• Korean Journal of Agricultural Science
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• v.42 no.1
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• pp.47-51
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• 2015

This study was conducted to make certain that the intramuscular fat score at 13th rib could represent the fat content of whole loin from Hanwoo in Korea beef grading system. A total 42 loins from 23 carcasses of grade $1^{{+}{+}}$, 16 carcasses of grade $1^+$, and 3 carcasses of grade 1 of Hanwoo were used for this study. The crude fat content and intramuscular fat score at the $1^{st}$, $6^{th}$, and $13^{th}$ rib, and the last lumbar position of loin were measured. The crude fat content was the highest at the $6^{th}$ rib of loin from the carcasses of grade $1^{{+}{+}}$ and $1^+$ (p<0.05). There were no significant difference of the intramuscular fat scores measured by image analysis and beef marbling score (BMS) between the 6th and $13^{th}$ rib of loin from the carcasses of $1^{{+}{+}}$ and $1^+$ and that were significantly higher than intramuscular fat scores at the $1^{st}$ rib and the last lumbar position of the loin. From the results, we conclude that the intramuscular fat score at the $13^{th}$ rib can represent the fat content of loin when meat graders decide the grade of Hanwoo carcass.

• Food Science of Animal Resources
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• v.39 no.2
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• pp.197-208
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• 2019

The aim of this study was to investigate the relation of sensory quality traits of cooked beef to fresh meat quality and histochemical characteristics, especially muscle bundle traits, in the longissimus thoracis muscle of Hanwoo steers. Cooking loss negatively correlated with softness, initial tenderness, chewiness, rate of breakdown (RB), and amount of perceptible residue (AR) after chewing (p<0.05), and drip loss showed negative correlation with RB and AR (p<0.05). All the attributes of tenderness exhibited negative correlation with the Warner-Bratzler shear force value (p<0.05). Marbling score and the intramuscular fat (IMF) content showed positive correlation with all the organoleptic characteristics, including tenderness attributes, juiciness, and flavor (p<0.05). Regarding histochemical characteristics, muscle fiber size did not have a significant correlation with all the sensory quality traits, although the area percentage of type I fiber was related with softness, initial tenderness, and chewiness (p<0.05). On the contrary, the characteristics of muscle bundle were related to all the sensory tenderness attributes (p<0.05), and the sensory tenderness increased with smaller muscle bundle size (p<0.05). These results suggest that the IMF content and bundle characteristics can be used as indicators for explaining the variations in sensory tenderness in well-marbled beef.

• 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.19 no.12
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• pp.1799-1808
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• 2006

This study was designed to explore the effects of marbling on meat quality characteristics and intramuscular connective tissue of beef longissimus muscle. Chemical determinations, histological and mechanical measurements were performed on the raw and cooked meat at d 4 postmortem. The results showed that crude fat, collagen, fiber diameter and maximum transition temperature of intramuscular connective tissue increased (p<0.05) with the increase of marbling score. The cooking losses, collagen solubility, WBSF and perimysial thickness decreased (p<0.05) with the increasing marbling. WBSF correlated (p<0.05) with moisture, crude fat, collagen, cooking losses, sarcomere length and perimysial thickness. The development of marbling results in the decline in cooking losses, the avoidance of sarcomere shortening, and the disorganization of the perimysia, which accounts for the improvement of beef tenderness.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.1003-1010
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• 2003

The effects of different rumen protected forms, oleamide, Ca oleate, of dietary oleic acid on the carcass quality and fatty acid composition in intramuscular and subcutaneous fat tissues of Hanwoo steer were examined. Sixty, 25 month old Hanwoo steers divided into three groups were fed no supplement (Control), 2% of oleamide (Oleamide) or Ca-oleate (Ca-Oleate) in their diet for 45 or 90 days. Disappearance rates of oleic acid supplements in digestive tracts (Rumen bypass, abomasal and intestinal disappearance rate) were 48.5, 68.4 for oleamide and Ca oleate, respectively. Both oleic acid supplements affected feed intake, growth rate, cold carcass weight and carcass fatness. Live weight gain, carcass weight, backfat thickness and marbling score were higher in the oleic acid supplemented steers compared with those from the control. Oleic acid supplements increased marbling score and ether extract in Hanwoo steer m. logissi thoracicmus. Rumen protected oleic acid increased not only the level of oleic acid but also polyunsaturated fatty acids in intramuscular and subcutaneous fat tissue. Total saturated fatty acid contents in both fat tissues were decreased whereas total unsaturated fatty acid content was increased compared with those from control. Linoleic acid, linolenic acid and polyunsaturated fatty acid contents were significantly higher in Ca oleate than any other steers. Lipid metabolites in blood were increased in rumen protected oleic acid treatments. HDL content in blood was increased in Ca-oleate supplemented steers whereas LDL was decreased compared with control. The changes of fatty acid compositions in the rumen protected oleic acid supplemented steers suggest that the oleic acid and unsaturated fatty acid were protected from rumen biohydrogenation and can be deposited in the fat tissues.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.3
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• pp.366-374
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• 2019

Objective: The purpose of this study was to determine the effects of feeding ethanol on growth performances, carcass characteristics, and lipid metabolism of finishing Korean cattle (Hanwoo) steers. Methods: Thirty (30) Hanwoo steers (average 25.1 months of age, body weight 660.1 kg) were assigned to three treatments: control (0% ethanol), E-3 (1.44% ethanol for 3 months), or E-5 (0.72% ethanol for 2 months followed by 1.44% ethanol for 3 months). The animals were allotted by treatment group into six pens and fed concentrate and perennial ryegrass. Ethanol (30%, v/v) was supplemented into drinking water twice a day to meet final concentrations based on average water consumption of finishing Hanwoo steers. Results: There were no statistical differences among the groups in final body weight, average daily gain, or carcass yield grade indices such as cold carcass weight, fat thickness, and loin area. The marbling score tended (p = 0.228) to increase with the highest score (6.7) in the E-5 group followed by 6.3 and 6.0 in E-3 and control groups, respectively. The appearance frequencies of quality grades of $1^{{+}{+}}$ (the best), $1^{+}$, 1, and 2, were; 30%, 50%, 0%, and 20% for control, 10%, 80%, 10%, and 0% for E-3, and 10%, 80%, 0%, and 10% for E-5 groups, respectively, indicating improvements of quality grades by feeding ethanol. Concentrations of serum glucose tended to decrease whereas those of insulin and non-esterified fatty acid to increase by feeding ethanol (E-3 and E-5; p>0.05). Conclusion: Feeding ethanol directly into drinking water of finishing Hanwoo steers stimulated lipogenesis in intramuscular adipose tissue (marbling) and thereby improved carcass quality grade. The serum metabolites results supported the hypothesis of lipolysis of existing adipose tissue, such as abdominal fats, and lipogenesis in intramuscular adipocytes.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1151-1159
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• 2009

This study was conducted to determine the effects of dietary level of whole flaxseed (WFS; 0, 10 and 15%) on performance, carcass characteristics and fatty acid composition of serum and subcutaneous, perirenal, and intramuscular adipose tissues of Korean Hanwoo cattle. The daily gains were not different among treatments. Dietary inclusion of WFS decreased (p<0.05) feed intake but improved (p<0.05) feed conversion ratio (feed/gain). Backfat thickness and marbling score were increased (p<0.05) by dietary WFS. Carcass weight, dressing percentage, loin-eye area, and carcass yield and quality were not different among treatments. The proportion of C18:3 in serum and, to a lesser extent, in adipose tissues were increased (p<0.01) by dietary WFS, indicating that lipids from WFS escaped ruminal biohydrogenation. Animals fed WFS had lower proportions of saturated fatty acid (SFA; C14:0 and 16:0) and higher proportions of polyunsaturated fatty acids (PUFA; C18:2. 18:3, 20:2, 20:4, 20:5 and 22:6) in perirenal and intramuscular fat than animals fed diets without WFS, resulting in an increased PUFA/SFA ratio. Furthermore, feeding WFS increased (p<0.01) proportions of $\omega$-3 and $\omega$-6 fatty acids in intramuscular fat but decreased (p<0.05) the $\omega$-6/$\omega$-3 ratio. Relative treatment effects were similar between 10 and 15% WFS. Feeding WFS can effectively alter composition of adipose tissues with enhanced feed conversion ratio.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.7
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• pp.1012-1020
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• 2013

The objective of this study was to investigate the effect of dietary supplementation with thiazolidinedione (TZD) on growth performance and meat quality of finishing pigs. In Experiment 1, 80 castrated finishing pigs (Large White${\times}$Landrace, BW = 54.34 kg) were randomly assigned to 2 treatments with 5 replicates of 8 pigs each. The experimental pigs in the 2 groups were respectively fed with a diet with or without a TZD supplementation (15 mg/kg). In Experiment 2, 80 castrated finishing pigs (Large White${\times}$Landrace, BW = 71.46 kg) were divided into 2 treatments as designed in Experiment 1, moreover, carcass evaluations were performed. The results from Experiment 1 showed that TZD supplementation could significantly decreased the average daily feed intake (ADFI) (p<0.05) during 0 to 28 d, without impairing the average daily gain (ADG) (p>0.05). In Experiment 2, the ADG was significantly increased by TZD supplementation during 14 to 28 d and 0 to 28 d (p<0.05) and the feed:gain ratio (F:G) was significantly decreased by TZD supplementation during 0 to 28 d (p<0.05). Compared with the control group, TZD group had significantly higher serum triglyceride (TG) concentration at 28h and serum high-density lipoprotein (HDL) levels at 14 d (p<0.05). Moreover, there was an apparent improvement in the marbling score (p<0.10) and intramuscular fat (IMF) content (p<0.10) of the longissimus dorsi muscle in pigs treated by TZD supplementation. Real-time RT-PCR analyses demonstrated that pigs of TZD group had higher mRNA abundance of $PPAR{\gamma}$ coactivator 1 (PGC-1) (p<0.05) and fatty acid-binding protein 3 (FABP3) (p<0.05) than pigs of control group. Taken together, these results suggested that dietary TZD supplementation could improve growth performance and increase the IMF content of finishing pigs through regulating the serum parameters and genes mRNA abundance involved in fat metabolism.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.3
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• pp.390-397
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• 2020

Objective: The objective of this study was to measure the special expression pattern of lipid metabolism genes and investigate the molecular mechanisms underlying intramuscular fat (IMF) deposition in Longissimus dorsi muscle of Laiwu pigs. Methods: Thirty-six pigs (Laiwu n = 18; Duroc×Landrace×Yorkshire n = 18) were used for the measurement of the backfat thickness, marbling score, IMF content, and expression of lipid metabolism genes. Results: Significant correlations were found between IMF content and the mRNA expression of lipid metabolism genes. Of the 14 fat deposition genes measured, fatty acid synthase (FASN) showed the strongest correlation (r = 0.75, p = 0.001) with IMF content, and of the 6 fat removal genes, carnitine palmitoyl transferase 1B (CPT1B) exhibited the greatest negative correlation (r = -0.66, p = 0.003) with IMF content in Laiwu pig. Multiple regression analysis showed that CPT1B, FASN, solute carrier family 27 member 1 (SLC27A1), and fatty acid binding protein 3 (FABP3) contributed 38% of the prediction value for IMF content in Laiwu pigs. Of these four variables, CPT1B had the greatest contribution to IMF content (14%) followed by FASN (11%), SLC27A1 (9%), and FABP3 (4%). Conclusion: Our results indicate that the combined effects of an upregulation in fat deposition genes and downregulation in fat removal genes promotes IMF deposition in Laiwu pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.6
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• pp.757-765
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• 2011

Fatty acid composition of beef intramuscular tissue is an important trait because high proportions of mono-unsaturated fatty acid are related to favorable beef flavor. In this study, we investigated the effects of genetic factors, such as stearoyl-CoA desaturase (SCD), on beef carcass traits, including fatty acid composition, in the Hanwoo. Analysis of fatty acids in Hanwoo was performed using a breed raised in Gyeonbuk province (n = 395). Compared to the homozygote, the GA, CT, and CT genotypes of exon 5 in the SCD polymorphism showed a higher content of oleic acid (p<0.05) and higher contents of mono-unsaturated fatty acid (p<0.05) and marbling scores (p<0.05) in intramuscular fat. Results of haplotype analysis showed a significant presence of unsaturated fatty acids and marbling score in the $ht1^*ht2$ and $ht2^*ht2$ groups (p<0.05). Furthermore, haplotype effects more powerful than a single gene were also observed. These ht1 and ht2 types also showed a significant difference in unsaturated fatty acids and marbling score, affecting beef flavor in the Hanwoo groups. Therefore, it can be inferred that the ht1 and ht2 types might be valuable new markers for use in improvement of Hanwoo.