Physical Sciences and Mathematics Commons^™

Effects Of Two Grazing Conditions On The Reproductive Achievement Of Male Alpaca In The Northern Peru Grasslands, C Pinares, E Malpartida, S Cortez

IGC Proceedings (1993-2023)

Alpaca have recently been introduced to the northern Peru grasslands (Jalca). Effects of two systems of grazing management, co-grazing (with sheep) under fair grassland condition (CGFC) versus exclusive grazing under good grassland condition (EGGC), upon the reproductive achievement was examined from the 6th to the 16th month of age. Each system involved 20 Huacaya animals, managed by individual herders. Availability of herbage preferred by alpaca (HMA) and animal measurements (herbage intake, liveweight, testicle size, penis release from preputial attachments, plasma testosterone) were monitored monthly. Puberty, judged by the penis release from the preputial attachments, was achieved by 7 …

Experiences Of Eight Ohio Beef And Sheep Producers With Year Round Grazing, H M. Bartholomew, S L. Boyles, B Carter, E Vollborn, D Miller, R M. Sulc

IGC Proceedings (1993-2023)

Livestock producers participated in a demonstration project to extend the grazing season and evaluate dormant forage quality and yield. Differences were not detected in yields among forage species but yield differences existed among sites. Yield estimates did not change over time across all forage species but some sites were only able to participate for two months. Producers utilizing fescue beyond November had reductions in herbage mass. Crude protein, available crude protein, acid detergent fiber, and neutral detergent fiber content differed among forage species and sites. Energy and lignin content were similar for all forage species and sites. Sodium and copper …

Forage Production Of Irrigated Lecerne- Grass Mixtures Grazed By Sheep, M L. Enrique, D P. Minon

IGC Proceedings (1993-2023)

The forage production and botanical changes of lucerne cultivars in pure stands and in grass mixtures were studied in a split-plot experiment with irrigation and sheep grazing. The non dormant lucerne cultivars (Medicago sativa) CUF 101, Monarca SPINTA, P 30 and common were the main plots, and tall fescue (Festuca arundinacea), canarygrass (Phalaris aquatica), cocksfoot (Dactylis glomerata), tall wheatgrass (Thynopirum ponticum) and prairie grass (Bromus catharticus) were the subplots. The experiment was grazed 3, 6 and 4 times during 3 years. Total yield was similar for all lucerne …

Oat Grazing: Forage Composition And Supplementation Response, A J. Freddi, M J. Arzadun, A A. Pissani, P Sastre

IGC Proceedings (1993-2023)

Oat forage (Avena sativa), which has low soluble carbohydrates (SC) and high soluble protein (SP) content, can reduce liveweight gain of grazing animals; supplementation with grain and low degradability protein may serve to counteract the effect. A grazing trial was carried out on two soils with different nitrogen (NO3 -) availability, from 16 April 1994 to 6 September 1994. Steers were randomly allocated to 3 treatments: low nitrogen (LN), high nitrogen (HN) and high nitrogen with supplementation (HNS). Forage of LN showed lower SP (p<0.05) during the first month of grazing, and higher SC (p<0.05), than HN during the first two months of the trial. Animal liveweight gain was: 892, 909 and 775 g/an/day for LN, HNS and HN, respectively, with animals in HN of significantly lower liveweight gain (p<0.05). Under the conditions of this trial, animals grazing on oat forage with lower SC and higher SP had lower liveweight gain and responded to supplementation.

Native And Introduced Forage Systems For Cow-Calf Production, S W. Coleman, W A. Phillips, J D. Volesky

IGC Proceedings (1993-2023)

The objectives of this study was to compare a highly productive introduced warm-season perennial grass to native range for cowcalf production over two years. Three systems, 1) native range with pelleted soybean or cottonseed meal as winter protein supplement (NC); 2) native range with wheat pasture (NW); and 3) Plains Bluestem with wheat pasture (PB) were compared. Protein supplements were given twice weekly and cows grazing wheat pasture were allowed 6 hrs to graze. Cows on NW were heavier with higher condition at breeding in the spring of 1994 than those on NC and cows on PB were heavier and …

Rotational Stocking And Soil Nutrient Distribution On Hawaiian Grasslands, B W. Mathews, J P. Tritschler, L E. Sollenberger

IGC Proceedings (1993-2023)

A naturalized kikuyu (Pennisetum clandestinum Hochst. ex Chiov.) grassland was grazed by heifers (Bos taurus) for 2 years to determine the effects of two rotational stocking methods (short vs. long grazing periods) on soil N, P, K, Ca, Mg, and S distribution in paddocks with natural shade. Additionally, kikuyugrass-greenleaf desmodium (Desmodium intortum Urb.) paddocks were used to evaluate soil nutrient distribution in rotationally stocked paddocks (long grazing periods) without shade. In the study with shade, soil N, P, and K distribution did not differ between stocking methods. These nutrients accumulated within 15 m of shade, but did not …

Relationship Between Height And Sward Quality In Rotational Dairy Systems, M R. Mosquera-Losada, A Gonzalez-Rodriguez

IGC Proceedings (1993-2023)

Height is a good guide for management in dairy systems.Intake by dairy cows depends on amount offered and quality of pasture and for this reason a relationship between that offered and pasture quality with height should be studied. The experiment was conducted in NW of Spain with three different stocking rates in dairy systems. A lower quality sward was found in the taller offered pasture as indicated by its higher ADF and lower CP percentages. Total sward ADF (kg x ha-a) was higher in taller offered pasture, which indicated a lower pasture quality, however the total CP was positively related …

Non-Destructive Methods For The Estimation Of Sward Production, M R. Mosquera-Losada, A Gonzalez-Rodriguez

IGC Proceedings (1993-2023)

Two non- destructive methods of grass production were compared: grassmeter and sward stick, in order to find an equation for transforming one into the other in dairy rotational systems. Linear, logarithmic and quadratic equations were fitted to the data. Linear equation was preferred by simplicity. General equations which included all the year periods showed no differences between sward stick and grassmeter. A detailed study of the different phenology states showed lower heights with grassmeter than with the sward stick method, which should take into account grazing management height recommendations.

Oregon State Rank Assessment For Midget Quillwort (Isoetes Minima), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for midget quillwort (Isoetes minima) using NatureServe methodology, 2024.

Formation And Development Of The Center For Grassland Studies At The University Of Nebraska, M A. Massengale

IGC Proceedings (1993-2023)

The Center for Grassland Studies was formed at the University of Nebraska in 1994 to implement focused interdisciplinary research, educational, and service programs and activities that emphasize the role of grasslands as a natural resource and conservation measure and that enhance the efficiency, profitability, sustainability, and aesthetic value of grasslands, wetlands, and turf. Although the Center is still in a developmental stage, it appears to be accomplishing those objectives.

The Transformation Of Greek Grasslands Under The Impact Of Socio-Economic Factors, R Thanopoulos

IGC Proceedings (1993-2023)

The impact of socio-economic factors on the transformation of Greek grasslands is examined. Factors like urbanisation, migration, collapse of traditional way of life, social pressure for land distribution, intensification of agriculture shaped the evolution of grasslands. Thus, these factors should be taken into consideration for the planning of grasslands management.

Microplastic Accumulation In The Marsh Periwinkle (Littoraria Irrorata), Sarah Keaton, Hannah Lukhard, Eli Windy, Manar Hasan

DePaul Discoveries

Contamination of oceans by microplastics (mm) currently poses a major threat to aquatic and terrestrial ecosystems worldwide. Recent attention towards this issue has raised questions about the extent to which microplastics have accumulated in the environment, and has led to an increase in studies on the effects of microplastics in various organisms. However, levels of contamination in protected natural areas are still largely unexplored, yet can offer an important empirical perspective on the issue. In addition, little is known about the potential effects of microplastics on behavior in the field. This research was conducted within the protected ACE Basin National …

Detection And Quantification Of Acetaminophen In Aquatic Samples From Cádiz, Spain, Hannah R. Desmarais, Michelle N. Mikos

DePaul Discoveries

Pharmaceutical contaminants in water are becoming increasingly prevalent. This could have potentially harmful effects on human health and aquatic environments, even at low concentrations. Acetaminophen, the active ingredient of Tylenol ®, was the target compound for this study, and the aim was to determine is presence and concentration in various aquatic samples in and around the city of Cádiz, Spain. It was predicted that acetaminophen would be detected in low concentrations in river water, drain outflow, University of Cádiz saltwater flow, and lagoon water, but undetectable in the University of Cádiz sink water and fountain water. The presence and concentration …

Spatial And Temporal Analysis Of Pm 2.5 Concentrations In Chicago Along The Lakefront Trail Using Wearable Air Quality Sensors, Jacob A. Johnson

DePaul Discoveries

Mass urbanization and transportation practices have resulted in high amounts of air pollution. Air pollution can have detrimental effects on human health causing respiratory issues as well as other health complications. Certain areas of cities experience more exposure to air pollution which can also cause them to have more health issues and lower life expectancy. These areas are often associated with disinvestment and minoritized communities of color. This research explores patterns of air quality related to environmental justice areas using low-cost wearable air quality monitoring sensors attached to a bicycle. Data was collected along the Lakefront Trail stretching from Irving …

A Seasonal Decomposition Comparison Between Forest And Turf Habitats: Implications For Climate Change, Amanda Shirmer

DePaul Discoveries

Decomposition is an essential ecosystem service in which microorganisms breakdown organic matter. This process improves soil health and acts as a vital step in global carbon cycles. In this study, we examined decomposition rates and associated soil properties in turf and forest habitats across summer and fall seasons in order to determine how land management practices and climate change may be altering local decomposition regimes. Our study determined that there was a statistically significant difference between decomposition rates in turf and forest ecosystems (P=0.003) and a significant difference in decomposition rate across season (P

Postweaning Skull Growth In Living Didelphid Marsupials: The Case Of Gracilinanus Agilis And Cryptonanus Chacoensis, Iveth A. Villalobos Guerrero, Noé U. De La Sancha

DePaul Discoveries

Ontogeny is described as the history of an organism through its lifetime including development, growth, and allometry. The ontogenetic approach in cranial dimensions has proved useful in interpreting evolutionary patterns. Among the largest Didelphidae family of Neotropical marsupials, the species of Gracilinanus agilis and Cryptonanus chacoensis are poorly known. In this study, we address three questions; Is there sexual dimorphism in these species? What is the pattern of allometry? Which allometric patterns best describe the patterns in the skull and mandible? We applied geometric morphometrics to describe and test these differences using MorphoJ. A discriminant function analysis was performed to …

The Impacts Of Urbanization On Soil: The Effect On Decomposition Rates And Microbial Communities, Maximus C. Halekakis

DePaul Discoveries

The anthropogenic impacts of industrialization have left many ecosystems polluted. Soil, being an imperative actor for ecosystem functions, is important to observe under anthropogenic change. My study examined soil organic matter decomposition, microbial biomass carbon(MBC) and the fungal to bacteria ratio(F:B) across an urban-suburban-exurban landuse gradient in San Luis Obispo, California. A cotton strip assay as well as microBIOMETER® testing was performed on three geographic locations in and outside of the city. The cotton strip decomposition acts as an indicator for organic matter breakdown as microorganisms break down the cellulose in the strips causing them to lose mass and tensile …

The Growth Of Ethanol In Brazil: Sugarcane, Corn, And A Few Other Things, Fabio Mattos

Cornhusker Economics

Although we can expect more ethanol produced from corn in the coming years, it is unclear whether it will keep expanding at the same pace as in recent years or how much it will contribute to total ethanol production.

One point to keep an eye on is the typical dynamics of markets. If supply and demand conditions and price movements make corn-ethanol more profitable, ethanol plants in Brazil will keep increasing their production. If it makes more economic sense to produce corn-ethanol (as it happened recently), they will use more corn to produce ethanol.

Supply and demand conditions for ethanol, …

Data Requirements For Whole-Farm Economic Analysis Of Grazing Alternatives, R O. Burton Jr

IGC Proceedings (1993-2023)

The purpose of this paper is to contribute to better communications among the agronomists, animal scientists, and agricultural economists on interdisciplinary teams, that wish to provide useful information to forage producers. This is accomplished by discussing major issues and data requirements for whole-farm economic analysis.

Native Grasslands Of Yugoslavia As A Potential For "Biologically High Quality Food" Production - To Be Preserved And Used For The Benefit Of All, Djordjevic-Milosevic Suzana, Negovanovic Dragan, Zakonovic Miodrag

IGC Proceedings (1993-2023)

Natural grasslands are the base of the livestock production in the hilly-mountainous regions of Yugoslavia. Poor economic power of the owners of these areas brought about a complete dying out of agricultural production in these regions in the last few years. In the same time, the lack of financial resources made it impossible for the farmers to use the fertilisers, protective and other chemical agents which result in a high degree of environmental preservation. Due to current economic policy at this time the population has moved out and there is no industrialisation. The revival of agriculture on the hilly-mountainous regions …

Some Economics Problems Of Range Resource Analysis In Free And Open Access Environment, E Tedonkeng Pamo

IGC Proceedings (1993-2023)

Economic analysis has been the traditional means by which the costs and benefits of rangeland conservation and sustained development have been identified. Conventional analysis has proved inadequate for dealing with the following realities : (1) open access in circumstances of poorly defined common-resource ownership tends to encourage over exploitation; (2) many costs of rangeland degradation involve externalities that will occur in the future; (3) the values of preservation and sustained management are substantial and can be translated into financial assistance; and (4) benefits from rangeland are not often appreciated because of lack of knowledge from rangeland. Recent approaches to economic …

Studies On The Distribution And Formation Of The Meadows In China, Feng Guojun, Zhang Xiujun, Zhu Libuo, Wei Shaocheng, Zhang Yongliang

IGC Proceedings (1993-2023)

The lowland meadows are distributed on the Northeast Plains in the temperate zone in China, and its area became less and less with an increase of longitude. There are some regularities for the distribution of montane meadows, sub-montane meadows and cold-alpinal meadows. And the distribution and formation for meadows are independent upon the zonal climate and their environmental soil moisture.

Sward Structure Under Continuous And Rotation Grazing, V Pavlu, J Velich

IGC Proceedings (1993-2023)

Sward structure under continuous (CG) and rotational (RG) grazing system was studied at an experimental pasture in the Jizerské hory mountains. Herbage mass and vertical distribution was assessed by cutting ten quadrats (0.1 x 0.5 m) and separated into grass, white clover, dandelion, other forbs and dead material. The proportions of grasses was higher at RG (on average 51% of the pasture mass) than at CG (41%). In the years with normal amount and distribution of precipitation the proportion of white clover was higher at CG (17%) than at RG (9%). The lack of summer precipitation damaged more significantly the …

Beef Cattle Production On Renovated Grass Pastures In Savannas Of Brazil, V.P B. Euclides, M.C M. Macedo, M P. Oliveira

IGC Proceedings (1993-2023)

A 3-year grazing trial was conducted, to study animal production on degraded grass pastures, renovated by two levels of fertilization. All paddocks were divided into halves: one received 1.5 t/ha of dolomitic limestone, 400 kg/ha of a fertilizer formula 0-16-18 and 50 kg/ha of microelements (FL1); and the other 3.0 t/ha , 800 kg/ha and 50 kg/ ha of the same fertilizers (FL2). Productivity on FL2 pastures was greater than that on FL1 pastures, averaging 565 and 395 kg of liveweight gain (LWG)/ha/year, respectively. For all grasses the productivity in both fertilizer treatments decreased linearly from the first to the …

Pasture Attributes And Live-Weight Gain Of Lambs Grazing With Different Supplementation Levels, P A. Martinez-Hernandez, M Meza-Nieto, J Perez-Perez, R Barcena, J G. Herrera

IGC Proceedings (1993-2023)

The purpose of this study was to determine pasture attributes, liveweight gain and stocking rate from a mixed pasture grazed by lambs recieving different supplementation levels. There were four treatments: in two, lambs grazed at 4 or 8% herbage allowance, no supplement; in the other two, lambs grazed at 4% herbage allowance plus a concentrate to cover 25 and 30 or 50 and 60% of estimated daily needs of metabolizable energy and crude protein. Pasture was of perennial and annual ryegrass, orchard grass and red clover. Pre and postgrazing forage mass, crude protein and dead material were not different (P …

Characteristics Of Grass Species In Pasture For High Producing Cows In Northern Japan, K Sudo, K Ochiai, T Ikeda

IGC Proceedings (1993-2023)

The prupose of this research was to investigate characteristics of grass species under different conditions appropriate to the intensive grazing system for high producing cows (8000 kg for a 305-day lactation) in northern Japan. Meadow fescue (Festuca elatior L.), timothy (Phleum pratense L.) and perennial ryegrass (Lolium perene L.) white clover (Trifolium repens L.) pastures were established and divided into two plots by difference of regulated plant height (meadow fescue and timothy) or of stocking intensity (perennial ryegrass). Each plot was 60m2 and was grazed when plant height reached 20cm or 30cm. Meadow fescue and perennial …

Agenda De Investigación Para El Manejo Sustentable Del Manglar En Tamaulipas, México [Research Agenda For The Sustainable Management Of Mangroves In Tamaulipas, Mexico], Carlos Zamora-Tovar, Alejandro Fierro-Cabo, Glenda Nelly Requena-Lara

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Se presenta un análisis de la información ecológica disponible sobre los manglares de Tamaulipas, México. El objetivo fue establecer una línea base de conocimiento que defina el estado del arte a partir de la información publicada; actualizar la estructura forestal con datos propios observados en el año 2018; y determinar una agenda de investigación prioritaria para el manejo sostenible del ecosistema de man-glar, ecosistema de vital importancia por la gran variedad de recursos y servicios ambientales que aporta a la sociedad. La investigación bibliográfica recopiló 32 trabajos relevantes: 16 publicaciones formales, siete ediciones institucionales y nueve consideradas literaturas gris; recopilación …

Live-Weight Gain Of Steers Grazing African Star Grass Four Herbage Allowances, J Perez-Perez, J O. Hernandez-Velez, J G. Herrera-Haro, R Barcena-Gama

IGC Proceedings (1993-2023)

The objective was to determine weight changes of steers grazing African star grass (Cynodon plectostachyus) at four herbage allowances (2.0, 2.5, 3.0 and 3.5 kg of dry matter/100 kg of live weight day-1). A rotational grazing system with 10 grazing days and 30 days rest was followed. A Split Plot Design with four replications was used. Response variables were: daily gain per steer (DGS) and per hectare (DGH), dry matter forage yield (FY), % of utilization (% U) and in vitro dry matter digestibility (DMIVD). DGS and DGH were not different (P >0.05) among allowances and grazing periods. …

Strategic Use Of Brachiaria Decumbens Pasture To Beef Heifers During Dry Season, E G. Cardoso, N F. Seiffert, J Marques Da Silva, V.P. B. Euclides, J M. Vieira

IGC Proceedings (1993-2023)

The main objective of this study was to evaluate a Brachiaria decumbens pasture, instead of a common rangeland, for zebu beef heifers during the dry season of the year as a means of anticipating the first calving age from four to three years of age, and so improve the production rate of the herd. Daily liveweight gains (DLWG) were analyzed for the effects of year and three stocking rates during the dry season (SR1=1.5; SR2=2.0 and SR3=2.5 head/ha). The main effect on heifers DLWG was the year (P<0.01), but SR was also important (P<0.05), mainly during the last half of the dry season when pastures are under severe constraints such as soil moisture deficit and low temperatures. The lowest SR presented the highest DLWG (0.204a, 0.174ab and 0.145b kg/head, respectively for SR1, SR2 and SR3), during the dry season. If climatic conditions are not exceptionally bad, heifer first calving occurs at 37 months of age when reared on B. decumbens.

Quality Grassland For Dairy Production In North-West Spain, A Gonzalez-Rodriguez

IGC Proceedings (1993-2023)

An experiment with two groups of 15 Friesian cows grazing independent areas, with no N and 240 kg N ha-1, was run during two years to see the levels of milk production based on a grass/white clover pasture, maintaining high levels of herbage quality. N application decrease clover content from 55% to 42%. The total DM response to N was low. Herbage utilization was maintained similar in both treatments. Moderate levels of milk production can be reached, more than 4000 litres cow-1 and 9000 litres ha-1, with low use of concentrates, only 400 kg cow-1. Crude protein levels were high …