• Journal of Animal Science and Technology
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• v.54 no.3
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• pp.175-183
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• 2012

The present study was conducted to investigate the relationships of muscle fiber characteristics to dietary energy density [3.0(Low-E) vs. 3.2 (Med-E) Mcal DE/kg)] and slaughter weight [SW; 110, 125, and 138 kg] in finishing pigs (gilt vs. barrow) using a $2{\times}3{\times}2$ factorial treatment design. Forty-one longissimus dorsi muscle (LM) samples were analyzed histochemically, with growth performance and physicochemical data for the 41 animals and their LM out of 192 animals and 72 LM used in a previous study retrospectively included. The ADG was less (P<0.01) in the Low-E than in the Med-E group (0.93 vs. 0.73 kg) whereas lightness ($L^*$) and redness ($a^*$) of LM were greater in the Low-E group SW did not influence these variables. The diameter and perimeter of the type I (slow-oxidative), type IIA (fast oxido-glycolytic) and type IIB (fast glycolytic) fibers increased with increasing SW whereas densities of the fibers decreased. However, the number and area percentages of the fiber types were not influenced by SW or dietary energy density. The percentage and per-$mm^2$ density of type IIB fibers were negatively correlated with SW (r = -0.33 and -0.57, with P<0.05 and <0.01, respectively), whereas type I fiber number percentage was positively correlated with SW (r = 0.31; P<0.05). Marbling score was negatively correlated (P<0.05) with type I (r = -0.36) and type IIB (r = -0.39) fiber densities. The $a^*$ was correlated (P<0.01) with both type I and type IIB fiber number percentages in the opposite way (r = 0.42 and -0.47, respectively). However, $L^*$ (lightness), drip loss and $pH_{24h}$ were not correlated with the fiber number percentage or density of any fiber type. Collectively, results indicate that muscle fibers grow by hypertrophy during the late finishing period, but that fiber characteristics other than the size are not significantly influenced by dietary energy density or SW.

• Journal of Animal Environmental Science
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• v.17 no.2
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• pp.101-106
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• 2011

One hundred and forty-four cross-bred market pigs weighing approximately 110 kg were randomly divided into four groups in a 2 (handling stress; minimal vs stimulated) ${\times}$ 2 (transport vehicle type; enclosed box vs conventional open) factorial arrangement of treatments. The stimulated handling stress group received overally rough handling including electric prod stimulation during loading, transport and lairage at least once at each step. All the animals received 3-h lairage prior to slaughter. Blood and longissimus dorsi muscle (LM) samples were taken at slaughter and after overnight chilling of the carcass, respectively. Plasma concentrations of stress indicators glucose, cortisol, creatine kinase and lactate dehydrogenase were greater in the stimulated vs minimal handling stress group. There were no interactions between the handling stress and transport vehicle type in their effects on these blood variables. The incidence of pale, soft and exudative (PSE) carcass and drip loss of LM, 24-h postmortem LM pH and color including the lightness and redness were not affected by the handling stress and transport vehicle type. In conclusion, results suggest that rough handling inflicts a stimulated stress on the animal, which is manifested by increased blood concentrations of stress indicators, and therefore should be avoided for animal welfare.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.731-738
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• 2003

The technique known as proteomics is useful for characterizing the protein expression pattern of a particular tissue or cell type as well as quantitatively identifying differences in the levels of individual proteins. In present study, we carried out the comparative expression patterns of white and red muscles. We used the two-dimensional electrophoresis(2-DE) for analyzing the protein expression. Proteins isolated from porcine white and red muscles were separated by 12% poly-acrylamide gel and then were detected by coomassie blue and silver staining. More than 600 protein spots were detected on each 2-DE gel. By visual analysis of the stained gel, five proteins were identified to be differentially expressed in the white vs red muscle. By database searching based on the molecular weights and pI(isoelectric point) of the five proteins, three of them were found to be most close to troponin I, T and myoglobin. However, further researche is needed for identification and functional analysis of the unidentified proteins. In conclusion, we found five proteins, which are differentially expressed in the white vs red muscle. The functional analysis of the differentially expressed proteins will provide valuable information on biochemical characteristics of the muscle type.

• Food Science of Animal Resources
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• v.26 no.2
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• pp.189-196
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• 2006

To investigate the effects of stretching and temperature of pre-rigor muscle on sarcomere length and tenderness of beef, hot boned M. Iongissimus dorsi thoracis were stretched or non-stretched, and stored at $0^{\circ}C$ for 48 hrs ($0^{\circ}C$ stretched and $0^{\circ}C$ non-stretched) or at $10^{\circ}C$ for 7 hrs followed by $0^{\circ}C$ for 41 hrs ($10^{\circ}C$ stretched and $10^{\circ}C$ non-stretched). There was no significant difference in muscle pH and drip loss between $10^{\circ}C$ stretched and $10^{\circ}C$ non-stretched samples, but they were significantly (p<0.05) lower in pH and drip loss than $0^{\circ}C$ stretched and $0^{\circ}C$ non-stretched samples. Stretched muscles at $0^{\circ}C$ showed significantly (p<0.05) higher cook loss than control muscles. Sarcomere length of $10^{\circ}C$ stretched muscle was significantly (p<0.05) longer than that of control. However, control muscle showed significantly (p<0.05) higher value of shear force at 2 and 14 days postmortem compared to that of $10^{\circ}C$ stretched muscle. Panels rated $10^{\circ}C$ stretched muscle as having a significantly (p<0.05) better tenderness, flavor and overall acceptability compared to those of control muscle. Results suggest that longer sarcomere length and tender beef could be obtained by stretching of pre-rigor muscle and storing it at $10^{\circ}C$ for 7 hrs followed by $0^{\circ}C$ for 41 hrs.

• Food Science of Animal Resources
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• v.26 no.2
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• pp.212-217
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• 2006

Effects of feeding high quality roughage (timothy hay) in growing period on growth performance and carcass characteristics during 24 month (5 month from 28 month to) in twenty of Hanwoo steers were investigated. The hanwoo steers were randomly allotted to 2 treatments (10 heads/treatment) ; rice straw group (control) and timothy hay group (treatment). The final body weights of rice straw group and timothy hay group on 28 month were 667.70 kg and 681.75kg, respectively. The daily gain of total period was slightly higher in timothy hay group (0.83kg ) than in rice straw group (0.81 kg). The daily roughage intake in the growing period was tended to be higher in timothy hay group (4.27kg ) than rice straw group (3.80 kg). The carcass grades (yield grade and quality grade) and Longissimus dorsi area were significantly higher in timothy hay group ($85.62 cm^2$, 2.02 and 2.20 point) than in rice straw group ($81.29 cm^2$, 2.00 and 1.60 point respectively) (p<0.05), and were affected by the feeding with high quality roughage in the growing period.

• Food Science of Animal Resources
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• v.31 no.2
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• pp.224-231
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• 2011

This study was conducted to investigate the effect of peppermint powder on meat quality and fatty acid composition in finishing Korean native black pigs. Ninety pigs were randomly allocated to three dietary treatments and fed peppermint powder at 0 (C), 0.2 (T1), and 0.4% (T2) in the basal diet, respectively for 50 d. The proximate composition of Longissimus dorsi muscle was not significantly different among the treatments; however, the fat content in T2 tended to be lower than the control. No difference in $pH_{45min}$ was observed, whereas $pH_{24h}$ was higher in T2 than the control (p<0.01). T2 showed the lowest lightness (p<0.01) and yellowness values (p<0.05), but shear force and drip loss were no different among the treatments. Individual fatty acid and cholesterol compositions did not differ among the treatments; however, T1 showed a decreasing trend for saturated fatty acid content and an increasing trend for unsaturated fatty acid content. The hypocholesterolemic index was significantly higher in T1 than in the control (p<0.05). These results suggest that dietary peppermint could positively affect fatty acid and cholesterol levels without changing meat quality in finishing Korean native black pigs.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1088-1097
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• 2018

Objective: It is commonly accepted that adiponectin binds to its two receptors to regulate fatty acid metabolism in adipocytes. To better understand their functions in the regulation of intramuscular adipogenesis in goats, we cloned the three genes (adiponectin [AdipoQ], adiponectin receptor 1 [AdipoR1], and AdipoR2) encoding these proteins and detected their mRNA distribution in different tissues. We also determined the role of AdipoQ in the adipogenic differentiation of goat skeletal muscle satellite cells (SMSCs). Methods: SMSCs were isolated using 1 mg/mL Pronase E from the longissimus dorsi muscles of 3-day-old female Nanjiang brown goats. Adipogenic differentiation was induced in satellite cells by transferring the cells to Dulbecco's modified Eagle's medium supplemented with an isobutylmethylxanthine, dexamethasone and insulin cocktail. The pEGFP-N1-AD plasmid was transfected into SMSCs using Lipofectamine 2000. Expression of adiponectin in tissues and SMSCs was detected by quantitative polymerase chain reaction and immunocytochemical staining. Results: The three genes were predominantly expressed in adipose and skeletal muscle tissues. According to fluorescence and immunocytochemical analyses, adiponectin protein expression was only observed in the cytoplasm, suggesting that adiponectin is localized to the cytoplasm of goat SMSCs. In SMSCs overexpressing the AdipoQ gene, adiponectin promoted SMSC differentiation into adipocytes and significantly (p<0.05) up-regulated expression of AdipoR2, acetyl-CoA carboxylase, fatty-acid synthase, and sterol regulatory element-binding protein-1, though expression of CCAAT/enhancer-binding $protein-{\alpha}$, peroxisome proliferator-activated receptor ${\gamma}$, and AdipoR1 did not change significantly. Conclusion: Adiponectin induced SMSC differentiation into adipocytes, indicating that adiponectin may promote intramuscular adipogenesis in goat SMSC.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1336-1344
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• 2018

Objective: This study aimed to observe whether high-pressure processing (HPP) affected aroma development and the degradation rate of umami taste-related ATP breakdown products, specifically inosinic acid in grass-fed beef during vacuum aging. Methods: Strip loin (longissimus lumborum) cuts obtained from six grass-fed Friesian Holstein steers (32 months old) on day 4 post slaughter were vacuum-packed and subjected to pressurization at 300 and 500 MPa for 180 s at $15^{\circ}C{\pm}2^{\circ}C$. The samples were then stored for 4 weeks at $5^{\circ}C{\pm}0.5^{\circ}C$ under vacuum and compared with the control (0.1 MPa). Results: HPP increased the shear force value, promoted moisture loss and lipid oxidation, induced surface paleness, stabilized pH during aging, and reduced bacterial load and growth. The shear force value of 500 MPa-treated samples remained higher than the control after aging, while no significant differences were found between the control and 300 MPa-treated samples. Degradation of inosinic acid and inosine occurred during pressurization, resulting in an increase in hypoxanthine content. However, the degradation rate in HPP-treated samples during aging was slower; therefore, inosinic acid and inosine content remained higher than in control samples. No significant differences were found in hypoxanthine content at the end of aging. HPP intensified the levels of hexanal, octanal, 2-methylbutanal, 3-methylbutanal, benzaldehyde, and 2,5-dimethylpyrazine in cooked-aged beef samples. Conclusion: HPP induced aroma development and delayed the degradation of inosinic acid. However, it also reduced the postmortem tenderization rate.

• Food Science of Animal Resources
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• v.24 no.3
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• pp.253-259
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• 2004

The effect of dietary clay mineral on meat quality in M. longissimus of Hanwoo (Korean cattle) bull beef during refrigerated storage (4$^{\circ}C$) was investigated. Experimental groups were divided into control (basal diet) and CT-1.25% (basal diet + 1.25% clay mineral) groups. There was no significant differences in proximate and fatty acid compositions between control and CT-1.25% groups. The pH of control group was significantly (p<0.05) changed during storage, but CT-1.25% group was little affected by storage time. CIE a＊ (redness), chroma (C＊) values and R630-R580 were significantly (p<0.05) decreased during storage for both groups. In particular, those values decreased more rapidly in the control group. The rate of metmyoglobin accumulation during storage increased more rapidly in the control group. Therefore, discoloration in the control group was more accelerated compared to the CT-1.25% group. TBARS (thiobarbituric acid reactive substances) which represents lipid rancidity were significantly (p<0.05) lower in CT-l.25% group than in the control. Water-holding capacity (WHC) was significantly (p<0.05) increased during storage for both groups, and CT-1.25% group had significantly (p<0.05) higher WHC than control group. Consequently, feeding of clay mineral (1.25%) was effective in increasing meat color stability and WHC, and retarding lipid oxidation than did control group.