Search Results (7)

Understanding the genetic regulatory mechanisms of fat accumulation is crucial for improving beef quality. Hanwoo (Korean native cattle) is renowned for its high intramuscular fat (marbling), yet the genetic regulation of adipose gene expression remains insufficiently understood. In this study, we performed expression quantitative trait loci (eQTL) analysis using RNA-Seq data and genotype data from backfat tissue of 75 Hanwoo steers to identify regulatory variants associated with adipose deposition. A total of 25,042 significant cis-eQTL associations (FDR < 0.05) were identified, and 5362 unique top cis-eQTL pairs were retained after gene-wise filtering. Key cis-regulated genes included AGBL1, CACNG1, MYO18B, and DUSP29, which are involved in cytoskeletal organization, muscle development and calcium signaling. Three major cis-regulatory hotspots were located on BTA15 (BTA15:50354741) and BTA21 (BTA21:21526143, and BTA21:21541921). Permutation-based analysis (100,000 iterations) was conducted to control false positives, identifying 12 statistically significant trans-eQTL hotspots (FDR q < 0.05), of which SNP 6:60512276 and SNP 21:17035557 exhibited extensive trans-regulatory activity influencing 429 and 161 genes, respectively. In particular, SNP 21:17035557 acted as a shared cis- and trans-regulatory hub, indicating hierarchical control of adipose gene networks. Functional enrichment analyses revealed significant involvement of cytoskeleton- and calcium-dependent pathways, highlighting the interplay between structural remodeling and metabolic regulation in adipose tissue. These findings provide a comprehensive, system-level view of adipose gene regulation in Hanwoo cattle and highlight candidate molecular targets for genome-assisted and precision breeding. Moreover, this study offers quantitative genomic resources that can support the development of prediction models and decision-support systems for improving carcass traits in Hanwoo breeding programs. Full article

Transportation, environmental changes, and overcrowding can induce short-term stress in livestock, leading to physiological imbalances even within a short period. Cortisol is a stress-response hormone and its concentration in the blood can rapidly fluctuate depending on the individual and situation. This study evaluated the short-term effects of cortisol by applying blood cortisol concentrations that mimicked the normal and stress-induced levels observed in Korean native cattle (Hanwoo) to the culture medium of Hanwoo muscle stem cells (HWSC). Treatments were designed with five cortisol concentrations (0, 5, 10, 30, and 70 ng/mL) and four treatment times (0.5, 1, 2, and 3 h), based on the CCK-8 and viable cell count results. The expression levels of cortisol receptor-related genes (NR3C1, HSP70, and HSP90AA1) increased and reached a peak at 30 min post-treatment. After 30 min, the expression of these genes gradually decreased. However, in the case of HSP70, expression tended to increase again after 3 h of treatment. This could be seen as the regulation of cortisol inflow into the HWSC. Upon examining the oxidative effects of cortisol on superoxide dismutase 1 (SOD1), glutathione peroxidase (GPX), catalase (CAT), and oxygen consumption rate (OCR), the expression of antioxidant factors increased and peaked at 30 min of treatment. Following this peak, their levels generally began to decrease. However, in the 70 ng/mL group, the expression of these factors remained at a high level compared to the control group even after 30 min. In addition, the cellular respiration index and ATP production increased as the treatment prolonged, regardless of the concentration, as shown by the OCR analysis. These results can be considered a phenomenon corresponding to the accumulation of oxidative by products, such as Reactive Oxygen Species (ROS), caused by cortisol. The gene expression of apoptosis factors (p53, BAX, Caspase-3) temporarily increased at 30 min but then decreased. Caspase-3 protein activity was elevated at 30 min in the 70 ng/mL group, which later reduced. These results suggested that short-term cortisol administration had no effect on apoptosis in muscle cell culture. Therefore, the study findings elucidating the effects of short-term cortisol treatment on HWSC suggest that short-term stress may not have a significant negative effect on Hanwoo muscle. However, as this study was limited to muscle stem cells derived from Hanwoo, further investigation is required to determine whether the observed responses are consistent across different species and in vivo environments. Full article

This study aimed to conduct a bioequivalence study of applying three pour-on ivermectin formulations at a dose of 1 mg/kg on the back of Korean native beef cattle (Hanwoo). To conduct bioequivalence testing, the pharmacokinetics of three groups (control Innovator, test Generic A, and test Generic B) of five clinically healthy Korean Hanwoo cattle (average weight 500 kg) were studied. After topical application to the skin, blood samples were drawn at the indicated times. These blood samples were analyzed using liquid chromatography–tandem mass spectrometry (LC-MS/MS). The time required to reach the maximum concentration (T_max), the maximum concentration (C_max), and the area under the curve (AUC_last) of each pharmacokinetic parameter were compared for bioequivalence. The results showed that the control had a T_max of 41 ± 1.24 h, a C_max of 0.11 ± 0.01 μg/mL, and an AUC_last of 9.33 ± 0 h*μg/mL). The comparator Generic A had a T_max of 40 ± 1.14 h, a C_max of 0.10 ± 0.01 (μg/mL, and an AUC_last of 9.41 ± 0.57 h*μg/mL, while Generic B had a T_max of 40 ± 2.21 h, a C_max of 0.10 ± 0.01 μg/mL, and an AUC_last of 9 h*μg/mL. The values of the bioequivalence indicators C_max, T_max, and AUC were all within the range of 80% to 120%, confirming that all three tested formulations were bioequivalent. In conclusion, the study showed that the two generic products were bioequivalent to the original product in Hanwoo cattle. Full article

Skeletal muscle-derived myogenic cells (SKMCs) are novel protein sources capable of replacing animal meat. However, SKMCs have not been commercialized owing to poor productivity and the high cost of in vitro cell culture. Therefore, we cultured SKMCs in varying serum (5–20%) and oxygen concentrations (5–20%) to investigate the parameters that most impact cell productivity (serum, hypoxia, and culture medium) and examined cell proliferation ability and genes involved in myogenesis/proliferation/apoptosis/reactive oxygen species (ROS). In fetal bovine serum (FBS) groups, hypoxia induction doubled cell number, and the 20% FBS/normoxia group exhibited similar cell numbers as 5% FBS/5% hypoxia, confirming that 5% hypoxia reduced serum requirement by four-fold. The use of 20% FBS downregulated MTF5/MYOD1/MYOG/MYH1, whereas hypoxia induction with ≤10% FBS upregulated them. Although 20% FBS lowered TERT expression through rapid cell proliferation, NOX1, a major factor of ROS, was suppressed. DMEM/F12 demonstrated better differentiation potential than F10 by upregulating MYF3/MYOD1/MYOG/MYH1 and downregulating MSTN, particularly DMEM/F12 with 2% FBS/5% hypoxia. The myogenic fusion index was higher in DMEM/F12 without FBS than in DMEM/F12 with FBS (0.5–5%); however, the total nuclei number was reduced owing to apoptosis. Therefore, high serum levels are essential in influencing SKMC growth, followed by hypoxia as a synergistic component. Full article

Hanwoo, an indigenous Korean cattle breed, has been genetically improved by selecting superior sires called Korean-proven bulls. However, cows still contribute half of the genetic stock of their offspring, and allelic-specific expressed genes have potential, as selective targets of cows, to enhance genetic gain. The aim of this study is to identify genes that have MAEs based on both the genome and transcriptome and to estimate their effects on breeding values (BVs) for economically important traits in Hanwoo. We generated resequencing data for the parents and RNA-sequencing data for the muscle, fat, and brain tissues of the offspring. A total of 3801 heterozygous single nucleotide polymorphisms (SNPs) in offspring were identified and they were located in 1569 genes. Only 14 genes showed MAE (seven expressing maternal alleles and seven expressing paternal alleles). Tissue-specific MAE was observed, and LANCL1 showed maternal allele expression across all tissues. MAE genes were enriched for the biological process of cell death and angiogenesis, which included ACKR3 and PDCL3 genes, whose SNPs were significantly associated with BVs of lean meat production-related traits, such as weight at 12 months of age, carcass weight, and loin eye area. In the current study, monoallelically expressed genes were identified in various adult tissues and these genes were associated with genetic capacity in Hanwoo. Full article

This study examined the effects of stevioside (S) and organic selenium (O-Se) supplementation on the sensory attributes, microbial activity, fatty acid composition, and meat quality traits of Hanwoo cattle (Korean native cattle). Twenty-four Hanwoo cattle (663 ± 22 kg body weight) were assigned to two dietary treatments for 8 months: control diet and 1% stevioside with 0.08% organic selenium supplemented diet. S and O-Se inclusion in the diet enhanced the final body weight, weight gain, and carcass crude protein (p < 0.05). Moreover, supplementation with S and O-Se had a significant effect on lowering the drip loss and shear force and enhanced the a* (redness) of the longissimus dorsi muscle (p < 0.05). The inclusion of dietary S and O-Se improved the sum of the polyunsaturated fatty acid (ΣPUFAs) content of the meat, and the oxidative status (TBARS) values during second week of storage decreased by 42% (p < 0.05). On the other hand, the microbial count tended to decrease (7.62 vs. 7.41 log₁₀ CFU), but it was not significant (p > 0.05), and all sensory attributes were enhanced in the S and O-Se supplemented diet. Overall, these results suggest that supplementation of the ruminant diet with stevioside and organic selenium improves the growth performance, carcass traits, and meat quality with enriched PUFAs profile and retards the lipid oxidation during the storage period in beef. Full article

The agricultural sector is considered one of the major sources of greenhouse gas (GHG) emissions globally. The livestock industry as a significant contributor, is accounting for about 18% of GHG emissions measured in carbon dioxide (CO₂) equivalent from agricultural practices. Depending on farming practices and climatic conditions, GHGs such as methane (CH₄) and nitrous oxide (N₂O) emissions from livestock agriculture can vary significantly. Country-specific emission factors are, therefore, needed for a precise estimation of GHG emissions and to avoid uncertainties. This study was aimed at estimating the CH₄ and N₂O emission fluxes from Hanwoo (the most famous and popular Korean native cattle) manure management systems. CH₄ and N₂O emission fluxes from litter in the Hanwoo cattle barn and composting lot were monitored and calculated for 52 weeks using the dynamic chamber method. The calculated monthly average fluxes of CH₄ and N₂O from litter in the cattle barn ranged from 0.0 to 30.0 ± 13.7 and 0.896 ± 0.557 to 2.925 ± 2.853 μg/m² s, respectively during the whole measurement period. While during the composting period, the monthly average of CH₄ and N₂O emission fluxes were varied from 1.449 ± 0.783 to 86.930 ± 19.092 and 0.511 ± 0.410 to 2.629 ± 1.105 μg/m² s, respectively. The calculated emission fluxes of CH₄ and N₂O from manure management systems in this study were almost 5.4 and 2.1 times, respectively higher than the values reported for the Asian, South and North American countries in the 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas Inventories. Overall, this study initiates the process along with signifies the importance of developing country-specific GHG inventories for the effective reduction of GHG emissions from the livestock sector in Korea. Full article