Physical Sciences and Mathematics Commons^™

Leaf Optical And Indirect Lai Measurements In Wheat And Alfalfa At Maciv: Agmet Progress Report 89-4, E. A. Walter-Shea, B. L. Blad

School of Natural Resources: Documents and Reviews

No abstract provided.

Environmental Dna Identifies Coastal Plant Community Shift 1,000 Years Ago In Torrens Island, South Australia, Nicole R. Foster, Alice R. Jones, Oscar Serrano, Anna Lafratta, Paul S. Lavery, Kor-Jent Van Dijk, Ed Biffin, Bronwyn M. Gillanders, Jennifer Young, Pere Masque, Patricia S. Gadd, Geraldine E. Jacobsen, Atun Zawadzki, Andria Greene, Michelle Waycott

Research outputs 2022 to 2026

Anthropogenic activities are causing detrimental changes to coastal plants– namely seagrass, mangrove, and tidal marshes. Looking beyond recent times to past vegetation dynamics is critical to assess the response and resilience of an environment to change. Here, we develop a high-resolution multi-proxy approach, providing a new evidence base to decipher long-term change in coastal plant communities. Combining targeted environmental DNA analysis with chemical analysis of soils, we reconstructed 4,000 years of change at a temperate wetland on Torrens Island South Australia and identified an ecosystem shift that occurred ~ 1000 years ago. What was once a subtidal seagrass system shifted …

Confocal Raman Spectroscopy Coupled With In Vitro Permeation Testing To Study The Effects Of Formalin Fixation On The Skin Barrier Function Of Reconstructed Human Epidermis, Hichem Kichou, Franck Bonnier, Amanda C. Caritá, Hugh Byrne, Igor Choupra, Emilie Munnier

Articles

Confocal Raman Spectroscopy is recognised as a potent tool for molecular characterisation of biological specimens. There is a growing demand for In Vitro Permeation Tests (IVPT) in the pharmaceutical and cosmetic areas, increasingly conducted using Reconstructed Human Epidermis (RHE) skin models. In this study, chemical fixation of RHE in 10% Neutral Buffered Formalin for 24 hours has been examined for storing RHE samples at 4°C for up to 21 days. Confocal Raman Spectroscopy, combined with Principal Components Analysis, revealed the molecular-level effects of fixation, notably in protein and lipid conformation within the stratum corneum and viable epidermis. IVPT by means …

An Experiment Study On Implementing Syngas On A Small Generator Set, Bui Van Chinh, Khong Vu Quang, Khanh Nguyen Duc

ASEAN Journal on Science and Technology for Development

This paper presents an experiment on syngas's influence on the performance and pollutant characteristics of a mechanical diesel engine generator set. Using syngas as an external fuel is good for medium and light loads of less than 80%. While a moderate substitution of syngas will contribute to good performance at high loads, a larger level of syngas provided may degrade engine performance. The brake-specific energy consumption rises as the replacement syngas flow increases. Using syngas as an external fuel to substitute for a part of the diesel might cause the engine to perform unstablely. The more syngas replacements, the greater …

Enzyme Encapsulation Within The Hk97 Virus-Like Particle: An Investigation Of Substrate Inhibition Kinetics Within A Confined And Crowded Environment, Joseph B. Lively

Chemistry Theses

Substrate inhibition is a paradoxical phenomenon observed in enzyme kinetics where increasing substrate concentrations lead to a marked decrease in the rates of enzyme-catalyzed reactions. Affecting an estimated 20% of studied enzymes, substrate inhibition poses significant challenges to the understanding of their function in essential biological processes and to their exploitation in industrial and therapeutic contexts. Studies show substrate inhibition to be a real limitation in vitro and rational conclusions have been drawn to explain the relevance of substrate inhibition in the self-regulation of biological pathways. However, there is currently no consensus on what role substrate inhibition plays in vivo …

Satellite Observations Indicate That Chia Uses Less Water Than Other Crops In Warm Climates, Brian Kirsch, Joshua B. Fisher, Thomas Piechota, Mohammad Hassani, Diego C. Suardiaz, Radhika Puri, Joseph Cahill, Hagop S. Atamian

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Many parts of the world face severe and prolonged drought conditions, stressing the sustainability of water resources and agriculture. Transitioning to water-efficient crops is one strategy that can help adapt to water scarcity. An emerging drought-tolerant crop of interest is chia (Salvia hispanica). Yet, no study has compared its large-scale water use dynamics to those of widely established crops across the globe. Here, we use satellite data over multiple years to assess the water use efficiency of chia, alfalfa, corn, and soybean globally. Results show that chia consumed 13-38% less water than alfalfa, corn, and soy and assimilated …

An Optimal Schedule Recovery Model For Transportation Carriers Under Uncertain Typhoon Disruption Periods, Yi-Chun Chen, Shangyao Yan

Journal of Marine Science and Technology

Due to the unsettled weather conditions caused by typhoons, it is not possible to forecast the time when a typhoon will arrive or depart accurately. The uncertainty regarding the duration of typhoon disruptions makes it challenging for transportation carriers to efficiently adjust their schedules. In this study, to deal with the problem of airline fleet rerouting, flight rescheduling, and passenger reassignment for uncertain disruption periods caused by a typhoon, we utilize network flow techniques with the concept of probability to construct a stochastic model for minimizing the total operating costs. A heuristic algorithm based on the divide-and-conquer technique is adopted …

Policies And Programs For Water-Wise Residential Landscaping In Utah, Charlotte Clark, Kendall Becker, Scott Hotaling

All Current Publications

Water-wise landscaping is the practice of using plants in a landscape that are adapted to local conditions and only need small amounts of water. Converting yards to water-wise landscaping conserves water and is a climate adaptation action residents can take to benefit Utah as temperatures rise and drought becomes more common. Many policies and programs in Utah help residents use water conscientiously and make changes. This fact sheet provides information regarding current and future water-wise landscaping policies and programs in Utah.

Climate Smart Agriculture, J. David Aiken

Cornhusker Economics

There are several programs encouraging producers to reduce their carbon intensity, including United States Department of Agriculture climate-smart agriculture programs, the 2024 Nebraska Climate Action Plan, and the 2024 Nitrogen Reduction Incentive Act. The hope is that producers with lower carbon intensity (CI) scores will receive a premium for their products. Producers would be well advised to learn more about these programs, as reducing carbon intensity in agriculture seems to be an emerging agricultural policy trend that will be with us for some time to come.

Chacahoula 2024, Vol 91, Alayna Pellegrin

Chacahoula

MERGING REALITIES:

The 2023 issue of Chacahoula includes December 2023 and May 2024 graduating classes, as well as stunning photography of Week of Welcome, Homecoming, Mardi Gras, and Spring Fever. With features covering notable students, faculty, and staff, this year's time capsule beautifully preserves an academic year in the life of the University of Louisiana at Monroe.

Development Of Intensive Grassland Systems: From Science To Practice, D G. Mccall, G W. Sheath

IGC Proceedings (1993-2023)

Level of nnimal production from grassland is determined by the amount of pasture grown, pasture utilisation and animal conversion efficiency. The key components affecting production are pasture growth and animal conversion efficiency. These arc mainly influenced by environment, genetics and through inputs to maintain soil fertility or animal health. Systems development aims to link pasture growth and animal conversion through efficient strategies for pasture utilisation. The means of influencing pasture utilisation is through adjustments to animal feed demand, feed supply or grazing management. Stock policies that adjust the pattern and level of feed demand are of greatest significance in developing …

The Ecology Of Grazing Management, R K. Heitschmidt

IGC Proceedings (1993-2023)

The broad objective of this paper is to review the fundamental principles of grazing management as a means of assessing the inherent value of intensive and extensive grazing systems. Conceptual analyses of intensive and extensive grazing systems reveal that the fundamental differences between intensive and extensive grazing systems are related to differences in non-grazing rather than grazing tactics. Intensive grazing systems employ a wide array of non-grazing tactics in an attempt to overcome the inherent ecological constraints that limit secondary (i.e., livestock) productivity in extensively grazed systems. Moreover, analyses of the ecological or true efficiency of various agricultural production systems …

An Analysis Of The Dry Matter Intake And Rate Of Live-Weight Gain Of Growing Cattle Fed Forage Diets, J G. Buchanan-Smith

IGC Proceedings (1993-2023)

The intake and rate of live-weight gain of 500 growing steer calves fed experimental forage diets in 7 trials were compared with corresponding values predicted using the Na1ional Research Council (NRC) model (1984). The cattle were predominantly weaned calves and most of the experimental diets were alfalfa-grass silage, either unsupplemented or supplemented with various protein sources, but some diets were based on maize silage or maize grain. The feeding period evaluated in this study ranged between the first 84 and 147 days when protein accretion rate in the cattle would be relatively high. Dry matter intakes were overpredicted by the …

Management Of Extensive Pastures For Dairy Youngstock, G.E J. Fisher, D J. Roberts

IGC Proceedings (1993-2023)

The effects of low input systems on the ground cover of species and yield and chemical composition of herbage cul from extensive lowland swards was studied over 3 years. The live-weight gain of dairy heifer replacements offered grazed or conserved forage from these pastures was also assessed, The swards were sown with a mixture of grasses, wildflowers and herbs and received no inorganic fertilizers, Applications of slurry in January and February increased herbage yield by 43%, but reduced the cover of flowers and herbs. Using a 2- cut conservation system improved yield of metabolisable energy/ha in herbage by 33%, and …

Intensive Grazing Of Alfalfa By Beef Steers, M Rasnake, W R. Burris, G D. Lacefield, J Randolph, N Gay, L Davis

IGC Proceedings (1993-2023)

In the temperate region of North America, high temperature and moisture deficit cause low forage growth during the summer of most years, making it difficult to grow beef (Bos taurus), calves through summer grazing. Alfalfa (Medicago sativa), offers some potential to provide high dry matter production during summer if an effective system of grazing can be developed. The objective of this study was to test a system of intensive grazing of beef steers on alfalfa to maximise live-weight gains/ha and maintain plant population. Alfalfa was no-till seeded into a 6.5 ha field in autumn 1988 after …

Variance Across Years In Growth Of Cattle On Annual Pastures In A Mediterranean Climate, K D. Greathead, J Zorrilla Rios

IGC Proceedings (1993-2023)

Annual pastures were continuously grazed by new drafts of yearling cattle each year for 4 years at 2 sites. The variability of weight gained across years at any date was not different between sites. The level of rainfall in April, but strongly influenced weight gained by the cattle in any year. Variances in weight change were small up to April, they increased rapidly from April to late July and were not different after July (P<0.05).

Modification Of The Botanical Composition Of Perennial And Annual Temperate Pastures By Strategic Grazing Practices, D R. Kemp, P M. Dowling

IGC Proceedings (1993-2023)

Where livestock production depends upon pastures, management is more difficult in environments where rainfall varies considerably from season to season and year to year. Flexible grazing practices are needed to optimise species composition and pasture productivity. Results presented in this paper show that pasture composition can be improved within climatic constraints, by grazing practices within seasons, In temperate annual pastures, long rests in winter (similar to a long rotation during that season) increased annual legume content in early spring from 20 to 50%. Annual grass content was unchanged. In perennial (phalaris) pastures, the dominant legume can change over years from …

Development Of Grass-Clover Pasture Systems For Autumn-Calving Beef Cows. I. Forage Production, G D. Mooso, D G. Morrison, J I. Feazel, D R. Morris

IGC Proceedings (1993-2023)

Four 8-ha areas of bermudagrass-based (Cynodon dactylon (L.) Pers.) grazing systems were sodseeded and received annual N fertiliser as follows: I) clover (Trifolium sp.)+81 kg Nnm, 2) annual ryegrass (Lolium multiflorum Lam)+clover +81 kg N/ha, 3) ryegrass+clover+l39 kg N/ ha, and 4) ryegrass+139 kg N/ha. Monthly forage accumulation was estimated for 3 years by clipping samples from 2 exclosures/pasture. Environmental conditions had a significant effect on total annual forage dry matter (DM) production. Systems 3 and 4 produced more (P<0.05) forage DM than Systems 1 and 2 (11.0 v. 10,3 Mg/ha). System I produced more (P<0.l) forage DM than 2 (10.6 ll, 9.8 Mg/ha). Systems 3 and 4 were similar, producing I 1.0 Mg/ha. Monthly forage accumulation was lowest in winter (December to February) and highest in spring and summer (March to August). The results of this study demonstrate that at a low N level, there was no benefii from including ryegrass in the system and al a moderate N level, there was no benefit from including clover.

Development Of Grass-Clover Grazing Systems For Autumn-Calving Beef Cows. Ii. Cow-Calf Production And Economic Analysis, D G. Morrison, J I. Feazel, G D. Mooso

IGC Proceedings (1993-2023)

Four 8-ha areas of bermudagrass-based (Cynodon dactylon (L.) Pers.) grazing systems were sod seeded and received annual N fertiliser as follows: I) clover (Trifolium sp.)+81 kg/ha, 2) annual rye grass (Lolium multiflorum Lsm.)+clover +81 kg/ha, 3) ryegrass+clover+139 kg/ha, and 4) ryegrass+l39 kg/ha. Each system was stocked year-round with 20 (2,5/lla) cows each with crossbred suckling calf. Cow and calf performance data for 3 of 4 years are included. Year affected (P<0.01) cow and calf live weight, Cows in System 2 were 25-50 kg lower in live weight in autumn and winter than cows in other systems. From February to July, cow daily live-weight gains were 0.11 kg higher (P<0.01) for Systems 2 and 3, Cow live weight in July was affected by N level (Systems 1,2<3,4; P<0,01), Year by system interactions (P<0.05) occurred for cow live weight in February, April and July because of live weight increasing over years in Systems 3 and 4 but not in Systems 1 and 2. Calf daily live-weight gain February to weaning (July) was higher (P<0.01) for System 2 v. 1 (0.06 kg), Syuem 3 v. 4 (0.07 kg), and Systems 3, 4 v. 1, 2 (0.07 kg), Estimated net returns favoured Systems 3 and 4 over Systems 1 and 2.

Improved Grazing Systems For Lamb Production On Appalachian Hill Farms, R L. Reid, J R. Puoli, G A. Jung, D P. Belesky

IGC Proceedings (1993-2023)

Improved grazing methods were tested to increase lamb outputs per ha from Appalachian hill farms. Components of a grazing system were cool-season grass [tall fescue (Festuca arundinacea Schreb.), Grasslands Matua prairie grass (Brom us willdenowii Kunth)J or grass­legume [Kentucky bluegrass (Poa pratensis L.)•red clover (Trifolium pralense L.)] pastures in spring and early autumn, warm-season grass [switchgrass (Panicum virgatum L.)] in summer, and brassicas in late autumn and early winter. Matua was highly productive in cool weather but was subject to fungal infection and grazing ewes had low Mg status in spring. Rotationally grazed switchgrass maintained high numbers …

Use Of Brassica Forage Crops To Extend The Grazing Season In The North-East Usa, G A. Jung, H W. Harpster, M G. Lambert, K T. Leath, R A. Byers

IGC Proceedings (1993-2023)

Forage turnip (Brassica rapa L,) can be made available for animal utilisation in late summer or In late autumn-early winter, when cool­season grass pastures have a low animal carrying capacity. field trials were conducted to identify and quantify factors that influence turnip yield in December or January and to determine whether these factors affect turnip cultivars similarly. Different levels of production in late autumn-winter were attributed to summer drought, foliar diseases, freezing temperatures and rate of leaf senescence. In all instances, the effects of these factors varied with turnip cultivar. However, cultivar ranking generally was the same whether mean …

Interactions Of Rotational And Continuous Grazing With Stocking Rate On Warm And Cool-Season Pastures, David I. Bransby

IGC Proceedings (1993-2023)

With more intense commercialisation of electric fencing many production and economic advantages have been claimed for rotational grazing compared with continuous grazing. However, very little research data are available from the south-eastern USA to verify these claims, Therefore, the objective of this study was to evaluate animal performance under conditions of continuous and IO-paddock rotational grazing on cool- and warm-season pastures commonly used in this region. Three 2-year grazing experiments were conducted, one each on a mixed rye-annual ryegrass (Secale cereale-Lolium multiflorum) pasture, Coastal bermudagrass ( Cynodon hybrid) and Pensacola bahiagrass (Paspalum notatum). In each experiment continuous …

Integrating Pasture Technology Research With Farm Management, R T. Cowan, T M. Davison, K F. Lowe, G K. Reason, G D. Chopping

IGC Proceedings (1993-2023)

An applied research programme which involved farmers in a continuum of trials measuring pasture, soil and milk responses to the application of nitrogen fertiliser to tropical grasses is described. Pasture responses were consistent across farms, grass species and, within limits, rainfall zones and soil types. Soil pH declined by 0.03 lo 0.2 units each year. Additional milk production ranged from 4 to 14 I/kg nitrogen, the response being greater at lower levels of application. Results from farm and research station experiments were consistent. The high adoption rate, reaching 68% in 6 years, was ' attributed to the integration of farm …

Hay Supplementation And Stocking Rate Effects On Live Weight Gain Of Steers Grazing Rye And Ryegrass, Susan E. Sladden, David I. Bransby

IGC Proceedings (1993-2023)

The objective of this study was to evaluate continuous ad lib. supplementation of hay as a means of compensating for the uneven growth distribution of rye (Secale cereale) and ryegrass pastures (Lolium multiflorum) grazed by steers in the south-eastern USA. Pastures were continuously grazed by 230 to 270 kg steers at stocking rates of 2.5, 3.1, 4.1 and 4.9 head/ha with and without hay supplementation for 2 grazing seasons. On average, average daily live-weight gain (ADO) at the highest stocking rate (4.9 steers/ha) was 0.47 kg higher (P<0.01) when hay supplement was provided. Although not significant, in both years ADO tended to be higher for h_ay supplementation even at low stocking rates .

Improved Pasture Species, Fertilizer And Pasture Use To Increase The Productivity Of Wool Sheep In South-Western Victoria, G R. Saul, D Jowett, T Morgan, P Noble, D Borg

IGC Proceedings (1993-2023)

Pastures were upgraded by sowing perennial grasses and subterranean clover (Trifolium subterranum) and applying fertiliser to paddocks on S farms in the wool sheep region of south-western Victoria. Upgraded pastures were stocked at higher rates to ensure utilisation of feed grown. In the third year after sowing, wool production was increased by 56% (35 v. SS kg/ha), and ewe live weights by 4% (49.4 v. 51.4 kg) from upgraded pastures compared with untreated pastures. The results demonstrate the considerable potential to increase output from sheep farms in the region by upgrading pastures. Poor persistence of sown perennial grasses may …

System Research: Preliminary Results From A Farmlet Comparison Between A Biological And Conventional Sheep And Beef System, A D. Mackay, D I. Gray, I M. Brookes, P J. Budding, B Devantier

IGC Proceedings (1993-2023)

Initial findings of a farm let study comparing biological (agrochemical­ free) and conventional sheep and beef production are presented and discussed. Little difference was found in sheep production between the two systems in 1991-92, despite large differences in the level of internal parasitism, particularly in young sheep. In contrast! growth rates of rising 1 year steers and heifers on the conventional unit were superior to those of the biological farmlet throughout spring and summer of the first year. While a reduction in the use of anthelmintic drench would have little impact on the productivity of sheep systems, the productivity of …

A Management System For The Planning, Implementation, And Monitoring And Evaluation Of Farmlet Trials, D I. Gray, A D. Mackay, P J. Budding, I M. Brookes

IGC Proceedings (1993-2023)

A management system used to operate the farmlet component of a farm· systems research programme investigating biological sheep and beef production is described and the advantages and disadvantages of this approach are discussed,

Economics Of Milk Production From Perennial Ryegrass Cultivars With Different Seasonal Growth Patterns, I M. Brookes, A F. Mcrae, D I. Gray, N Cameron

IGC Proceedings (1993-2023)

Cutting trials at 4 sites throughout New Zealand over 2 years with perennial ryegrass (Lolium perenne L) cultivars showed that Bmbassy (B) produeed similar annual dry matter (DM) yields to Supernui (S) and Yatsyn (Y). However, B grew 10% more DM in January-August, but 5% less DM in September-December. The economic value of these diffecent patterns of growth for milk production was assessed using a computer model. The model constrained pasture covers within specified limits by removing excess feed for conservation and adding additional feed as supplements during periods of deficit. Stocking rates needed to maintain the system in equilibrium …

Effect Of Sward Surgace Height On Herbage Intake, Grazing Behavior And Productivity Of Ewes Lambing In June (Winter) Or August (Spring), S T. Morris, W J. Parker, H T. Blair, S N. Mccutcheon

IGC Proceedings (1993-2023)

Herbage organic mailer intakes (OMI) were measured, using chromic oxide capsules, during the last 4 weeks of pregnancy in ewes due to lamb in June (winter) or August (spring). OM! (averaged across lambing date groups) were 1.4±0.1, 1.8±0.1, 1.8±0.1 and 2.0±0.1 kg OM/ewe/day (mcan±s.e.m. P<0.05) in ewes maintained at sward surface heights (SSH) of 20, 40, 60 and 80 mm respectively. There were no differences in OM! between June- and August-lambing ewes from pregnancy day 122 to day 125 (Pl22-Pl25), but between Pl35 and 139 June-lambing ewes had lower OMI than August-lambing ewes (1.5±0.1 v. 1.7±0.1 kg OM/ewe/day (P<0.05)). Live-weight gain of ewes was lowest on the 20 mm sward and highest on the 80 mm sward (157±34 v. 315±31 g/day, P<0.05). SSH had no effect on lamb birth weight. Preliminary data presented here suggest that, at the same SSH, June-lambing pregnant ewes can achieve OMI similar to those of August-Jambers.

Seasonal Herbage Intake Of Once-Bred Heifers, A A. Khadem, S T. Morris, W J. Parker, R W. Purchas, S N. Mccutcheon

IGC Proceedings (1993-2023)

Once-bred heifer (ODH) beef production systems, which are new to New Zealand, involve mating heifers at 15 months of age to cnlve as 2-year-olds and then slaughtering the heifers (at less than 30 months of age) as prime beef. Never-pregnant, pregnant and lactating Hereford x Friesian heifers were used in 4 experiments. There were no significant differences between pregnant (days 260-270 of pregnancy) and never-pregnant heifers in their herbage organic matter intake (OMI), ingestive behaviour or daily live-weight gain (LWG) when a restricted pasture allowance of 7 kg DM/head/day was offered. Heifers at days 50-60 of lactation and never-pregnant heifers …