Rib Location Research Articles

Factors affecting the numerical response and fracture location of the GHBMC M50 rib in dynamic anterior-posterior loading

Rib fractures are common traumatic injuries, with links to increased morbidity and mortality. Finite element ribs from human body models have struggled to predict the force-displacement response, force and displacement at fracture, and the fracture location for isolated rib tests. In the current study, the sensitivity of a human body model rib with updated anisotropic and asymmetric material models to changes in boundary conditions, material properties, and geometry was investigated systematically to quantify contributions to response. The updated material models using uncalibrated average material properties from literature improved the force-displacement response of the model, whereas the cross-sectional geometry was the only parameter to effect fracture location. The resulting uncalibrated model with improved material models and cross-sectional geometry closely predicted experimental average force-displacement response and fracture location.

Hydatid disease of the ribs: An exceptional location.

Hydatid disease is a zoonosis caused by larval stages of cestodes belonging to the genus Echinococcus. The rib location is exceptional. It presents a real diagnostic and therapeutic challenge. To describe the clinical, serological and radiological features and surgical management of rib hydatidosis. This is a retrospective study conducted over 4 years, on five cases of rib hydatidosis. We analysed the clinical and radiological presentations and the adopted therapeutic procedure. The average age of our patients was 44 years, without gender predominance. The clinical signs were dominated by the presence of an immobile swelling of fluid consistency without inflammatory sign, accompanied by moderate and intermittent localised pain. The laboratory assessment was nonspecific. The radiological assessment, including chest X-ray and thoracic computed tomography, with and without contrast, was essential in order to assess the extent of the lesion. Thoracic magnetic resonance imaging was requested in one case because of suspicions of a spinal extension. All of our patients underwent a rib excision accompanied by medical treatment of albendazole 24 hours after the surgery. The follow-up ranged from 1 year to 4 years and did not show any recurrence. Hydatidosis of the ribs is an exceptional location of hydatid disease. The diagnosis was based on radiology and intraoperative exploration. The treatment remained essentially surgical by rib excision with anthelmintic drugs to prevent recurrence.

The influence of the Gaussian curvature sign of the compound shell structure’s middle surface on local and overall buckling under combined loading

The buckling problem of an elastic compound shell structure with a variable Gaussian curvature of the middle surface, especially the middle surface meridian curvature sign, under the action of external pressure and axial loading is considered. In continuation of the previous research of the authors, this paper is devoted, in particular, to examining the influence of the negative Gaussian curvature sign of one of its compartments on stability. The solution is based on using the method of finite differences for basic stability equations of each compartment in the case when one of them can have a negative curvature of the meridian, taking into account the discreteness of the intermediate rib location and their rigidity from the initial curvature plane as well. The obtained solution allows visualizing the buckling modes under various combinations of external loading and identifying rational, according to overall buckling modes, geometric and rigidity parameters of the system being investigated.

Numerical studies on aerodynamic forces and flow control regimes of square cylinder with four surface ribs

Façade ribs attached to building surface are effective in mitigating wind-induced effects. In this paper, LES approach is adopted to explore the impact of four surface ribs on aerodynamic forces and flow structure around a square cylinder with width D. ANSYS Fluent is used to carry out the simulations at Re=2.2 × 104, the standard sub-grid scale (SGS) model is used. Simulation results indicate that small vortices formed near ribs can remarkably suppress flow separation, and reduce the shear layer's curvature and periodic flapping. Facade ribs accelerate the vortex shedding process, and clearly reduce the wake vortices’ intensity. The change of the flow field clearly mitigates surface pressure with increase in rib extension depth dr, resulting in a clear reduction in wind forces. When the depth dr is greater than 0.06D, the variation trends of drag coefficient C¯D and lift coefficient C’L are relatively complex with change of rib location br. This is due to the significant changes of flow patterns with different rib configurations. The maximum reduction rates of C¯D and C’L are 61% and 82%. It is found that extension of rib dr from around 0.08D to 0.1D with distance to the corner br from about 0.16D to 0.2D may show the best performance in reducing wind load.

Impact of Surface Roughness on Flow Physics and Entropy Generation in Jet Impingement Applications.

In this paper, a numerical investigation was performed of an air jet incident that normally occurs on a horizontal heated plane. Analysis of flow physics and entropy generation due to heat and friction is included using a simple easy-to-manufacture, surface roughening element: a circular rib concentric with the air jet. This study shows how varying the locations and dimensions of the rib can deliver a favorable trade-off between entropy generation and flow parameters, such as vortex generation and heat transfer. The performance of the roughness element was tested at three different radii; R/D = 1, 1.5 and 2, where D was the jet hydraulic diameter and R was the radial distance from the geometric center. At each location, the normalized rib height (e/D) was increased from 0.019 to 0.074 based on an increment of (e/D) = 0.019. The jet-to-target distance was H/D = 6 and the jet Reynolds number (Re) ranged from 10,000 to 50,000 Re, which was obtained from the jet hydraulic diameter (D), and the jet exit velocity (U). All results are presented in the form of entropy generation due to friction and heat exchange, as well as the total entropy generated. A detailed comparison of flow physics is presented for all ribs and compared with the baseline case of a smooth surface. The results show that at higher Reynolds numbers, adding a rib of a suitable height reduced the total entropy () by 31% compared to the no rib case. In addition, with ribs of heights 0.019, 0.037 and 0.054, respectively, the entropy generated by friction () was greater than that due to heat exchange () by about 42%, 26% and 4%, respectively. The rib of height e/D = 0.074 produced the minimum St at R/D = 1. As for varying R/D, varying rib location and Re values had a noticeable impact on , and (). Placing the rib at R/D = 1 gave the highest total entropy generation () followed by R/D = 1.5 for all Re. Finally, the Bejan number increased as both rib height and rib location increased.

Preoperative computed tomographic evaluation of neonatal foals with rib fractures.

To compare ultrasonographic and computed tomographic findings in neonatal foals prior to surgical repair of rib fractures as well as postoperative outcomes in foals with and without preoperative thoracic computed tomography (CT). Study design Retrospective cohort study. Sample population 43 neonatal foals undergoing surgical treatment of rib fractures between 2013 and 2021. Medical records were reviewed for age, sex, delivery method, comorbidities, presurgical anesthetic time, surgical time, number and location of fractured ribs identified with ultrasound and CT, number and location of ribs surgically repaired, survival to discharge, and post-mortem findings. Statistical analyses were performed using chi-square, Fisher's exact, and t-tests. Twenty-two foals underwent surgical repair of rib fractures after preoperative CT from 2019-2021 (median: 4/18/20) and 21 foals were anesthetized (20 underwent repair) for surgical repair of rib fractures without preoperative CT from 2013-2020 (median: 4/9/15). Ultrasound and CT findings differed in number and location of fractured ribs in 13/17 (76%) foals (p=.049). More cranially positioned ribs were identified as fractured with CT than with ultrasonography (p=.035). Survival to discharge was improved when foals underwent CT (20/22, 91%) than when they did not (12/20, 60%, p=.019). Ultrasound findings differed from CT findings in most foals. Foals evaluated with CT were more likely to survive to hospital discharge. When available, CT is recommended prior to surgical repair of rib fractures in neonatal foals.

Conjugate heat transfer investigation of impingement cooling for ribbed internal passage of a turbine vane

In this study, the effect of internal cooling configuration on overall cooling effectiveness of gas turbine vane is investigated using conjugate heat transfer approach. The C3X turbine vane with internal cooling and a turbine vane leading edge model with combined impingement and film cooling scheme are used as primary cases. An impingement cooling configuration is designed in order to enhance cooling effectiveness on the leading edge of the internally cooled C3X vane. In an attempt to further improvement, two rows of ribs are added on regions where impingement jets do not cover. In the leading edge model, the effect of modification for internal cooling channel and within film cooling holes are investigated by adding different rib configurations in those regions. The SST model is adopted for turbulence modeling in fluid zones. In the C3X vane, overall cooling effectiveness is generally enhanced using impingement cooling configuration. Furthermore, span wise distribution of overall cooling effectiveness becomes uniform in the leading edge of the vane. In the leading edge model, it is found that overall cooling effectiveness is varied due to the change in distribution of coolant flow in internal cooling channel and on external surface of the vane by adding ribs in internal cooling channel. The case with ribs perpendicular to the internal channel cross flow provides higher overall effectiveness. The results also indicate that cooling performance of the film cooled vane is sensitive to the location of ribs installed within film holes. The interaction between coolant flow and hot gas flow and its contribution in cooling performance of the vane are elaborately discussed for the leading edge model.

Microchannel flow and heat transfer enhancement via ribs arrangements

Enhanced heat transfer rates in microchannel flow remain challenging in terms of channel design, proper selection of carrier fluid, and setting the appropriate flow conditions. Introducing extended surfaces, such as ribs, in microchannel design, and the use of nanofluids enable to enhance the thermal performance of the flow system. In the present study, heat transfer characteristics in a microchannel flow incorporating the ribs arrangements on the channel wall are considered and the influence of the ribs location and carrier fluid on the thermal performance of the channel is examined. Temperature and velocity variations in the channel are predicted numerically and the findings of the Nusselt number are compared with that obtained from the experiments. The location of ribs along the channel wall is altered and the resulting variation of the Nusselt number and pressure drop along the microchannel is assessed. Al2O3 and TiO2 nanofluids are incorporated as a working fluid and water are also considered for the comparison. Temperature parameters are introduced to scale the rise of the maximum fluid temperature and temperature difference across the channel length. It is found that locating the ribs in the close region of the channel exit improves the Nusselt number by 25% and increases the pressure drop along the microchannel by 10% as compared to those corresponding to no-ribs arrangements. In addition, nanofluids improve the heat transfer rates and slightly alter the pressure drop across the microchannel.

Factors Affecting the Numerical Response and Fracture Location of the Ghbmc M50 Rib in Dynamic Anterior-Posterior Loading

Factors Affecting the Numerical Response and Fracture Location of the Ghbmc M50 Rib in Dynamic Anterior-Posterior Loading

Characteristic expression of CGRP and osteogenic and vasculogenic markers in the proximal and distal regions of the rib during male mouse development

BackgroundNeuropeptide calcitonin gene-related peptide (CGRP) is a neurotransmitter related to vasculogenesis and osteogenesis during bone formation and organ development. From the foetal period to the postnatal period, the thorax, which is necessary for lung respiration, forms. The thorax exhibits the same cartilage ossification as the bones of the extremities, but a specific system within the thorax exists as costal cartilage after birth. The relationship among CGRP, osteogenesis and vasculogenic markers in the two rib locations during thorax formation is not fully understood. Materials and methodsIn our study, male mice were used to provide ribs under different development conditions on various embryonic days (E12. 5, E14.5, and E17.5) and postnatal days (P1 and P5). The mRNA expression levels of CGRP, vascular endothelial growth factor (VEGF-A), type 1 collagen (Col1a-1), type 2 collagen (Col2a1), neuropeptide Y (NPY), osteocalcin (OCN) and osteopontin (OPN) were analysed by qRT-PCR. We also analysed the mRNA expression of CGRP, VEGF-A and OPN by in situ hybridization. Multivariate modelling with principal component analysis (PCA) was performed to estimate the interactions among the quantitative real-time RT-PCR data. ResultsThe mRNA expression levels of CGRP, VEGF-A, Col2a, Col1a-1, OCN, and NPY in the male mouse rib gradually increased during development. An antisense probe for CGRP mRNA was strongly detected in the central region of the mouse rib at E12.5 and the hypertrophic and ossification zones at E17.5 by in situ hybridization. VEGF-A was also located in the same region as CGRP at E12.5 and E17.5. OPN was strongly detected at the rib formation stage from E14.5 to E17.5. The expression of CGRP also differed between the proximal and distal regions of the rib at E17.5. As demonstrated by in situ hybridization, CGRP continuously participates in cartilage formation in the distal regions of the rib after birth. The PCA revealed that the mRNA expression of CGRP was related to that of Col1a-1 and VEGF-A during rib formation. ConclusionThis study shows that CGRP is involved in vascular and bone formation during rib development and may also be involved in cartilage formation after birth. The findings suggest that CGRP may temporarily participate in bone formation and continuously participate in cartilage formation in the rib, which may also be related to the formation of the anterior thoracic wall after birth

Оптимизация формы шпангоутов и углов укладки полимерного композиционного материала силового набора хвостовой части легкого самолета

The paper presents the methodology for designing the load bearing elements of tail section of a light aircraft through the sequential application of methods of parametric and topological optimization. First, we analyzed the loads acting on the aircraft at its maneuvering in the vertical and horizontal planes. Then, for these loads, by the parametric optimization method, we selected the locations of ribs of the tail section of the aircraft, which were subsequently used to develop individual forms of ribs based on the topology optimization method. Next, we carried out parametric optimization of layup angles of polymer composite material, intended for the production of ribs. Finally, we developed a structural layout for the load bearing elements of the fuselage, which meets the criteria of minimum weight when restrictions are imposed on the level of stresses in some layers of the composite material.

Analytical investigation of a new direct Column-to-Cased shaft connection

In regions of high seismicity, the large seismic design forces sustained by the superstructure must be transferred to the bridge foundations. In these situations, in particular in situations with weak soils, cased shafts, which are concrete filled steel tube (CSFT) components, are used for piles and drilled shafts. Prior research shows that these components have large flexural, axial and shear strengths. Typically, the forces are transferred from the column to the pile through a pile cap. However, direct connections are becoming more common, in particular because they have efficiency in terms of placement and can facilitate accelerated bridge construction. This research studies two different connections: (1) direct embedment of the column reinforcement into the pile and (2) an enhanced connection using a ring at the top of the tube in the pile to enhance mechancial bond and reduce embedment depth. The study was conducted using a high-resolution finite element analysis modeling approach validated using large-scale test results of reinforced concrete (RC) and CFST components and connections. The model included advanced constitutive modeling of the concrete as well as modeling of the bond between the steel tube and concrete fill and the reinforcing steel and the concrete fill. The transfer of forces from the yielding reinforcing bars in the RC pier to the concrete fill and tube of the pile is critical for this connection. Different approaches were investigated to achieve transfer without loss of strength or ductility. A supplemental rib inside the tube ultimately was used to enhance the load transfer with the minimum embedment length. The model was used to conduct a parametric study with the following study parameters: the rib location (lR), tube diameter (D), reinforcing bar diameter, and embedment depth (ld). The results were used to propose initial design recommendations.

Automatic recognition of tunnel lining elements from GPR images using deep convolutional networks with data augmentation

Tunnel lining inspection using ground penetrating radar (GPR) is a routine procedure to ensure construction quality. Yet, the interpretation of GPR data relies heavily on manual experience that may lead to low efficiency and recognition error when a large volume of data is involved. We introduced a deep learning-based automatic recognition method to identify tunnel lining elements, including steel ribs, voids, and initial linings from GPR images. Based on the mask region-based convolutional neural network (Mask R-CNN), this approach uses the 101-layer deep residual network (ResNet101) with the feature pyramid network (FPN) to extract features, the region proposal network (RPN) to generate candidate regions, a group of fully connected layers to detect the presence and locations of steel ribs and voids, and a fully convolutional network (FCN) to segment the area of the initial lining. To improve the recognition performance of the network, the finite-difference time-domain (FDTD) method and deep convolutional generative adversarial network (DCGAN) are employed to create synthetic GPR images for data augmentation. The test results on a synthetic example show that the mean absolute errors for steel rib, void, and initial lining thickness recognition are 1.2, 2.2, and 4.2mm, respectively, demonstrating the feasibility of the recognition network. In a field GPR survey experiment, the recognition accuracies achieved 96.02%, 91.17%, and 95.45% for the three targets. With the optimal proportions of synthetic images added to the training dataset, the accuracies were further improved to 98.86%, 94.53%, and 99.27%, respectively.

Layout Optimization of Stiffeners in Heavy-Duty Thin-Plate Box Grider

The optimization of layout and sizes of the stiffeners in heavy-duty box girder could make this kind of the structure more compact and reasonable, which has certain engineering values. In this study, on the basis of the establishment of parametric finite element model, the function approaching method and gradient search method are combined to form a high-precision optimization algorithm, which makes structural analysis be integrated into the optimization process. The optimization takes the type and location of longitudinal stiffening ribs and the thickness and hole position of transverse diaphragms as design variables, the box girder structural behaviors as constraint conditions, and the total volume as objective function. Finally, the weight is reduced by nearly 7%. More importantly, the new asymmetrical layout of the stiffeners is obtained, the distance between the longitudinal stiffening ribs on the main web and the neutral layer is longer than the distance between the longitudinal stiffening ribs on the secondary web and the neutral layer, and the hole position of transverse diaphragms is close to the secondary web. Compared with the current production of symmetrical layout structure, this layout provides a new idea for the design of stiffeners in the bias-rail box girder.

Differentiated Thyroid Carcinoma With Metastatic Presentation: 2 Clinical Cases

Introduction: Papillary thyroid carcinoma is the most common endocrine malignancy. Distant metastasis from differentiated thyroid carcinoma is infrequent, usually seen in lungs and bone. The incidence of bone metastasis is 1%-7% in papillary thyroid carcinoma. Hurtlhe cell carcinoma is a rare malignancy of the thyroid gland that can present with local or distant metastases. Main treatment for metastatic well-differentiated thyroid carcinoma includes radioactive iodine (131I) and surgical resection.Clinical case 1: In 2019, a 57 year-old woman, without significant prior medical history, with diffuse upper back and thoracic (10th -12th rib location) pain complaints, for over a year, is submitted to full body bone scintigraphy which reveals a lytic lesion located in the 10th left rib: histology is compatible with metastatic disease, from thyroid follicular carcinoma. Thoracic-abdominal-pelvic computed tomography (CT) has no sign of disease, but thyroid ultrasound shows a left located 24 mm nodule. The patient is submitted to total thyroidectomy and after histology revealed a papillary thyroid carcinoma (follicular variant), 131I treatment takes place (5550 MBq /150 mCi). Post–treatment131I scintigraphy presents with neck foci, in relation with thyroid residual tissue along with intense uptake in a massive lesion around the 10th left rib. Excision of this lesion is decided. The patient remains under clinical and imaging surveillance, being treated with levothyroxine 125 µg and without further complications, until today. Clinical case 2: In 2018, a 78 year-old woman, with prior medical history of hypertension and dyslipidemia, is sent to Neurology practice in the set of diplopia of recent onset. During the evaluation, a thoracic CT reveals a single 4 mm pulmonary lesion and a calcified infracentimetric thyroid nodule. The patient is submitted to bronchofibroscopy and immunohistochemistry of the collected tissue was compatible with metastasis of oncocytic thyroid carcinoma. Thyroid nodule citology is suggestive of Hurthle cell thyroid carcinoma. Total thyroidectomy with central neck lymphadenectomy takes place and histology confirms the diagnosis. After 131I treatment (5550 MBq/150 mCi), 131I scintigraphy reveals 131I uptake foci on the neck, in relation with thyroid residual tissue and a pulmonary uptake focus (known lesion). A second 131I treatment is performed and posterior scintigraphy shows improvement of metastatic disease. The patient remains under clinical and imaging surveillance, being treated with levothyroxine 100 µg and without further complications, until today.Conclusion: These cases reflect the importance of patient complaints in the differential diagnosis, especially osteoarticular complaints, showing that thyroid cancer can present itself already in the metastatic phase and the need to better treat our patients.

The effect of loading mode on isothermal local loading forming of magnesium alloy rib-web component

The lightweight of aerospace equipment has urgent demand for the large-scale reinforced wall structure with higher strength and toughness. In this research, the isothermal local loading forming (ILLF) process was proposed to decrease the extremely larger forming load and promote the material filling at rib locations. A typical rib-web component with two cross ribs was investigated and the experiment setup was designed to fabricate it under three loading modes (two new local loading modes and one conventional integral loading mode). The parallel finite element (FE) models were established and verified by comparing the experimental points and simulation curve. The material filling effect and forming load were compared under three loading mode, and the Lode parameter together with hydrostatic pressure was applied to analyze these differences during the deformation processes. Based on the principle of more uniform equivalent strain and larger filling rate, the best loading mode was determined and its corresponding process parameters were optimized.

The diagnostic performance of chest computed tomography in the detection of rib fractures in children investigated for suspected physical abuse: a systematic review and meta-analysis

ObjectivesTo assess the diagnostic performance of chest CT in the detection of rib fractures in children investigated for suspected physical abuse (SPA).MethodsMedline, Web of Science and Cochrane databases were searched from January 1980 to April 2020. The QUADAS-2 tool was used to assess the quality of the eligible English-only studies following which a formal narrative synthesis was constructed. Studies reporting true-positive, false-positive, true-negative, and false-negative results were included in the meta-analysis. Overall sensitivity and specificity of chest CT for rib fracture detection were calculated, irrespective of fracture location, and were pooled using a univariate random-effects meta-analysis. The diagnostic accuracy of specific locations along the rib arc (anterior, lateral or posterior) was assessed separately.ResultsOf 242 identified studies, 4 met the inclusion criteria. Of these, 2 were included in the meta-analysis. Chest CT identified 142 rib fractures compared to 79 detected by initial skeletal survey chest radiographs in live children with SPA. Post-mortem CT (PMCT) has low sensitivity (34%) but high specificity (99%) in the detection of rib fractures when compared to the autopsy reference standard. PMCT has low sensitivity (45%, 21% and 42%) but high specificity (99%, 97% and 99%) at anterior, lateral and posterior rib locations, respectively.ConclusionsChest CT detects more rib fractures than initial skeletal survey chest radiographs in live children with SPA. PMCT has low sensitivity but high specificity for detecting rib fractures in children investigated for SPA.Key Points• PMCT has low sensitivity (34%) but high specificity (99%) in the detection of rib fractures; extrapolation to CT in live children is difficult.• No studies have compared chest CT with the current accepted practice of initial and follow-up skeletal survey chest radiographs in the detection of rib fractures in live children investigated for SPA.

Numerical Investigation on Turbulence Statistics and Heat Transfer of a Circular Jet Impinging on a Roughened Flat Plate

Abstract A detailed heat transfer numerical study of a three-dimensional impinging jet on a roughened isothermal surface is presented and is investigated from flow physics vantage point under the influence of different parameters. The effects of the Reynolds number, roughness location, and roughness dimension on the flow physics and heat transfer parameters are studied. Additionally, the relations between average heat transfer coefficient (AHTC) and flow physics including pressure, wall shear and flow vortices with thermodynamic nonequilibrium are offered. This paper studies the effect of varying both location and dimension of the roughness element which took the shape of square cross-sectional continuous ribs to deliver a favorable trade-off between total pressure loss and heat transfer rate. The roughness element was tested for three different radial locations (R/D) = 1, 1.5, and 2 and at each location its height (i.e., width) (e) was changed from 0.25 to 1 mm in incremental steps of 0.25. The study used a jet angle (α) of 90 deg, jet-to-target distance (H/D = 6), and Re ranges from 10,000 to 50,000, where H is the vertical distance between the target plate and jet exit. The results show that the AHTC can be significantly affected by changing the geometry and dimensions of the roughness element. This variation can be either an augmentation of, or decrease in, the (HTC) when compared with the baseline case. An enhancement of 12.9% in the AHTC was achieved by using optimal location and dimensions of the roughness element at specific Reynolds number. However, a diminution between 10% and 30% in (AHTC) was attained by the use of rib height e = 1 mm at Re = 50k. The variation of both rib location and height showed better contribution in increasing heat transfer for low-range Reynolds numbers.

PSVII-18 Fatty acid composition of the longissimus muscle from Angus and Wagyu sired cattle at the 6th and 12th rib location

Abstract The fatty acid (FA) composition of the longissimus muscle (LM) of Angus and Wagyu sired cattle raised to a similar body weight (612 kg) were compared at the 6th and 12th rib locations. Angus sired steers represented T1, cattle from a Wagyu sire selected for growth represented T2, and cattle from a Wagyu sire selected for marbling represented T3. Data were analyzed mixed model with repeated measurements on animal (LM location); the model include the fixed effect of treatment, LM location, and their interaction, and random effect of sex. The percentage of 16:0, 18:1cis9, 18:3, and monounsaturated FA (MUFA) exhibited a treatment*LM location interaction (P ≤ 0.7), where T2 cattle had a greater percentage of 16:0 and a lesser percentage of 18:1cis9, 18:3, and MUFA at the 12th rib vs. 6th rib location compared with T1 and T3 cattle. The percentage of total FA lipid, polyunsaturated FA(PUFA), and PUFA:SFA ratio in the LM were greater (P ≤ 0.02) for T3 cattle compared with T1 and T2 cattle. The percentage of 18:0 was greater (P ≤ 0.01) for T1 cattle compared with T2 and T3 cattle, while T1 cattle had a greater (P ≤ 0.01) percentage of saturated FA (SFA) compared to T3 cattle. The percentage of 18:1cis9, other 18:1cis isomers, 18:2, MUFA, and MUFA:SFA ratio were greater (P ≤ 0.02) for T3 cattle compared with T1 cattle, with T2 cattle being intermediate. The percentage of total FA lipid, 18:0, 18:1 trans isomers, and SFA were greater (P ≤ 0.01) at the 6th rib LM location, while 14:1, 18:cis9, other 18:1 cis isomers, MUFA, MUFA:SFA, and PUFA:SFA ratio were greater (P ≤ 0.02) at the 12th rib LM location

PSVII-7 Fatty acid profile is not affected by feeding finishing cattle essential oils and/or benzoic acid

Abstract Fatty acid profile of beef subcutaneous fat was evaluated in two separate studies where blends of essential oils and/or benzoic acid were fed to finishing steers. Study 1 had sixty-eight finishing steers that were fed 1 of 5 finishing diets: no additional supplement, monensin/tylosin, essential oil blend #1 (Victus Liv, DSM Nutritional Products), benzoic acid (VevoVitall, DSM Nutritional Products), or a combination of essential oil blend #1 and benzoic acid. Study 2 had seventy-six finishing steers that were fed 1 of 7 finishing diets: no additional supplement, monensin/tylosin, essential oil blend #1, essential oil blend #2 (Fortissa Fit 45, Provimi Canada), benzoic acid, a combination of essential oil blend #1 and benzoic acid, or a combination of essential oil blend #2 and benzoic acid. All feed additives were supplemented according to manufacturer instructions, which were 33 mg/kg of monensin, 11 mg/kg of tylosin, 1 g/steer/day of essential oil blend #1, 4 g/steer/day of essential oil blend #2, and 0.5% inclusion level (on a DM basis) of benzoic acid. Fatty acid profile was determined on a 4 cm × 1 cm × 1 cm sample of subcutaneous fat from the 12th rib location of each steer. Fatty acid methyl esters were used to identify and quantify individual fatty acids using gas chromatography. Data were analyzed separately for the two studies, using a RCBD with fixed effect of treatment, and random effects of block (allocation weight of the steers) and the interaction of treatment and block. Total saturated fatty acids (SFA), total monounsaturated fatty acids (MUFA), total polyunsaturated fatty acids (PUFA), MUFA:SFA, PUFA:SFA, and n6:n3 were not different (P > 0.09) between treatments for either study. Overall, it was concluded that supplementation of essential oils and/or benzoic acid did not affect fatty acid profile of beef subcutaneous fat.