Comparative Analysis of Adaptation Behaviors of Different Types of Drivers to Steer-by-Wire Systems.

As one of the advanced automotive chassis technologies, the steer-by-wire system offers a high level of precision, responsiveness, and controllability in the driving experience. It can also adjust and optimize parameters to adapt to the preferences of different drivers. However, when faced with the steer-by-wire system, both experienced drivers and novice drivers are in the novice stage, exhibiting learning or adaptation behaviors when using this steering system. In this paper, a small-scale pilot evaluation was conducted by means of a questionnaire survey and driving-simulator experiment, and the learning behavior and adaptability of four experienced and four novice drivers to the steer-by-wire system were analyzed when using the traditional steering system. The study found that experienced drivers show significant changes in their adaptation to the steering system, mainly due to their habitual driving with traditional steering systems. In contrast, novice drivers show no significant changes in their adaptation to the steering system, which is attributed to their lack of driving experience and skills, resulting in less sensitivity to changes in the steering system. Additionally, the study found that novice drivers under the steer-by-wire system grasp control over speed and steering-wheel angle more quickly. This research provides a reference for improving drivers' learning and adaptation abilities to the steer-by-wire system and optimizing the design of the steer-by-wire system.

Combining Optimization and Simulation for Next-Generation Off-Road Vehicle E/E Architectural Design.

The automotive industry, with particular reference to the off-road sector, is facing several challenges, including the integration of Advanced Driver Assistance Systems (ADASs), the introduction of autonomous driving capabilities, and system-specific requirements that are different from the traditional car market. Current vehicular electrical-electronic (E/E) architectures are unable to support the amount of data for new vehicle functionalities, requiring the transition to zonal architectures, new communication standards, and the adoption of Drive-by-Wire technologies. In this work, we propose an automated methodology for next-generation off-road vehicle E/E architectural design. Starting from the regulatory requirements, we use a MILP-based optimizer to find candidate solutions, a discrete event simulator to validate their feasibility, and an ascent-based gradient method to reformulate the constraints for the optimizer in order to converge to the final architectural solution. We evaluate the results in terms of latency, jitter, and network load, as well as provide a Pareto analysis that includes power consumption, cost, and system weight.

Impact of replacing protein pellets with soybean grain on nutrient utilization and the rumen and blood parameters of feedlot cattle under tropical conditions.

The aim of this study was to explore the effect of replacing protein pellets with soybean grain in high-concentrate diets with or without the addition of silage, on the intake, digestibility, and rumen and blood parameters of feedlot cattle in tropical regions. Four cannulated, crossbred steers were used, 4.5 ± 0.5 years old, with an average weight of 685.55 ± 111.78 kg. The steers were distributed in a 4 × 4 Latin square, in a 2 × 2 factorial scheme (two sources of protein: protein pellets or whole soybean grain, with or without added dietary bulk). There was no effect (P ≥ 0.109) from the interaction between the source of protein and the addition of silage to the diet on dry matter (DM) and nutrient intake, or the digestibility (P ≥ 0.625) of DM or crude protein (CP). However, both factors affected (P ≤ 0.052) the intake of DM, neutral detergent fiber (NDF), and non-fiber carbohydrates (NFC), as well as the independent digestibility (P ≤ 0.099) of fat, NFC, total carbohydrates (TC), and total cholesterol concentration. There was an effect (P ≤ 0.053) from the interaction between the source of protein and the addition of silage to the diet on the digestibility of NDF and total digestible nutrients (TDN), as well as on the glycose concentration (P = 0.003). Blood parameters (i.e. protein, albumin, creatinine, triglycerides, aspartate aminotransferase (AST), and alanine aminotransferase (ALT)) were not affected (P ≥ 0.139) by the source of protein, the addition of silage, or their interaction. Lastly, including 150 g/kg silage DM in a high-grain diet, and using soybean grain as a source of protein in substitution of protein pellet could be a suitable nutritional strategy to ensure adequate DM and nutrient intake and digestibility, with no detrimental effects on rumen and blood parameters of feedlot cattle in the tropics.

Evaluation of pineapple stem starch as a substitute for corn grain or ground cassava in a cattle feedlot for 206 or 344 days: feedlot performance, carcass characteristics, meat quality, and economic evaluation.

The pineapple stem starch substituted for ground cassava or corn as a carbohydrate source in the concentrate diet. The experiment used 36 Holstein crossbred steers (aged 22 months) with an average initial body weight of 453.0 ± 35.3 kg. The experimental units were randomly assigned to three different starch sources of concentrate diets: ground corn (GC), ground cassava (CA), or pineapple stem starch (PS) with two different feeding periods: (1) period 1 for 206 days or (2) period 2 for 344 days with six replicates per treatment (two steers per replication), arranged in a completely randomized design. The animals were slaughtered at the end of the experimental periods. After that, the feedlot performance, carcass characteristics, meat quality, and economic return were evaluated. The results showed that the steers fed PS had a greater weight gain, average daily gain, and lower feed: gain ratio when fed for 206 days than when fed for 344 days, but dry matter intake, carcass characteristics, meat quality, and fatty acids profile did not differ between treatments in both periods of feeding except C14:1 and C18:0. The steers fed PS showed the greatest economic return. As a substitute for cassava or corn, pineapple stem starch had no negative impact on the feedlot performance, carcass characteristics, and meat quality. These results indicate that pineapple stem starch could be a useful feedstuff for the feedlot steers diets as an alternative starch source.

Effect of pelvic suspension and post-mortem ageing on the quality of three muscles from Holstein Friesian bulls and steers.

BACKGROUND: The use of bulls rather than steers from the dairy herd offers a more profitable and environmentally friendly option; however, the beef eating quality from bulls is an issue of concern. This study assessed the effect of two tenderization techniques - pelvic suspension and ageing - on three different muscles of Holstein Friesian males from two different production systems. RESULTS: The results indicate that a production system based on steers slaughtered at 24 months (S24) produced beef with better eating quality than from bulls slaughtered at 19 months (B19) when tenderization techniques were not applied. Instrumental texture of longissimus thoracis and gluteus medius muscles was improved with ageing and/or pelvic suspension, with both tenderization techniques exerting greater impact on B19 meat. No differences were found in semitendinosus muscle due to suspension method, whereas ageing for longer than 14 days decreased its instrumental tenderness. Sensory results indicate that, after 14 days of ageing, panellists still preferred meat from S24, and they could differentiate between pelvic and traditional suspension. CONCLUSION: Tenderization methodologies should be optimized for each production system and muscle; however, both panel and instrumental texture results indicate that eating quality of beef from either production systems is acceptable after 14 days of ageing, or even earlier if the suspension method is applied. © 2020 Society of Chemical Industry.

Drive-By-Wire Development Process Based on ROS for an Autonomous Electric Vehicle.

This paper presents the development process of a robust and ROS-based Drive-By-Wire system designed for an autonomous electric vehicle from scratch over an open source chassis. A revision of the vehicle characteristics and the different modules of our navigation architecture is carried out to put in context our Drive-by-Wire system. The system is composed of a Steer-By-Wire module and a Throttle-By-Wire module that allow driving the vehicle by using some commands of lineal speed and curvature, which are sent through a local network from the control unit of the vehicle. Additionally, a Manual/Automatic switching system has been implemented, which allows the driver to activate the autonomous driving and safely taking control of the vehicle at any time. Finally, some validation tests were performed for our Drive-By-Wire system, as a part of our whole autonomous navigation architecture, showing the good working of our proposal. The results prove that the Drive-By-Wire system has the behaviour and necessary requirements to automate an electric vehicle. In addition, after 812 h of testing, it was proven that it is a robust Drive-By-Wire system, with high reliability. The developed system is the basis for the validation and implementation of new autonomous navigation techniques developed within the group in a real vehicle.

Effects of concentrate levels and pineapple stem on growth performance, carcass and meat quality of dairy steers.

The objective of this study was to determine a suitable level of concentrate using pineapple stem by-product as a roughage source for the growth performance, carcass traits and meat quality of Holstein steer. Forty Holstein steers with an average initial body weight of 404.2 ± 38.2 kg (18 months of age) were used in a completely randomised design. The treatments consisted of four levels of restricted concentrate (4, 5, 6 and 7 kg/head/day as fed basis), and the animals were fed ad libitum pineapple stem by-product as a roughage source. The data were analysed by using orthogonal polynomial contrasts of trend response, represented by the linear and quadratic effects of the concentrate levels. Total dry matter intake (DMI) increased with increasing concentrate levels and was the highest in the dairy steer fed 6 kg/head/day (P < 0.05). Pineapple stem by-product intake was decreased by 5.51, 4.70, 4.04 and 2.59 kg DM/day with increasing concentrate levels, and the linear effect was significant (P < 0.01). Ruminal pH decreased with increasing concentrate levels (6.54, 6.46, 6.12 and 6.00), and the linear effect was significant (P < 0.01). The overall carcass characteristics were not affected by the treatments. The steers fed 4 kg/head/day of the concentrate presented the lowest feed cost per gain. These results indicated that pineapple stem by-product is suitable for use as a roughage source.

Nutritional value and in situ degradability of fruit-vegetable byproducts and their feeding effects on performance of growing Hanwoo steers.

OBJECTIVE: This study was conducted to evaluate nutritional value and in situ degradability of fruit-vegetable byproducts and their feeding effects on performance of growing Hanwoo steers. METHODS: Nutritional value and in situ degradability of cabbage, Chinese cabbage and fruit-vegetable byproducts were assessed. In vivo feeding trial was also performed for 12 weeks. Thirty-six growing steers were randomly allocated into three groups according to body weight (BW) and age in 12 pens (4 replications/treatment) and assigned to one of the three dietary treatments: control (byproduct 0%), FV-B (fruit-vegetable byproduct 20%), and CA-B (cabbage peel 15% plus Chinese cabbage peel 15%, total byproduct 30%). RESULTS: The crude protein contents of cabbage, Chinese cabbage and fruit-vegetable byproducts were 18.69%, 20.20%, and 10.07%, respectively. Concentrations of neutral detergent fiber (NDF) were higher in cabbage (22.31%) and Chinese cabbage (28.83%) than fruit-vegetable (13.94%). Higher concentrations of non-fiber carbohydrate were observed for fruit-vegetable (66.72%) than cabbage (44.93%) and Chinese cabbage byproducts (24.69%). The effective degradability (ED) of both dry matter (DM) and NDF for fruit-vegetable byproduct (DM, 84.69%; NDF, 85.62%) was higher (p<0.05) than cabbage (DM, 68.47%; NDF, 55.97%) and Chinese cabbage byproducts (DM, 68.09%; NDF, 54.22%). The DM intake was not different among treatments because the amount of feed was kept constant according to the BW of growing steers to prevent overweight during the growing period. The average daily gain during the whole experimental period was not different among treatments (1.26, 1.25, and 1.34 kg/d for control, FV-B, and CA-B). The ED of both DM and NDF degradability of the total mixed ration (TMR) diets were very similar among treatments. Feed conversion ratio during the whole period showed no significant difference among treatments. CONCLUSION: This study demonstrates that fruit-vegetable and cabbage byproducts up to 20% and 30% (as fed basis), respectively can be included in TMR diets for growing beef cattle.

Effects of vitamin and mineral premix withdrawal from diets on carcass and meat quality of feedlot steers.

The primary objective of the present study was to assess the effects of vitamin and mineral premix (VMP) withdrawal from the diets 30 and 60 days ahead of slaughter on carcass and meat quality of Holstein Friesian steers. A total of 45 animals at 16 to 17 months of age were used and the selected animals were divided into three experimental groups: control group (fed with a diet with VMP), VMP withdrawal 30 days ahead of slaughter (VMP30 group), and VMP withdrawal 60 days ahead of slaughter (VMP60 group). Meat samples were taken at 24 h postmortem from the 13th rib section and meat quality was evaluated on the Longissimus dorsi thoracis (LT) muscle. After slaughter, carcass yield and meat drip loss, cooking loss, thawing loss, and shear force traits were determined. Meat pH and color parameters were measured at 24, 48, 72, 96, 120, and 144 h of postmortem. The fatty acid composition in 13th rib section' adipose tissue was determined. The hot and cold carcass weights, carcass yield and chilling loss were not affected by the withdrawal of VMP from the diet. Withdrawal of VMP from the diets 30 and 60 days ahead of slaughter did not have any significant effects on ultimate pH, drip loss, cooking loss, thawing loss, shear force, and meat color. Additionally, dry matter, crude protein, ash, fat contents, moisture-protein ratio of the meat samples, and fatty acid profiles were not affected by VMP30 and VMP60 treatments. It was concluded based on present finding VMP could be withdrawn safely from the diets 30 and 60 days ahead of slaughter without any negative effects on carcass and meat quality traits of feedlot steers. Withdrawal of VMP may reduce feeding costs and environmental damages generated by animal breeding systems.

The co-injection of antioxidants with foot-and-mouth disease vaccination altered growth performance and blood parameters of finishing Holstein steers.

OBJECTIVE: This study was conducted to evaluate whether the co-injection of antioxidants together with foot-and-mouth disease (FMD) vaccination has the potential to attenuate the negative effects caused by vaccination in Holstein finishing steers. METHODS: A total of 36 finishing Holstein steers (body weight [BW]: 608±45.6 kg, 17 months old) were randomly allocated to one of three treatments: i) control (CON, only FMD vaccination without any co-injection), ii) co-injection of commercial non-steroidal anti-inflammatory drugs (NSAID) with FMD vaccination at a ratio of 10:1 (NSAID vol/FMD vaccine vol) as a positive control (PCON), iii) co-injection of commercial mixture of vitamin E and selenium with FMD vaccination (VITESEL) (1 mL of FMD vaccine+1 mL of antioxidants per 90 kg of BW). Changes in growth performance and blood parameters because of treatments were determined. RESULTS: No significant difference in BW, average daily gain, and dry matter intake of the steers was observed among the treatments. The FMD vaccination significantly increased white blood cells (WBC), neutrophils, platelets, and mean platelet volume (p<0.01) in blood analysis. The count of lymphocyte tended to increase after vaccination (p = 0.08). In blood analysis, steers in VITESEL tended to have higher numbers of WBC, neutrophils, and platelets compared to that of other treatments (p = 0.09, 0.06, and 0.09, respectively). Eosinophils in VITESEL were higher than those in PCON (p<0.01). Among blood metabolites, blood urea nitrogen and aspartate transaminase were significantly increased, but cholesterol, alanine transferase, inorganic phosphorus, Mg, and albumin were decreased after FMD vaccination (p<0.01). CONCLUSION: The use of antioxidants in FMD vaccination did not attenuate growth disturbance because of FMD vaccination. The metabolic changes induced by vaccination were not controlled by the administration of antioxidants. The protective function of antioxidants was effective mainly on the cell counts of leukocytes.

Steer-PROP: a GRASE-PROPELLER sequence with interecho steering gradient pulses.

PURPOSE: This study demonstrates a novel PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) pulse sequence, termed Steer-PROP, based on gradient and spin echo (GRASE), to reduce the imaging times and address phase errors inherent to GRASE. The study also illustrates the feasibility of using Steer-PROP as an alternative to single-shot echo planar imaging (SS-EPI) to produce distortion-free diffusion images in all imaging planes. METHODS: Steer-PROP uses a series of blip gradient pulses to produce N (N = 3-5) adjacent k-space blades in each repetition time, where N is the number of gradient echoes in a GRASE sequence. This sampling strategy enables a phase correction algorithm to systematically address the GRASE phase errors as well as the motion-induced phase inconsistency. Steer-PROP was evaluated on phantoms and healthy human subjects at both 1.5T and 3.0T for T2 - and diffusion-weighted imaging. RESULTS: Steer-PROP produced similar image quality as conventional PROPELLER based on fast spin echo (FSE), while taking only a fraction (e.g., 1/3) of the scan time. The robustness against motion in Steer-PROP was comparable to that of FSE-based PROPELLER. Using Steer-PROP, high quality and distortion-free diffusion images were obtained from human subjects in all imaging planes, demonstrating a considerable advantage over SS-EPI. CONCLUSION: The proposed Steer-PROP sequence can substantially reduce the scan times compared with FSE-based PROPELLER while achieving adequate image quality. The novel k-space sampling strategy in Steer-PROP not only enables an integrated phase correction method that addresses various sources of phase errors, but also minimizes the echo spacing compared with alternative sampling strategies. Steer-PROP can also be a viable alternative to SS-EPI to decrease image distortion in all imaging planes. Magn Reson Med 79:2533-2541, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Design and Characterisation of a Fast Steering Mirror Compensation System Based on Double Porro Prisms by a Screw-Ray Tracing Method.

This study proposes a novel FSM compensation system for four degrees of freedom (DOF) laser errors compensation, which has the advantage of shorter optical path length, fewer elements and an easier set-up process, meaning that it can be used at different locations. A commercial software, Zemax, is used to evaluate the function of the proposed FSM compensation system and the mathematical modelling of the proposed FSM compensation system is established by using a skew-ray tracing method. Finally, the proposed FSM compensation system is then verified experimentally using a laboratory-built prototype and the result shows that the proposed FSM compensation system achieves the ability to compensate the 4 DOF of the laser source.

Effects of dietary protein levels and 2-methylbutyrate on ruminal fermentation, nutrient degradability, bacterial populations and urinary purine derivatives in Simmental steers.

The objective of this study was to evaluate the effects of dietary crude protein (CP) levels and 2-methylbutyrate (MB) supplementation on ruminal fermentation, bacterial populations, microbial enzyme activity and urinary excretion of purine derivatives (PD) in Simmental steers. Eight ruminally cannulated Simmental steers, averaging 18 months of age and 465 ± 8.6 kg of body weight (BW), were used in a replicated 4 × 4 Latin square design by a 2 × 2 factorial arrangement. Low protein (98.5 g CP/kg dry matter [LP] or high protein (128.7 g CP/kg dry matter [HP]) diets were fed with MB supplementation (0 g [MB-] or 16.8 g steer-1  day-1 [MB+]). Steers were fed a total mixed ration with dietary corn straw to concentrate ratio of 50:50 (dry matter [DM] basis). The CP × MB interaction was observed for ruminal total VFA, molar proportions of acetate and propionate, acetate to propionate ratio, ammonia-N, effective degradability of neutral detergent fibre (NDF) and CP, microbial enzyme activity, bacterial populations and total PD excretion (p < .05). Ruminal pH decreased (p < .05), but ruminal total VFA concentration increased (p < .05) with increasing dietary CP level or MB supplementation. Acetate molar proportion increased (p = .043) with MB supplementation, but was not affected by dietary CP level. Propionate molar proportion decreased (p < .05) with increasing dietary CP level or MB supplementation. Consequently, acetate-to-propionate ratio increased (p = .001) with MB supplementation, but was not affected by dietary CP level. Ruminal ammonia-N content increased (p = .034) with increasing dietary CP level, but decreased (p = .012) with MB supplementation. The effective degradability of NDF and CP increased (p < .05) with increasing dietary CP level or MB supplementation. Microbial enzyme activity, bacterial populations and total PD excretion also increased (p < .05) with increasing dietary CP level or MB supplementation. The results indicated that ruminal fermentation, nutrient degradability, microbial enzyme activity, ruminal bacterial populations and microbial protein synthesis improved with increasing dietary CP level or MB supplementation in steers.

Effects of concentrate-to-forage ratios and 2-methylbutyrate supplementation on ruminal fermentation, bacteria abundance and urinary excretion of purine derivatives in Chinese Simmental steers.

This study evaluated the effects of dietary concentrate levels and 2-methylbutyrate (2MB) supplementation on performance, ruminal fermentation, bacteria abundance, microbial enzyme activity and urinary excretion of purine derivatives (PD) in steers. Eight ruminally cannulated Simmental steers (12 months of age; 389 ± 3.7 kg of body weight) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement. Moderate-concentrate (400 g/kg diet [MC]) or high-concentrate (600 g/kg diet [HC]) diets were fed with or without 2MB (0 g/day [2MB-] or 15.0 g/day [2MB+]). Dry matter intake and average daily gain increased, but feed conversion ratio decreased with the HC diet or 2MB supplementation. Ruminal pH decreased, but total volatile fatty acid increased with the HC diet or 2MB supplementation. Molar proportion of acetate and acetate-to-propionate ratio decreased with the HC diet, but increased with 2MB supplementation. Propionate molar proportion and ruminal NH3 -N content increased with the HC diet, but decreased with 2MB supplementation. Neutral detergent fibre degradability decreased with the HC diet, but increased with 2MB supplementation. Crude protein degradability increased with the HC diet or 2MB supplementation. Abundance of Ruminococcus albus, Ruminococcus flavefaciens, Fibrobacter succinogenes and Bufyrivibrio fibrisolvens as well as activities of carboxymethyl cellulase, cellobiase, xylanase and pectinase decreased with the HC diet, but increased with 2MB supplementation. However, abundance of Prevotella ruminicola and Ruminobacter amylophilus as well as activities of α-amylase and protease increased with the HC diet or 2MB supplementation. Total PD excretion also increased with the HC diet or 2MB supplementation. The results suggested that growth performance, ruminal fermentation, CP degradability and total PD excretion increased with increasing dietary concentrate level from 40% to 60% or 2MB supplementation. The observed diet × 2MB interaction indicated that supplementation of 2MB was more efficacious for improving growth performance, ruminal fermentation and total PD excretion with promoted ruminal bacteria abundance and enzyme activity in the MC diet than in the HC diet.

An assessment of nutrients and sedimentation in the St. Thomas East End Reserves, US Virgin Islands.

Nutrients and sedimentation were monitored for approximately 2 years at six sites in the St. Thomas East End Reserves (STEER), St. Thomas, USVI, as part of a NOAA project to develop an integrated environmental assessment. Concentrations of ammonium (NH4+) and dissolved inorganic nitrogen (DIN) were higher in Mangrove Lagoon and Benner Bay in the western portion of STEER than in the other sites further east (i.e., Cowpet Bay, Rotto Cay, St. James, and Little St. James). There was no correlation between rainfall and nutrient concentrations. Using a set of suggested nutrient thresholds that have been developed to indicate the potential for the overgrowth of algae on reefs, approximately 60% of the samples collected in STEER were above the threshold for orthophosphate (HPO4=), while 55% of samples were above the DIN threshold. Benner Bay had the highest sedimentation rate of any site monitored in STEER, including Mangrove Lagoon. There was also an east to west and a north to south gradient in sedimentation, indicative of higher sedimentation rates in the western, more populated areas surrounding STEER, and sites closer to the shore of the main island of St. Thomas. Although none of the sites had a mean or average sedimentation rate above a suggested sedimentation threshold, the mean sedimentation rate in Benner Bay was just below the threshold.

Investigation of blood biomarkers related to meat quality and quantity in Hanwoo steers.

OBJECTIVE: This study was conducted to investigate the correlation between blood components and carcass traits, and to find the biomarkers related to meat quality and quantity in Hanwoo steers. METHODS: One hundred twenty-six Hanwoo steers (8 to 9 months of age, body weight of 185.6±24.38 kg) were used to find the correlation between blood compositions and carcass traits. The steers were fed concentrate and rice straw (30 steers) or total mixed rations (96 steers) during the whole experimental period. Blood samples were collected from the jugular vein at the growing (8 to 12 months), fattening (13 to 23 months) and finishing phases (24 to 30 months). Steers were slaughtered at 30 to 31 months of age (body weight of 701.6±60.45 kg) and the carcass traits were evaluated. Blood metabolites and hormones were analyzed and the correlation coefficients and regression equations with carcass traits were determined. RESULTS: Average concentrations of retinol, leptin and insulin were 1.10 IU, 30.34 ng, and 35.35 ng per mL of blood plasma, respectively. Retinol has negative correlations (p<0.01) with insulin and leptin. Blood insulin and total protein decreased with the age of steers, but retinol, aspartic acid transaminase (AST), glucose, cholesterol and triglyceride increased. In the finishing phase, significant (p<0.01) negative correlations occurred between blood retinol content and marbling score, and between blood AST content and longissimus muscle area of 13th rib, and the following regression equations were obtained: Marbling score (1-9) = -0.009×retinol (IU/100 mL)+ 9.125 (R2 = 0.643), Longissimus muscle area (cm2) = -0.250× AST(U/L)+112.498 (R2 = 0.450). CONCLUSION: It is possible to make highly marbled beef by controlling the blood retinol content during the fattening and finishing phases of Hanwoo steers. Accordingly, blood retinol and AST could be biomarkers for determining beef quality and quantity, respectively, prior to slaughter.

Effect of corn grain particle size on ruminal fermentation and blood metabolites of Holstein steers fed total mixed ration.

OBJECTIVE: This study was conducted to investigate the effect of corn grain particle size on ruminant fermentation and blood metabolites in Holstein steers fed total mixed ration (TMR) as a basal diet to explain fundamental data of corn grain for cattle in Korea. METHODS: Four ruminally cannulated Holstein steers (body weight 592±29.9 kg) fed TMR as a basal diet were housed individually in an auto temperature and humidity modulated chamber (24°C and 60% for 22 h/d). Treatments in a 4×4 Latin square design were TMR only (control), TMR with whole corn grain (WC), coarsely ground corn grain (CC), and finely ground corn grain (FC), respectively. The corn feeds substituted for 20% energy intake of TMR intake. To measure the ruminal pH, ammonia N, and volatile fatty acids (VFA), ruminal digesta was sampled through ruminal cannula at 1 h intervals after the morning feeding to determine ruminal fermentation characteristics. Blood was sampled via the jugular vein after the ruminal digesta sampling. RESULTS: There was no difference in dry matter (DM) intake between different corn particle size because the DM intake was restricted to 1.66% of body weight. Different corn particle size did not change mean ammonia N and total VFA concentrations whereas lower (p<0.05) ruminal pH and a ratio of acetate to propionate, and higher (p<0.05) propionate concentration were noted when the steers consumed CC compared with WC and FC. Concentration of blood metabolites were not affected by different particle size of corn grain except for blood triglyceride concentration, which was significantly (p<0.05) increased by FC. CONCLUSION: Results indicate that feeding CC may increase feed digestion in the rumen, whereas the FC group seemed to obtain inadequate corn retention time for microbial degradation in the rumen.

The Lateral Tracking Control for the Intelligent Vehicle Based on Adaptive PID Neural Network.

The intelligent vehicle is a complicated nonlinear system, and the design of a path tracking controller is one of the key technologies in intelligent vehicle research. This paper mainly designs a lateral control dynamic model of the intelligent vehicle, which is used for lateral tracking control. Firstly, the vehicle dynamics model (i.e., transfer function) is established according to the vehicle parameters. Secondly, according to the vehicle steering control system and the CARMA (Controlled Auto-Regression and Moving-Average) model, a second-order control system model is built. Using forgetting factor recursive least square estimation (FFRLS), the system parameters are identified. Finally, a neural network PID (Proportion Integral Derivative) controller is established for lateral path tracking control based on the vehicle model and the steering system model. Experimental simulation results show that the proposed model and algorithm have the high real-time and robustness in path tracing control. This provides a certain theoretical basis for intelligent vehicle autonomous navigation tracking control, and lays the foundation for the vertical and lateral coupling control.

Effect of particle size and partial replacement of alfalfa hay by soya bean hulls on nutrient intake, total tract digestibility and rumen degradability of diets by Holstein steers.

This study examined the effect of alfalfa hay (AH) particle size and the replacement of soya bean hull (SH) for AH within the diet of restricted fed Holstein steers on dry matter intake (DMI), total tract digestion, ruminal digestion, ruminal pH and ammonia nitrogen content, and faecal pH. Four rumen-cannulated Holstein steers averaging 353 ± 9.6 kg of BW were assigned to a 4 × 4 Latin square experiment with four periods and a 2 × 2 factorial arrangement of treatments. Factor A was AH particle size (fine vs. coarse) and factor B was diet SH content (0% vs. 10%; substituted for AH). Steers were fed at 1% of body weight of TMR containing 400 g/kg forage and 600 g/kg concentrate. Chopping of AH to fine particles decreased (p = 0.01) amount of dietary materials retained on the medium sieve (8 mm). The inclusion of SH significantly increased (p = 0.01) materials retained on the 1.18-mm sieve and tended to decrease (p = 0.07) materials on 19-mm sieves. The inclusion of SH increased (p = 0.01) ether extract (EE) intake and increased (p = 0.07) DMI. Inclusion of SH increased (p = 0.01) EE digestion and decreased (p < 0.01) faecal pH. Neither AH particle size nor SH inclusion in diets affected (p > 0.10) the in situ ruminal degradability coefficients of DM ('a', 'b', 'c' or 'a+b'). No interaction of AH×SH was seen on nutrient intake, digestibility and in situ ruminal degradability of Holstein steers.

Effects of feeding system on growth performance, plasma biochemical components and hormones, and carcass characteristics in Hanwoo steers.

OBJECTIVE: This study was conducted to compare growth performance, blood components and carcass traits by two feeding systems (concentrate with roughage separately [CON] vs total mixed ration [TMR]) in Hanwoo steers, and to learn the relationship between blood components during fattening or finishing phases and carcass traits in Hanwoo steers. METHODS: Sixty steers aged 8 months were allotted to two feeding systems and fed similar amounts of average dry matter and total digestible nutrient throughout whole experimental period according to each feeding program. Steers were weighed monthly, taken blood at the end of growing, fattening and finishing periods, and slaughtered at 30 month of age. RESULTS: Growing performance was higher (p<0.05) in the CON group compared to the TMR group during fattening and finishing periods. The CON group was lower (p<0.05) in blood aspartic acid transaminase, blood urea nitrogen and retinol levels during growing period, but higher in triglyceride and cholesterol levels during fattening and finishing periods compared to the TMR group. The CON group was greater (p<0.05) in rib-eye area, and lighter (p<0.05) red in meat color compared to the TMR group. In the correlation coefficients between blood components of steers and carcass traits, retinol had a negative (p<0.05) correlation with marbling score and rib-eye area. Leptin had a positive (p<0.05) correlation with back fat thickness. Blood cholesterol and triglyceride were positively (p<0.05) correlated with carcass weight and rib-eye area. CONCLUSION: Growth performance, carcass ribeye area and meat color showed a more desirable result in the CON compared to the TMR in Hanwoo steers. Assessing the accumulated data of carcass traits with blood components including hormones-particularly retinol, cholesterol, triglyceride, and leptin-during the fattening or finishing phases, it may be possible to find a biomarker for determining beef quality in living animals.