185 Opportunities and Challenges of Conducting Grazing Experiments in Pasturelands

Abstract Grasslands cover approximately 30% of the world area and research conducted in pasturelands has been crucial to realize the benefits of grassland contributions to livestock production and ecosystem services. The Forage and Grazing Terminology Task Force has developed a list of recommended nomenclature for grazing lands research and this effort has been a landmark to avoid misleading terms in research reports. Other challenges remain. The intrinsic variability of pastureland research data limits the capacity of researchers to detect differences among treatments. In addition, the quantity of resources and labor required by pastureland experiments may lead researchers to decrease the size of experimental units and/or number of replicates, exacerbating the limitations in detecting differences among treatments. In general, experimental units in grazing studies encompass relatively large areas, which may pose a challenge to identifying representative sampling units that reflect the experimental area. The use of indirect measurements to estimate forage mass is a feasible approach to increase the representativeness of forage quantity evaluations. The nutritive value determination of forage samples from grazing studies also has many limitations. The collection of samples representing the animal diet and the methods of nutritive value determination, primarily digestibility, are major areas of concern. For animal performance evaluations, determination of the correct experimental unit has been a frequent issue. Among animal measures, forage intake is one of the most influential factors affecting animal performance and the existent methodology to estimate forage intake by grazing animals has limitations, reducing the accuracy of the results. Development and validation of mathematical models to estimate the benefits of grasslands on livestock performance and ecosystem services are important steps in the evolution of grassland science, but in some cases additional data are needed to support this effort.

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Warm-season annual forages in forage-finishing beef systems: I. Forage yield and quality

Translational Animal Science ◽

10.1093/tas/txz075 ◽

2019 ◽

Vol 3 (2) ◽

pp. 911-926 ◽

Cited By ~ 2

Author(s):

Deidre D Harmon ◽

Dennis W Hancock ◽

Robert L Stewart ◽

Jenna L Lacey ◽

Robert W Mckee ◽

...

Keyword(s):

Pearl Millet ◽

Nutritive Value ◽

Pennisetum Glaucum ◽

Block Design ◽

Warm Season ◽

Forage Yield ◽

Experimental Unit ◽

Beef Production ◽

Sorghum Sudangrass ◽

Value Determination

Abstract The demand for a year-round supply of fresh, locally grown, forage-finished beef products has created a need for forage-finishing strategies during the summer months in the southeast. A 3-yr study was conducted to evaluate four warm-season annual forages in a southeastern forage-finishing beef production system. Treatments were four forage species and included brown-midrib sorghum × sudangrass (Sorghum bicolor var. bicolor*bicolor var. sudanense; BMR), sorghum × sudangrass (SS), pearl millet [Pennisetum glaucum (L.) R. Br.; PM], or pearl millet planted with crabgrass [Digitaria sanguinalis (L.) Scop.; PMCG]. Treatments were distributed in a randomized complete block design with four replicates. Pastures (0.81 ha, experimental unit) were assigned to one of four forage treatments, subdivided, and rotationally stocked with a variable stocking density. British-cross beef steers (n = 32; 3-yr average: 429 ± 22 kg) grazed for 70, 63, and 56 d in 2014, 2015, and 2016, respectively. Put-and-take animals were used to maintain a forage allowance of 116 kg forage dry matter /100 kg body weight. Forage mass was measured by clipping a 4.3-m2 area in triplicate on d 0 and on 14-d intervals. Hand grab samples for forage nutritive value determination and quadrat clippings for species compositions were measured on d 0 and on 34-d intervals until termination of the trial. Forage mass was lowest (P < 0.01) for PMCG at the initiation of the grazing trial, whereas BMR was greater (P < 0.01) than SS at wk 6. Total digestible nutrients in 2014 were greater for SS compared to BMR and PM at the middle harvest (P < 0.01) and BMR, PM, and PMCG at the final harvest (P < 0.01). At the middle and final harvests in both 2015 and 2016, PM and PMCG contained greater (P < 0.01) concentrations of crude protein than SS. These results suggest that BMR, SS, PM, and PMCG may all be used in southeastern forage-finishing beef production systems, as long as the producer strategically accounts for the slight growth and nutritive value differences throughout the season.

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Conserved forage-based systems for backgrounding weaned beef calves1

Translational Animal Science ◽

10.1093/tas/txy063 ◽

2018 ◽

Vol 2 (3) ◽

pp. 272-279 ◽

Cited By ~ 1

Author(s):

Erin M Forte ◽

Mary Kimberly Mullenix ◽

Jennifer J Tucker ◽

Joshua B Elmore ◽

Werner G Bergen

Keyword(s):

Free Choice ◽

Nutritive Value ◽

Experimental Unit ◽

Animal Performance ◽

Soybean Hulls ◽

Beef Calves ◽

Corn Gluten ◽

Corn Gluten Feed ◽

Gluten Feed

Abstract A 45-d backgrounding study was conducted to compare animal performance, forage nutritive value, digestion dynamics, and diet costs of conserved forage systems for weaned beef calves. One hundred and eight weaned Angus × Simmental beef calves (initial BW 279 ± 34 kg) were randomly assigned to one of three diets (n = 3 pens/treatment): 1) free-choice annual ryegrass (RB; cv. ‘Marshall’) baleage and 4 kg of a 50/50 mixture of pelleted soybean hulls and corn gluten feed, 2) free-choice Tifton 85 bermudagrass (BH) and 3 kg of a 50/50 mixture of pelleted soybean hulls and corn gluten feed, or 3) free-choice corn silage (CS; cv. Pioneer P1662YHR) and 2 kg of a 85% cracked corn and 15% cottonseed meal mixture. Diets were formulated to achieve a target gain of 0.9 kg/d based on the NRC (2000) requirement for a 270 kg growing calf. Animal performance (initial BW, final BW, and ADG) was measured on days 0 and 45 of the study. Forage nutritive value and an in vitro digestion trial were conducted to evaluate supplementation effects on forage diet digestion dynamics. Data were analyzed using PROC Mixed in SAS 9.4 as a completely randomized design. Pen was the experimental unit. Mean initial and final BW of the animals did not differ (P = 0.50 and P = 0.99, respectively) across treatments. Calf ADG for RB, BH, and CS diets were 0.61, 0.72, and 0.72 kg/d, respectively, and did not differ across treatments (P = 0.57). Based on these results, these forage options supported a similar level of gain when used for backgrounding beef calves. Forage in vitro DM digestibility differed 48 h after digestion, and BH + 50:50 had greater 48-h digestibility than when unsupplemented, which may be related to complementary forage-supplement interactions. In diets containing RB and CS, digestibility was greater with no supplementation at the 48-h time point. These data support the observation that supplementation type and level influence conserved forage diet digestibility compared with forage alone. The cost of feeding a baleage-based diet in this system was higher ($1.37/d) than CS or BH diets ($1.02 and $0.95/d, respectively). Results suggest that RB baleage-based diets may support a similar level of gain to BH or CS diets in growing beef calves, but supplement type, level, and ration costs should be evaluated when determining cost-effective backgrounding options in the Southeastern United States.

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Faculty Opinions recommendation of Guidelines for the determination of brain death in infants and children: an update of the 1987 Task Force recommendations.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.13381969.14750151 ◽

2011 ◽

Author(s):

Francis Leclerc

Keyword(s):

Brain Death ◽

Task Force ◽

Infants And Children ◽

In Infants And Children

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Determining the Rate of Ergot-alkaloid Degradation in Toxic Endophyte-infected Tall Fescue Hay and Haylage During Long Term Storage

Journal of Animal Science ◽

10.1093/jas/skab096.038 ◽

2021 ◽

Vol 99 (Supplement_2) ◽

pp. 22-22

Author(s):

Charles A Zumbaugh ◽

Susannah A Gonia ◽

Kathryn M Payne ◽

Thomas B Wilson

Keyword(s):

Tall Fescue ◽

Ergot Alkaloid ◽

Fixed Effects ◽

High Performance ◽

Nutritive Value ◽

Day Treatment ◽

Random Effect ◽

Storage Period ◽

Neutral Detergent Fiber ◽

Experimental Unit

Abstract The objectives of this experiment were to determine changes in the nutritive value and ergot alkaloid concentrations of endophyte-infected tall fescue hay and haylage during a 180-d storage period. Forage from a single field of Kentucky-31 tall fescue was cut for hay in late June and allowed to dry in the field. The dry matter (DM) of the windrow of cut forage was measured every 2 h after clipping. Forage was sampled from the windrow in 6 location blocks once forage DM reached target levels for haylage and hay treatments. Haylage and hay samples were taken when the DM of the windrow reached 50% and 80%, respectively. Seven subsamples of each treatment within block were chopped to 1.91 cm in length with a lettuce chopper and vacuum sealed in oxygen-excluding bags. Sample bags were stored indoors and opened at 30 d intervals over the 180-d storage period. Samples were analyzed for pH, nutritive value, and individual ergot alkaloid concentrations using high-performance liquid chromatography. Within each storage day, treatment within block was considered the experimental unit. Data were analyzed in SAS using the MIXED procedure with fixed effects of treatment, day, and the treatment by day interaction. Location block was considered a random effect. As expected, pH was decreased for haylage compared to hay at all time points (P < 0.01) and DM was greater (P < 0.01) for hay compared to haylage. Neutral detergent fiber values were greater (P < 0.01) for hay compared to haylage and declined during storage (P < 0.01). Total ergot alkaloid concentrations did not differ by treatment (P = 0.61), but ergovaline concentrations declined (P < 0.01) during storage. Collectively, these results indicate minimal differences in nutritive value and ergot alkaloid concentrations between hay and haylage during storage, and that ergovaline concentrations decline during storage.

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6 Animal performance in grass monoculture or silvopasture systems using tree legumes

Journal of Animal Science ◽

10.1093/jas/skz397.041 ◽

2020 ◽

Vol 98 (Supplement_2) ◽

pp. 18-19

Author(s):

Izabela Aline Gomes da Silva ◽

Jose Carlos Batista Dubeux ◽

Alexandre C Leão de Mello ◽

Márcio Vieira da Cunha ◽

Mércia Ferreira dos Santos ◽

...

Keyword(s):

Ecosystem Services ◽

Experimental Design ◽

Accumulation Rate ◽

Average Daily Gain ◽

Gliricidia Sepium ◽

Tropical Region ◽

Stocking Rate ◽

Animal Performance ◽

Management Option ◽

Daily Gain

Abstract Silvopasture systems (SPS) area management option to enhance delivery of ecosystem services and diversification of income. This study evaluated productive responses of signalgrass (UrochloadecumbensStapf.) in monoculture or in SPS in the sub-humid tropical region of Brazil during six months of the rainy season. The experimental design was randomized complete block with three replications. Treatments were signalgrass + Mimosa caesalpiniifolia Benth. (SPS-Mimosa); signalgrass + Gliricidia sepium (Jacq.) (SPS-Gliricidia); and signalgrass monoculture. Cattle were managed under continuous stocking with variable stocking rate. Response variables included herbage mass (HM), herbage accumulation (HA), stocking rate (SR), average daily gain (ADG), and gain per area (GPA). Herbage mass (HM) was greater (P < 0.0001) on signal grass monoculture (2045 kg DM/ha) than in SPS (1370 kg DM/ha, average for both SPS). Herbage accumulation rate was similar for signalgrass in monoculture and SPS-Gliricidia (avg. 61 kg DM ha-1 d-1), and both were greater than SPS-Mimosa (37 kg DM ha-1 d-1). Average daily gain was greater(P < 0.0001) for SPS-Gliricidia (1.1 kg head-1 d-1), followed by signalgrass in monoculture (0.9 kg head-1 d-1), and SPS-Mimosa (0.3 kg head-1 d-1). Stocking rate ranged from 0.6 animal units (1AU = 450-kg animal) per ha in April to 2.2 AUha-1 in June. Stocking rate and animal performance per area were similar for signalgrass in monoculture and SPS-Gliricidia, and both greater than SPS-Mimosa. Gliricidia enhanced animal performance and provided ecosystem services. Mimosa, however, reduced animal performance likely due to the competition with signalgrass. Mimosa trees, however, are an important source of income (timber used for fence posts) and that might overcome the losses in animal performance.

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On factors affecting surface free energy of carbon black for reinforcing rubber

Nanotechnology Reviews ◽

10.1515/ntrev-2020-0015 ◽

2020 ◽

Vol 9 (1) ◽

pp. 170-181 ◽

Cited By ~ 2

Author(s):

Shangyong Zhang ◽

Ruipeng Zhong ◽

Ruoyu Hong ◽

David Hui

Keyword(s):

Free Energy ◽

Carbon Black ◽

Surface Free Energy ◽

Surface Activity ◽

Gas Flow ◽

Influential Factors ◽

Chromatographic Column ◽

Factors Affecting ◽

Carrier Gas Flow

AbstractThe surface activity of carbon black (CB) is an important factor affecting the reinforcement of rubber. The quantitative determination of the surface activity (surface free energy) of CB is of great significance. A simplified formula is obtained to determine the free energy of CB surface through theoretical analysis and mathematical derivation. The surface free energy for four kinds of industrial CBs were measured by inverse gas chromatography, and the influential factors were studied. The results showed that the aging time of the chromatographic column plays an important role in accurate measurement of the surface free energy of CB, in comparison with the influences from the inlet pressure and carrier gas flow rate of the chromatographic column filled with CB. Several kinds of industrial CB were treated at high temperature, and the surface free energy of CB had a significant increase. With the increase of surface free energy, the maximum torque was decreased significantly, the elongation at break tended to increase, the heat generation of vulcanizates was increased, and the wear resistance was decreased.

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2017 publication guidelines for structural modelling of small-angle scattering data from biomolecules in solution: an update

Acta Crystallographica Section D Structural Biology ◽

10.1107/s2059798317011597 ◽

2017 ◽

Vol 73 (9) ◽

pp. 710-728 ◽

Cited By ~ 107

Author(s):

Jill Trewhella ◽

Anthony P. Duff ◽

Dominique Durand ◽

Frank Gabel ◽

J. Mitchell Guss ◽

...

Keyword(s):

Small Angle ◽

Task Force ◽

Data Bank ◽

Small Angle Scattering ◽

Scattering Data ◽

Quality Data ◽

Angle Scattering ◽

Publication Guidelines ◽

Guidelines And Recommendations

In 2012, preliminary guidelines were published addressing sample quality, data acquisition and reduction, presentation of scattering data and validation, and modelling for biomolecular small-angle scattering (SAS) experiments. Biomolecular SAS has since continued to grow and authors have increasingly adopted the preliminary guidelines. In parallel, integrative/hybrid determination of biomolecular structures is a rapidly growing field that is expanding the scope of structural biology. For SAS to contribute maximally to this field, it is essential to ensure open access to the information required for evaluation of the quality of SAS samples and data, as well as the validity of SAS-based structural models. To this end, the preliminary guidelines for data presentation in a publication are reviewed and updated, and the deposition of data and associated models in a public archive is recommended. These guidelines and recommendations have been prepared in consultation with the members of the International Union of Crystallography (IUCr) Small-Angle Scattering and Journals Commissions, the Worldwide Protein Data Bank (wwPDB) Small-Angle Scattering Validation Task Force and additional experts in the field.

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Palisadegrass pastures with or without nitrogen or mixed with forage peanut grazed to a similar target canopy height. 2. Effects on animal performance, forage intake and digestion, and nitrogen metabolism

Grass and Forage Science ◽

10.1111/gfs.12533 ◽

2021 ◽

Author(s):

Bruno G. C. Homem ◽

Italo Braz G. Lima ◽

Paola P. Spasiani ◽

Lucas P. C. Borges ◽

Robert M. Boddey ◽

...

Keyword(s):

Nitrogen Metabolism ◽

Canopy Height ◽

Animal Performance ◽

Forage Intake

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Determination of emergency roads to emergency accommodation using loss analysis results

Geoenvironmental Disasters ◽

10.1186/s40677-021-00190-2 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Sajad Ganjehi ◽

Khadijeh Norouzi Khatiri

Keyword(s):

Estimation Method ◽

Emergency Evacuation ◽

Influential Factors ◽

Urban Crisis ◽

Time Duration ◽

Loss Analysis ◽

Expert Choice ◽

Data Layers ◽

Temporary Accommodation

AbstractTeh present study aims to identify proper places to build temporary accommodation for people and accessible roads using damage analysis results during a probable earthquake. Teh HAZUS damage estimation method, which is one of teh most common ones currently used in teh world, was used in dis study. Teh influential factors in locating teh temporary accommodation in Shiraz were studied by using damage results, AHP model, and Expert Choice software. Then, map for temporary accommodation was prepared. By integrating layers, teh ultimate map of optimal locating for temporary accommodation was presented. Subsequently, all teh parameters influencing teh safety of emergency evacuation and relief network were identified and teh impact rate of each one was determined based on experts’ opinions through AHP. Based on teh importance of each index, roads were weighed and coded. Then, teh optimal safe road for relief and emergency evacuation was proposed. Teh results suggested dat relief roads are different based on different indices and teh optimal road was obtained through overlapping teh data layers according to teh importance of each parameter. dis optimal road could provide maximum services in teh minimum time duration and subsequently create capacity building in urban crisis management.

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