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Hemarthria Altissima: A Pasture Grass For The Tropics, K H. Quesenberry, W R. Ocumpaugh, O C. Ruelke

IGC Proceedings (1977-2023)

Limpograss (Hemarthria altissima [Poir] Stapf. et C.E. Hubb), introduced into the U.S. in 1964, has been evaluated for use as a pasture grass. Under Florida conditions it has shown yield potential equal to or greater than other tropical pasture grasses. The cultivar Bigalta has higher in-vitro organic-matter digestion (IVOMD) than other tropical grasses at comparable growth stages. Early evaluations of limpograss involved only three clones, but additional genotypes were collected and introduced during the late 1960s and early 1970s, and an evaluation scheme for this germ plasm was undertaken. Our objectives were to evaluate rapidly the available germ plasm of …

Case Study On Operational Performance Improvement By Turbocharger Nozzle-Ring Modification In Shipboard Generators, Jong-Hun Im, Mukyeong Kang, Sang-Deuk Lee

Journal of Marine Science and Technology–Taiwan

Owing to increasingly stringent emission regulations imposed by the International Maritime Organization and rising fuel prices, the demand for enhanced energy efficiency and emission control in marine power systems is increasing. This study presents a case study in which the performance of an aging auxiliary generator is restored by modifying the turbocharger nozzle ring. The vessel, a 12-year-old crude-oil tanker, experienced repeated operational issues with its No. 3 generator. This included elevated exhaust gas temperatures, reduced intake air pressure, and frequent turbocharger surges. To address these challenges, the nozzle-ring blade angle was reduced by approximately 2° using spare components, while …

Towards Sustainable Marine Education: Assessing High School Students’ Understanding Of Conservation Concepts, Cheng-Chieh Chang, Tsuyoshi Sasaki, Ya-Yin Liao, Ling-Ya Hung, Liang-Ting Tsai

Journal of Marine Science and Technology–Taiwan

This study assesses the concepts of marine resource conservation and sustainability among Taiwanese high school students by developing a Chinese version of the Marine Resources Conservation and Sustainability Scale. Grounded in the cognitive, socio-emotional, and behavioral learning objectives outlined in UNESCO’s Education for Sustainable Development Goals (ESDGs), the scale targets students aged 16 to 18 to examine gender differences in marine knowledge and conservation concepts. The scale comprises 31 items across four dimensions: the first section evaluates marine knowledge, while the remaining dimensions utilize a four-point Likert scale to assess cognitive, socio-emotional, and behavioral learning objectives, respectively. The results indicate …

Dynamic Governance Of Transboundary Fisheries Through Deep Learning And High-Frequency Vessel Tracking Data For Climate-Resilient Management: An Application To The East China Sea, Qin Lin, Yaqing Shu, Manel Grifoll, Hongxiang Feng

Journal of Marine Science and Technology–Taiwan

Transboundary fisheries governance is increasingly challenged by jurisdictional conflicts, regulatory asymmetries, and climate-induced stock shifts in fish stocks, especially in contested regions like the East China Sea (ECS). This study capitalizes on China’s high-frequency BeiDou Navigation Satellite System (BDS) data (June 2021–May 2022) to pioneer a CNN-BiLSTM deep learning model to dynamically identify fishing hotspots and evaluate policy effectiveness. By integrating vessel trajectories, environmental variables, and regulatory events, we examine spatiotemporal patterns of fishing effort relative to seasonal bans, extreme weather, and quota systems. Key findings reveal: (1) post-moratorium (September–December) concentration of fishing intensity, peaking in November; (2) significant weather-driven …

Face-To-Face Versus Distance Education In Competence-Based Maritime Education And Training, Clara Borén, Marcella Castells-Sanabra, Manel Grifoll

Journal of Marine Science and Technology–Taiwan

The COVID-19 pandemic created significant challenges for higher education, with universities being shut down and face-to-face teaching and assessment shifting to an online format. This presented an opportunity to focus on the continuity of learning through distance education, especially in the maritime context, due to the on-board training requirements, and even though five years have passed, this shift has reshaped the education landscape, proving that remote learning has come to stay.

At the Barcelona School of Nautical Studies, we have developed a weather routing software in the framework of distance education and teaching innovation. We conducted a teaching trial alternatively …

Allosteric And Uncompetitive Inhibition Of Yeast Alcohol Dehydrogenase Identified By Enzyme Kinetics, Dylan Jeremy Harrison, Jenny A. Cappuccio

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

Enzyme kinetics is a powerful technique used to quantify the rate at which an enzyme converts a substrate into a product and to identify potential inhibitors. In this study, kinetic analysis was employed to assess the activity of yeast alcohol dehydrogenase (YADH) in the presence and absence of sweeteners commonly found in alcoholic beverages. YADH catalyzes the oxidation of ethanol to acetaldehyde using NAD⁺ as a cofactor; the reduction to NADH can be monitored spectrophotometrically at 340 nm. Based on structural similarities to the ribose moiety of NAD⁺, it was hypothesized that sucrose and sucralose could directly interact with the …

Ka Here Tāngata:1 Mātauranga And Te Ao Māori In Biocultural Kākāpō (Strigops Habroptilus) Conservation Approaches, Sophie Perfetto

Electronic Theses and Dissertations

This master's thesis examines conservation as a form of living cultural heritage practice through the co-management of kākāpō (Strigops habroptilus), a critically endangered parrot and taonga species in Aotearoa New Zealand. Situated within ongoing histories of colonial dispossession and Western frameworks of land and species management, contemporary kākāpō conservation is shaped through the partnership between the Department of Conservation’s Kākāpō Recovery Programme and Ngāi Tahu. Drawing on semi-structured interviews collected during fieldwork from July to August 2025, this study examines how institutional partnerships structure decision-making, authority, and responsibility in contemporary conservation governance. Findings demonstrate that Māori knowledge systems …

Desert Dichotomies: Climatic Imaginaries Of The Arid+[Ant]Arctic, Amanda Aman

Mavs Open Press Open Educational Resources

Desert Dichotomies is a research-based architecture design studio that examines the impacts of climate change across arid and polar desert environments, revealing unexpected parallels between landscapes often understood as environmental opposites. Focusing on Antarctica, Arctic Alaska and the Sonoran Desert, the project investigates how climate change, resource extraction and human systems of control are transforming ecological processes, water systems and cultural landscapes. While arid deserts face increasing drought and water scarcity, polar deserts are experiencing accelerated warming, ice loss, permafrost thaw and flooding. Despite these contrasting conditions, both regions exhibit similar consequences, including declining water quality, biodiversity loss, infrastructural vulnerability …

A Comparative Evaluation Of Six Ryegrass Cultivars Under Grazing And Conservation Managements, M Ryan

IGC Proceedings (1977-2023)

Meat and dairy products command overriding importance in the Irish agricultural economy. They are derived primarily from Irish grasslands, which occupy 89% of the arable land area. Use of improved grass cultivars is probably the best means of increasing grassland output once the basics, optimal fertilizer use, and high stocking rates have been met. Objective identification of superior cultivars is the responsibility of state agencies. A recommended list, published annually in Ireland, presently contains 47 ryegrass (Lolium perenne) cultivars. There is some doubt, however, that results from small-plot cutting trials can be extrapolated to equivalent performance by grazing …

Potential Grass Production In Ireland, A J. Breeton

IGC Proceedings (1977-2023)

Variation in weather geographically and between years can have a significant impact on intensive animal production systems dependent on grass as feed. This work was undertaken to quantify the effect of weather variations on grass production. The first objective was to relate grass growth quantitatively to radiation and temperature. These relationships are obscured by large changes in sward growth potential within the season, which are related to changes in the physiological status of the crop. Therefore, it was necessary to quantify this physiological effect. Production data were drawn from production experiments, and weather data were drawn from the published records …

Production Of Big Trefoil On Acid, Low-Fertility Soils In New Zealand, R S. Scott

IGC Proceedings (1977-2023)

On undeveloped, acid (pH< 5.0) soils in New Zealand, growth of the conventional legumes white clover (Trifolium repens L.), red clover (T. pratense L.), and alsike clover (T. hybridum L.) is limited by acidity. The objective of this research was to identify an alternative legume species better adapted to both acidity and low inputs of phosphorus (P) and to examine grazing management. Big trefoil (Lotus pedunculatus Cav.) cv. Grasslands Maku and birdsfoot trefoil (L. rorniculatus L.) cv. Maitland were examined. Seed was inoculated with appropriate strains of rhizobia and sown into undisturbed tussock grasslands on acid soils of low P status at altitudes of 550-880 m. Lime and phosphorus …

Animal Production With Controlled And Fixed Stocking And Managed Stocking Rates, R E. Blaser, J T. Johnson, F Mcclaughterty, J P. Fontenot, R C. Hammes Jr, H T. Bryant, D D. Wolf, D A. Mays

IGC Proceedings (1977-2023)

Grazing experiments were conducted to implement and improve animal-grazing-management systems. The primary objec­tives were (experiment 1) to investigate animal production with fixed and controlled stocking and (experiment 2) to study animal production and canopy characteristics with three managed stocking rates. Live-weight gains/head for the grazing season were similar for fixed and controlled stocking; during a summer period, gains/head were higher for controlled stocking. Gains/head were not associated with available herbage. The canopies with fixed stocking had 28% to 82% more forage than those with controlled stocking, the former being high in dead tissues and stems. Controlled stocking gave 61 % …

Influence Of Sward Structure Upon Herbage Intake Of Cattle Grazing A Perennial Ryegrass Sward, M H. Wade, Y.L P. Le Du

IGC Proceedings (1977-2023)

To examine the influence of structural distribution of herbage within a sward on intake by grazing animals, two swards of contrasting structure were established at two periods in the grazing season by either infrequent mowing (C) or hard sheep graz­ing (G) of a perennial ryegrass (Lolium perenne) pasture. The plots were then allowed to grow undisturbed for about 5 weeks before being grazed by young cattle for periods of 2 weeks at two levels of herbage allowance, 30 and 60 g dry matter/kg live weight/day, in July (1) and in September (2). Detailed measurements of sward structure were …

A Mathematically And Conceptually Unified Approach To Grazing-Management Terminology, D L. Scarnecchia, M M. Kothmann

IGC Proceedings (1977-2023)

Expressions such as "stocking density," "stocking rate," "grazing pressure," "herbage allowance," "grazing intensity," "stock­ing intensity," and "stocking pressure" have long been used to describe animal-pasture systems. In general, these expressions describe relationships among the basic variables of animal demand, forage quantity, pasture area, and grazing duration. Our objective was to develop a conceptually dynamic mathematical framework of expressions summarizing all of the meaningful relationships among these variables. Elementary differential and integral calculus were used to develop this dynamic approach. The resulting expressions are dimensionally valid and are capable of accurately describing dynamic animal-pasture systems. Adoption of this system would standardize …

Screening Perennial Forages By Mob-Grazing Technique, P Mislevy, G O. Mott, F G. Martin

IGC Proceedings (1977-2023)

Mob-grazing allows the study of forage response to severe defoliation by grazing animals on a limited land area. This tech­nique was used to evaluate two Digi,taria spp., one Paspalum sp., and 13 Cynodon spp. at grazing frequencies of 2, 3, 4, 5, and 7 weeks. Average dry-matter (DM) yield generally increased as grazing frequency decreased from 2 to 7 weeks. Decreasing the grazing frequency from 4 to 7 weeks resulted in a DM yield increase of 50% to 75% for most entries. Grazing at 4-and 5-week intervals resulted in the highest (42%) and lowest (22%) weed contamination, respectively, when compared …

Grazing Techniques For Evaluating Quality Of Forage Cultivars In Small Pastures, A G. Matches, F A. Martz, D A. Sleeper, R L. Belyea

IGC Proceedings (1977-2023)

Because plant beeders have few laboratory analyses of forage quality that are good predictors of animal performance when grazing pasture, • we studied the feasibility of grazing small pastures with cattle in order to detect possible forage-quality dif­ferences among cultivars of tall fescue (Festuca anmdinacea Schreb). Kentucky 31, Kenmont, Fawn, and Missouri 96 tall fescue cultivars and Kenhy, a Lolium-Festuca derivative, were grown in 0.47-ha pastures and grazed in separate periods ranging from 35 to 68 days during the spring, summer, and autumn of 1974-1976. Between grazing periods, cattle grazed a reserve pasture of the same cultivar. All test pastures …

Using A Dynamic Model Of Fiber Digestion And Passage To Evaluate Forage Quality, D R. Mertens, L O. Ely

IGC Proceedings (1977-2023)

Assessing forage quality depends not only upon the characteristics of the plant and animal, but also upon the dynamic interac­tion of the forage, rumen microorganisms, and animal. Although static variables, such as composition or 48-hour in-vitro fermentation, are important for characterizing feeds and predicting in-vivo responses under standard conditions, they provide little information that can be used to assess forage quality in dynamic situations. Dynamic properties, such as rates of digestion and passage, can be used to predict digestion under varied circumstances but require an appropriate mathematical model. Our objectives were to describe a dynamic model of fiber digestion and …

Methodology For Determining Pasture And Animal Response Differences In Unbalanced Experiments With Intercorrelations Among Treatments, J C. Burns, R W. Harvey, F G. Giesbrecht

IGC Proceedings (1977-2023)

Conventional statistical analyses require balanced data sets. Unbalanced data can be analyzed using regression procedures, but excessive adjustments may be needed for some treatment means. The objective of this paper is to evaluate an analysis of grazing-trial data using generalized least squares. The data was obtained from a 6-year study involving 12 treatments with not all treatments being made in all years. The analyses involved estimating variance components due to years, fields, and random error and then using these estimates to obtain adjusted treatment means. Variance-component estimates for the complete data set were similar to estimates from two balanced subsets …

Effect Of Experimental Methods On Results Of Voluntary Intake Experiments With Grass Cultivars, U Simon, P Daniel

IGC Proceedings (1977-2023)

The amount of forage eaten by farm animals when forage is offered ad libitum is a major factor in the nutritive value of forage grasses. It is influenced by a number of internal and external factors. Experimental results of studies on the subject :reported in the literature are often contradictory, partially because, perhaps, of the methods of evaluation employed. We studied whether and to what extent different experimental procedures influenced the results of intake experiments in grass cultivars. Four cultivars of Lolium perenne differing in ploidy level and precocity were fed to sheep ad libitum, and voluntary intake was assessed …

Review Of Mechanisms Of Toxicity Of 3-Nitropropanoic Acid In Nonruminant Animals, D L. Bustine, B G. Moyer

IGC Proceedings (1977-2023)

Crownvetch (Coronilla varia L.) now has limited use in the U.S.A. as a forage crop for ruminant animals. Even though crown vetch forage can contain high amounts of nutrients, intake by ruminants may be reduced. Toxicity problems upon feeding crownvetch to nonmminants have been traced to 3-nitropropanoic acid (NPA), which occurs esterified to glucose in the plant. Understanding mechanisms of toxicity in nonruminants will be helpful in avoiding livstock losses and in treating poisoned animals. Symptoms of NPA toxicity are similar in rats, mice, meadow voles, chickens, and rabbits and probably reflect central nervous system disorders and oxygen deprivation. …

Beef Production From Tall Fescue Treated With Mefluidide A Chemical Plant-Growth Regulator, T W. Robb, D G. Ely, C E. Rieck, S Glenn, L Kitchen, B P. Glenn, R J. Thomas

IGC Proceedings (1977-2023)

Mefluidide treatment of Kentucky 31 tall fescue (Festuca arundinacea Schreb.) in the spring will inhibit seed-head formation, maintain the forage in an immature and vegetative stage, and increase forage N and soluble-sugar content and in-vivo nutrient utilization in the ovine. Productivity of animals grazing mefluidide-treated tall fescue, however, has not been determined. The objective of this study was to evaluate agronomic characteristics of forage and productivity of yearling beef steers and heifers grazing mefluidide-treated (T) and nontreated control (C) pastures of Kentucky 31 tall fescue. Experimental pastures of Kentucky 31 tall fescue ( 4 replications at location I and one …

Role Of Alkaloids And Toxic Compounds In The Utilization Of Tall Fescue By Ruminants, J A. Boling, R W. Hemken, L P. Bush, R C. Buckner, J A. Jackson Jr, S G. Yates

IGC Proceedings (1977-2023)

Tall fescue (Festuca arundinacea Schreb.) contains several alkaloids. Studies in our laboratory showed that perloline is a prin­cipal alkaloid in tall fescue during the summer and that concentration peaks at a time when cattle grazing tall fescue pastures fre­quently have severely reduced performance (summer syndrome or summer fescue toxicosis). The objectives of the following studies were (1) to determine the influence of perloline on in-vitro fermentation and in-vivo ruminant metabolism and (2) to determine the effects of two tall fescue strains selected for perloline concentration on performance of growing cattle and lactating dairy cows and on interrelationships with environmental …

Feeding Value Of The Legume Component In Pasture And Silage, K.F M. Reed, P T. Kenny

IGC Proceedings (1977-2023)

Grazing experiments were conducted to examine the feeding value of various pastures for grazing sheep and, in some cases, as silage. Recently, the use of legumes for improving the growth of weaned lambs during the dry summer and early autumn was in­vestigated at Hamilton, Victoria. Studies in Australia showed that the fleeceweights of weaner sheep grazed on eight pasture mixtures of varying grass species increased as the amount of clover in the pasture increased (r -0.88 • *). In a separate study, young sheep grew faster on lucerne· grass pasture than on grass-subtenanean dover pasture. Most recently, live-weight gains of …

Increasing Productivity And Extending Grazing Season Of Cynodon Pastures For Steers With N And Overseedings Of Trifolium And Festuca In The Southeastern U.S.A, H A. Fribourg, J B. Mclaren, R J. Carlisle

IGC Proceedings (1977-2023)

A series of grazing experiments has been conducted 80 km east of Memphis, Tennessee, since 1969 on fine-silty, mixed, ther­ mic, Typic Hapludalfs soils to evaluate productivity and quality of Cynodon pastures grown with N fertilizer or in combination with Festuca arundinacea and/or Ladino, TnJolium repens, and sometimes with T. pmtense, for growing beef steers. Pastures were grazed by the put-and-take system, and forage growth and consumption were determined by the cage-and-strip method. These experiments have shown that bermudagrass pastures can support many young beef animals for 5 months/yr if they are fertilized with N, can produce rapid gains in …

Simulation Of Complementary Forage Cropping By Feeding Oat Grain To Ewes, J L. Wheeler, D A. Hedges, C Mulcahy

IGC Proceedings (1977-2023)

In many parts of the world where year-round grazing is feasible, complementary forages such as oats or sorghum are sown to impove the quantity and quality of the forage available at specific periods. Experiments in which these crops complement well­fertilized grassland have generally not shown an increase in animal production compared with all-grassland systems. The pres­ent experiment aimed to determine the effects of a simulated complementary forage crop on pasture yield and on the production of breeding ewes. Eight groups of 10 sheep grazed 0.6-ha plots of Phalaris aquo.tica L.-Trifolium repens L., and eight groups of 10 sheep grazed 0.8-ha …

Effect Of Feeding Level And Forage: Concentrate Ratio On The Digestibility Of Pelleted Diets By Sheep And Cattle, G.M J. Horton, M J. Farmer, B E. Melton, S Sklane

IGC Proceedings (1977-2023)

Sheep are frequently used to determine the nutritive value of cattle feeds. However, there is some evidence that digestion coef­ficients for cattle and sheep may differ and that digestibility may be influenced by feeding level. The purpose of this study was to investigate the effects of feeding level and animal species on the digestibility of pelleted diets containing different ratios of alfalfa hay to barley grain. Five 4O-kg yearling crossbred lambs and four 35O-kg yearling steers were used to evaluate each diet. The six diets were isonitrogenous, containing the following proportions of barley grain and alfalfa hay (percentage as fed …

Effect Of Supplements On The Live-Weight Gain Of Beef Cattle Given Forage During The Dry Season, C Thomas, P N. Mbugua

IGC Proceedings (1977-2023)

The low quality of standing pasture grasses in the dry seasons presents a major problem in the intensification of beef produc­tion in the tropics. The objective of this research was to examine the role of maize and grass silage or standing napiergrass (Pen­nisetum purpureum) as sources of forage when given alone or with supplements to beef cattle. In the first of three trials conducted at the National Agricultural Research Station, Kitale, Kenya, 36 Friesian castrates, initially 249 kg live weight (LW), were given silage of whole-crop maize either alone or supplemented with corn-and-cob meal. Each of these two basal diets …

Utilization Of Energy Of Fresh Pasture By Lactating Dairy Cows, T E. Trigg, C R. Parr, N R. Cox

IGC Proceedings (1977-2023)

The New Zealand dairy industry is almost totally reliant on grazed herbage for the production of milk solids, but few data ex­ist on the efficiency with which lactating cows utilize energy of fresh herbage offered as the sole diet. One hundred thirty-two energy balances have been conducted by indirect calorimetry using cows at two levels of feeding and at two stages of lactation over 3 years. Mixed pasture suitable for grazing and cut twice daily was the sole diet. Data for the utilization and partitioning of energy have been subjected to regression analysis on a within-cow basis. Efficiency of utilization …

Energy Balance Studies With Lactating Cows Fed Fresh Or Frozen Grass From Pasture Suitable For Grazing, Y Van Der Honing, A.J H. Van Es

IGC Proceedings (1977-2023)

Information on feeding value and energy utilization of grass consumed by grazing cattle, especially lactating cows, is limited. It is nearly impossible to perform calorimetric studies with grazing dairy cows. Similar studies indoors often show low intakes of fresh grass and require much labor. Still, in much of the world, cattle graze at least half the year; therefore, knowledge of the feeding value of grass is important for practice. In the Netherlands, each year (1973-1974) each of four permanent pastures in the grazing stage of maturity was cut twice daily and either fed fresh or stored at - 20°C to …

Seasonal Changes In Botanical And Chemical Composition And Digestibility Of Diets Of Large Herbivores On Shortgrass Prairie, G M. Van Dyne, J D. Hanson, R C. Jump

IGC Proceedings (1977-2023)

Studies were conducted from 1969 through 1974 on northeastern Colorado shortgrass prairie during different grazing seasons and under different grazing intensities to evaluate bison, cattle, sheep, and pronghorn antelope diets. The purpose was to ex­amine seasonal changes in chemical and botanical composition and digestibility of diets of large herbivores. Bison, cattle, and sheep diets were obtained from esophageal fistula samples. Fistula samples were analyzed microscopically to determine botanical composition. Pronghorn antelope diets were obtained by bite-count methodology. Data, presented for im­portant plant species and species groups, were averaged for 28-day intervals to show typical seasonal trends in diets. During all …