• Animal Bioscience
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• v.37 no.4
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• pp.555-566
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• 2024

Objective: This study aimed to assess the genetic parameters and accuracy of genomic predictions for twenty-four linear body conformation traits and overall conformation scores in Korean Holstein dairy cows. Methods: A dataset of 2,206 Korean Holsteins was collected, and genotyping was performed using the Illumina Bovine 50K single nucleotide polymorphism (SNP) chip. The traits investigated included body traits (stature, height at front end, chest width, body depth, angularity, body condition score, and locomotion), rump traits (rump angle, rump width, and loin strength), feet and leg traits (rear leg set, rear leg rear view, foot angle, heel depth, and bone quality), udder traits (udder depth, udder texture, udder support, fore udder attachment, front teat placement, front teat length, rear udder height, rear udder width, and rear teat placement), and overall conformation score. Accuracy of genomic predictions was assessed using the single-trait animal model genomic best linear unbiased prediction method implemented in the ASReml-SA v4.2 software. Results: Heritability estimates ranged from 0.10 to 0.50 for body traits, 0.21 to 0.35 for rump traits, 0.13 to 0.29 for feet and leg traits, and 0.05 to 0.46 for udder traits. Rump traits exhibited the highest average heritability (0.29), while feet and leg traits had the lowest estimates (0.21). Accuracy of genomic predictions varied among the twenty-four linear body conformation traits, ranging from 0.26 to 0.49. The heritability and prediction accuracy of genomic estimated breeding value (GEBV) for the overall conformation score were 0.45 and 0.46, respectively. The GEBVs for body conformation traits in Korean Holstein cows had low accuracy, falling below the 50% threshold. Conclusion: The limited response to selection for body conformation traits in Korean Holsteins may be attributed to both the low heritability of these traits and the lower accuracy estimates for GEBVs. Further research is needed to enhance the accuracy of GEBVs and improve the selection response for these traits.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.3
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• pp.58-65
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• 2016

This study analyzed the structural weld strength for a door hinge for a field artillery ammunition support vehicle. In order to determine the optimal conditions, we measured the modal analysis and analyzed the leg length of a rear door hinge. From these methods, we acquired the vibration frequency of normal mode and the optimal welding leg length conditions. It was possible to obtain a structural stability for a rear door hinge of the field artillery ammunition support vehicle. In the future, this should be used as a reference source for the weld strength analysis of high vibration and high weight structures for another welding system design.

• Korean Journal of Applied Biomechanics
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• v.13 no.2
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• pp.161-173
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• 2003

This study was performed to investigate the kinematic and kinetic differences between functional walking shoe(FWS) and general sports shoe(GSS). The subjects for this study were 4 male adults who had the walking pattern of rearfoot strike with normal feet. The movement of one lower leg was measured using force platform and 3 video cameras while the subjects walked at the velocity of 2/1.5 m/s. The findings of this study were as follows 1. The angle of lower leg-ground and angle of knee with FWS was greater than with GSS at the moment of strike the floor and the moment of second peak ground reaction force. The decreasing rate of angle of ankle was smaller in FWS from the strike phase to the second peak ground reaction force. These mean upright walking and round walking along the shoe surface. 2. The maximal Increased angle of Achilles tendon and the minimal decreased angle of rearfoot were smaller in FWS very significantly(p<0.001). Thus FWS prevent the excessive pronation of ankle and have good of rear-foot control. 3. The vortical ground reaction force and the rate of it to the BW were smaller in FWS statistically(p<0.001). The loading rate was smaller in FWS, too, and thess represent the reduction of load on ankle joint and prevention of injuries on it.

• Journal of the Korean Society of Food Culture
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• v.36 no.1
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• pp.76-83
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• 2021

This study investigated the effect of the addition of various levels of pig head meat (HM) as a substitute for rear leg meat (RLM) on the physico-chemical quality characteristics of non-emulsified, smoked, and cooked sausage during refrigerated storage. Sausages were prepared in four variations according to the proportion (0%, 10%, 20%, or 30%) of HM added and maintained at 4℃. Quality measurements were taken for 28 days. The sausages added with the addition of 20% and 30% HM had significantly (p<0.05) higher moisture and lower protein content compared to those without the addition of HM. The pH value during the storage period was higher (p<0.05) in the sausages to which the HM had been added than in those without HM. The sausages with 30% HM showed the lowest (p<0.05) L⁎ and b⁎ values and the highest (p<0.05) a⁎ value during the storage period. The 2-thiobarbituric acid reactive substances (TBARS) content, hardness, cohesiveness, springiness, gumminess, and chewiness of the sausages showed no significant variations with the addition of various levels of HM. These data suggest that RLM could be substituted with 30% HM because it does not negatively affect the quality of the non-emulsified sausage. However, a further study on sausages made with 100% HM instead of RLM may be needed to improve its utilization.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1527-1530
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• 2002

Factor analysis was applied to the phenotypic correlation matrix of 15 linear type traits (scored linearly 1 to 50 points) for 2035 Holstein cows of 38 sires computed from data collected between 1988 and 1992 in Beijing Shuangqiao Farm and Beijing Xijiao Farm. The 15 linear type traits were stature, body strength, body depth, dairy form, rump angle, rump length, rump width, rear leg side view, foot angle, fore udder attachment, rear udder height, rear udder width, udder cleft, udder depth and teat placement rear view. The first four components accounted for 49.1% of the total variance in type scores. Factor 1 reflected strong cows, with deep bodies, with long and wide rumps, and tall in stature. Factor 2 reflected cows with well attached fore udders, wide rear udders and whose udders were supported by strong suspensory ligaments with close teat placement. Factor 3 reflected cows with good dairyness, sickled in the hocks, high rear udders and udder floors above the hocks. Factor 4 reflected cows with sloping rumps from hooks to pins and with steep foot angle. Principal component and factor analyses are useful to clarify the relationships among type traits.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.1-10
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• 2008

This study analyzed the rear foot angle of the supporting leg and the anatomical rotation angle of the kicking angle in soccer instep kick and drew conclusions as follows. When the supporting leg was landing on the ground, the valgus angle of the ankle joint reached the maximum peak, and plantar flexion was slightly different in the timing of the maximum peak between the two groups. The flexion angle of the rear foot was statistically significantly different between the two groups, and the movement of the crus on the landing of the supporting foot did not show a statistically significant difference between the groups. The crus leaned backward most before the impact, and the side to side gradient of the crus on impact was $22^{\circ}$. The flexion/extension of the hip joint of the kicking leg reached the maximum peak when the supporting foot was landing on the ground, and at the moment, the maximum extension angle of the hip joint was over $30^{\circ}$. The flexion angle of the knee joint of the kicking leg was largest after landing. While the maximum plantar flexion angle and maximum valgus angle of the ankle joint were not significantly different between the two groups, the maximum external rotation angle was significantly different.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.945-946
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• 2012

• Korean Journal of Applied Biomechanics
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• v.12 no.1
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• pp.115-124
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• 2002

The purpose of this study is to analyze the ground reaction force of arm landing on arm and leg during sports aerobics. Subjects of this study were total 10 players of 5 males and 5 females who have are domain sports aerobics medalists more than the third place in national tournaments. The subjects jumped between the two ground reaction force analyzers, while landing their right hand on the front platform(#1) and their right leg on the rear platform(#2), and the data frequency was set to 200Hz. Findings of this study are as follows; More than 3 times of impact peak force of vertical reaction force acted on arm joint than on leg joint. And, when ground reaction force on foot increased, ground reaction force on hand decreased. 3 impact peaks of curve of ground reaction force were found - Impact Peak 1 incurred on the time the palm lands on the ground, Impact Peak 2 absorbing shock secondarily on wrist joint, and Active Peak incurred on the time of holding the weight while pushing out the severly bent elbow joint.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.5
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• pp.617-623
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• 2008

A fine-mapping method exploiting linkage disequilibrium was used to detect quantitative trait loci (QTL) on the X chromosome affecting milk production, body conformation and productivity traits. The pedigree comprised 22 paternal half-sib families of Black-and-White Holstein bulls in the Netherlands in a grand-daughter design for a total of 955 sons. Twenty-five microsatellite markers were genotyped to construct a linkage map on the chromosome X spanning 170 Haldane cM with an average inter-marker distance of 7.1 cM. A covariance matrix including elements about identical-by-descent probabilities between haplotypes regarding QTL allele effects was incorporated into the animal model, and a restricted maximum-likelihood method was applied for the presence of QTL using the LDVCM program. Significance thresholds were obtained by permuting haplotypes to phenotypes and by using a false discovery rate procedure. Seven QTL responsible for conformation types (teat length, rump width, rear leg set, angularity and fore udder attachment), behavior (temperament) and a mixture of production and health (durable prestation) were detected at the suggestive level. Some QTL affecting teat length, rump width, durable prestation and rear leg set had small numbers of haplotype clusters, which may indicate good classification of alleles for causal genes or markers that are tightly associated with the causal mutation. However, higher maker density is required to better refine the QTL position and to better characterize functionally distinct haplotypes which will provide information to find causal genes for the traits.

• Food Science and Preservation
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• v.12 no.5
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• pp.507-510
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• 2005

This study was carried out to analyze the pork market of Mongolia and to find the continuous export possibility of Korean pork. The main results are as follows; First, pork consumption in Mongolia relies on import because pork production is not sufficient and pork price is high compared to beef or sheep meat. Second, Korean pork parts for export to Mongolia are pork fat and rear leg. Third, the authorities concerned have to keep a good relationship between Korean pork market and Mongolian pork market to export Korean pork to Mongolia when Korea pig farming is in depression.