• Journal of Animal Science and Technology
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• v.51 no.6
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• pp.443-452
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• 2009

Adipocytes are differentiated from preadipocytes and have large capacity for storing fats inside cells. In cattle, intramuscular fat (IMF) content is one of the major determinants for meat quality and also highly affects market prices, especially in Japan and Korea. In order to profiling differentially expressed genes between intramuscular fibroblast-like cells (preadipocytes) and their differentiated adipocytes, we have established intramuscular fibroblast-like cells from M. longissimus thoracis in Korean cattle (Hanwoo). The differentially expressed genes were selected by comparing these two types of cells ug thecommercially available 23kese two types of cells ug theco. The results indan ced that 206 arecomelements were differentially expressed. Of these, 67 and 94 ks wn genes were up and d wn regulaced, respectively, in adipocytes ug ng both 2-fold difference and Welch's t-test as the cut-off points. The differentially expressed genes identified in this study can be used as good markers for improving meat quality traits with further verification of their biological functions, especially IMF contents in cattle.

• Journal of Animal Science and Technology
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• v.64 no.6
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• pp.1173-1183
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• 2022

Adipogenesis is a complex process comprising commitment and a differentiation stages. Through research, many different transcriptional factors were found to mediate preadipocyte commitment and differentiation. Lysine has a potential of regulating the commitment and differentiation of preadipocytes. In the present study, intramuscular stromal vascular cells (SVC) isolated from Hanwoo beef cattle were used to elucidate the effects of low lysine level on adipogenesis. SVC were isolated and incubated with various concentrations of lysine (0, 37.5, 75, 150 and 300 µg/mL). No significant difference were observed in the proliferation of SVC after 24 and 48 h of incubation with different concentration of lysine. On preadipocyte determination, reducing the level of lysine significantly increased the expression of preadipocyte commitment gene Zinc finger protein 423 and Preadipocyte factor-1. Upon differentiation, Oil Red O staining revealed that lipid accumulation and triglyceride content significantly increased with the decreasing lysine levels in the media. Expression levels of peroxisome proliferator-activated receptor-γ, CCAAT enhancer binding protein-α, sterol regulatory element binding protein-1c, Fatty Acid Binding Protein 4 and stearoyl CoA desaturase were upregulated by the decreased level of lysine. These data suggest the potential mechanism of action for the improved preadipocyte commitment and adipocyte differentiation in bovine intramuscular SVC upon treatment with low levels of lysine. These findings may be valuable in developing feed rations that promote deposition of intramuscular fat in beef cattle through lysine level modification.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.7
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• pp.1043-1061
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• 2018

Intramuscular fat (IMF) content in skeletal muscle including the longissimus dorsi muscle (LM), also known as marbling fat, is one of the most important factors determining beef quality in several countries including Korea, Japan, Australia, and the United States. Genetics and breed, management, and nutrition affect IMF deposition. Japanese Black cattle breed has the highest IMF content in the world, and Korean cattle (also called Hanwoo) the second highest. Here, we review results of research on genetic factors (breed and sex differences and heritability) that affect IMF deposition. Cattle management factors are also important for IMF deposition. Castration of bulls increases IMF deposition in most cattle breeds. The effects of several management factors, including weaning age, castration, slaughter weight and age, and environmental conditions on IMF deposition are also reviewed. Nutritional factors, including fat metabolism, digestion and absorption of feed, glucose/starch availability, and vitamin A, D, and C levels are important for IMF deposition. Manipulating IMF deposition through developmental programming via metabolic imprinting is a recently proposed nutritional method to change potential IMF deposition during the fetal and neonatal periods in rodents and domestic animals. Application of fetal nutritional programming to increase IMF deposition of progeny in later life is reviewed. The coordination of several factors affects IMF deposition. Thus, a combination of several strategies may be needed to manipulate IMF deposition, depending on the consumer's beef preference. In particular, stage-specific feeding programs with concentrate-based diets developed by Japan and Korea are described in this article.

• Journal of Animal Science and Technology
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• v.44 no.5
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• pp.599-606
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• 2002

This study was carried out to determine the physico-chemical components and to examine it the consumers can tell the difference in eating quality of loins of Hanwoo with grade and sex. Loins of 36 carcasses were selected and their intramuscular fat, color, pH, water holding capacity, shear force, the amount of myoglobin and moisture content were measured. The result was that only intramuscular fat was significantly different with grades. In Pearson correlation coefficients among quality factors, moisture content increased significantly with the amount of myoglobin(0.514) and shear force(0.503) and decreased as intramuscular fat(－0.957) and water holding capacity(－0.491) increased. Also, content of intramuscular fat decreased as shear force(－0.565) increased. According to descriptive analysis, aroma and acceptability in the 2nd grade steer showed the highest score. Aroma, juiciness and tenderness may affect acceptability of cooked meat. Also, juiciness, tenderness and acceptability had a negative correlation with moisture content and the intramuscular fat did not affect tenderness directly.

• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.229-236
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• 2014

This study presents the estimates of heritabilities of body measurement traits and carcass traits, and genetic and phenotypic correlations of those traits for crossbred pigs in Korea. Body and ultrasound (A mode: Piglog 105) measurements in 221 pigs including body weight, length, height and width, three back fat thickness at the points of 4th, 14th rib and chine bone, eye muscle area and lean meat percent were collected at the ages of 70, 145 and 180 days and then slaughtered to measure carcass weight, back fat, belly, collar butt, spare rib, picnic shoulder, hind leg, loin, tenderloin, lean meat yield and intramuscular rough fat content in loin. Genetic analysis was done using a multi-trait animal model. Heritabilties of the body measurements were ranged from 0.331 to 0.559 and three measurements of back fat thickness were also high as range varying from 0.402 to 0.475 for the ages of 145 and 180 days. However, eye muscle area was moderate (0.296) at the age of 180 days. Heritabilities of retail cut yields were also high as ranged from 0.387 to 0.474 and of IMF content in loin was 0.499. Heritabilities of the cut percent traits were ranged from 0.249 to 0.488. Important positive genetic and phenotypic correlations were noted for all carcass yield traits (0.298 to 0.875 and 0.432 to 0.922, respectively). IMF showed low negative genetic correlations with carcass yield traits, such as carcass weight, picnic shoulder, hind leg, loin, tenderloin and lean meat yield whereas low positive genetic correlations with back fat, belly, collar butt and spare rib. Loin, tenderloin and lean meat percent showed negative genetic correlations with carcass weight, back fat thickness, collar butt, spare rib and picnic shoulder percent. The four body measurements at the ages of 70, 145 and 180 days had positive genetic correlations with belly, shoulder butt, spare rib, picnic shoulder and hind leg percent, but negative genetic correlations were shown with loin and tenderloin percent except body measurements at 70 days. The results suggest that carcass yield are negatively correlated with intramuscular fat content, which is a major factor deciding pork quality and the yield of loin and tenderloin are not increased as much as increase in body size. However, the proportions of belly and collar butt are increased with the body size. In conclusion, selection strategy should be designed according to the preference on composition of carcass in each country.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.593-598
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• 2017

The objective of this study was to determine the influence of quality grade (QG) on meat tenderness characteristics of ten major muscles from Hanwoo steers. A total of 25 Hanwoo carcasses ($5\;carcasses{\times}5\;QGs$) were selected. Intramuscular fat content, collagen content, sarcomere length, and Warner-Bratzler shear force (WBSF) of Longissimus thoracis (LT), Longissimus lumborum (LL), Psoas major (PM), Semisponals (SS), Triceps brachii (TB), Semimembranosus (SM), Gluteus medius (GM), Rectus Abdominis (RA), Superficialis flexor (SF), and Internal and external intercostal (IC) were determined. IC had the highest fat content, followed by LT, RA, LL, PM, GM, SS, SF, TB, and SM. High-fat muscles such as LT, LL, IC, RA, and PM had significantly (p<0.05) different fat contents among QGs. Collagen contents were significantly (p<0.05) different among QGs. With decreasing QG, increasing collagen content was found in muscles. There were significant (p<0.05) differences in sarcomere length among QGs of several muscles. However, no significant (p>0.05) difference in sarcomere length was found among QGs for LL, PM, or RA muscle. PM had the lowest WBSF, followed by LL, LT, RA, IC, GM, SM, SF, SS, and TB. WBSF of QG $1^{{+}{+}}$ was lower than that of QG 1 for SS, TB, and SM. All muscles of QG 1 showed lower WBSF than QG 3 except TB or IC. Results of this study suggested that differences in WBSF among these 10 muscles by QG were due to differences in collagen content and sarcomere length.

• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.117-124
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• 2013

근내지방도(IMF)가 한우육의 품질 및 기능성분에 미치는 영향을 조사하기 위하여, 250두의 한우를 근내지방 함량에 따라 Low(<14%, n=96), Medium(14~17%, n=83), High(>17%; n=71) 세 그룹으로 분류하고, 7일간 숙성 후 등심육의 품질 및 기능성분을 분석하였다. 한우 등심육의 수분 함량은 IMF와 반비례하였으며, High IMF 그룹은 Low IMP 그룹에 비하여 낮은 드립 감량을 나타내었다. 기능성 didpeptide 함량은 IMF에 따라 유의적 차이가 없었으나, High IMF 그룹은 다른 그룹보다 낮은 inosine monophosphate, 높은 hypoxanthine, 낮은 histidine 함량은 나타내었다. 불포화지방산의 비율은 IMF에 따라 유의적 차이가 없었다. 저지방육의 건강지향적 가치를 고려할 때 지나친 IMF를 목표로 하는 육종 및 사양은 지양되어야 할 것으로 판단되었다.

• 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.23 no.8
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• pp.987-992
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• 2010

This study was to detect the expression of heart fatty acid-binding protein (H-FABP) and adipocyte fatty acid-binding protein (A-FABP) gene mRNA in different tissues of Rugao and Luyuan chickens at 56 d and 120 d by real-time fluorescence quantitative reverse transcription polymerase-chain reaction (FQ-RT-PCR). The primers were designed according to the sequences of HFABP, A-FABP and GAPDH genes in Gallus gallus, which were used as target genes and internal reference gene, respectively. The levels of H-FABP and A-FABP gene expression were detected by SYBR Green I FQ-RT-PCR. The relative H-FABP and A-FABP gene mRNA expression level was calculated with 2-$^{{\Delta}Ct}$. Melting curve analysis showed a single peak of three genes. Intramuscular fat (IMF) content in breast muscle and leg muscle of the two chicken breeds at 120 d was higher than at 56 d. IMF content in breast muscle and leg muscle at 56 d and 120 d in Luyuan was significantly higher than in Rugao, however, abdominal fat of Luyuan was significantly lower than that of Rugao. The relative H-FABP gene mRNA expression level in cardiac muscle was the highest in both chicken breeds. The relative H-FABP and A-FABP gene expression of different tissues in Luyuan was higher than in Rugao. H-FABP gene mRNA expression had a negative effect on IMF of leg and breast muscles, and was significantly negatively correlated with IMF content. The relative A-FABP gene mRNA level in abdominal fat was higher than in liver. The A-FABP gene mRNA was not expressed in leg, breast and cardiac muscles. A-FABP gene mRNA expression level was significantly positively correlated with abdominal fat and had a significant effect on abdominal fat but not IMF content.

• Animal Bioscience
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• v.36 no.2
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• pp.175-190
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• 2023

Objective: The study was conducted to screen differentially expressed long noncoding RNA (lncRNA) in chickens by high-throughput sequencing and explore its mechanism of action on intramuscular fat deposition. Methods: Herein, Rose crown and Cbb broiler chicken embryo breast and leg muscle lncRNA and mRNA expression profiles were constructed by RNA sequencing. A total of 96 and 42 differentially expressed lncRNAs were obtained in Rose crown vs Cobb broiler chicken breast and leg muscle, respectively. lncRNA-ENSGALT00000046546, with high interspecific variability and a potential regulatory role in lipid metabolism, and its predicted downstream target gene 1-acylglycerol-3-phosphate-O-acyltransferase 2 (AGPAT2), were selected for further study on the preadipocytes. Results: lncRNA-46546 overexpression in chicken preadipocyte 2 cells significantly increased (p<0.01) the expression levels of AGPAT2 and its downstream genes diacylglycerol acyltransferase 1 and diacylglycerol acyltransferase 2 and those of the fat metabolism-related genes peroxisome proliferator-activated receptor γ, CCAAT/enhancer binding protein α, fatty acid synthase, sterol regulatory element-binding transcription factor 1, and fatty acid binding protein 4. The lipid droplet concentration was higher in the overexpression group than in the control cells, and the triglyceride content in cells and medium was also significantly increased (p<0.01). Conclusion: This study preliminarily concludes that lncRNA-46546 may promote intramuscular fat deposition in chickens, laying a foundation for the study of lncRNAs in chicken early embryonic development and fat deposition.