61 research outputs found

    The use of near infrared reflectance spectroscopy (NIRS) for prediction of the nutritive value of barley for growing pigs

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    peer-reviewedThere is a need in the feed industry for a rapid means of evaluating the nutritive value of feeds and feed ingredients. Chemical analysis provides only basic information and most of the laboratory techniques take too long for this information to be of use in feed formulation at the feed mill. Near infrared reflectance spectroscopy (NIRS) has been proposed as an alternative means of predicting nutritive value. In this study, NIRS was used to predict the digestible energy (DE) concentration and in vitro ileal digestibility of crude protein (CP) and total-tract digestibility of energy of locally produced barley. The calibration and validation statistics were developed using modified partial least squares (MPLS). Derivatisation and scatter correction procedures were carried out to reduce interference from external effects. The correlations between actual and predicted DE values, based on both calibration (R2 0.93) and validation (R2 0.69), were strong with corresponding low standard errors of calibration (SEC) and cross validation (SECV) (SEC 0.128, SECV 0.279). Strong correlations were also observed between predicted and actual in vitro digestibility values for both calibration and validation exercises. It was noted that validation weakened the correlations (R2 0.73 vs. 0.50 for in vitro ileal digestibility of CP and 0.80 vs. 0.68 for in vitro total tract digestibility of energy) and fractionally increased the standard errors (0.016 vs. 0.020 for in vitro ileal digestibility of CP and 0.018 vs. 0.024 for in vitro total tract digestibility of energy). The correlations obtained by cross validation of the lowest SECV equations were not significantly different to those obtained by the scatter correction treatments. The strong relationships and low standard errors obtained between the actual and predicted values indicates that NIRS may be of use in predicting the nutritive value of barley for growing pigs, although more research is required to include larger sample sets

    A note on the effect of the composition of barley produced at different locations on performance of growing pigs.

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    peer-reviewedLocation of production has been shown to affect the nutritive value of barley for growing pigs, but there is a lack of information regarding the effect of this factor on pig performance. The barley variety “Riviera” was produced at nine different locations in Northern Ireland and formulated into diets (barley, soyabean meal and tallow at 650, 283 and 30 g/kg, respectively) for growing pigs. Diets were offered ad libitum to a total of 72 individually housed pigs from 8 to 11 weeks of age. Average start and end weights were 19 and 34 kg, respectively. Location of production had no significant effect on animal performance although a wide range was observed, which may be important under commercial conditions. Barley specific weight was not strongly correlated (r2 < 0.10) with any performance trait indicating that an alternative means of predicting the nutritive value of barely for pigs is required. A significant positive relationship was observed between barley β-glucan concentration and feed conversion ratio (r2 = 0.65).The authors acknowledge the Trustees of the Thomas Henry Scholarship, The Queen’s University of Belfast (QUB) and the Department of Agriculture and Rural Development for Northern Ireland (DARD), for the financial support which enabled this research to be undertaken

    Effect of variety, endosperm hardness, the 1B/1R translocation and enzyme addition on the nutritive value of wheat for growing pigs

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    It has been widely recognised that wheat chemical composition and nutritive value can vary as a result of genotypic differences, but there is a lack of information on wheat grown in Northern Ireland. Furthermore, there have been conflicting reports regarding the effect of endosperm hardness, the 1B/1R translocation and enzyme addition on the nutritive value of wheat for growing pigs. The effects of wheat variety, endosperm hardness, the presence of the 1B/1R translocation and enzyme addition were examined in four experiments involving a total of 326 Large White Landrace pigs. Performance traits of individually housed pigs were measured in Experiments 1, 3 and 4 and apparent in vivo digestibility coefficients were determined at the total tract and ileal level from post-valve-T-caecum cannulated pigs in Experiment 2. The results obtained for the analysis of the chemical composition of the eight varieties were mainly within reported limits. However, there was a wide range of crude protein concentrations (97.8 to 138.7g/kg dry matter) suggesting varietal differences. There was no effect of endosperm hardness or the 1B/1R translocation on chemical composition. In contrast to other research reports, there were no significant differences in pig performance as a result of either variety, endosperm hardness or the presence of the 1B/1R translocation. However, there were significant variety effects on apparent total-tract digestibility coefficients. Enzyme supplementation had no significant effect on pig performance, despite the fact that the basal diet did not have a high nutrient specification.The authors acknowledge the Department of Agriculture and Rural Development for Northern Ireland (DARD) and Danisco Animal Nutrition for the financial support which enabled this research to be undertaken. Appreciation is expressed to the staff from the Agri-Food and Biosciences Institute who assisted with this work

    The global burden of falls: Global, regional and national estimates of morbidity and mortality from the Global Burden of Disease Study 2017

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    Background: Falls can lead to severe health loss including death. Past research has shown that falls are an important cause of death and disability worldwide. The Global Burden of Disease Study 2017 (GBD 2017) provides a comprehensive assessment of morbidity and mortality from falls. Methods: Estimates for mortality, years of life lost (YLLs), incidence, prevalence, years lived with disability (YLDs) and disability-adjusted life years (DALYs) were produced for 195 countries and territories from 1990 to 2017 for all ages using the GBD 2017 framework. Distributions of the bodily injury (eg, hip fracture) were estimated using hospital records. Results: Globally, the age-standardised incidence of falls was 2238 (1990-2532) per 100 000 in 2017, representing a decline of 3.7% (7.4 to 0.3) from 1990 to 2017. Age-standardised prevalence w

    Assessing the impact of aerodynamic modelling on manoeuvring aircraft

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    This paper investigates the impact of aerodynamic models on the dynamic response of a free-flying aircraft wing. Several options for the aerodynamics are evaluated, from two-dimensional thin aerofoil aerodynamics and unsteady vortex-lattice method up to computational fluid dynamics. A nonlinear formulation of the rigid body dynamics is used in all cases. Results are generated using a numerical framework that will allow in the near future multi-disciplinary fluid/structure/flight analysis. In this paper, flexibility effects are neglected. A validation for fluid/flight models is presented. The well-established approach based on stability derivatives is also used, and is found in good agreement with solutions obtained from linear aerodynamic models. The uncertainties in predicted trajectories of the free-flying wing are, in general, large and attributed to the aerodynamics only. This suggests that a careful control law synthesis should be done to account for uncertainties from modelling technique

    Assessment of tabular models using CFD

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    Tabular aerodynamic models are frequently used for computational flight simulation. It is necessary to understand the limitations of such models to ensure adequacy for the relevant manoeuvres. The assessment is carried out for an aerofoil with a trailing edge flap for both forced and free–response manoeuvres. The limitations of the tabular model are then assessed through a comparison of loads or trajectories against a time–accurate computational fluid dynamics solution. A number of manoeuvres are used covering both linear and nonlinear aerodynamic regimes. It is seen that the assumptions in the tabular model are adequate except for neglecting history effects for certain regimes where nonlinearities are significant
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