• Korean Journal of Organic Agriculture
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• v.29 no.1
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• pp.137-148
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• 2021

The present study investigated the effect of average daily gain (ADG) on carcass traits of Hanwoo steers. A total of 233 heads of Hanwoo steer slaughtered from 2017 to 2020 were employed in the analysis. Their body weight profiles during feedlot and carcass traits were used. The entire feedlot period is split into two periods. ADG during the first period (ADG1) was then defined as an independent variable in statistical analysis. In the meantime, it was examined that how the cutoff month for the period split altered the significance of the effect of ADG1 on carcass traits. Subsequently, steers were assigned to two groups (High vs. Low) based on the median of total ADG1, and we compared the carcass traits of each group using a linear mixed model. ADG1 during 10 to 23 months showed a significant effect on all carcass traits except the marbling score. ADG1 significantly influenced carcass weight and eye muscle area of Hanwoo steers. And it was found that greater ADG1 could get greater carcass weight and eye muscle area (p<0.001). The result of this study provides preliminary information for the target month in the calculation of ADG1 mostly influencing carcass performance, and feeding strategy of Hanwoo steer in terms of sustainability.

• Korean Journal of Agricultural Science
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• v.46 no.3
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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.

• Korean Journal of Agricultural Science
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• v.43 no.4
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• pp.603-611
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• 2016

The aim of this study was to analyze the contribution factors (backfat thickness, eye muscle area, carcass weight, marbling score, and feeding period) affecting meat unit price (South-Korean Won / Kg of meat). The best slaughtering age to maximize unit price was also assumed. All data used in this study were acquired from the Korea Institute for Animal Products Quality Evaluation from 2010 to 2014. Contributions to the estimated unit price of cows by the following factors, backfat thickness, eye muscle area, carcass weights, feeding period, and marbling score were 2.65%, 0.04%, 1.58%, 1.58%, and 95.72%, respectively. Contribution to estimated unit price of steers by the same factors (backfat thickness, eye muscle area, carcass weights, feeding period, and marbling score) were 7.88%, 1.24%, 0.07%, 90.81%, and 95.72%, respectively. Slaughtering ages ranged from 26 to 36 months and the data were separated into each month for an 11 month period. The unit price of meat from Hanwoo slaughtered at 30 months was highest among groups. The lowest unit price was observed in the group belonging to the Hanwoo slaughtered at 36 months. In conclusion, of all contributing factors, marbling score affected unit price the most. Based on our results, it is recommended that the optimal slaughtering age be set at 30 months to maximize unit price. Moreover, the feeding of beef cattle past 30 months of age is not recommended because of the increase in feeding costs.

• Food Science of Animal Resources
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• v.37 no.5
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• pp.716-725
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• 2017

The objective of this study was to determine the relationship between composition of muscle fiber types and meat quality traits of eight major muscles from Hanwoo steers. Longissimus lumborum (LL), psoas major (PM), semimembranosus (SM), semitendinosus (ST), gluteus medius (GM), triceps brachii (TB), rectus abdominis (RA) and superficialis flexor (SF) muscles were obtained from 9 Hanwoo steers and subjected to histochemical analysis. There were significant (p<0.05) differences in fiber number percentage (FNP) and fiber area percentage (FAP) of fiber types among these 8 major muscles. SF had the highest FNP of type I (55.9%), followed by PM (46.4%), TB (45.4%), RA (38.5%), LD (36.8%), GM (36.0%), SM (22.2%), and ST (18.8%). FAP of type IIB ranged from 9.9% in SF to 58.7% in ST. Meat quality traits, including fat content, myoglobin content, collagen content, CIE $L^*$ and $a^*$, drip and cooking loss, sarcomere length and Warner-Bratzler shear force, were all significantly (p<0.05) different among these muscles. Due to such diversities among these 8 muscles, lack of correlations were found between fiber type composition and meat quality traits. These results suggest that correlation for each individual muscle should be used to improve meat quality and profitability of retail beef cuts.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.8
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• pp.1074-1080
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• 2017

Objective: The growth, carcass and retail cut yield records on 1,428 Hanwoo steers obtained through progeny testing were analyzed in this study, and their heritability and genetic relationships among the traits were estimated using animal models. Methods: Two different models were compared in this study. Each model was fitted for different fixed class effects, date of slaughter for carcass traits and batch of progeny test live measurement traits, and a choice of covariates (carcass weight in Model 1 or backfat thickness in Model 2) for carcass traits. Results: The differences in body composition among individuals were deemed being unaffected by their age at slaughter, except for carcass weight and backfat thickness. Heritability estimates of body size measurements were 0.21 to 0.36. Heritability estimates of retail cut percentage were high (0.56 from Model 1 and 0.47 from Model 2). And the heritability estimates for loin muscle percentage were 0.36 from Model 1 and 0.42 from Model 2, which were high enough to consider direct selection on carcass cutability traits as effective. The genetic correlations between body size measurements and retail cut ratio (RCR) were close to zero. But, some negative genetic correlations were found with chest girths measured at yearling (Model 1) or at 24 months of age or with chest widths. Loin muscle ratio (LMR) was genetically negatively correlated with body weights or body size measurements, in general in Model 1. These relationships were low close to zero but positive in Model 2. Phenotypic correlation between cutability traits (RCR, LMR) and live body size measurements were moderate and negative in Model 1 while those in Model 2 were all close to zero. Conclusion: Therefore, the body weights or linear body measurements at an earlier age may not be the most desirable selection traits for exploitation of correlated responses to improve loin muscle or lean meat yield.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.1
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• pp.19-29
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• 2013

Marbling (intramuscular fat) is an important trait that affects meat quality and is a casual factor determining the price of beef in the Korean beef market. It is a complex trait and has many biological pathways related to muscle and fat. There is a need to identify functional modules or genes related to marbling traits and investigate their relationships through a weighted gene co-expression network analysis based on the system level. Therefore, we investigated the co-expression relationships of genes related to the 'marbling score' trait and systemically analyzed the network topology in Hanwoo (Korean cattle). As a result, we determined 3 modules (gene groups) that showed statistically significant results for marbling score. In particular, one module (denoted as red) has a statistically significant result for marbling score (p = 0.008) and intramuscular fat (p = 0.02) and water capacity (p = 0.006). From functional enrichment and relationship analysis of the red module, the pathway hub genes (IL6, CHRNE, RB1, INHBA and NPPA) have a direct interaction relationship and share the biological functions related to fat or muscle, such as adipogenesis or muscle growth. This is the first gene network study with m.logissimus in Hanwoo to observe co-expression patterns in divergent marbling phenotypes. It may provide insights into the functional mechanisms of the marbling trait.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.11
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• pp.1592-1598
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• 2015

This study was conducted to determine the effects of feeding a trace minerals-fortified microbial culture (TMC) on the performance and carcass characteristics of late-fattening Hanwoo steers. A mixture of microbes (0.6% [v/w] of Enterobacter sp., Bacillus sp., Lactobacillus sp., and Saccharomyces sp.) was cultured with 99% feedstuff for ensiling and 0.4% trace minerals (zinc, selenium, copper, and cobalt). Sixteen late-fattening steers (mean age, 21.8 months) were allocated to two diets: a control diet (concentrate mix and rice straw) and a treated diet (control diet+3.3% TMC). At a mean age of 31.1 months, all the steers were slaughtered. The addition of TMC to the diet did not affect the average daily weight gain of the late fattening steers, compared with that of control steers. Moreover, consuming the TMC-supplemented diet did not affect cold carcass weight, yield traits such as back fat thickness, longissimus muscle area, yield index or yield grade, or quality traits such as meat color, fat color, texture, maturity, marbling score, or quality grade. However, consumption of a TMC-supplemented diet increased the concentrations of zinc, selenium, and sulfur (p<0.05) in the longissimus muscle. With respect to amino acids, animals consuming TMC showed increased (p<0.05) concentrations of lysine, leucine, and valine among essential amino acids and a decreased (p<0.05) concentration of proline among non-essential amino acids. In conclusion, the consumption of a TMC-supplemented diet during the late-fattening period elevated the concentrations of certain trace minerals and essential amino acids in the longissimus muscle, without any deleterious effects on performance and other carcass characteristics of Hanwoo steers.

• Journal of Life Science
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• v.27 no.7
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• pp.760-766
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• 2017

Genotypes of the nucleotide substitution g.23655332G>C of SNP marker rs385360448 at Lysophospholipase I (LYPLA1) gene intron 7, were tested for their effect on the carcass traits of Hanwoo and Jeju Crossbred cattle ($F_1$ progeny produced between Hanwoo ${\times}$ Jeju Black cattle) populations on Jeju Island. In the Hanwoo steer population, the meats containing LYPLA1 rs385360448 G/- genotypes showed significantly higher marbling scores and greater texture indices, compared to those of rs385360448 C/C homozygous animals (p<0.05). However, the LYPLA1 genotypes were not associated with the levels of carcass weight, backfat thickness, eye muscle area (EMA), meat color, and fat color (p>0.05). On the other hand, in the JCC steer population, the LYPLA1 G/- harboring meats showed significantly greater EMA levels, compared to those of C/C homozygotes (p<0.05). The results of the present study indicate that the LYPLA1 genotypes could alter the levels of intramuscular fat deposition, texture index, and eye muscle area via phospholipid metabolism in the Longissimus dorsi muscle of the cattle. These findings suggested that LYPLA1 genotypes may effect molecular genetic markers in the improvement of carcass traits of Hanwoo and Jeju Black industrial cattle populations on Jeju Island.

• Animal Bioscience
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• v.35 no.10
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• pp.1545-1555
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• 2022

Objective: Our study aimed to investigate the effects of a 2% increase in dietary total digestible nutrients (TDN) value during the growing (7 to 12 mo of age) and fattening (13 to 30 mo of age) period of Hanwoo steers. Methods: Two hundred and twenty Hanwoo steers were assigned to one of two treatments: i) a control group (basal TDN, BTDN, n = 111 steers, growing = 70.5%, early fattening = 71.0%, late fattening = 74.0%) or high TDN (HTDN, n = 109 steers, growing = 72.6%, early = 73.1%, late = 76.2%). Growth performance, carcass traits, blood parameters, and gene expression of longissimus dorsi (LD) (7, 18, and 30 mo) were quantified. Results: Steers on the BTDN diets had increased (p≤0.02) DMI throughout the feeding trial compared to HTDN, but gain did not differ appreciably. A greater proportion of cattle in HTDN received Korean quality grade 1 (82%) or greater compared to BTDN (77%), while HTDN had a greater yield grade (29%) than BTDN (20%). Redness (a^*) of LD muscle was improved (p = 0.021) in steers fed HTDN. Feeding the HTDN diet did not alter blood parameters. Steers fed HTDN diet increased (p = 0.015) the proportion of stearic acid and tended to alter linoleic acid. Overall, saturated, unsaturated, monounsaturated, and polyunsaturated fatty acids of LD muscle were not impacted by the HTDN treatment. A treatment by age interaction was noted for mRNA expression of myosin heavy chain (MHC) IIA, IIX, and stearoyl CoA desaturase (SCD) (p≤0.026). No treatment effect was detected on gene expression from LD muscle biopsies at 7, 18, and 30 mo of age; however, an age effect was detected for all variables measured (p≤0.001). Conclusion: Our results indicated that feeding HTDN diet could improve overall quality grade while minimum effects were noted in gene expression, blood parameters, and growing performance. Cattle performance prediction in the feedlot is a critical decision-making tool for optimal planning of cattle fattening and these data provide both benchmark physiological parameters and growth performance measures for Hanwoo cattle feeding enterprises.

• Journal of Animal Reproduction and Biotechnology
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• v.39 no.2
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• pp.114-120
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• 2024

Background: The Hanwoo industry must develop technologies that can increase the production of preferred cuts to match changing consumer trends. In this study, we aimed to estimate the genetic parameters for carcass traits (carcass weight, eye muscle area, back fat thickness, and intramuscular fat) and primal cut traits (tenderloin, loin, strip loin, neck, clod, top round, bottom round, brisket, shank, and rib) in a Hanwoo population to obtain basic data for improving primal cut productivity. Methods: Data from 1,905 Hanwoo steers, including carcass traits and primal cut weights, were collected. Genetic parameters were estimated using REMLF90 in a multi-trait analysis. Results: High heritability was found for carcass weight (0.52) and strip loin yield (0.63). Genetic correlations between carcass weight and primal cut weights ranged from 0.52 to 0.93. Conclusions: This study demonstrates the significant potential for genetic improvement in Hanwoo cattle through selective breeding, particularly for traits with high heritability and genetic correlations. These findings provide crucial insights into optimizing breeding programs to improve Hanwoo cattle production efficiency.