• Asian-Australasian Journal of Animal Sciences
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• 제23권3호
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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.

• Asian-Australasian Journal of Animal Sciences
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• 제27권9호
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• pp.1250-1253
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• 2014

The objective of this study was to estimate the parameters of Gompertz growth curves with the measurements of body conformation, real-time ultrasound longissimus dorsi muscle area (LMA) and backfat thickness (BFT) in Hanwoo cows. The Hanwoo cows (n = 3,373) were born in 97 Hanwoo commercial farms in the 17 cities or counties of Gyeongbuk province, Korea, between 2000 and 2007. A total of 5,504 ultrasound measurements were collected for the cows at the age of 13 to 165 months in 2007 and 2008. Wither height (HW), rump height (HR), the horizontal distance between the top of the hips (WH), and girth of chest (GC) were also measured. Analysis of variance was conducted to investigate variables affecting LMA and BFT. The effect of farm nested in location was included in the statistical model, as well as the effects of HW, HR, WH, and GC as covariates. All of the effects were significant in the analysis of variance for LMA and BFT (p<0.01), except for the HR effect for LMA. The two ultrasound measures and the four body conformation traits were fitted to a Gompertz growth curve function to estimate parameters. Upper asymptotic weights were estimated as $54.0cm^2$, 7.67 mm, 125.6 cm, 126.4 cm, 29.3 cm, and 184.1 cm, for LMA, BFT, HW, HR, WH, and GC, respectively. Results of ultrasound measurements showed that Hanwoo cows had smaller LMA and greater BFT than other western cattle breeds, suggesting that care must be taken to select for thick BFT rather than an increase of only beef yield. More ultrasound records per cow are needed to get accurate estimates of growth curve, which, thus, helps producers select animals with high accuracy.

• Asian-Australasian Journal of Animal Sciences
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• 제26권5호
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• pp.723-731
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• 2013

This study provides a comparative analysis of the effects of pre-slaughter penetrative and non-penetrative stunning and post-slaughter stunning on meat quality attributes in longissimus lumborum (LL) and semitendinosus (ST) muscles in heifers. Ten animals were assigned to each of four treatment groups: i) animals were subjected to conventional Halal slaughter (a clean incision through the structures at the front of the upper neck - the trachea, oesophagus, carotid arteries and jugular veins) and post-cut penetrating mechanical stun within 10 to 20 s of the neck cut (Unstunned; US); ii) high power non-penetrating mechanical stunning followed by the neck cut (HPNP); iii) low power non-penetrating mechanical stunning followed by the neck cut (LPNP); and iv) penetrative stunning using a captive bolt pistol followed by the neck cut (P). For each carcass, muscle samples were removed within 45 min of slaughter, portioned and analysed for pH, cooking loss, water holding capacity (WHC), tenderness (WBS), lipid oxidation (TBARS) and color, over a two week storage period. Stunning did not affect pH and cooking loss. Significant differences in water holding capacity, tenderness, lipid oxidation and color were present at different storage time points. HPNP stunning resulted in lower WHC and color values, particularly lightness ($L^*$), higher TBARS values and peak force values compared with those stunned using LPNP, P and US. These adverse effects on quality were mostly encountered in the ST muscle. In conclusion, the meat quality achieved using P, LPNP and US treatments was comparable, and no treatment stood out as considerably better than another.

• Asian-Australasian Journal of Animal Sciences
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• 제17권1호
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• pp.7-12
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• 2004

Real time ultrasonic measurements for 13th rib fat thickness (LBF), longissimus muscle area (LEMA) and marbling score (LMS) of live animal at pre-harvest and subsequent carcass measurements for fat thickness (BF), longissimus muscle area (EMA), marbling score (MS) as well as body weight of live animal, carcass weight (CW), dressing percentage (DP), and total merit index (TMI) on 755 Korean beef steers were analyzed to estimate genetic parameters. Data were analyzed using multivariate animal models with an EM-REML algorithm. Models included fixed effects for year-season of birth, location of birth, test station, age of dam, linear and quadratic covariates for age or body weight at slaughter and random animal and residual effects. The heritability estimates for LEMA, LBF and LMS on RTU scans were 0.17, 0.41 and 0.55 in the age-adjusted model (Model 1) and 0.20, 0.52 and 0.55 in the weight-adjusted model (Model 2), respectively. The Heritability estimates for subsequent traits on carcass measures were 0.20, 0.38 and 0.54 in Model 1 and 0.23, 0.46 and 0.55 in Model 2, respectively. Genetic correlation estimate between LEMA and EMA was 0.81 and 0.79 in Model 1 and Model 2, respectively. Genetic correlation estimate between LBF and BF were high as 0.97 in Model 1 and 0.98 in Model 2. Real time ultrasonic marbling score were highly genetically correlated to carcass MS of 0.89 in Model 1 and 0.92 in Model 2. These results indicate that RTU scans would be alterative to carcass measurement for genetic evaluation of meat quality in a designed progeny-testing program in Korean beef cattle.

• Asian-Australasian Journal of Animal Sciences
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• 제26권10호
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• pp.1490-1495
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• 2013

Texture and 'tenderness' in particular, is an important sensory characteristic for consumers' satisfaction of beef. Objective and detailed sensory measurements of beef texture have been needed for the evaluation and management of beef quality. This study aimed to apply the sensory scales defined in ISO11036:1994 to evaluate the texture of beef. Longissimus and Semitendinosus muscles of three Holstein steers cooked to end-point temperatures of $60^{\circ}C$ and $72^{\circ}C$ were subjected to sensory analyses by a sensory panel with expertise regarding the ISO11036 scales. For the sensory analysis, standard scales of 'chewiness' (9-points) and 'hardness' (7-points) were presented to the sensory panel with reference materials defined in ISO11036. As a result, both 'chewiness' and 'hardness' assessed according to the ISO11036 scales increased by increasing the cooking end-point temperature, and were different between Longissimus and Semitendinosus muscles. The sensory results were in good agreement with instrumental texture measurements. However, both texture ratings in this study were in a narrower range than the full ISO scales. For beef texture, ISO11036 scales for 'chewiness' and 'hardness' are useful for basic studies, but some alterations are needed for practical evaluation of muscle foods.

• Asian-Australasian Journal of Animal Sciences
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• 제19권12호
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• pp.1691-1695
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• 2006

The identification method that inflects real time ultrasound (RUT) and the potential application of marker assisted selection (MAS) for improvement of a cow population of Hanwoo (Korean Native cattle) was studied. The averages of RUT longissimus muscle area, RUT fat thickness, and RUT marbling score scanned at the 13th rib were 55.78 $cm^2$, 3.70 mm and 3.83 scores, respectively. We investigated the effects of the two SNPs (Kpn2 I and Msp I) in the leptin gene on carcass traits for Hanwoo cows by using ultrasound measurements. Genotype CC of the Kpn2 I had a significantly higher effect on back fat thickness (4.23 mm) and longissimus muscle area (57.57 $cm^2$) than genotype TT (3.14 mm, 53.93 $cm^2$, respectively, p<0.05). Genotype AA of the Msp I had a significantly higher effect only on marbling score (5.37) than genotype AB (3.57, p<0.05) and BB (3.37, p<0.05). Significant effects of SNPs in the leptin gene were found for the ultrasound measures of body composition in live cattle.

• Communications for Statistical Applications and Methods
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• 제16권1호
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• pp.67-74
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• 2009

고품질 한우를 만들기 위해 여러 경제형질에 영향을 주는 유전자 즉 single nucleotide polymorphisms(SNPs)를 규명하려고 한다. 이미 Lee 등 (2008a)에 의해 SNP(19_1)$^*$SNP(28_2)가 등심단면적 (LMA: longissimus muscle dorsi area)에 주요한 유전자로 규명되었다. 여기에 추가로 도체중 (CWT: carcass cold weight)과 일당증체량 (ADG: average daily gain)을 선형 모형에 적용하였으며 또한 상호작용에 더 유리하고 연속형 데이터에도 사용할 수 있는 expanded multifactor dimensionality reduction (expanded MDR)을 이용하여 주요한 SNP를 파악하였다. Expanded MDR 적용결과 등심단면적과 같은 결과인 SNP(19_1)과 SNP(19_1)$^*$SNP(28_2)의 상호작용 형태가 가장 좋은 SNP로 선정되었으며, 최종적으로 SNP(19_1)*SNP(28_2) 마커가 한우의 여러 경제형질에 우수 유전자임을 규명하였다.

• 한국축산식품학회지
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• 제34권6호
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• pp.742-748
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• 2014

This study was conducted to evaluate the activities of antioxidant enzyme (glutathione peroxidase (GSH-Px)) and lysosomal enzymes (alpha-glucopyranosidase (AGP) and beta-N-acetyl-glucosaminidase (BNAG)) of the longissimus dorsi (LD) muscle from Hanwoo (Korean cattle) in three freezing conditions. Following freezing at -20, -60, and $-196^{\circ}C$ (liquid nitrogen), LD samples (48 h post-slaughter) were treated as follows: 1) freezing for 14 d, 2) 1 to 4 freeze-thaw cycles (2 d of freezing in each cycle), and 3) refrigeration ($4^{\circ}C$) for 7 d after 7 d of freezing. The control was the fresh (non-frozen) LD. Freezing treatment at all temperatures significantly (p<0.05) increased the activities of GSH-Px, AGP, and BNAG. The $-196^{\circ}C$ freezing had similar effects to the $-20^{\circ}C$ and $-60^{\circ}C$ freezing. Higher (p<0.05) enzymes activities were sustained in frozen LD even after 4 freeze-thaw cycles and even for 7 d of refrigeration after freezing. These findings suggest that freezing has remarkable effects on the activities of antioxidant enzyme and lysosomal enzymes of Hanwoo beef in any condition.

• 농업과학연구
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• 제46권3호
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• pp.671-682
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• 2019

This study was conducted to evaluate the effects of rumen-protected methionine and lysine (RPML) on the growth performance, carcass characteristics, and meat properties of Hanwoo steers. Fourteen late fattening steers were randomly assigned to either the control (commercial concentrate + rice straw) or the treatment (commercial concentrate + rice straw + 20 g of RPML/head/day) group. The average daily gain (ADG) and feed conversion ratio (FCR) were not different between the treatment and control group. The rib eye area was slightly but not significantly higher in the treatment group than in the control group. The back fat thickness decreased with the RPML supplementation, although not significantly, and the appearance of yield C grade was lower in the treatment group than in the control group. The marbling score was similar between the control and treatment groups. The supplementation of RPML had no effect on the physicochemical compositions, myoglobin values, Commission Internationale de $l^{\prime}{\acute{E}}clairage$ (CIE) color values, fatty acid composition, and thiobarbituric acid reactive substances (TBARS) values in the longissimus muscle. Thus, the supplementation of RPML does not any negative effects on the growth performance, carcass characteristics, and meat properties of late fattening Hanwoo steers.

• Asian-Australasian Journal of Animal Sciences
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• 제31권12호
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• pp.1923-1929
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• 2018

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 $185.6{\pm}24.38kg$) 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 $701.6{\pm}60.45kg$) 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 $(1-9)=-0.009{\times}retinol(IU/100mL)+9.125$ ($R^2=0.643$), Longissimus muscle area $(cm^2)=-0.250{\times}AST(U/L)+112.498$ ($R^2=0.450$). 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.