71 research outputs found
Impacts of added roughage on growth performance, digestibility, ruminal fermentation, and ruminal pH of feedlot steers fed wheat-based feedlot diets containing 30% modified distillers grains with solubles
Two experiments were conducted to evaluate the inclusion rate roughage in wheat-based diets containing modified distillers grains with solubles (MDGS) on feedlot performance (Feedlot Experiment), as well as digestibility, ruminal pH, and ruminal fermentation characteristics (Digestibility Experiment). The feedlot experiment utilized 72 Angus steers (392 ± 46.3 kg initial body weight) which were randomly assigned to 1 of 12 pens, 3 pens per treatment, to evaluate feedlot performance and carcass characteristics. Dietary treatments were 1) control; 10% roughage, 2) 12% roughage, 3) 14% roughage, and 4) 16% roughage. The digestibility experiment used four ruminally and duodenally cannulated steers (393 ± 33.0 kg) in a 4 × 4 Latin Square with either 10%, 12%, 14%, or 16% roughage as in the feedlot experiment. However, dietary roughage source was different between these two experiments and included a combination of grass hay and wheat straw (Feedlot Experiment), and corn silage (Digestibility Experiment). All data were analyzed with the Mixed Procedures of SAS. Feed intake was recorded, with duodenal and fecal output calculated using chromic oxide. Ruminal pH and fermentation were assessed. Growth performance and most carcass characteristics were not affected by increasing roughage (P ≥ 0.11). Marbling tended to decrease linearly (P = 0.10) with increasing roughage inclusion. Increasing dietary roughage content had no effect on organic matter intake (P = 0.60) in the digestibility experiment. Intake, duodenal flow, and digestibility of neutral detergent fiber and acid detergent fiber were not affected by treatment (P ≥ 0.16). Ruminal pH increased linearly (P \u3c 0.01) as rate of roughage inclusion increased. Ruminal concentrations of acetate and butyrate increased, and propionate decreased in a linear fashion (P \u3c 0.01) thereby increasing (P \u3c 0.01) acetate and butyrate to propionate ratio with increasing dietary roughage. Our data indicate that increasing roughage inclusion in wheat-based diets including 30% MDGS increased ruminal pH and shifted ruminal fermentation patterns. Additionally, increasing roughage inclusion did not affect feedlot performance in steers fed wheat at 36% to 42% of dietary dry matter in combination with 30% MDGS
Interaction of replacing corn silage with soyhulls as a roughage source with or without 3% added wheat straw in the diet: impacts on intake, digestibility, and ruminal fermentation in steers fed high-concentrate diets
Six ruminally cannulated steers [475.0 ± 49.6 kg initial body weight (BW)] were used in a 6 × 3 incomplete Latin square design (six treatments and three periods), to evaluate the impacts replacing of corn silage with pelleted soyhulls as roughage in high-concentrate finishing diets containing 30% modified distillers grains with solubles. Treatments were based on increasing dietary inclusion of soyhulls and consisted of: (1) Control (0), roughage supplied by dietary inclusion of 20% corn silage [dry matter (DM) basis]; (2) 50% replacement of corn silage with soyhulls (50); (3) 100% replacement of corn silage with soyhulls (100), and the same three treatments repeated with 3% added wheat straw (DM basis) replacing corn in the diet (0S, 50S, and 100S, respectively). Absolute dry matter intake (DMI; kg/d basis) tended to decrease both linearly and quadratically (P ≤ 0.09) and proportional DMI (% of BW) decreased linearly (P = 0.04) with increasing soyhull inclusion but was not affected by the addition of straw in the diet (P = 0.68). Total tract digestibility of organic matter and crude protein were not affected by soyhull inclusion or added straw (P ≥ 0.32). Ruminal pH did not differ (P = 0.65) with increasing soyhull inclusion but increased with the addition of straw (P \u3c 0.01; 5.9 vs. 6.1 for no straw and straw, respectively). Molar proportions of acetate and butyrate decreased while propionate increased with increased soyhull inclusion (P ≤ 0.03; linearly and quadratically, respectively). Ruminal fluid kinetics were unaffected by either rate of replacement of corn silage with soyhulls or wheat straw inclusion (P ≥ 0.13). Decreases in DMI observed in this study would likely decrease finishing cattle performance and underscores the need for additional research before recommending this practice to cattle feeders
Educational Interventions and Animal Consumption: Results from Lab and Field Studies
Currently, there are many advocacy interventions aimed at reducing animal consumption. We
report results from a lab (N = 267) and a field experiment (N = 208) exploring whether, and to what extent, some of those educational interventions are effective at shifting attitudes and behavior related to animal consumption. In the lab experiment, participants were randomly assigned to read a philosophical ethics paper, watch an animal advocacy video, read an advocacy pamphlet, or watch a control video. In the field experiment, we measured the impact of college classes with animal ethics content versus college classes without animal ethics content. Using a pretest, post-test matched control group design, humane educational interventions generally made people more knowledgeable about animals used as food and reduced justifications and speciesist attitudes supporting animal consumption. None of the interventions in either experiment had a direct, measurable impact on self-reported animal consumption. These results suggest that while some educational interventions can change beliefs and attitudes about animal consumption, those same interventions have small impacts on animal consumption
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Structure-functional changes in eNAMPT at high concentrations mediate mouse and human beta- cell dysfunction in type 2 diabetes
Aims/hypothesis
Progressive decline in functional beta cell mass is central to the development of type 2 diabetes. Elevated serum levels of extracellular nicotinamide phosphoribosyltransferase (eNAMPT) are associated with beta cell failure in type 2 diabetes and eNAMPT immuno-neutralisation improves glucose tolerance in mouse models of diabetes. Despite this, the effects of eNAMPT on functional beta cell mass are poorly elucidated, with some studies having separately reported beta cell-protective effects of eNAMPT. eNAMPT exists in structurally and functionally distinct monomeric and dimeric forms. Dimerisation is essential for the NAD-biosynthetic capacity of NAMPT. Monomeric eNAMPT does not possess NAD-biosynthetic capacity and may exert distinct NAD-independent effects. This study aimed to fully characterise the structure-functional effects of eNAMPT on pancreatic beta cell functional mass and to relate these to beta cell failure in type 2 diabetes.
Methods
CD-1 mice and serum from obese humans who were without diabetes, with impaired fasting glucose (IFG) or with type 2 diabetes (from the Body Fat, Surgery and Hormone [BodyFatS&H] study) or with or at risk of developing type 2 diabetes (from the VaSera trial) were used in this study. We generated recombinant wild-type and monomeric eNAMPT to explore the effects of eNAMPT on functional beta cell mass in isolated mouse and human islets. Beta cell function was determined by static and dynamic insulin secretion and intracellular calcium microfluorimetry. NAD-biosynthetic capacity of eNAMPT was assessed by colorimetric and fluorescent assays and by native mass spectrometry. Islet cell number was determined by immunohistochemical staining for insulin, glucagon and somatostatin, with islet apoptosis determined by caspase 3/7 activity. Markers of inflammation and beta cell identity were determined by quantitative reverse transcription PCR. Total, monomeric and dimeric eNAMPT and nicotinamide mononucleotide (NMN) were evaluated by ELISA, western blot and fluorometric assay using serum from non-diabetic, glucose intolerant and type 2 diabetic individuals.
Results
eNAMPT exerts bimodal and concentration- and structure-functional-dependent effects on beta cell functional mass. At low physiological concentrations (~1 ng/ml), as seen in serum from humans without diabetes, eNAMPT enhances beta cell function through NAD-dependent mechanisms, consistent with eNAMPT being present as a dimer. However, as eNAMPT concentrations rise to ~5 ng/ml, as in type 2 diabetes, eNAMPT begins to adopt a monomeric form and mediates beta cell dysfunction, reduced beta cell identity and number, increased alpha cell number and increased apoptosis, through NAD-independent proinflammatory mechanisms.
Conclusions/interpretation
We have characterised a novel mechanism of beta cell dysfunction in type 2 diabetes. At low physiological levels, eNAMPT exists in dimer form and maintains beta cell function and identity through NAD-dependent mechanisms. However, as eNAMPT levels rise, as in type 2 diabetes, structure-functional changes occur resulting in marked elevation of monomeric eNAMPT, which induces a diabetic phenotype in pancreatic islets. Strategies to selectively target monomeric eNAMPT could represent promising therapeutic strategies for the treatment of type 2 diabetes
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A protocol for an intercomparison of biodiversity and ecosystem services models using harmonized land-use and climate scenarios
To support the assessments of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the IPBES Expert Group on Scenarios and Models is carrying out an intercomparison of biodiversity and ecosystem services models using harmonized scenarios (BES-SIM). The goals of BES-SIM are (1) to project the global impacts of land-use and climate change on biodiversity and ecosystem services (i.e., nature's contributions to people) over the coming decades, compared to the 20th century, using a set of common metrics at multiple scales, and (2) to identify model uncertainties and research gaps through the comparisons of projected biodiversity and ecosystem services across models. BES-SIM uses three scenarios combining specific Shared Socio-economic Pathways (SSPs) and Representative Concentration Pathways (RCPs)-SSP1xRCP2.6, SSP3xRCP6.0, SSP5xRCP8.6-to explore a wide range of land-use change and climate change futures. This paper describes the rationale for scenario selection, the process of harmonizing input data for land use, based on the second phase of the Land Use Harmonization Project (LUH2), and climate, the biodiversity and ecosystem services models used, the core simulations carried out, the harmonization of the model output metrics, and the treatment of uncertainty. The results of this collaborative modeling project will support the ongoing global assessment of IPBES, strengthen ties between IPBES and the Intergovernmental Panel on Climate Change (IPCC) scenarios and modeling processes, advise the Convention on Biological Diversity (CBD) on its development of a post-2020 strategic plans and conservation goals, and inform the development of a new generation of nature-centred scenarios
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Point-of-care Ultrasound Diagnosis of Acute Sialolithiasis with Sialadenitis
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