• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.287-291
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• 2010

The purpose of this study was to detect quantitative trait loci (QTL) for growth and carcass quality traits on BTA6 in a population of Hanwoo cattle. Three hundred and sixty one steers were produced from 39 sires that were sired by 17 grandsires in the two Hanwoo farming branches of the National Livestock Research Institute of Korea, between Spring 2000 and Fall 2002. DNA samples were collected for all of the steers, sires and grandsires, and the phenotypes for six growth and carcass quality traits were measured at 24 months of age. Twelve microsatellite markers were chosen on BTA6 and a linkage map was constructed by using seven of the twelve markers. Then, a chromosome-wide QTL scan was performed by applying an Animal Model, in which effects of QTL alleles within the grand sires were fitted as a random term. Three QTL were detected at the 5% chromosome-wise level for backfat thickness, average daily gain, and final weight. The most likely positions for the QTL were in the proximal region, i.e. 0 cM, 35 cM, and 63 cM, respectively. Also, another QTL for longissimus dorsi muscle area was detected at the 10% chromosome-wise level at 67 cM. These results were, in general, consistent with our previous report, in which candidate gene analyses showed that a SNP near ILSTS035 flanked by BM4621 (62.5 cM) and BMS2460 (81.3 cM) was associated with final weight, carcass weight, average daily gain, and longissimus dorsi muscle area in the same Hanwoo population.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.205-212
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• 1999

The present study was designed to examine the effects of selenium(Se), vitamin E(Vit. E) and recombinant Bovine Somatotropin(rBST) administration on the selenium and vitamin E concentrations of blood in Hanwoo sires Hanwoo sires were randomly assigned to five groups; 1. control, 2. rBST, 0.09mg/kg body weight (BW) 3. Vit E, 1,500IU/kg BW, 4. Se 0.lmg/kg BW, 5. Vit E, 1.500IU plus Se 0.1mg/kg BW. rBST, Vit. E and Se for each experimental group were given 6 times at 15 days interval by intramuscular injection. Blood samples were collected 10 times for experimental periods, separated the serum by centrifugation, and stored at －7$0^{\circ}C$. Se and Vito E concentrations in blood were measured by fluorophotometer and HPLC. Se concentrations of blood in control, rBST, Vito E, Se and Se plus Vito E groups were 64.55, 65.50, 68.15, 73.11 and 74.09 ppb/$m\ell$, respectively. Se concentration in Vit. E plus Se group was significantly higher than in control and rBST groups (P＜0.05), but Vito E group was not significantly different in control and rBST groups(P＞0.05). The Vit. E concentrations of blood in control, rBST, Vit. E, Se and Se plus Vit. E groups were 2.27, 2.32, 2.80, 2.58 and 2.75 ppm/$m\ell$, respectively. Vit. E and Vit. E plus Se groups were slightly higher than those of any other groups, but not significantly difference in 외 I experimental groups(P＜0.05). These results indicate that Se and Vit. E concentrations of blood were slightly increased with the injection of Se and Vit. E in Hanwoo sires.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.191-203
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• 1999

The objectives of this study were to investigate 1) the effects of Selenium(Se), Vitamin E (Vit. E) or recombinant Bovine Somatotropin(rBST) administration on fresh and frozen/thawed semen characteristics and 2) the effect of taurine on frozen/thawed semen characteristics in Hanwoo sires Hanwoo sires were randomly assigned to five groups (1. control, 2. rBST, 0.09mg/kg body weight (BW), 3. Vito E 1,500IU/kg BW, 4. Se 0.l mg/kg BW, 5. Vit. E 1,500IU plus Se 0.1 mg/kg BW). The administration of Se, Vit. E and rBST for each experimental group were given 6 times at 15 days interval by intramuscular injection. The administration of Se, Vit. E or rBST in Hanwoo sires didn't affect semen volume and pH values, but sperm viability was significantly increased comparing to the control group. Also, frozen/thawed semen analysis showed that the sperm viability increased, but any other effects were not found in total sperm :lumber, motility and abnormality among treatments. The addition of taurine in semen freezing extender had a beneficial effects on frozen/thawecl semen characteristics in all groups. The administrations of rBST, Vit. E and Se did not affect the sperm capacitation and acrosome reaction, either the ratio of F pattern(uncapacitated and acrosome intact sperm) or AR pattern(capacitated and acrosome-reacted sperm), but the ratio of B patten(capacitated and acrosome intact sperm) of treatment groups was significantly higher than that of control group, These results indicated that the viability, motility and quality of semen in Hanwoo sires were slightly increased by the injection of rBST, Vit. E and Se, and the addition of taurine in semen freezing extender were also increased the semen characteristics after thawing.

• Korean Journal of Animal Reproduction
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• v.24 no.2
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• pp.163-170
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• 2000

This study was conducted to examine the effects of recombinant Bovine Somatotropin (rBST), vitamin E(Vit. E) and selenium (Se) administration on the blood chemical values and hormone concentrations of serum in Hanwoo sires. Hanwoo sires were randomly assigned to five groups; 1) control, 2) rBST,0.09mg/kg body weight (BW), 3) Vit E, 1,500IU/kg BW, 4) Se 0.1mg/kg BW, 5) Vit E, 1,500IU plus Se 0.1mg/kg BW. rBST, Vit. E and Se for each experimental group were given 6 times at 15 days interval by intermuscular injection. Blood samples were collected ten times for experimental periods and separated the serum by centrifugation and stored into deep freezer. The concentration of albumin was the highest in Se group than those of any other groups (P＜0.05) and Vit. E plus Se group was significantly higher than in the control and rBST groups (P＜0.05). The concentrations of blood urea nitrogen (BUN) and creatinine were significantly higher in rBST group than any other groups (P＜0.05). The concentration of total protein in rBST, Se and Vit. E plus Se groups were significantly higher than in control group (P＜0.05). The concentrations of calcium, cholesterol,, glucose, inorganic phosphorus and triglycerides in serum were not difference in all experimental groups (P＞0.05). The concentration of estradiol was slightly higher in Se and Vit. E plus Se groups than those of any other groups, but not significantly difference among the experimental groups (P＜0.05). The concentration of testosterone was not affected by the administration of rBST, Vit. E and Se.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.363-372
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• 2023

The genetic diversity of three Hanwoo populations was analyzed using 11 microsatellite (MS) markers for the traceability of Hanwoo beef in this study. A total of 1,099 Hanwoo cattle from two populations (694 line-breeding and 405 general Hanwoo) at the Hanwoo Research Institute (HRI) of the National Institute of Animal Science and 1,171 Korean proven bulls (KPNs) were used for the analysis. Specific alleles of four markers (ETH10, INRA23, TGLA122, and TGLA227) were identified only in the line-breeding population, although at a low allele frequency (0.001 - 0.02). The genetic distance (Nei's D) between line-breeding Hanwoo and KPN was the greatest (0.064), whereas general Hanwoo and KPN were relatively close genetically (0.02); the distance between line-breeding and general Hanwoo was found to be 0.054. These results are expected because the HRI has performed closed breeding via selecting its line-breeding sires without utilizing KPN since 2009. Therefore, the line-breeding Hanwoo population of HRI show different genetic diversity from the KPN population, based on the 11 MS markers. The results of this study provide basic data for securing the genetic diversity of Hanwoo cattle and utilizing line-breeding Hanwoo cattle from the HRI.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.1
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• pp.17-21
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• 2012

The purpose of this study was to improve mapping power and resolution for the QTL influencing carcass quality in Hanwoo, which was previously detected on the bovine chromosome (BTA) 6. A sample of 427 steers were chosen, which were the progeny from 45 Korean proven sires in the Hanwoo Improvement Center, Seosan, Korea. The samples were genotyped with the set of 2,535 SNPs on BTA6 that were imbedded in the Illumina bovine 50 k chip. A linkage disequilibrium variance component mapping (LDVCM) method, which exploited both linkage between sires and their steers and population-wide linkage disequilibrium, was applied to detect QTL for four carcass quality traits. Fifteen QTL were detected at 0.1% comparison-wise level, for which five, three, five, and two QTL were associated with carcass weight (CWT), backfat thickness (BFT), longissimus dorsi muscle area (LMA), and marbling score (Marb), respectively. The number of QTL was greater compared with our previous results, in which twelve QTL for carcass quality were detected on the BTA6 in the same population by applying other linkage disequilibrium mapping approaches. One QTL for LMA was detected on the distal region (110,285,672 to 110,633,096 bp) with the most significant evidence for linkage (p< $10^{-5}$). Another QTL that was detected on the proximal region (33,596,515 to 33,897,434 bp) was pleiotrophic, i.e. influencing CWT, BFT, and LMA. Our results suggest that the LDVCM is a good alternative method for QTL fine-mapping in detection and characterization of QTL.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1057-1067
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• 2020

Objective: This study evaluated the effect of pedigree errors (PEs) on the accuracy of estimated breeding value (EBV) and genetic gain for carcass traits in Korean Hanwoo cattle. Methods: The raw data set was based on the pedigree records of Korean Hanwoo cattle. The animals' information was obtained using Hanwoo registration records from Korean animal improvement association database. The record comprised of 46,704 animals, where the number of the sires used was 1,298 and the dams were 38,366 animals. The traits considered were carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), and marbling score (MS). Errors were introduced in the pedigree dataset through randomly assigning sires to all progenies. The error rates substituted were 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, and 80%, respectively. A simulation was performed to produce a population of 1,650 animals from the pedigree data. A restricted maximum likelihood based animal model was applied to estimate the EBV, accuracy of the EBV, expected genetic gain, variance components, and heritability (h²) estimates for carcass traits. Correlation of the simulated data under PEs was also estimated using Pearson's method. Results: The results showed that the carcass traits per slaughter year were not consistent. The average CWT, EMA, BFT, and MS were 342.60 kg, 78.76 ㎠, 8.63 mm, and 3.31, respectively. When errors were introduced in the pedigree, the accuracy of EBV, genetic gain and h² of carcass traits was reduced in this study. In addition, the correlation of the simulation was slightly affected under PEs. Conclusion: This study reveals the effect of PEs on the accuracy of EBV and genetic parameters for carcass traits, which provides valuable information for further study in Korean Hanwoo cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1406-1410
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• 2014

Age at first calving is an important trait for achieving earlier reproductive performance. To detect quantitative trait loci (QTL) for reproductive traits, a genome wide association study was conducted on the 96 Hanwoo cows that were born between 2008 and 2010 from 13 sires in a local farm (Juk-Am Hanwoo farm, Suncheon, Korea) and genotyped with the Illumina 50K bovine single nucleotide polymorphism (SNP) chips. Phenotypes were regressed on additive and dominance effects for each SNP using a simple linear regression model after the effects of birth-year-month and polygenes were considered. A forward regression procedure was applied to determine the best set of SNPs for age at first calving. A total of 15 QTL were detected at the comparison-wise 0.001 level. Two QTL with strong statistical evidence were found at 128.9 Mb and 111.1 Mb on bovine chromosomes (BTA) 2 and 7, respectively, each of which accounted for 22% of the phenotypic variance. Also, five significant SNPs were detected on BTAs 10, 16, 20, 26, and 29. Multiple QTL were found on BTAs 1, 2, 7, and 14. The significant QTLs may be applied via marker assisted selection to increase rate of genetic gain for the trait, after validation tests in other Hanwoo cow populations.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.4
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• pp.457-462
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• 2011

The purpose of this study was to detect QTL for carcass quality on bovine chromosome (BTA) 6 using a high density SNP map in a Hanwoo population. The data set comprised 45 sires and their 427 Hanwoo steers that were born between spring of 2005 and fall of 2007. The steers that were used for progeny testing in the Hanwoo Improvement Center in Seosan, Korea, were genotyped with the 2,535SNPs on BTA6 that were embedded in the Illumina bovine SNP 50K chip. Four different linkage disequilibrium (LD) mapping models were applied to detect significant SNPs for carcass quality traits; the fixed model with a single marker, the random model with a single marker, the random model with haplotype effects using two adjacent markers, and the random model at hidden state. A total of twelve QTL were detected, for which four, one, three and four SNPs were detected on BTA6 under the respective models (p<0.001). Among the detected QTL, four, two, five and one QTL were associated with carcass weight, backfat thickness, longissimus dorsi muscle area, and marbling score, respectively (p<0.001). Our results suggest that the use of multiple LD mapping approaches may be beneficial in increasing power to detect QTL given a limited sample size and magnitude of QTL effect.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.293-301
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• 2019

This study was done to estimate the effect of progeny numbers and pedigree depth on the accuracy of the estimated breeding value (EBV) using best linear unbiased prediction (BLUP) method in Hanwoo. The experiment groups (sire = 100, 200, and 300; progeny = 4 and 8) were made by random sampling and by genetic evaluation of the following traits: Body weight (BW), carcass weight (CW), eye muscle area (EMA), back fat thickness (BFT) and marbling score (MS9). As a result of the genetic evaluation, the accuracy of the EBV was roughly 30 - 60% with 4 progenies, and the accuracy of the EBV increased by about 50 - 75% with 8 progenies. In the other words, when the number of progenies increased from 4 to 8, the accuracy of the EBV simultaneously increased by about 15 - 20%. Moreover, when the number of sires was higher, variations in the accuracy of the EBV within the groups for each trait decreased. Therefore, this result indicates that not only the number of progeny but also the number of sires can affect the accuracy of the EBV. Consequently, collecting information on the progeny and careful management of that information are very important things in the Hanwoo breeding system. Therefore, the EBV can show more precise results when conducting genetic evaluations.