373 research outputs found

    Strategies to maximize feed quality and poultry performance

    Get PDF
    The majority of the research in this dissertation was conducted specifically to benefit a local turkey integrator, Virginia Poultry Grower\u27s Cooperative, which has turkey growers in both West Virginia and Virginia. All of the research presented in this dissertation is applied in nature and may be directly implemented in the commercial poultry industry to improve production. Many commercial feed mills utilize low mixer-added fat (MAF) to increase ingredient binding opportunities and pellet quality, but this technique may decrease feed nutrient digestibility. In Chapter 2, two experiments were conducted in order to determine the best feed manufacture technique (MTECH) to maximize pellet quality and subsequent true amino acid digestibility (TAAD) of practical turkey diets. Experiment 1 was a 3 Binder (Binder 1, Binder 2, or No Binder) x 2 MTECH (1% MAF + 38.1 mm die or 3% MAF + 44.96 mm die) factorial design that utilized practical turkey starter diets manufactured at West Virginia University\u27s pilot feed mill. In Experiment 2, diets containing either No Binder of Binder 1 at each MTECH were chosen to test TAAD, using cecectomized roosters. Results from this research established that Binder 1 and 3% MAF maintained feed quality while improving amino acid digestibility using a rooster model. This led to the development of the experiments conducted in Chapter 3, where the objective was to determine the effect of commercial turkey starter diets varying in amino acid density (AAD) (Normal or High) and MTECH (MTECH1-1% MAF + 0.5% Sand or MTECH2-3% MAF + 0.5% Binder) on commercial feed mill manufacture efficiency, D10-40 poult performance and broiler feed retention time. Feed quality was maintained utilizing MTECH2 as compared to feed produced with MTECH1. In addition, MTECH2 also created larger, more uniform crumbles. Chapter 3 results indicated that High AAD diets manufactured with MTECH2 may enhance poult performance due to improved feed quality and associated benefits, increased feed retention time in the gastrointestinal tract, and perhaps improved fat digestibility. Chapter 4 was designed in order to test diet formulation strategies (one of two Yeast Product (YP) inclusion) to improve brooder phase performance (D1-42). Another goal of research conducted in this chapter was to determine feed form advantages during grower/finisher phase production of large toms (D42-118) due to this period of high feed volume consumption. On D42 one of the tested YP improved poult ending weight and feed conversion ratio (FCR). At the end of grow-out, feeding high quality pellets produced toms that were 0.29 kg/bird heavier with 9 points lower FCR, as compared to toms fed ground pellets. Research in Chapter 5 was conducted with the overall goal of improving brooder phase performance (D1-42) by varying phytase level inclusions (Normal or High) into commercial turkey diets. Recent research has indicated that phytase inclusion may help decrease gut inflammation and subsequent immune response caused by phytate phosphorus (P); therefore, other objectives of research conducted in Chapter 5 were to assess the effect of increasing phytase inclusion on D40 gut inflammation via ileal mRNA expression of Interleukin (IL)-1beta and IL-6, and D40 total P content of litter. Phytase inclusion levels had no effect on brooder phase poult performance or gut health; however, High Phytase diets fed to poults placed on fresh shavings from D1-40 reduced total P content of litter by ∌11%. For the last chapter of this dissertation (Chapter 6) two experiments were conducted that utilized practical diets and regression analyses to evaluate the utilization of lysine (Experiment 1) and phosphorus (Experiment 2) in corn distiller\u27s dried grains and solubles (DDGS) using a broiler chicken model. This research is warranted because technologies employed to produce this coproduct of corn ethanol production have evolved; thereby potentially changing the availability of its key nutrients. In both Experiments 1 and 2, multiple analyses verified the original nutrient coefficients for digestible lysine (0.7031%) and available P (0.66%) suggested for the specific DDGS tested; however, depending on analysis and performance variable, availability may be underestimated by up to 0.07 and 0.02 percentage points, respectively

    Theory of Pump Depletion and Spike Formation in Stimulated Raman Scattering

    Full text link
    By using the inverse spectral transform, the SRS equations are solved and the explicit output data is given for arbitrary laser pump and Stokes seed profiles injected on a vacuum of optical phonons. For long duration laser pulses, this solution is modified such as to take into account the damping rate of the optical phonon wave. This model is used to interprete the experiments of Druhl, Wenzel and Carlsten (Phys. Rev. Lett., (1983) vol. 51, p. 1171), in particular the creation of a spike of (anomalous) pump radiation. The related nonlinear Fourier spectrum does not contain discrete eigenvalue, hence this Raman spike is not a soliton.Comment: LaTex file, includes two figures in LaTex format, 9 page

    The role of HO_x in super- and subsonic aircraft exhaust plumes

    Get PDF
    The generation of sulfuric acid aerosols in aircraft exhaust has emerged as a critical issue in determining the impact of supersonic aircraft on stratospheric ozone. It has long been held that the first step in the mechanism of aerosol formation is the oxidation of SO_(2) emitted from the engine by OH in the exhaust plume. We report in situ measurements of OH and HO_(2) in the exhaust plumes of a supersonic (Air France Concorde) and a subsonic (NASA ER-2) aircraft in the lower stratosphere. These measurements imply that reactions with OH are responsible for oxidizing only a small fraction of SO_(2) (2%), and thus cannot explain the large number of particles observed in the exhaust wake of the Concorde

    The role of HO\u3csub\u3ex\u3c/sub\u3e in super- And subsonic aircraft exhaust plumes

    Get PDF
    The generation of sulfuric acid aerosols in aircraft exhaust has emerged as a critical issue in determining the impact of supersonic aircraft on stratospheric ozone. It has long been held that the first step in the mechanism of aerosol formation is the oxidation of SO2 emitted from the engine by OH in the exhaust plume. We report in situ measurements of OH and HO2 in the exhaust plumes of a supersonic (Air France Concorde) and a subsonic (NASA ER-2) aircraft in the lower stratosphere. These measurements imply that reactions with OH are responsible for oxidizing only a small fraction of SO2 (2%), and thus cannot explain the large number of particles observed in the exhaust wake of the Concorde

    Evaluation Research and Institutional Pressures: Challenges in Public-Nonprofit Contracting

    Get PDF
    This article examines the connection between program evaluation research and decision-making by public managers. Drawing on neo-institutional theory, a framework is presented for diagnosing the pressures and conditions that lead alternatively toward or away the rational use of evaluation research. Three cases of public-nonprofit contracting for the delivery of major programs are presented to clarify the way coercive, mimetic, and normative pressures interfere with a sound connection being made between research and implementation. The article concludes by considering how public managers can respond to the isomorphic pressures in their environment that make it hard to act on data relating to program performance.This publication is Hauser Center Working Paper No. 23. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers

    Prevalence and characteristics of game transfer phenomena: a descriptive survey study

    Get PDF
    Previous qualitative studies suggest that gamers experience Game Transfer Phenomena (GTP), a variety of non-volitional phenomena related to playing videogames including thoughts, urges, images, sounds when not playing. To investigate (i) which types of GTP were more common and (ii) their general characteristics, the present study surveyed a total of 2,362 gamers via an online survey. The majority of the participants were male, students, aged between 18 and 27 years, and 'hard-core' gamers. Most participants reported having experienced at least one type of GTP at some point (96.6%), the majority having experienced GTP more than once with many reporting 6 to 10 different types of GTP. Results demonstrated that videogame players experienced (i) altered visual perceptions (ii) altered auditory perceptions (iii) altered body perceptions (iv) automated mental processes, and (v) behaviors. In most cases, GTP could not be explained by being under the influence of a psychoactive substance. The GTP experiences were usually shortlived, tended to occur after videogame playing rather than during play, occurred recurrently, and usually occurred while doing day-to-day activities. One in five gamers had experienced some type of distress or dysfunction due to GTP. Many experienced GTP as pleasant and some wanted GTP to happen again

    Partitioning of the reactive nitrogen reservoir in the lower sratosphere of the southern hemisphere: Observations and modeling

    Get PDF
    Measurements of nitric oxide (NO), nitrogen dioxide (NO2), and total reactive nitrogen (NOy = NO + NO2 + NO3 + HNO3 + ClONO2 + 2N2O5 + ...) were made during austral fall, winter, and spring 1994 as part of the NASA Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft mission. Comparisons between measured NO2 values and those calculated using a steady state (SS) approximation are presented for flights at mid and high latitudes. The SS results agree with the measurements to within 8%, suggesting that the kinetic rate coefficients and calculated NO2 photolysis rate used in the SS approximation are reasonably accurate for conditions in the lower stratosphere. However, NO2 values observed in the Concorde exhaust plume were significantly less than SS values. Calculated NO2 photolysis rates showed good agreement with values inferred from solar flux measurements, indicating a strong self-consistency in our understanding of UV radiation transmission in the lower stratosphere. Model comparisons using a full diurnal, photochemical steady state model also show good agreement with the NO and NO2 measurements, suggesting that the reactions affecting the partitioning of the NO2 reservoir are well understood in the lower stratosphere
    • 

    corecore