• Food Science of Animal Resources
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• v.32 no.6
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• pp.776-782
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• 2012

Marbling (intramuscular fat) is the most economically important meat quality trait in Hanwoo (Korean cattle). The endothelial differentiation G-protein coupled receptor 1 (EDG1) gene, involved in blood vessel formation, is located within the genomic region of a quantitative trait locus (QTL) for marbling on bovine chromosome 3. Thus, the EDG1 gene can be considered as a positional and functional candidate gene for meat quality in beef cattle. This study aimed to identify single nucleotide polymorphisms (SNPs) in the EDG1 gene and to evaluate their associations with carcass traits in Hanwoo population. We have sequenced a fragment of 5'-UTR of the EDG1 gene and identified one SNP. Genotyping of the g.166A>G SNP marker was carried out using PCR-RFLP analysis in 309 Hanwoo steers in order to evaluate their association with carcass traits. The g.166A>G SNP marker showed a significant effect on the marbling score. Animals with the GG genotype had higher marbling score compared with AA and AG genotypes (p<0.05). This SNP marker also showed a significant additive effects for the marbling score (p<0.05). These results suggest that the EDG1 gene can be used as a molecular marker for DNA marker-assisted selection in order to increase the levels of the marbling score in Hanwoo.

• 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.

• 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.22 no.9
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• pp.1225-1233
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• 2009

Fat composition of beef, taken here to mean marbling, can be manipulated by time on feed, finishing diet, and breed type. These three factors also strongly influence the fatty acid composition of beef. Both the amount of marbling and the concentration of monounsaturated fatty acids (MUFA) increase with time on feed in grain-fed and pasture-fed cattle, but much more dramatically in grain-fed cattle. High-concentrate diets stimulate the activity of adipose tissue stearoyl-CoA desaturase (SCD), which is responsible for the conversion of saturated fatty acids (SFA) to their $\Delta{9}$ desaturated counterparts. Also, grain feeding causes a depression in ruminal pH, which decreases those populations of ruminal microorganisms responsible for the isomerization and hydrogenation of polyunsaturated fatty acids (PUFA). The net result of elevated SCD activity in marbling adipose tissue and depressed ruminal isomerization/hydrogenation of dietary PUFA is a large increase in MUFA in beef over time. Conversely, pasture depresses both the accumulation of marbling and SCD activity, so that even though pasture feeding increases the relative concentration of PUFA in beef, it also increases SFA at the expense of MUFA. Wagyu and Hanwoo cattle accumulate large amounts of marbling and MUFA, and Wagyu cattle appear to be less sensitive to the effects of pastures in depressing overall rates of adipogenesis and the synthesis of MUFA in adipose tissues. There are small differences in fatty acid composition of beef from Bos indicus and Bos taurus cattle, but diet and time on feed are much more important determinants of beef fat content and fatty acid composition than breed type.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.12
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• pp.1785-1793
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• 2008

Fifty-four PIC barrows were used to evaluate the effects of lower dietary lysine content and energy level on carcass characteristics and meat quality in slaughter pigs. Pigs were allotted to one of three treatments by body weight with six replicate pens in each treatment. The dietary treatments for body weights of 20-50 kg, 50-80 kg and 80-90 kg were as follows, respectively: control diet (digestible energy 14.22 MJ/kg, lysine/DE 0.67 g/MJ, 0.53 g/MJ and 0.42 g/MJ); a low lysine group (digestible energy 14.22 MJ/kg, lysine/DE 0.49, 0.38 and 0.30 g/MJ); and a low lysine-low energy group or low nutrient group (digestible energy 13.11 MJ/kg, lysine/DE 0.49, 0.38 and 0.30 g/MJ). The daily weight gain, daily feed intake and feed efficiency were calculated in the overall growth period (nearly 12 weeks). Meanwhile, carcass characteristics and meat quality were evaluated at 60 and 90 kg body weight respectively. During the overall growth trial, lowering dietary lysine and nutrient level both decreased weight gain (p<0.05) and feed efficiency (p<0.01). At 60 kg body weight, decreasing dietary lysine and nutrient level noticeably decreased dressing percentage (p<0.01) and back fat depth at last rib of PIC pigs (p<0.01), but enhanced marbling scores (p<0.10), intramuscular fat content (p<0.10) and water loss rate (p<0.01) of the longissimus dorsi muscle. At 90 kg body weight, lean percentage (p<0.01) was evidently reduced by both lowering lysine content and nutrient level in the diet. However, the shoulder back fat depth (p<0.05) and marbling scores of the loin eye muscle (p<0.05) were increased; Lowering dietary nutrient level could improve back fat depth of 10th rib (p<0.01) and last rib (p<0.01), intramuscular fat content (p<0.10), redness (p<0.01) and water loss rate of the loin eye muscle (p<0.05), but decrease loin area (p<0.05). Finally, when comparing the 60 kg and 90 kg slaughter weights, it was found that the shoulder back fat depth (p<0.01, p<0.10), 6th-7th rib (p<0.01, p<0.01), 10th-rib (p<0.01, p<0.01) and last rib back fat depth (p<0.01, p<0.01) of the low lysine and low nutrient group were all obviously increased comparing with the control group. Taken together, the results showed that decreasing dietary lysine content and nutrient level increased intramuscular fat content and water loss rate of longissimus dorsi muscle; On the other hand, both lowering dietary lysine and nutrient level markedly compensated to increase back fat deposition in the later finishing period (body weight from 60 to 90 kg) in contrast to the control group.

• 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.

• Journal of Life Science
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• v.18 no.8
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• pp.1090-1095
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• 2008

Marbling (intramuscular fat) is an important factor in determining meat quality in Korean beef market. A grain based finishing system for improving marbling leads to inefficient meat production due to an excessive fat production. Identification of intramuscular fat-specific gene might be achieved more targeted meat production through alternative genetic improvement program such as marker assisted selection (MAS). We carried out ddRT-PCR in 12 and 27 month old Hanwoo steers and detected 300 bp PCR product of the inducible cAMP early repressor (ICER) gene, showing highly gene expression in 27 months old. A 1.5 kb sequence was re-sequenced using primer designed base on the Hanwoo EST sequence. We then predicted the open reading frame (ORF) of ICER gene in ORF finder web program. Tissue distribution of ICER gene expression was analysed in eight Hanwoo tissue using realtime PCR analysis. The highest ICER gene expression showed in Small intestine followed by Longissimus dorsi. Interestingly, the ICER gene expressed 2.5 time higher in longissimus dorsi than in same muscle type, Rump. For gene expression analysis in high- and low marbled individuals, we selected 4 and 3 animal based on the muscle crude fat contents (high is 17-32%, low is 6-7% of crude fat contents). The ICER gene expression was analysed using ANOVA model. Marbling (muscle crude fat contents) was affected by ICER gene (P=0.012). Particularly, the ICER gene expression was 4 times higher in high group (n=4) than low group (n=3). Therefore, ICER gene might be a functional candidate gene related to marbling in Hanwoo.

• 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.

• BMB Reports
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• v.40 no.5
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• pp.757-764
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• 2007

Marbling of cattle meat is dependent on the coordinated expression of multiple genes. Cattle dramatically increase their intramuscular fat content in the longissimus dorsi muscle between 12 and 27 months of age. We used the annealing control primer (ACP)-differential display RT-PCR method to identify differentially expressed genes (DEGs) that may participate in the development of intramuscular fat between early (12 months old) and late fattening stages (27 months old). Using 20 arbitrary ACP primers, we identified and sequenced 14 DEGs. BLAST searches revealed that expression of the MDH, PI4-K, ferritin, ICER, NID-2, WDNMI, telethonin, filamin, and desmin (DES) genes increased while that of GAPD, COP VII, ACTA1, CamK II, and nebulin decreased during the late fattening stage. The results of functional categorization using the Gene Ontology database for 14 known genes indicated that MDH, GAPD, and COP VII are involved in metabolic pathways such as glycolysis and the TCA cycle, whereas telethonin, filamin, nebulin, desmin, and ACTA1 contribute to the muscle contractile apparatus, and PI4-K, CamK II, and ICER have roles in signal transduction pathways regulated by growth factor or hormones. The final three genes, NID-2, WDNMI, and ferritin, are involved in iron transport and extracellular protein inhibition. The expression patterns were confirmed for seven genes (MDH, PI4-K, ferritin, ICER, nebulin, WDNMI, and telethonin) using real-time PCR. We found that the novel transcription repressor ICER gene was highly expressed in the late fattening stage and during bovine preadipocyte differentiation. This information may be helpful in selecting candidate genes that participate in intramuscular fat development in cattle.

• 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.