Digital Commons Network^™

Evaluation Of Centrosema Rotundifolium For Sand-Soil Savannas In Eastern Venezuela, I. Rodríguez, R. Schultze-Kraft, S. González

IGC Proceedings (1977-2023)

An evaluation of a collection of amphicarpic Centrosema rotundifolium showed considerable variability among the six accessions tested, regarding above- and below-ground seed production. Dry-season forage yields were very low but rainy-season yields reached acceptable levels. Contents of crude protein, P and Ca were intermediate to high (CP and P) or low (Ca). Three accessions are suggested for on-farm testing in association with grasses in order to explore the plant persistence implications of belowground seed production under practical conditions. Furthermore, the potential of this amphicarpic species for the conservation of sandy soils deserves attention.

Genetic Resources For Tropical Areas: Achievements And Perspectives, Cacilda B. Do Valle

IGC Proceedings (1977-2023)

This paper analyses the present status of tropical forage resources and their utilization in the development of novel cultivars based on the accumulated information from past decades of collecting, evaluation and whatever little breeding has been pursued. The situation of world collections of tropical forages is presented and discussed in the light of limited investment and dwindling resources. A cause for concern is the lesser priority assigned to conservation and manipulation of official tropical germplasm banks, such as CSIRO’S and CIAT’s. In order to assure the availability of tropical genetic resources for the future it is imperative that international efforts …

Genetic Resources For Temperate Areas - Achievements And Perspectives, Mónica Rebuffo, T. Abadie

IGC Proceedings (1977-2023)

The processes of natural evolution and domestication of temperate forage genetic resources resulted in a build-up of genetic diversity, being remarkable in natural populations of grasses and legumes from Central Europe and the Mediterranean basin. Worldwide utilization of few species caused further increment in intraspecific genetic differentiation, meanwhile landraces became adapted to local agricultural production systems. Highlights are given to the risk of genetic erosion of indigenous grasslands as a consequence of the ecosystem modifications imposed by agriculture, as well as the drastic reduction of intraspecific genetic diversity caused by the process of plant breeding and environmental leveling in modern …

Forage Production And Nutritive Value Of Four Promising Sorghum X Sudangrass Hybrid In Korea, S. Seo, J. G. Kim, E. S. Chung, J. K. Lee, S. H. Yoon

IGC Proceedings (1977-2023)

Sorghum x sudangrass hybrid (Sorghum bicolor (L.) Moench) is one of the most important annual grass utilized for supplemental summer forage. There were 14 National Livestock Cooperative Federation (NLCF)’s recommended forage sorghum´sudangrass hybrids in Korea. Among them several hybrids were produced widely, however, they have not been evaluated under same environmental conditions. Therefore, a field experiment was carried out to compare the plant height, forage yield and nutritive value of the NLCF’s recommended cultivars at NLRI, Suwon, Korea in 1995. The four promising cultivars of sorghum´sudangrass hybrid used in this study were P 988, TE-Haygrazer, NC+ 855 (heading type), …

Intake And Digestibility Of Black Locust Foliage Fed To Growing Goat Wethers, L. J. Unruh, J-M. Luginbuhl, J. P. Mueller

IGC Proceedings (1977-2023)

Leaves of Black locust (BL, Robinia pseudoacacia), a native southeastern United States tree species known to contain substantial levels of condensed tannins, were fed to 16, four month old (20.4 kg body weight [BW]) Boer wether goats (Capra hircus hircus) to determine their effects on intake and digestibility. Four diets were stall fed in a randomized complete block design (RCBD) with four replications. Diets included: (1) 100% eastern gamagrass (EGH; Tripsacum dactyloides) hay; (2) 70% EGH and 30% mixture of ground corn (GC; Zea mays) and soybean (Glycine max) meal (SBM); (3) 75% …

Importance Of Considering Rate Of Passage When Determining Energy Content Of Forages For High Producing Animals, Dan J. Undersander, D. K. Combs, Edgard P. Beyer, Marcello T. Rodrigues

IGC Proceedings (1977-2023)

The objective of this study was to determine the effect of higher rates of passage and correspondingly lower rumen retention times on digestion of forages. One hundred and fifty samples of legumes, grasses and grass-legume mixtures were collected from farmer samples submitted to commercial forage testing laboratories and 32 samples of alfalfa at varying maturity were collected from research plots. In vitro digestions were performed for either 24 or 48 hours followed by neutral detergent analysis. Neither acid detergent fiber (ADF) nor neutral detergent fiber (NDF) predicted the standard 48-hour digestion very well (r² = -0.38 and B0.26, respectively). …

Nutritional Quality Of Digitaria Eriantha Steudel. Subsp. Eriantha Cv. Irene, M. J. L. Privitello, R. L. Sager

IGC Proceedings (1977-2023)

Digitaria eriantha is a South African perennial grass, C4 type, that grows during spring and summer with rainfalls higher than 400mm. The aim of this paper was to evaluate its nutritional quality profile: Crude Protein (%CP), True Protein (%TP), Soluble Protein (%SP), Non-Protein Nitrogen (%NPN), Neutral Detergent Fiber (%NDF) and Acid Detergent Fiber (%ADF) in cumulative production cuttings during a species cycle. In-sacco technique was applied to estimate the degradability of dry matter (DM). A simple regression statistics method was applied to relate different nutritional parameters. Digitaria eriantha presents low percentage of CP from flowering and of NPN during its …

Agronomic Potential And Nutritive Value Of Promising Leucaena Species In The Yucatan Peninsula, Luis Ramírez-Avilés, W. O. Cruz, Francisco J. Solorio-Sánchez

IGC Proceedings (1977-2023)

Two experiments were carried out in order to evaluate the agronomic potential, the nutritive value and the tolerance to psyllid (Heteropsilla cubana) of nine Leucaena species. A randomized block design with four repetitions was used. There were significant (P< 0.01) differences on dry matter production (i.e. leaf and twigs yield ). L. collinsii showed the most promising result, which could be related to its high psyllid tolerance. In a second experiment, the preference indices of Leucaena species was assessed with sixteen male pelibuey sheep in a cafeteria trial. There were significant (P< 0.0001) differences among Leucaena species. L. esculenta paniculata was the species most preferred . There was no relationship between chemical composition …

Exposure Of Predatory And Scavenging Birds To Anticoagulant Rodenticides In France: Exploration Of Data From French Surveillance Programs, Meg-Anne Moriceau, Sébastien Lefebvre, Isabelle Fourel, Etienne Benoit, Florence Buronfosse-Roque, Pascal Orabi, Barnett A. Rattner, Virginie Lattard

United States Geological Survey: Staff Publications

Wild raptors are widely used to assess exposure to different environmental contaminants, including anticoagulant rodenticides (ARs). ARs are used on a global scale for rodent control, and act by disruption of the vitamin K cycle that results in haemorrhage usually accompanied by death within days. Some ARs are highly persistent and bioaccumulative, which can cause significant exposure of non-target species.We characterized AR exposure in a heterogeneous sample of dead raptors collected over 12 years (2008–2019) in south-eastern France. Residue analysis of 156 liver samples through LC-MS/MS revealed that 50% (78/156) were positive for ARs, with 13.5% (21/156) having summed second-generation …

First Ecological Characterization Of Whip Black Coral Assemblages (Hexacorallia: Antipatharia) In The Easter Island Ecoregion, Southeastern Pacific, Jan M. Tapia-Guerra, Cynthia M. Asorey, Erin E. Easton, Daniel Wagner, Matthias Gorny, Javier Sellanes

School of Earth, Environmental, & Marine Sciences Faculty Publications

One of the main priorities of marine scientific research is to provide practical information and guidance for biodiversity conservation and management. In this context, the identification of key and fragile habitat-forming species is particularly important. Despite their ecological importance, whip corals in the order Antipatharia remain poorly studied around the world, and especially in the South Pacific. During recent expeditions to explore mesophotic and deep benthic habitats around Rapa Nui (Easter Island), dense assemblages of whip black corals were observed in situ. We here report the first detailed description of the distribution and abundance of these black coral assemblages …

Ramon (Brosimun Alicastrum) Foliage As Supplement For Lactating Dual Purpose Cows, Carlos A. Sandoval-Castro, R. Cetina, I. Pérez, Luis Ramírez-Avilés

IGC Proceedings (1977-2023)

The objective of the present study was to asses the value of ramón (Brosimun alicastrum) foliage as a N-source in replacement of soybean-N in lactating dual purpose cows (Bos indicus x B. taurus). Four lactating cows were used in a latin rectangle design. Ramón was included to replace 0, 33, 66 and 100 % of the soybean-N contained in the supplement. Basal diet was fresh “Taiwán” a cultivar of Elephant grass (Pennisetum purpureum) fed ad libitum. Basal and total dry matter intake, digestibility (total fecal collection), saleable and calf suckled milk yields, and …

Dry Matter Yield, In Vitro Digestibility, Protein And Fiber Composition Of 'Tifton 9' Bahiagrass (Paspalum Notatum) At Six Maturities, J. M. B. Vendramini, C. M. Haddad, Carlos G. S. Pedreira

IGC Proceedings (1977-2023)

The objective of this research was to evaluate dry matter yield, in vitro digestibility, and the concentrations of protein and cell wall components in 'Tifton 9’clipped at six maturities. Herbage was cut at the age of 20, 27, 34, 41, 48 and 55 days. The experimental design was a randomized complete block with six trataments (ages) and four replications. Dry matter yield and acid detergent fiber ranged from 188 g m^-2, to 593 g m^-2 and 386.9 g kg^-1 to 375.1 g kg^-1 respectively, with the cubic regression model having the best fit (P< 0.05). Concentrations of crude protein decreased linearly (P< 0.05) from 121 to 69 g kg^-1. …

In Situ Degradability Of Hand Harvested Or Extrusa Samples Of Tanzania Grass (Panicum Maximum, Jacq.), T. T. Berchielli, A. K. D. Salman, R. N. Silveira, W. V. B. Soares, J. R. Nogueira, S. N. Kronka

IGC Proceedings (1977-2023)

In order to compare the in situ degradability of tanzania grass samples obtained as by extrusa or hand plucked, three ruminal fistulated cows were used in a completely randomized block design with split-plot scheme. Five grams of extrusa or hand harvested grasses were placed in nylon bags rumen incubated during 3, 6, 12, 24, 48, 96 and 120 hours. The degradability of DM, CP, NDF and ADF were, in this sequence, 62.59, 80.88, 50.73 and 46.65%, for hand harvested grass; and 79.53, 90.97, 71.21 and 65.68%, for extrusa. In situ degradability data of hand harvested samples were not reliable.

Herbivore Preference For Afternoon- And Morning-Cut Forages And Adoption Of Cutting Management Strategies, H. F. Mayland, J. C. Burns, D. S. Fisher, Glenn E. Shewmaker, R. Carlstrom, D. S. Cash

IGC Proceedings (1977-2023)

Photosynthesizing forage plants accumulate total nonstructural carbohydrates (TNC) during daylight, but then TNC concentrations are reduced during the night. Afternoon-cut forage (PM) has greater TNC value and thus economic value, than morning-cut (AM). Livestock prefer PM-cut hay and this can be readily demonstrated by offering animals a choice of hays cut in PM and AM. Alfalfa growers in the western United States are readily adopting PM-cutting technology to increase profits.

Near Infra-Red Measurement Of Nonstructural Carbohydrates In Alfalfa Hay, H. F. Mayland, J. C. Burns, D. S. Fisher, Glenn E. Shewmaker

IGC Proceedings (1977-2023)

Recently documented benefits from afternoon versus morning cut forage have encouraged laboratory reporting of total nonstructural carbohydrate (TNC) values as part of forage quality testing. Our objective was to determine if infra-red spectroscopy (NIRS), which is being used in many forage testing labs, could be reliably used to quantify forage sugars in hay samples. We used two alfalfa (Medicago sativa L.) sample populations that were analyzed by wet chemistry for sugars and scanned by NIRS. The first set consisted of field-dried hay samples that were oven dried at 70^oC and the second consisted of fresh, freeze-dried samples. …

Intake And Qualitative Aspects Of Guinea Grass Grazed By Sheep Over Three Different Seasons, Willem A. Van Niekerk

IGC Proceedings (1977-2023)

The objective of this study was to determine the influence of season on intake by sheep as well as certain selected qualitative characteristics of Panicum maximum (cv Gatton) (Guinea grass) at the mature growing stage. The lower DM content of the spring and summer grass (41.6 and 40.2%) did not hamper DOMI (48.1 and 26.7 W^0.75/d), respectively. The N concentration of the spring and summer grass was well within the limit required for optimal rumen microbial production (1.8 - 2.0%). The high cell wall components of the winter grass resulted most probably in a significant lower IVDOM value …

Determination Of N-Alkanes At Different Stratum Heights In A Pasture Of Panicum Maximum Cv. Mombaça, T. C. M. Genro, L. R. L. De S. Thiago, Ê. R. Prates, M. Herrero, V. Sabatel

IGC Proceedings (1977-2023)

The aim of this experiment was to determine n-alkane levels in the stem + leaf sheath and leaf blade components of a pasture of Panicum maximum cv. Mombaça, harvested in 20 cm stratified layers. This pasture was under rotational grazing for intensive beef production throughout the year. The grazing system was based on the use of 16 paddocks with a 2-day grazing period followed by a 30-day resting period. Profiles of n-alkanes were determined in samples harvested in three separate periods: in the middle of the dry season (August 97; PERIOD 1), at the beginning of the wet season (November …

Observation Of Bundle Sheath Digestion Of Panicum Maximum Jacq,, B. Lempp, Valéria P. B. Euclides, Maria Da Graça Morais, D. M. Victor

IGC Proceedings (1977-2023)

Cross-sections of available forage and extrusa fractions of leaf blades of Tanzânia-1, Mombaça and Massai grasses were evaluated for anatomic structure and observations of residue of in vitro digestibility. The observations showed greater frequency of scherenchyma girders in leaf blades of cv Massai, compared with order grasses. Tanzânia-1 and Mombaça residues were more susceptible to digestion, while Massai presented more frequently scherenchyma girders associated with less digestible bundle sheath.

A Simple Method For Estimating Alfalfa Fiber Content In The Field, Reuben M. Sulc, K. A. Albrecht, V. N. Owens

IGC Proceedings (1977-2023)

Predictive equations for alfalfa (Medicago sativa L.) quality (PEAQ) based on length of the longest stem and maturity stage of the most mature stem in a sample were developed and validated for estimating neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations in alfalfa. The objective of this research was to validate PEAQ with a simplified maturity scale when estimating fiber content. Alfalfa samples varying in height and maturity were collected throughout the growing season from fields across six states in USA. Observed NDF and ADF values (determined via wet chemistry) were regressed on estimated values. The estimated …

Research Sites Get Closer To Field Camps Over Time: Informing Environmental Management Through A Geospatial Analysis Of Science In The Mcmurdo Dry Valleys, Antarctica, Stephen M. Chignell, Madeline E. Myers, Adrian Howkins, Andrew Fountain

Geology Faculty Publications and Presentations

As in many parts of the world, the management of environmental science research in Antarctica relies on cost-benefit analysis of negative environmental impact versus positive scientific gain. Several studies have examined the environmental impact of Antarctic field camps, but very little work looks at how the placement of these camps influences scientific research. In this study, we integrate bibliometrics, geospatial analysis, and historical research to understand the relationship between field camp placement and scientific production in the McMurdo Dry Valleys of East Antarctica. Our analysis of the scientific corpus from 1907–2016 shows that, on average, research sites have become less …

Duration Of Regrowth Of Ryegrass (Lolium Perenne) Swards: Effects On Rumen Fermentation Of Lactating Dairy Cows, P. Chilibroste, S. Tamminga, H. Boer

IGC Proceedings (1977-2023)

The relative importance of duration of sward regrowth and rumen fill and fermentation on the control of grazing time and intake rate during the first grazing session of the day were studied. Four lactating dairy cows were allowed to graze ryegrass (Lolium perenne) swards, with five different regrowth periods after mowing (6, 9, 16, 22 and 30 d). The cows were allowed to graze until they stopped voluntarily. Samples of rumen liquid were taken at approximately 0, 30, 60, 120 and 240 min after the grazing session was finished. Concentration of volatile fatty acids (VFA) followed a significant …

Establishment Of Tanzania Grass Pasture Using Millet As A Companion Crop, José C. Pinto, M. C. Maia, I. F. De Andrade, I. P. A. Dos Santos, E. R. P. Bomfim, K. R. Soares

IGC Proceedings (1977-2023)

Forage yield and quality of millet [Pennisetum glaucum (L.) R. Br.] and tanzania grass (Panicum maximum Jacq. cv. Tanzania I) were evaluated when grown in mixture. The treatments evaluated were four seed mixture combinations, based on a standard sowing density of 8 kg.ha^-1, of tanzania grass/millet (08/00; 05/03; 04/04 and 03/05 kg.ha^-1) and three cutting frequencies (1 cutting – 100th day after sowing; 2 cuttings – 50th and 100th days after sowing and 3 cuttings – 40th, 70th and 100th days after sowing), in a randomized complete block design, with four replications, in a …

Effects Of Selection On Morphological Characteristics In Setaria Sphacelata (Schumach.) Moss, Liana Jank, Kenneth H. Quesenberry, P. Mislevy

IGC Proceedings (1977-2023)

Cattle production in Florida is limited by the lack of available warm-season forages adapted to the cool winters of the region. Setaria (S. sphacelata) has demonstrated green growth during cool conditions in subtropical climates around the world, and has the potential to fill this niche in cattle production in Florida. Four populations were selected in Gainesville and Ona, Florida: two cycles of selection for increased head number, one cycle for increased leaf width and one cycle for grazing tolerance. The objectives of this research were to compare these populations morphologically to determine changes due to selection. Selection for …

Evaluation Of Leucaena Genotypes, F. B. Sousa, M. R. A. Araujo, J. A. Araujo Filho, J. Sousa Neto

IGC Proceedings (1977-2023)

The objectives of this study were to evaluate the leucaena (Leucaena leucocephala) performance and to select the best genotypes, based on yield,.stability parameters, and quality parameters. Annual leucaena yields were obtained by cuts over the rainy and dry seasons. A combined analysis of variance for yield, and quality parameters was performed. Also stability parameters and coeficients of determination were estimated. The combined ANOVA for edible dry matter yield and for acid detergent fiber, and digestibility revealed a significant difference for genotypes, environments, genotypes x environments, row spacings, cutting frequencies, and cutting heights, Six genotypes of leucaena were selected …

Late Pleistocene And Early Holocene Sea-Level History And Glacial Retreat Interpreted From Shell-Bearing Marine Deposits Of Southeastern Alaska, Usa, James F. Baichtal, Alia J. Lesnek, Risa J. Carlson, Nicholas S. Schmuck, Jane L. Smith, Dennis J. Landwehr, Jason P. Briner

Publications and Research

We leverage a data set of >720 shell-bearing marine deposits throughout southeastern Alaska (USA) to develop updated relative sea-level curves that span the past ~14,000 yr. This data set includes site location, elevation, description when avail-able, and 436 14C ages, 45 of which are published here for the first time. Our sea-level curves suggest a peripheral forebulge developed west of the retreating Cordilleran Ice Sheet (CIS) margin between ca. 17,000 and 10,800 calibrated yr B.P. By 14,870 ± 630 to 12,820 ± 340 cal. yr B.P., CIS mar-gins had retreated from all of southeastern Alaska’s fjords, channels, and passages. At …

College Of Natural Sciences Scholarship Brunch Program, November 6th 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

This is the program for the first annual College of Natural Sciences Scholarship Brunch, held on November 6th, 2021 at McCrory Gardens.

College Of Natural Sciences Newsletter, November 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 2, Issue 11

Page 1 Dean's Message
Page 2 Awards & Recognition
Page 3 Media Coverage of CNS
Page 4 2021 Day of Scholars
Page 5 Astronomy Outreach
Page 6 SDSU Faculty & Students Host American Society for Microbiology Annual Conference
Page 7 Scholarship Brunch
Page 8 Open PRAIRIE Data, SI Final Exam Review Sessions
Page 9 Aamlid Family Anatomy Lab Photos

Next-Generation Ensemble Projections Reveal Higher Climate Risks For Marine Ecosystems, Derek P. Tittensor, Camilla Novaglio, Cheryl S. Harrison, Ryan F. Heneghan, Nicolas Barrier, Daniele Bianchi, Laurent Bopp, Andrea Bryndum-Buchholz, Gregory L. Britten, Matthias Büchner

School of Earth, Environmental, & Marine Sciences Faculty Publications

Projections of climate change impacts on marine ecosystems have revealed long-term declines in global marine animal biomass and unevenly distributed impacts on fisheries. Here we apply an enhanced suite of global marine ecosystem models from the Fisheries and Marine Ecosystem Model Intercomparison Project (Fish-MIP), forced by new-generation Earth system model outputs from Phase 6 of the Coupled Model Intercomparison Project (CMIP6), to provide insights into how projected climate change will affect future ocean ecosystems. Compared with the previous generation CMIP5-forced Fish-MIP ensemble, the new ensemble ecosystem simulations show a greater decline in mean global ocean animal biomass under both strong-mitigation …

Disentangling Diverse Responses To Climate Change Among Global Marine Ecosystem Models, Ryan F. Heneghan, Eric Galbraith, Julia L. Blanchard, Cheryl S. Harrison, Nicolas Barrier, Catherine Bulman, William Cheung, Marta Coli, Tyler D. Eddy, Maite Erauskin-Extramiana

School of Earth, Environmental, & Marine Sciences Faculty Publications

Climate change is warming the ocean and impacting lower trophic level (LTL) organisms. Marine ecosystem models can provide estimates of how these changes will propagate to larger animals and impact societal services such as fisheries, but at present these estimates vary widely. A better understanding of what drives this inter-model variation will improve our ability to project fisheries and other ecosystem services into the future, while also helping to identify uncertainties in process understanding. Here, we explore the mechanisms that underlie the diversity of responses to changes in temperature and LTLs in eight global marine ecosystem models from the Fisheries …

Prediction Of Dry Matter Intake Based On Ruminal Degradation From Milking Cows Grazing Coast-Cross Grass, T. T. Berchielli, J. P. G. Soares, L. J. M. Aroeira, C. L. Furlan, A. K. D. Salman, R. N. Da Silveira, E. B. Malheiros

IGC Proceedings (1977-2023)

Dry matter intake (DMI) of coast-cross grazing by crossbred Holstein-Zebu and Zebu lactating cows was calculated using in vitro dry matter digestibility from extrusa (four esophageal fistulated cows) and fecal output estimate with mordent chromium. Pasture was rotationally grazed with three days grazing period and 27 days resting period, adopting a stocking rate of 1.6 and 3.2 cows/ha, during the dry and rainy season respectively. Voluntary DMI was estimated from degradation characteristics using different equations. Predicted coast-cross DMI varied with models. The prediction of tropical forages dry matter intake from equations based in ruminal degradation parameters needs further investigation before …