In Rhizomes Of Lowland And Upland Switchgrass (Panicum Virgatum) From Early Season Through Dormancy Onset, Nathan A. Palmer, Gautam Sarath, Michael J. Bowman, Aaron J. Saathoff, Serge J. Edmé, Robert B. Mitchell, Christian M. Tobias, Soundararajan Madhavan, Erin D. Scully, Scott E. Sattler

Department of Agronomy and Horticulture: Faculty Publications

High-biomass-yielding southerly adapted switchgrasses (Panicum virgatum L.) frequently suffer from unpredictable winter hardiness at more northerly sites arising from damage to rhizomes that prevent effective spring regrowth. Previously, changes occurring over the growing season in rhizomes sampled from a cold-adapted tetraploid upland cultivar, Summer, demonstrated a role for abscisic acid (ABA), starch accumulation, and transcriptional reprogramming as drivers of dormancy onset and potential keys to rhizome health during winter dormancy. Here, rhizome metabolism of a high-yielding southerly adapted tetraploid switchgrass cultivar, Kanlow—which is a significant source of genetics for yield improvement—was studied over a growing season at a northern …

The Bellarmine Bee Bed: Organizing A Native Plant Garden Using Feedback From The Local Community, Kate Moran

Undergraduate Theses

Animal pollinators are the cornerstone of healthy ecosystems. Their survival is essential for the persistence of entire food chains: from the flowers they cross-pollinate directly, to the animals who depend on those plants for nutrition. The establishment of pollinator gardens—particularly ones that consist of native plants—is an effective way to enhance their biodiversity, abundance, and well-being.

The main goal of this thesis is to construct a pollinator garden that maximizes the benefits for animal pollinators using feedback from local gardeners. A survey was used to gather information about the popularity and preferences of 40 flowering plants, and after analyzing the …

Differential Behaviour Of Guineagrass (Panicum Maximum Jacq.) Hybrids, With Different Al+3 Reactions, As To Major Nutrient Translocations To The Leaves, R. S. Paterniani, J. A. Usberti Jr., J. C. Werner

IGC Proceedings (1997-2023)

Most of the Brazilian cultivated pasture fields presents soils with high Al⁺³ levels and liming is economically unfeasible. So, there is an urgent need for grasses with good forage yielding potentials that can withstand Al⁺³ deleterious effects (abnormal root development: short, thick and poorly branched roots, which are unable to effectively translocate water and essential nutrients to the leaves) (Foy, 1984); as a consequence, susceptible genetic materials have their field persistences greatly affected, mainly during drought periods. Researches on Al⁺³ reaction are usually compare supposedly resistant/tolerant genotypes with a resistant control check; doing so, the genotypic effect …

Animal Performance And Productivity Of New Ecotypes Of Brachiaria Brizantha In Brazil, Valéria P. B. Euclides, Manuel C. M. Macedo, Cacilda B. Do Valle, R. Flores, M. P. Oliveira

IGC Proceedings (1997-2023)

Brazil has the competitive advantage of a very dynamic and cost effective animal production system on pastures over other countries. The pursuit for more productive forages that will result in higher quality beef at a lower cost is then justified. Brachiaria is the most important forage genus utilised in Brazil, thus an intense search for new cultivars amongst collected and introduced ecotypes from Africa is underway. Following agronomic evaluation of this material in plots, 8 pre-selected Brachiaria ecotypes were tested under intermittent grazing in paddocks (Euclides et al., 2001). Continuing on the process of cultivar development, two out of …

Development Of A Bahiagrass Paspalum Notatum Flugge With Increased Short-Day Biomass, P. Mislevy, Ann R. Blount, T. R. Sinclair

IGC Proceedings (1997-2023)

Low herbage productivity of subtropical grasses during the short-day winter months of October through to March can place a severe burden on livestock producers in Southeastern U.S. Researchers at the University of Florida (Sinclair et al., 2001) hypothesised that the decrease in forage production might result from physiological dormancy induced by short day length. A study using artificial lights to extend the day length demonstrated that maintaining the day length at 15 hr during the short-day length period increased 'Pensacola' bahiagrass P. notatum Flugge saure Parodi forage yield 122% when compared with normal photoperiod (Mislevy et al., 2001). …

Genetic And Molecular Characterization Of Temperate And Tropical Forage Maize Inbred Lines, B. Alarcón-Zúñiga, E. Valadez-Moctezuma, T. Cervantes-Martinez, T. Cervantes-Santana, M. Mendoza‐Rodriguez

IGC Proceedings (1997-2023)

The livestock feeding in the Central highland of Mexico is based on harvest, grazing and annual forage conservation, being forage maize the most important silage crop (Alarcón, 1995). Even though forage maize is extensively bred in Europe, USA and Asia since 1900's, this started in Mexico in the 1960's, and little is known about the genetic diversity in both agronomic and nutritive value traits. Our breeding program goals are to analyze combining ability of biomass and quality predictors and to study the genetic relationship of inbred lines between lowland tropical and temperate races from Mesa Central, by genetic and molecular …

Preliminary Performance Of Panicum Maximum Accessions And Hybrids In Brazil, Liana Jank, Rosangela M. S. Resende, S. Calixto, M. M. Gontijo Neto, V. A. Laura, Manuel C. M. Macedo, Cacilda B. Do Valle

IGC Proceedings (1997-2023)

Due to the lack of high quality forages adapted to the distinct ecosystems in Brazil, a national network to evaluate 14 accessions, 4 hybrids and 5 commercial standards of Panicum maximum was established in 2002, in 5 regions of Brazil (states of Mato Grosso do Sul, Acre, Rondônia, Minas Gerais and in the Federal District). Staff of the Embrapa Beef Cattle group co-ordinated the network and pre-selected the accessions and hybrids (Jank, 1995; Jank et al., 2001; Resende et al., 2004). We present their performance as to leaf dry matter yield (LDMY) and leaf percentage (LP) obtained from …

Effect Of Applied Biosolids To Bahiagrass Pastures On Copper Status Of Cattle, M. E. Tiffany, L. R. Mcdowell, G. A. O'Connor, N. S. Wilkinson

IGC Proceedings (1997-2023)

When grazing ruminants consume forages high in Mo but adequate in S, there is a risk of molybdenosis (a Mo-induced Cu deficiency). This occurs when Mo, S, and Cu join to form Cu-thiomolybdate complexes in the rumen that are not readily absorbed (Suttle, 1991). High dietary S reduces Cu absorption, possibly due to unabsorbable Cu sulphide formation, independent from its part in thiomolybdate complexes. The use of municipal sludge (biosolids) as a pasture fertiliser is of interest since some contain high Mo which may induce Cu deficiency. The objective of this study was to evaluate the performance and Cu status …

An In Vitro Investigation Of Forage Factors Which Affect The Production Of Conjugated Linoleic Acid And Trans Vaccenic Acid In The Rumen. Ii. Wilting & Cell Damage, Michael R. F. Lee, J. K. S. Tweed, Nigel D. Scollan, R. J. Dewhurst

IGC Proceedings (1997-2023)

Previous studies have shown that cis 9 trans 11 conjugated linoleic acid (CLA) concentrations are higher for summer milk produced from cows grazing fresh pastures than for winter milk when conserved forages are fed (Jahreis et al., 1997). Furthermore, Offer (2003) showed that a similar depression in milk fat CLA occurred if grass was simply cut and fed after a short wilt. This experiment investigated the effect of wilting on the production of CLA and trans vaccenic acid (TVA) in an in vitro rumen simulation, and whether any differences could be related to changes in plant structure. It was …

Effects Of Grassland Management On Herbage Lipid Composition And Consequences For Fatty Acids In Milk, Anjo Elgersma, P. Maudet, I. Witkowska, A. C. Wever

IGC Proceedings (1997-2023)

Herbage provides bulk feed and is the basis for ruminant nutrition. Herbage lipids, especially C18:3, are a major source of beneficial fatty acids (FA) in milk. These desired FA are unsaturated FA such as CLA (conjugated linoleic acid), especially the isomer rumenic acid, and also vaccenic acid, both trans omega-7 FA (Ellen & Elgersma, 2004). As information on lipids in forages is scarce, effects were studied of N application level and regrowth period on the lipid concentration and FA composition of perennial ryegrass (Lolium perenne L.), the most important forage in temperate climate zones. A linear relation had previously …

Effect Of Feeding L-Carnitine And Sunflower Seeds On Cla Content Of Pasture-Fed Beef, S. L. Scott, W. P. Mccaughey, K. E. Buckley

IGC Proceedings (1997-2023)

Pasture finishing enhances levels of conjugated linoleic acids (CLA) in beef lipids (Shanta et al. 1997). CLA (e.g., C18:2 c9, t11), formed during biohydrogenation of polyunsaturated fatty acids (PUFA) in the rumen, can reduce the incidence of heart disease, cancer and obesity in humans. However, pasture finishing cattle can reduce carcass grade. Feeding pasture-fed cattle a high-grain diet for a short finishing period (~60 d) improves grades but may reduce lipid CLA levels. A feeding regime is required that maintains the positive nutritional attributes of pasture-fed beef and improves the meat grade. The objective of this study was to investigate …

Content, Pattern And Esterification Of Fatty Acids In Fresh Grass In Relation To Extraction Solvents And Sample Storage Conditions, Marta Lourenço, Veerle Fievez

IGC Proceedings (1997-2023)

The relatively high content of linolenic acid (C18:3 n-3) in forages has lead to research on the role of forage based feeding strategies in the production of healthier milk. In these studies, forage samples are often stored, although analysis immediately after harvest has been considered to avoid oxidative deterioration and transformation of unsaturated fatty acids (FA) (Christie, 1993; Frankel, 1998). In the current study, we evaluated the effect of different storage conditions (fresh grass samples under liquid nitrogen (liq.N₂) or in a cool box during 3h or at -20ºC, -80ºC or in the extraction solvent at -20°C, during …

Traditional Cattle Feeding Stuffs: Fatty Acid Profile, A. M. Peres, L. Dias, J. Sá Morais, F. Sousa, J. M. Pires

IGC Proceedings (1997-2023)

Dietary polyunsaturated fatty acids (PUFA) are perceived to be healthier than saturated fatty acids. Therefore, in order to be able to manipulate the fatty acid profile of meat and/or milk, to respond to the consumer demands, knowledge of the fatty acid profile of feeding stuffs for cattle is of major importance (LeDoux et al., 2002; Petit, 2002). In this work a preliminary study was made of the fatty acid profile of the cow's diet in a traditional farm production system.

Finishing Effect On Fatty Acid Profile Of Intramuscular Fat In Extensively Reared Steers, N. Aldai, B. E. Murray, A. I. Nájera, K. Osoro

IGC Proceedings (1997-2023)

Both the amount and the composition of fat depots in beef may be influenced by several factors i.e. feeding system. Related to this factor, extensively reared cattle may produce beef with a more desirable fatty acid (FA) composition in terms of beneficial effect on human health, especially in relation to the content of n-3 type FAs. However, concentrate finishing improves some carcass traits and meat quality. In this sense, the objective of this work was to study the effect of concentrate finishing on intramuscular (IM) FA profile of Longissimus thoracis (LT) muscle in pasture fed steers.

Effect Of Perennial Ryegrass Cultivars On The Fatty Acid Composition In Milk Of Stall-Fed Cows, Anjo Elgersma, H. J. Smit, G. Ellen, S. Tamminga

IGC Proceedings (1997-2023)

Herbage provides bulk feed for ruminants and plant lipids, especially C18:3, are a major source of benefical fatty acids (FA) in milk. There are very few direct comparisons allowing a precise evaluation of the effects of the basal forage diet on milk FA composition. Grass quality differences can affect rumen metabolism and there could be opportunities to change the composition of ruminant products through choice of grass cultivar. To test this hypothesis, six cultivars were fed to dairy cows in a stall-feeding trial with fresh grass to evaluate the effect of grass cultivar on rumen VFA and milk FA composition …

Quantitative And Qualitative Characteristics Of The Loin Of Grazing Lambs From Different Production Systems, Alda L. G. Monteiro, C. H. E. C. Poli, G. J. Bosquetto, T. D. M. Ribeiro, O. R. Prado, Maria Angela M. Fernandes, C. Gasperin

IGC Proceedings (1997-2023)

The international sheep market is supplied mainly from New Zealand and Australia, where there are advanced production systems and marketing organisations, and where the product is exported mainly in the form of carcasses and cuts. In Brazil, the farmers should aim to produce a younger animal, with an adequate fat level at an optimum stage of muscle development, in order to gain market share The proportions of muscle, bone and fat largely determine the value of the carcass, and the breed and age of animal, in addition to other factors such as feeding systems, cause variation in the proportions (Purchas …

Processing Quality Of Organic And Conventional Milks From Irish Pasture Based Systems, B. O'Brien, P. Murphy, N. Culleton, P. O'Connor

IGC Proceedings (1997-2023)

The maintenance of white clover in the pasture sward is essential to viable organic farming in Ireland. Thus, the diet of the organically and conventionally managed cow is different. It is well documented that milk composition is affected by cow diet (Kefford et al., 1995). This study addresses the issue of technological quality differences between conventionally and organically produced milks.

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.

The Effect Of Post-Weaning Management On The Physico-Chemical And Textural Quality Of Beef From Bulls And Steers, M. Oliván, P. García, M. J. Martínez, M. Mocha, A. Martínez, P. Castro, K. Osoro

IGC Proceedings (1997-2023)

There is an increasing interest for extensification in Europe due to environmental and animal welfare concerns. Furthermore, forage-fed beef may present benefits for human health. However, animals fed at pasture produce in some cases darker and tougher meat. It has been shown that castration or a grain-finishing period before slaughter could improve some sensory traits of beef from pasture. The objective of this work was to study the impact of castration and four feeding systems (grazing, grazing + 70 days concentrate, grazing + 100 days concentrate, 200 days concentrate) on the quality of beef from yearling bulls and steers.

Effects Of Supplementary Concentrate Level And Separate Or Mixed Feeding Of Grass Silage And Concentrates On Carcass Tissue Colour Traits In Steers, J. Caplis, M. G. Keane, A. P. Moloney, F. P. O'Mara

IGC Proceedings (1997-2023)

The level of supplementary concentrates fed with grass silage and the method of feeding (separate or mixed) may affect carcass tissue colour in steers. The objectives were to determine the effects of (1) supplementary concentrate level with grass silage, and (2) separate or mixed feeding of silage and concentrates, on muscle and fat colour.