bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis and Interpretation of Data-Driven Closure Models for Large Eddy Simulation of Internal Combustion Engine
Authors: Mitra Peetak , Haghshenas Majid , Dal Santo Niccolò , Dias Ribeiro Mateus , Mitra Shounak , Daly Conor , Schmidt David
Published: April 2021

We present an automatic data-driven machine learning (ML) approach for the development, evaluation and interpretation of deep neural networks (DNNs) for turbulence closures and demonstrate their usage in the context of cold-flow large-eddy simulation (LES) of the four-stroke Darmstadt engine using an open-source compressible multi-dimensional CFD solver OFICE, in a hybrid PDE-ML framework. Rather than explicitly using canonical formulations of closure terms, these DNNs robustly discover the functional relationships between the large-scale features of the resolved flow (cell Re, strain and rotation rate tensors etc.) obtained by solving the Navier Stokes to the small-scale unresolved terms. Experimentally validated high-fidelity LES solutions of the engine at different crank angles are utilized as the ground truth to train the DNN based closure models. Since optimizing these DNNs can be a laborious process for scientific datasets, and often require specialized expertise, we propose a Bayesian optimization framework that automatically determines the best set of network parameters, including the architecture and training hyperparameters - batch size, regularization etc. for optimum performance. We compare and contrast various networks for their effectiveness in an a-priori testing setting. Finally, the best ‘learnt’ network is integrated with the open-source CFD solver (OFICE), and solutions are obtained over several injection cycles. These experiments reveal that the DNN models temporally track resolved scalar variance with a good accuracy. Additionally, we interpret the artificial neural networks with sensitivity analysis to determine the relevant large-scale features for the learning process.
CFD Modeling of Reacting Diesel Sprays with Primary Reference Fuel
Authors: Zhou Qiyan , Lucchini Tommaso , D'Errico Gianluca , Novella Ricardo , Garcia-Oliver Jose M , Lu Xingcai
Published: April 2021

Computational fluid dynamics (CFD) modeling has many potentials for the design and calibration of modern and future engine concepts, including facilitating the exploration of operation conditions and casting light on the involved physical and chemical phenomena. As more attention is paid to the matching of different fuel types and combustion strategies, the use of detailed chemistry in characterizing auto-ignition, flame stabilization processes and the formation of pollutant emissions is becoming critical, yet computationally intensive. Therefore, there is much interest in using tabulated approaches to account for detailed chemistry with an affordable computational cost. In the present work, the tabulated flamelet progress variable approach (TFPV), based on flamelet assumptions, was investigated and validated by simulating constant-volume Diesel combustion with primary reference fuels - binary mixtures of n-heptane and iso-octane. Simulations were initially carried out to evaluate and compare the performance of two kinetic models in homogeneous reactors and laminar diffusion flames, followed by turbulent reacting spray simulations considering different fuels, ambient temperatures, and oxygen concentrations. The sensitivity study of the turbulent Schmidt number was then conducted, and results in terms of ignition delay and lift-off length were compared with experimental data to determine a more appropriate global constant. Finally, parametric variations of ambient temperature and oxygen concentration were performed for six fuel blends ranging from PRF0 (n-heptane) to PRF100 (iso-octane), confirming the validity of the TFPV model.
Torque Converter Launch and Lock with Multi-Input Multi-Output Control
Authors: Xu Yang , Dai Edward , Chen Weitian , Ford Stuart , Liu Pinzhi , Keller Bret , Jiang Hong
Published: April 2021

A torque converter is a type of fluid coupling device used to transfer engine power to the gearbox and driveline. A bypass clutch equipped in a torque converter assembly is a friction element which when fully engaged, can directly connect the engine to the gearbox. The torque converter is an important launch device in an automatic transmission which decouples engine speed from gearbox input speed while providing torque multiplication to drive the vehicle. During partial pedal launch, it is desired to engage the bypass clutch early and reduce the converter slippage in order to reduce power loss and achieve better fuel economy. However, engaging the bypass clutch early and aggressively may disturb the wheel torque and cause unpleasant driving experiences. This paper describes a multi-input multi-output (MIMO) control method to coordinate both engine and converter bypass clutch to simultaneously deliver desired wheel torque and reduce converter slippage. The proposed control method leverages a feedforward control derived from a standard converter hydrodynamic model and a Linear-quadratic regulator (LQR) feedback control. It considers the desired gearbox input torque and converter slippage as two control targets and engine torque and bypass clutch capacity as two control inputs to achieve the targets. This method enables aggressive converter lock-up without degrading driveability and will potentially improve calibration efficiency.
On the Expansion of On-Board Diagnostics (OBD) to Electric Propulsion Systems in Battery Electric Vehicles
Authors: Guo Yichao
Published: April 2021

Currently the On-Board Diagnostics (OBD) requirements enforced by government agencies do not cover electric vehicles. Although the California Air Resources Board (CARB) mandates all light and medium duty vehicles and heavy duty engine dynamometer certified engines equipped with fossil fuel-powered engines, including all hybrid vehicles, must follow the OBD requirements in California Code of Regulation (CCR) 1968.2 and 1971.1, Battery Electric vehicles (BEVs), are exempted from OBD requirements. The legislators, such as CARB, have started to make proposals for on-board systems to monitor electric propulsion system health. In addition, there may be customer needs to obtain standard vehicle service information and the Original Equipment Manufacturers (OEMs) may also have the desire for common diagnostic strategies across different vehicle applications to lower the development costs. This paper, different from other published technical papers or proposals from OEMs or government agencies, analyzes the feasibility and compatibility of the existing OBD system design requirements, and aligns them with the need of industrial-common OBD system architecture and existing/upcoming SAE standards to propose the monitoring and reporting requirements on the identified primary propulsion system components/systems from technical point of view. This study makes some key technical proposals/solutions for the possible use of OBD-like monitoring and reporting requirements for Electric Propulsion Systems, including, what are the monitoring requirements, what is to be monitored, what are the malfunction indicator light (MIL) illumination requirements, and what are the generic scan tool (GST) interface requirements that are based on J1979-2 (i.e., Unified Diagnostic Services -UDS) to facilitate the repair service by technicians, including from independent service shops.
Experimental Comparison of Low-Load Piston Compounding Deactivation for the DBDC+EC Engine Architecture
Authors: Andruskiewicz Peter , Durrett Russell , Najt Paul
Published: April 2021

An experimental piston compounded engine was designed with guidance from thermodynamic modeling, then was built and tested to compare the model predictions to measured results. This Downsized Boosted Dilute Combustion, Exhaust Compounded (DBDC+EC) engine concept has shown great potential for improvements in efficiency at high loads through extended second expansion process, but suffered from excessive expander cylinder pumping and low exhaust temperatures at low loads. Four expander operating strategies were experimentally tested and simulated at a range of engine speeds and loads to determine the most efficient method to deactivate the piston compounding at low loads. The most effective method involved deactivating all the expander valves and operating it as an air-spring while diverting power cylinder exhaust gasses through a separate bypass port. While this method requires some unique hardware development to enable on-the-fly actuation, it offers 15% to 22% improvements in low-load BSFC over the active expander method while improving exhaust temperatures by 100° to 150°C.
A Novel Piston Insulation Technique to Simultaneously Improve Both Heat Loss and Thermal Efficiency for Diesel Engines
Authors: Kawaharazuka Fumihiro , Uchida Noboru , Osada Hideaki
Published: April 2021

This study investigates simultaneous improvement in thermal efficiency and cooling loss in the wider operating condition. To suppress the heat flux of the piston, the piston top and cavity were treated with thin thermal spraying of stainless steel. Thermal diffusivity of stainless steel (X5CrNiMo17-12-2, SUS316) is very low in comparison with the forged steel piston raw material (34CrMoS4, SCM435) to sustain local surface temperature at where spray flame directly interfered. In addition, its surface roughness was very fine finished aiming to reduce the convective heat transfer. The experimental results with the stainless-steel coated piston by utilizing a single cylinder engine showed the significant improvement in both cooling loss and thermal efficiency even in higher load operating conditions with compression ratio of 23.5:1. From the analysis of the experimental result, it is assumed that not only convective heat transfer but radiative heat transfer could play an important role in the cooling loss mechanism.
High Temperature HCCI Critical Compression Ratio of the C1-C4 Alcohol Fuels
Authors: Gainey Brian , Hoth Alexander , Waqas Muhammad , Lawler Benjamin , Kolodziej Christopher
Published: April 2021

In this work, a high temperature (HT) homogeneous charge compression ignition (HCCI) critical compression ratio (cCR) was defined as the compression ratio which resulted in HCCI combustion with a crank angle location of 50% fuel burned (CA50) of 3.0 degrees after top dead center (aTDC) while operating at an equivalence ratio of 0.33 (λ = 3), an intake pressure of 1.0 bar (naturally aspirated), an intake temperature of 473 K (200°C), and an engine speed of 600 rpm. Using a Cooperative Fuel Research engine, the HT HCCI cCR of seven alcohol fuels were experimentally determined and found to be ordered as follows (ordered from least reactive to most reactive): isopropanol > sec-butanol > methanol ≈ ethanol ≈ n-propanol ≈ isobutanol > n-butanol. The HT HCCI cCR for the alcohol fuels correlated well with experimental HCCI data from a modern gasoline direct injection (GDI) engine architecture with a pent-roof head and a rebreathe valvetrain. The HT HCCI cCR was also correlated with available cetane number (CN), motor octane number (MON), and research octane number (RON) values found in the literature. The coefficient of determination (R2) for these correlations was 0.02, 0.95, and 0.69, respectively. When the RON values were modified to account for the high cooling potential of the alcohol fuels, the R2 increased from 0.69 to 0.96. When a wider array of other fuels were considered, including pure components of different fuel classes, pure-component fuel blends, and gasoline fuel blends, the critical compression ratio no longer correlated well with MON or HOV-modified RON. It was concluded that when fuels of a similar fuel class are considered, such as neat C1-C4 alcohols, MON or an HOV-modified RON may be sufficient to compare the HCCI reactivity of the fuels at MON-like cylinder conditions. However, due to the complex nature of the octane number tests, the HCCI ignition propensity is not well predicted by the standard octane numbers when fuels of varying chemical characteristics and combustion chemistry attributes are considered. Therefore, a metric for characterizing gasoline-like fuels under compression ignition conditions is required, such as an HCCI test method on the CFR octane rating engine.
Using Virtual Product Development with Design of Experiments to Design Battery Packs for Electrified Powertrain
Authors: Bao Ran , Fotias Nikolaos , McGahan Paul
Published: April 2021

Stringent automotive legislation is driving requirements for increasingly complex battery pack solutions. The key challenges for battery pack development drive cost and performance optimisation, growth in architecture solutions, monitoring and safety through lifetime, and faster-to-market expectations.

The battery Virtual Product Development (VPD) toolchain addresses these challenges and provides a solution to reduce the battery pack development time, cost and risk. The battery VPD toolchain is built upon scalable, validated sub-models of the battery pack that capture the interactions between the various domains; mechanical, electrical, thermal and hydraulic. The model fidelity can be selected at each stage of the design process allowing the right amount of detail, and available data, to be incorporated. The toolchain is coupled with vehicle simulation tools to rapidly assess performance of the complete electrified powertrain.

The aim of this study is to demonstrate an agile approach to battery pack concept development using VPD, enabled by Design of Experiments (DoE) and optimisation. Key battery parameters such as cell type, electrical configuration, thermal heat path design and cooling strategy are chosen as the design variables of a multi-staged DoE. The DoE test matrices of these parameters are generated and imported into the battery VPD toolchain with the vehicle simulation model to perform the energy efficiency and performance simulations.

Finally, the simulation results are analysed to create surrogate models which can be used to predict powertrain attributes and optimise the battery pack design. The ability to front-load virtual battery pack concepts with vehicle simulations allow for wholistic performance assessment, ensuring that vehicle attribute targets such as pure electric range of WLTP, acceleration and maximum speed are met and reducing concept development time by up to 50% compared to the baseline approach.
Development of Coated Gasoline Particulate Filter Design Method Combining Simulation and Multi-Objective Optimization
Authors: Ota Yuki , Takahasi Hiroaki , Maekawa Ryosuke
Published: April 2021

In recent years, GPFs (Gasoline particulate filters) have been installed in gasoline engines to comply with stricter environmental regulations in China and Europe. In particular, coated-GPFs having a catalytic purification function are required to have high conversion performances, high filter efficiencies in the sense of a high collection efficiency, and low pressure loss. It is not easy to design a filter that satisfies all these parameters. Experimental studies are being conducted, but it is costly to study in trial productions. In this technical paper, a GPF design optimization method will be proposed that combines multi-scale simulation, surrogate models by machine learning, and an optimization algorithm. By using this method, a GPF design that minimizes pressure loss while providing high conversion performance and particle collection rates that satisfy current regulations can be created. In addition, the examination period could be shortened by 97% compared to experimental verifications.
Residential Indoor Radon Assessment in the Vicinity of some Dumpsites in Lagos, Nigeria
Authors: Olaoye M.A. , Ademola A.K. , Jegede O.
Published: April 2021

Dumpsites in Nigeria are generally open and significantly elevate the pollution and contamination level of the total environment.  Indoor radon was measured with CR-39 detectors in some buildings in the vicinity of dumpsites in Lagos, Nigeria. Eight (8) dumpsites (4 dormant and 4 active dumpsites) were chosen for this study. Detectors were exposed in 50 houses randomly selected within 0 and 100m away from the dumpsites. The detectors were exposed for 3 months. They were then retrieved and etched in a 6M NaOH solution in a water-bath at a temperature of 90o C for 3 hours. Tracks were counted using a semi-automatic system with a DCE camera mounted on a microscope and connected to a PC. Radon concentration ranged from 24.00±4.86 to 656.00±131.20 Bqm-3 in the active dumpsites.Mean concentrations were 120.3±24.0, 257±51.4, 179.8±33.6, and 131.5±19.4, respectively in Oke-Odo, MRF, Olusosun, and Solus-3. In the dormant sites, concentration ranged from 16±3.2 to 931±186.3 Bqm-3 having means of 194.17±38.80, 206.75±41.33, 223.25±44.69, and 334±66.85Bqm-3 , respectively in Oke-Afa, Solus-1, Solus-2, and Solus-4. The annual effective dose and cancer risk in the active and dormant dumpsites were (3.60 mSv, 8.97 per million person-yearly) and (4.53 mSv, 12.47 per million person-yearly), respectively. This study revealed some high value of radon concentrations in some houses close to the dormant dumpsites than in the active dumpsites. This is unsafe and can cause severe health issues in the long term.

Keywords: Radon, dumpsites, Olusosun, CR-39, buildings, Lagos state, SOLUS
Assessment of Indoor Air Quality and Health Impact associated with the use of Different Types of Cooking Stoves amongst Rural Households in Kwara State, Nigeria
Authors: Olaoye I.J. , Akingbade A.V. , Alatise I.
Published: April 2021

The study focused on assessing the health impact of indoor air pollution and coping strategies adopted among rural households in Kwara state, Nigeria. A three-stage random sampling techniques was used to select 150 household respondents. The data for the study were collected using a well-structured questionnaire and an MSA gas-detector used to monitor the concentration of Carbon-monoxide (CO), Sulphur-dioxide (SO2) and Hydrogensulphide (H2S) pollutants. Descriptive and inferential statistics were employed to analyze the data. However, the result revealed that the mean concentration of CO, SO2 and H2S in the kitchen during cooking were 77.20, 1.97 and 0.25 parts-per millions (ppm) respectively. The World Health recommends exposure limits of 35ppm for 1hour and 9ppm for 8hours for CO concentration in a household. While, the recommended exposure limits of 0.5ppm and 1.0ppm for 8 hours, and 5.0ppm and 10.0ppm for 15minutes for SO2 and H2S concentrations in a household respectively. Eye irritation, Sneezing and headache were the 1st, 2nd and 3rd perceived health problems found to be associated with indoor air pollution. Also, the Pearson χ2 result (15.051, 15.454, and 11.853 with P<0.05) revealed that cold/catarrh/cough, headache/fever, and body pain ailments respectively have significant association with types of cooking stove used by rural households. Thus, inefficient wood and charcoal stoves influence rural household health negatively and they cope by adopting indigenous management practices.

Keywords: Pollution, concentration, irritation, stove, ailments
Evaluation of Water Quality Index Using Physicochemical Characteristics of Ogbor River in Aba, Abia State, Nigeria
Authors: Okey-Wokeh C.G. , Obunwo C.C. , Wokeh O.K.
Published: April 2021

The study was carried out to evaluate water quality index (WQI) of Ogbor River, a freshwater system flowing through the commercial city of Aba, Southern Nigeria using selected physicochemical parameters. The levels of the physicochemical parameters were determined using standard analytical procedures in the Laboratory. The values obtained were subjected to statistical analysis using Excel spreadsheet (Version 16).Water Quality index was calculated using mean values of the selected nine parameters and the World Health Organisation standard for drinking water. The result of physicochemical parameters used showed that Dissolved Oxygen (DO) with mean 4.44 ± 0.70 mg/L, and Nitrate (NO3- ) with mean 7.58 ± 6.25 mg/L were below National and International standards. The value of WQI calculated was 83.05. The result revealed that Ogbor River water quality was very poor, so it is unfit for human consumption, and should be treated to avoid water related diseases.

Keywords: Characteristics, Evaluation, Ogbor River, Physicochemical, Water Quality Index
Well-to-Seismic Tie of a Field Onshore of the Nigerian Delta
Authors: Inichinbia S. , Saule P.O.
Published: April 2021

This work presents a modern procedure for understanding seismic data wavelets through well-toseismic tie on an onshore field in the Nigerian Delta using the state-of-the-art techniques. The purpose of this work is the correlation of formation tops and seismic  reflectors in the field. The objectives among others include the calibration of the seismic data in terms of polarity and phase, as well as to ensure that the seismic data is descriptive to well markers and discoveries, extending knowledge from the well location to rest of the field and reducing uncertainties. Logs from the two wells on the field and also logs from three wells on neighbouring fields were used to establish lateral continuity of the reservoirs H1000 and H4000. Their results show that the top, base and thickness of both reservoirs are quite variable laterally and this posed some challenges in the correlation from well to well. The field does not have checkshot data, so checkshot data from one of the wells on the neighbouring field was borrowed. Calibrated sonic and density logs of well01 and  well-02 were used to assess the seismic ties at the well locations. Strong correlations at the wells are fundamental to the evaluation of the spatial extent of the horizons around the wells from the seismic data. Seismic-to-well ties are a very important part of the interpreter’s business as they provide a means of correctly identifying horizons to pick, and estimating the wavelet for inverting seismic data to impedance and rock property indicators.

Keywords: Seismic, horizons, correlation, synthetics
An improved percentage rate accuracy in predicting mortality in hepatitis-c using an artificial neural network
Authors: Matthias Daniel , Davies I.N. , Olumide O.
Published: April 2021

Background accurate prediction of mortality in Hepatitis-C (Hep C) is essential for policy action and planning. While studies have used artificial intelligent technique (e.g., artificial neural network (ANN)), their appropriateness to predicting mortality in hepatitis-c has been debated. This study presents an improved percentage rate accuracy that is capable of predicting whether a patient suffering from Hepatitis-C Virus (HCV) is likely to survive or die. The constructive research method was adopted for this study, while an Object Oriented Design Approach was adopted for the systems structural design. The Artificial Neural Network system was implemented using java programming language with many program modules and four (4) design classes namely; the Driver class that runs the application program, the Neural Network class, the Neuron and the Layer classes. The network was trained using back propagation machine learning algorithm, a learning rate of 0.8 and a learning error of 0.05. While the weights used for the training were random numbers ranging from -1.0 to +1.0. The maximum number of training sessions was set to 10000 assuming the network does not converge to the leaning error of 0.05. The result of the network showed 85% accuracy in predicting cases of the patients with positive hepatitis C virus that may survive and also 50% accuracy in predicting cases of patients with positive Hepatitis-C Virus (HCV) that may likely to die given the provided data. Neural network is a powerful classification and prediction tools that can help in predicting the outcome of Hepatitis-C virus (HCV) infections. Recommending experiment on the network architecture with a view to either increase the hidden layers or increasing the number of units in the hidden layer. Also, more extensive testing and training should be carried out to achieve the desired result.
Internet of Things (IoT) and emerging Wireless Technologies in the 21st Century
Authors: Ngige O.C. , Chibudike C.E. , Omotosho D.O.
Published: April 2021

This paper accesses the Internet of Things (IoT) in conjunction with the emergence of Wireless Technologies. Internet of Things (IoT) refers to a type of network to connect anything with the Internet, based on stipulated protocols through information sensing equipment to conduct information exchange and communications; in order to achieve smart recognitions, positioning, tracing, monitoring, and administration. This investigates the Internet of Things (IoT) and its incorporation of multiple long-range, short-range, and personal area wireless networks and technologies into the designs of IoT applications. Particularly, it focuses on ZigBee, 6LoWPAN, Bluetooth Low Energy, LoRa, and so on. This enables numerous business opportunities in fields as diverse as e-health, smart cities, and smart homes, among many others. This research briefly discussed about IoT, some of the major evolving and enabling wireless technologies in the IoT, Smart Environnent Application Domain, and Application of IoT. Benefits and Challenges of IoT.
The Determinants of Households Having Savings Accounts in Rwanda
Authors: Ruranga Charles , Hacker Scott
Published: April 2021

This paper analyses the determinants of Rwandan households having savings accounts using Integrated Household Living Conditions Survey  (IHLCS) data of 2010/11. After a background discussion and literature review an empirical analysis is presented with different variables adopted and analysed as determinants of household’s head having savings accounts. Poverty level, age, gender, residential area and level education of household head (literate or not) were considered as independent variables of the study. Findings from the estimations of logit models indicate the likelihood of a household having a savings account is positively and significantly related to each of the following: non-poor status of the household,the household residing in an urban area, the household head being male, and the household head being literate. Having the household head be literate tends to be more important for younger household heads and for non-poor households. The proportion of households having money in a savings account more than doubled over the decade between the IHLCS 2000/2001 survey and the IHLCS 2010/2011 survey. Government policies on savings and poverty reduction may explain the trend of increased cash balances in saving accounts.

Key Words: Savings, Bank Accounts, Households, Determinants,
Capital structure and financial sustainability of Microfinance Institutions (MFIs) in Rwanda
Authors: Rutanga Jean Marie , Barayandema Jonas , Mutarindwa Samuel
Published: April 2021

The aim of this study was to assess the effect of capital structure on financial sustainability of microfinance institutions (MFIs), and find out the extent to which capital structure affects financial sustainability of MFIs in Rwanda. Data was collected from annual financial reports of MFIs and SACCOs for the period 2014-2018. Due to data availability, only a panel of 20 MFIs and SACCOs was considered using fixed effects OLS regression models. Findings from this study reveal that the use of debt as financing sources adversely affects firms‘ financial self-sufficiency and performance. In contrast, the use of share capital strongly improves firms‘ operational and financial sustainability as well as their return on assets. Using retained earnings moderately and positively increases firm‘s financial sustainability. Results from sample splits show that compared to MFIs, SACCOs are more likely to be adversely affected by debt financing than their MFI counterparts. With respect to share capital, there is significant difference between the two groups. Using share capital to finance MFIs‘ investments significantly increases their return on assets, their operational and financial self-sufficiency. With respect to SACCOs, results show that using share capital as means of financing firms‘ assets negatively and significantly affects their return on total assets as well as their operating and financial self-sufficiency.
Digestible threonine and its effects on growth performance, gut morphology and carcass characteristics in broiler Japanese quails (Coturnix coturnix japonica)
Authors: Rasheed M.F. , Rashid M.A. , Mahmud Saima, A. , Yousaf M.S. , Malik M.I.
Published: April 2021

Threonine is the third limiting amino acid in corn-soy-based poultry diets and has an important role in body and intestinal development of chicken. Although work on threonine (Thr) in chicken is well established, information about the effects of digestible threonine (dThr) on quail performance is limited. Therefore, the current study was designed to determine the impact of increasing levels of dThr on growth performance, feed conversion ratio (FCR), gut health and carcass characteristics in meat-type quails. A total of 324 mixed-sex day-old quail were randomly allocated to three treatments with six replicates per treatment and 18 birds per replicate. There were three dietary treatments, namely control (C) with recommended levels of dThr according to the Brazilian Tables guidelines for Japanese quails: 10% dThr (C diet supplemented with 10% more dThr) and 20%dThr (C diet supplemented with 20% more dThr). At day 35 of the experiment, three birds from each pen were slaughtered. A duodenal sample was collected and preserved to evaluate gut health. The carcass characteristics were determined from the slaughtered birds. Total feed intake and average daily feed intake were higher in the C treatment than in 10% dThr. Final bodyweight (BW), weight gain and average daily gain (ADG) increased linearly. The birds fed diets supplemented with 20% extra dThr had the highest final weight and bodyweight gain (BWG) compared with those birds that were fed on C and 10% dThr supplemented diets. Feed conversion ratio was improved in 10% dThr compared with the C birds. Villus height (VH) was similar among treatments. The highest crypt depth (CD) was observed in C, followed by 10% dThr and 20% dThr. The birds fed 20% dThr had higher VH:CD than 10% dThr. The birds in the C treatment had lowest VH:CD. Carcass weights with and without giblets were higher in the 20% dThr than in the 10% dThr and C treatments. Breast mass yield (BMY) was greatest in 20% dThr compared with C and 10% dThr. It may be concluded that supplementation of Thr higher than the requirements referred to in Brazilian Tables improves growth performance and gut health of meat-type quail.Keywords: Crypt depth, mucin, performance, quail, villus height
Performance, water intake, carcass characteristics and intestinal histomorphology of broilers supplemented with phytase
Authors: Van Emmenes L. , Pieterse E. , Hoffman L.C.
Published: April 2021

A 32-day experiment was conducted to study the effects of supplementation of phytase enzyme, Ronozyme® HiPhos (DSM Nutritional Products, Basel, Switzerland), on the production parameters, water intake, intestinal histomorphology, carcass characteristics and bone mineralization of broiler chickens. A total of 1920 one-day-old Cobb 500 broilers were randomly allocated to one of three treatments, each comprising eight replicate cages (eight replications per treatment) with 80 birds per cage. Dietary treatments were created using a standard commercial diet as the positive control (CON); reducing the nutrient content of the CON diet with values similar to the matrix values of 1500 FYT (phytase units) Ronozyme® HiPhos to create the negative control diet (NEG); and supplementing the NEG diet with 1500 FYT/kg Ronozyme HiPhos to create the phytase diet (HiPhos). Supplementation of the NEG diet with HiPhos significantly improved average daily gain (ADG), feed conversion ratio (FCR), bodyweight (BW) at slaughter and the European production efficiency factor (EPEF) of broilers compared with those in the NEG treatment group, but had no effect on total feed intake, water intake, villi height, crypt depth, dressing percentage, portion yields, pH of the meat or colour of the meat. Fat-free bone ash percentage and tibia breaking strength of broilers in the HiPhos treatment group were intermediate to broilers in the NEG and CON treatment groups. Results from the study proved that broilers could be supplemented with HiPhos phytase without detrimental effects on growth parameters, bone mineralization, carcass characteristics and water intake.Keywords: Bone breaking strength, chickens, phosphorus, villus height, weight gain
Prediction of solid digesta passage rate using liquid passage rate as one of the input variables in ruminants
Authors: Moyo M. , Gueguim Kana E.B. , Nsahlai I.V.
Published: April 2021

This study ascertained the influence of liquid passage rates on solid digesta passage rates and the possibilities of simultaneous prediction of solid and liquid passage rates in ruminants. Artificial neural networks were used to develop models of solid and solid-plus-liquid passage rates. Studies that reported fractional passage rates, class and body mass of ruminants were included in the dataset. Animal and feed factors that affect the rate of passage were identified. The database had observations of domestic and wild ruminants of variable body mass from 74 (solid using predicted liquid passage rate) and 31 (solid using observed liquid passage rate) studies. Observations were randomly divided into two data subsets: 75% for training and 25% for validation. Developed models accounted for 76% and 77% of the variation in prediction of solid passage rates using predicted and observed liquid passage rate as inputs, respectively. Simultaneous prediction accounted for 83% and 89% of the variation of solid and liquid passage rates, respectively. On validation using an independent dataset, these models attained 45% (solid using predicted liquid), 66% (solid using observed liquid), 50% (solid predicted with liquid) and 69% (liquid predicted with solid) of precision in predicting passage rates. Simultaneous prediction of solid and liquid passage rate yielded better predictions compared with independent predictions of solid passage rate. Simultaneous prediction of solid and liquid passage rates accounted for more variation compared with independent predictions of solid rates. Inclusion of liquid passage rate as an input variable gave better predictions of solid passage rates.Keywords: Fractional passage rate, prediction model, simultaneous predictions
Effects of air temperature on physiology and productive performance of pigs during growing and finishing phases
Authors: Oliveira R.F. , Moreira R.H.R. , Abreu M.L.T. , Gionbelli M.P. , Teixeira A.O. , Cantarelli V.S. , Ferreira R.A.
Published: April 2021

Thirty-six castrated male pigs were used to determine the influence of thermal environment and reduction of consumption on performance and carcass composition. Animals were housed in two climate chambers. In one, animals were in thermal comfort (TN) (22 °C), and in the other, pigs were under heat stress (HS) (34 °C). Animals were distributed in a randomized block design, making three treatments (TN, HS and animals in thermal comfort with food consumption paired with that observed in HS (PFTN)), with six replicates and two animals per experimental unit. Data were obtained on performance and carcass composition. The weight gains of HS and PFTN animals were reduced by 40.5% and 34.7%, respectively, reflecting a reduction of 13.2% in the final weight of PFTN animals. Triiodothyronine concentration was not affected by heat, but there was an increase in lymphocyte numbers in PFTN animals. The HS and PFTN animals showed lower hot carcass weight. However, there were no effects on hot carcass yield and relative weights of heart, lung and spleen. Heat stress compromised performance. The negative effects of high temperature on pigs include reduction in feed intake and changes in physiology.Keywords: Environment, heat stress, pair feed, pig growth, pig production
Effect of various levels of isoflavone aglycone-enriched fermented soybean meal on redox status, serum hormones and milk quality in ewes
Authors: Luo Z. , Yu S. , Zhu Y. , Zhang J. , Xu W. , Xu J.
Published: April 2021

The study investigated the effects of various levels of isoflavone aglycone-enriched fermented soybean meal (FSBM) on the redox status, serum hormones and milk quality of ewes from late pregnancy to early lactation. Twenty Chongming White ewes were chosen and divided into four treatment groups (n = 5): basal diet without FSBM (CON); basal diet with 2% (FSBM2); 4% (FSBM4); and 6% FSBM (FSBM6) replacing equal amounts of soybean meal (SBM). At parturition, maternal serum, the placenta and colostrum were collected. At day 21 of lactation, maternal serum and milk were collected. Results showed that, compared with CON, feeding ewes with FSBM6 reduced the concentrations of hydrogen peroxide (H2O2) and 8-hydroxy-2-deoxyguanosine (8-OHdG), and increased the activity of superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) concentration in the placenta. At parturition and day 21 of lactation, the serum SOD activity and T-AOC concentration in FSBM4 and FSBM6 were higher than those in CON. Furthermore, the concentration of serum 8-iso prostaglandin (8-ISO-PGF2α) was markedly lower in FSBM6 than in CON. Serum prolactin (PRL), insulin-like growth factor 1 (IGF-1) and epidermal growth factor (EGF) concentrations were increased in FSBM4 and FSBM6 compared with CON. PRL concentration was increased in FSBM2. FSBM4 increased the levels of fat, protein, lactose, IgA, IgG and IgM in colostrum and milk. In conclusion, feeding ewes with FSBM from late pregnancy to early lactation seemed to increase maternal and placental anti-oxidative capacity, and improve serum hormones and milk quality. Considered overall, the level of 4% supplementation is recommended.Keywords: Milk contents, oxidative stress, placenta, serum parameters
Concentrations of faecal glucocorticoid metabolites in South African Mutton Merino sheep fed various sources of roughage
Authors: O’Neill H.A. , Einkamerer O.B. , Elago B.T. , Ganswindt A.
Published: April 2021

The objective of this study was to determine whether various sources of roughage in nutritionally balanced feedlot diets would evoke a stress response in sheep. A nutritional stress response test was performed on 20 ewes, randomly divided into four treatment groups with 5 ewes per group. Ewes were kept individually in metabolic crates for thirty days. Rations were balanced nutritionally, and various sources of roughage were included; T1: alfalfa hay, T2: maize stover, T3: soya hulls; and T4: Eragrostis tef. Faeces was removed manually from the caudal rectum of each ewe at 05h00 and 19h00. Samples were frozen at -20°C until analyses. A total of 520 faecal samples were analysed to determine the concentrations of faecal glucocorticoid metabolites (fGCM) by enzyme immunoassay (EIA). These concentrations were expressed as mass/g dry weight (ng/g DW). Baseline values were determined, and those greater than the mean plus 2 standard deviations were removed. Baseline values were compared between the groups with one-way ANOVA analysis. The average concentrations of fGCM were 178.77 ± 21.7 in the morning and 183.2 ± 14.4 in the evening. Sheep fed T4 had significantly higher fGCM concentrations in both morning (302.0 ± 86.1 ng/g DW) and evening (237.0 ± 48.1 ng/g DW) compared with the other treatment groups. Thus, fGCM concentrations in sheep were related to the source of roughage, and Eragrostis tef caused a stress response.

Keywords: animal welfare, cortisol, dietary fibre, selective grazer, stress response
Rearing system effects on live weight gain of large white turkeys
Authors: Inci H. , Çelik Ş. , Söğüt B. , Şengül T. , Şengül A.Y. , İlkaya M.
Published: April 2021

The aim of this study was to determine the effect of three production systems on live weight gain (LWG) of white turkeys by repeated measures analysis of variance (ANOVA) and profile analysis. A total of 81 turkey poults were assigned to intensive (7 male and 19 female), semi-intensive (9 male and 19 female) and extensive groups (11 male and 16 female) at one day old. The poults were wing-banded at day 1 after hatching and weighed individually each week through 16 weeks old. The birds were managed similarly through eight weeks old. After that time, the intensive group was fed concentrated feed indoors. The birds of the semi-intensive group had access to pasture for eight hours a day, and received 50% of the concentrated feed that was consumed by the intensive group. The birds in the extensive group were kept outdoors with shade and grazed on pasture, but did not receive concentrated feed. The bi-weekly LWG of the extensive, intensive and semi-intensive groups were 1191.4 g, 990.6 g and 872.1 g, respectively. Through the 16 weeks of the trial, the effects on LWG of production system, age, and interaction of age and production system were highly significant (P <0.01) in the repeated measures ANOVA. The profile analysis also showed highly significant (P <0.01) production system effects and interaction of production system and age on LWG. Scheffe’s test indicated that the intensive, semi-intensive, and extensive treatments differed (P <0.05).
Dietary inclusion of ensiled avocado oil cake affects growth, nutrient digestion, and carcass characteristics of pigs
Authors: Seshoka M.L. , Fourie P.J. , Kanengoni A.T. , Malebana I.M.M. , Thomas R.S. , Nkosi B.D.
Published: April 2021

In this experiment, the effects were evaluated of various dietary inclusion levels of avocado oil cake (AOC) silage on growth performance, nutrient digestibility, and carcass characteristics in pigs. A mixture of 70% AOC, 25% wheat bran, and 5% sugarcane molasses was ensiled in 200 L drums for 90 days. It was then incorporated at 0%, 3% and 5% in the experimental diets. Twenty-seven Large White cross Landrace (LW x LR) weaner pigs, with an average live weight of 22 kg, were stratified by weight and randomly allocated to the three experimental diets (9 pigs/diet). Pigs were weighed individually each week throughout the trial. Daily feed intake, average daily gain (ADG) and feed conversion rates (FCRs) were recorded. A nutrient digestibility study was carried out on completion of the growth trial. At the end of the experiment, pigs were fasted for twelve hours and weighed to determine the final weight. The pigs were then slaughtered, and carcass samples were collected and analysed. The growth performance of pigs was not affected by diet, irrespective of fibre levels in the AOC silage. However, the addition of 3% AOC silage improved the digestibility of fibre fractions. The weights of the cold carcass, chops, and backfat thickness were reduced with AOC silage addition.
Clinical evaluation of chemo-sterilization through histomorphology and hormonal changes in bucks
Authors: Hasan M. , Miah M.A.H. , Alam M.M. , Juyena N.S.
Published: April 2021

The study was aimed to evaluate methods for nonsurgical castration of Black Bengal bucks by intra-testicular injection of calcium chloride, sodium chloride, citric acid solutions or sterile deionized water. Twelve healthy bucks were randomly allotted to groups A, B, C, and D, consisting of three bucks each. The local anesthetic, 2% lidocaine hydrochloride, was infused into the spermatic cord of each buck, followed by bilateral intra-testicular injections of 30% calcium chloride (CaCl2), 25% sodium chloride (NaCl), 50% citric acid (C6H8O7) solutions, and sterile deionized water dosed at 2 ml per testis in groups A, B, C and D respectively. To evaluate the efficacy of chemical agents on the inactivation of testes, clinical parameters, changes in scrotal circumference, testicular fine needle aspiration (TFNA), histopathology and serum concentration of testosterone and LH were monitored. A significant decrease in the scrotal circumference was observed between the intra-testicular injection and day 14 in all the bucks. Absence of spermatogenic cells and spermatozoa in the testicular biopsy was observed on day 14 post injection in the bucks, except for one in group C. Histopathology revealed massive destruction of seminiferous tubules and disorganization of the testicular parenchyma. Serum testosterone concentration declined significantly on day 14 compared with day 0. Consequently, the gradual elevation in serum LH concentration was significant. Thus, intra-testicular injections of CaCl2 and NaCl were more effective than C6H8O7 in inducing chemical-based nonsurgical castration.
Effects of olive cake meal on serum constituents and fatty acid levels in breast muscle of Japanese quail
Authors: Ozcan C. , Cimrin T. , Yakar Y. , Alasahan S.
Published: April 2021

This study was aimed at determining the effects of various levels of dietary olive cake meal (OCM) on certain blood parameters and breast muscle fatty acid and cholesterol levels. For this purpose, 400 day-old Japanese quail (Coturnix coturnix japonica) chicks of both sexes were randomly assigned to four trial groups, each including five replicates of 20 animals. The quail were fed on a maize and soybean meal-based basal diet supplemented with 0%, 2.5%, 5% and 7.5% of OCM for six weeks. Dietary supplementation with 5% and 7.5% of OCM decreased total cholesterol and low-density lipoprotein cholesterol levels in the blood serum, and increased cholesterol levels in the breast muscle. Dietary supplementation with various levels of OCM decreased saturated fatty acid and polyunsaturated fatty acid levels, and increased monounsaturated fatty acid and total unsaturated fatty acid levels in the breast muscle. As a result, it was concluded that, olive cake meal, which contains a high level of olive oil, could be incorporated in poultry feed at a level of 5%, owing to its beneficial effects of decreasing serum LDL cholesterol, which plays a major role in the aetiology of cardiovascular diseases, and in reducing saturated fatty acid levels in breast muscle.
Effects of a starch binding agent on in vitro rumen degradability of maize and sorghum starch
Authors: Shipandeni M.N.T. , Cruywagen C.W. , Raffrenato E.
Published: April 2021

The objective of the study was to quantify the potential of a starch binding agent (BioProtectTM) to reduce in vitro rumen starch degradation of maize and sorghum particles that varied in size. Maize and sorghum grain samples were ground through 2-mm sieves with a Wiley mill and subsequently sieved to obtain these sizes: less than 250, 250 - 500, 500 - 1180, and 1180 - 2000 μm (i.e., very fine to coarse). All fractions were analysed separately for starch content. Samples were treated 24 hours before fermentation by spraying BioProtect onto the substrate. Both treated and untreated samples were fermented in vitro for 0, 6, 12 and 24 hours to quantify starch degradability. Rates of degradability (kd) were calculated with a first-order decay model. BioProtect was effective in decreasing starch degradability and rates of degradability for both grains (P <0.0001). The product was more effective with smaller particle size, by reducing starch degradability 17% for the smallest particles as opposed to 7% for the largest particles. A time interaction was observed (P <0.0001), which showed that the highest impact of BioProtect occurred after 12 hours of fermentation for both grains. The starch binding agent resulted in an effective decrease of in vitro starch degradation, but results were affected by particle size and fermentation time. Starch digestion could possibly be shifted to the small intestine with BioProtect.