Search Results (113)

The present study was conducted to demonstrate the effects of Codium fragile extract on methane production using in vitro and in vivo experiments. An in vitro batch experiment was conducted to evaluate different inclusion levels of Codium fragile extract (0, 0.25, and 0.5% of substrate dry matter). Methane production significantly decreased in the 0.5% treatment (p < 0.05), whereas dry matter digestibility and total volatile fatty acid concentration were not significantly affected (p > 0.05). Based on the in vitro results, an in vivo feeding experiment was conducted using a 0.5% inclusion level of Codium fragile extract on Hanwoo steers. Methane emissions were significantly decreased by approximately 10% in steers fed Codium fragile extract (p < 0.05). In contrast, rumen fermentation characteristics, feed intake, average daily gain, and blood parameters were not significantly different between the treatments (p > 0.05). These results demonstrate that a dietary additive with 0.5% Codium fragile extract effectively reduced methane emissions without negatively affecting rumen fermentation and growth performance in Hanwoo steers. Full article

This study aimed to derive a more accurate and representative ammonia emission factor specifically for Hanwoo manure composting. We monitored real-time emissions using a large-scale flux chamber 2400 m³), which we modified from an actual composting shed at a Hanwoo ranch in Chuncheon. Measurements were conducted across summer, autumn, and winter using a laser-based ammonia analyzer. The results indicated that ammonia emissions followed a seasonal order of Summer (61.7633 μg s⁻¹ t⁻¹) > Autumn (38.8512 μg s⁻¹ t⁻¹) > Winter (8.3189 μg s⁻¹ t⁻¹). The final calculated emission factor was 0.8368 kgNH₃ yr⁻¹ animal⁻¹ as an all season average. While seasonal differences were statistically significant, hourly variations were less distinct compared to emission spikes induced by periodic mechanical agitation during the composting process. Our emission factor is significantly lower than national inventories, which is attributed to the inclusion of disturbances and the huge scale of the experimental chamber. These results offer a scientific foundation for updating the national inventory and provide a framework for future research on greenhouse gas emissions from diverse livestock sectors. Full article

This study identified genomic regions associated with carcass traits and primal cut yields in Hanwoo cattle using weighted single-step genome-wide association study (WssGWAS). A total of 50,227 carcass records and genomic data from 23,573 animals with 45,057 single-nucleotide polymorphisms were analyzed. Heritability estimates were 0.24 for carcass weight, 0.22 for eye muscle area, 0.31 for backfat thickness, and 0.36 for marbling score, while those for primal cut yields ranged from 0.02 to 0.26. For carcass traits, candidate genes were identified for carcass weight (XKR4 2.35%, COBL 1.26%), eye muscle area (LCORL 1.56%, TGFBR2 1.49%), backfat thickness (ATG7 1.27%, MYPN 1.33%), and marbling score (TWIST2 1.16%, BMP4 1.14%). For primal cut yields, the chromosome 6 region containing WDR1 was commonly identified across six traits and the chromosome 4 region containing CACNA2D1 across five traits; the chromosome 28 region containing SIRT1 explained the highest genetic variance (6.46%) for striploin. These pleiotropic regions are potential targets for genomic selection to improve production efficiency and carcass value in Hanwoo. Full article

Mitigating enteric methane emissions through diet formulation remains a significant challenge in cattle nutrition. This study developed a system to evaluate the methane production potential of feeds, expressed as the effective ruminal methane production rate (eRMR, mL/g dry matter [DM]), using a discontinuous in vitro ruminal fermentation system using rumen fluid. Sixteen concentrate feeds and two forages were tested, with a reference diet (ryegrass straw:corn:corn gluten feed = 1:1:1) included in each batch to standardize conditions and account for associative effects among feeds. Test feeds were incubated with the reference diet in closed bottles under strictly anaerobic conditions. Methane and total gas production were measured at 2, 4, 6, and 24 h, and true dry matter digestibility was calculated after 6 and 24 h. For each batch, sample feed values were corrected and standardized using those of the reference diet. The eRMR value was calculated by integrating a differential equation with parameters incorporating ruminal digestion and passage dynamics. The test feed eRMR values ranged from 1.2 mL/g DM (soybean meal) to 56.7 mL/g DM (soybean hull), with the reference diet at 14.8 mL/g DM. Evaluation of feed eRMR using data from two in vivo studies demonstrated strong correlations between predicted diet-specific eRMR values and measured methane emissions from Hanwoo steers (r = 0.93 and 0.85). This system, incorporating rumen dynamics with a reduced sampling schedule, provides a precise and practical tool for predicting in vivo enteric methane production and optimizing diet formulations to mitigate methane emissions from cattle. Full article

Carcass weight (CW) is a major determinant of beef yield and market value in Korea, yet the genetic basis of this trait remains largely unexplored in cattle from Jeju Island. In this study, we performed a genome-wide association study (GWAS) using both a mixed linear model (MLM) and the FarmCPU approach, followed by pathway and network analyses to identify loci and biological functions underlying CW variation. A total of 256 Jeju cattle (92 Jeju Black and 164 Jeju Black × Hanwoo crossbreds) were initially sampled. One crossbred sample failed genotyping, leaving 255 animals (92 Jeju Black and 163 crossbreds) for analysis. Animals were genotyped using the Illumina BovineSNP50 v3 BeadChip, and 39,055 high-quality single nucleotide polymorphisms (SNPs) were retained after quality control. The MLM analysis detected no genome-wide significant associations, whereas the FarmCPU analysis identified six significant loci on Bos taurus chromosomes 3, 5, 6, 10, and 13, each explaining 2.55–9.58% of the phenotypic variance. Candidate genes located near these loci included EIF2B3, HECTD3, SOX5, KLF6, PHACTR3, and two uncharacterized protein-coding genes. Functional enrichment analysis identified biologically relevant pathways including lysine degradation, tryptophan metabolism, glycerolipid metabolism, fatty acid biosynthesis, extracellular matrix–receptor interaction, and signaling cascades such as PI3K–Akt and Rap1, although most pathways were not statistically significant after FDR correction. Protein–protein interaction (PPI) network analysis using STRING highlighted modules of signaling, extracellular matrix, and metabolic genes. These clusters suggest that coordinated interactions among these pathways contribute to carcass growth and development. These findings provide new insights into the molecular basis of CW in Jeju Black and Hanwoo × Jeju Black crossbred cattle and identify candidate genes and pathways that may be useful for genomic selection and the sustainable improvement of Jeju Black cattle populations. Full article

This study investigates the environmental impact of rising meat consumption in Japan, focusing on water and carbon footprints associated with livestock production and transportation. We quantify the water footprint of beef cattle and swine, differentiating between direct water use (drinking and service water) and indirect water use (feed production). Our findings reveal a significant contribution of indirect water use to the overall water footprint, with 15,090.3 m³/ton for beef and 4398.6 m³/ton for swine, primarily attributed to feed crop production. These results are consistent with previous studies, with minor variations. Furthermore, we simulate transportation scenarios for beef and pork products, considering both road and rail transport. This analysis encompasses key parameters such as transportation volume, direct and indirect water use, CO₂ emissions, and fuel consumption. By evaluating the environmental implications of both livestock farming and product transportation, this study provides valuable insights for sustainable practices and informed policy development in Japan’s specific context. Our research contributes to a nuanced understanding of water use patterns in livestock production by distinguishing between direct and indirect water footprints. The integration of transportation simulations further enhances the scope of the study, offering a holistic perspective on the interconnectedness of meat production and distribution. This comprehensive approach aims to support informed decision-making processes in sustainable agriculture, environmental conservation, and policy development within Japan’s unique context. Full article

This study analyzed the economic feasibility of utilizing Undaria pinnatifida sporophylls (UPSs), a major by-product of seaweed aquaculture, as feed for Hanwoo cattle. It employed a partial equilibrium framework to quantify processing costs, avoided disposal costs, substitution savings from reduced grain imports, and monetized methane abatement benefits, calibrated with national statistics on Hanwoo production and feed use for 2022–2024. The analysis revealed that, in the absence of environmental valuation, additional collection, transport, and drying costs (KRW 25,714–102,857 per head at 0.25–1.0% inclusion) outweighed savings from disposal avoidance and import substitution. When methane abatement was priced under Korea’s Emissions Trading Scheme, however, net benefits emerged, ranging from KRW 22,757 to 40,859 per head, with welfare gains of KRW 19,108 million at 1.0%. Sensitivity analysis confirmed a strong dependence on carbon prices: benefits were substantial at KRW 40,000 per ton of CO₂, remained positive yet relatively limited at KRW 20,000, and shifted into negative territory at KRW 10,000. These findings demonstrate that UPS feed utilization can advance climate mitigation and feed security, provided it is supported by effective carbon pricing and producer-oriented policies. Full article

This study aimed to characterize behavioral differences between true estrus (TE) and false estrus (FE) in cows using neck-mounted six-axis inertial measurement unit sensors to reduce false positives in automated detection systems. A retrospective analysis was conducted on 1464 validated estrus alerts from 414 Hanwoo cows across 13 commercial farms in South Korea. Alerts were classified as TE (625 alerts) or FE (839 alerts) based on comprehensive validation criteria, including standing heat observation, artificial insemination records, ovulation confirmation, and pregnancy outcomes. Mounting activity, rumination time, and lying time were analyzed. True estrus exhibited significantly higher (p < 0.0001) total number of mounts and maximum mounting duration compared to FE over the entire observation period. Notably, the maximum number of mounts per hour was higher (p < 0.0001) in FE before alert generation but higher (p < 0.0001) in TE afterward, with FE declining rapidly. Coefficients of variation for rumination and lying time were significantly higher (p < 0.0001) in TE than in FE, indicating greater behavioral disruption. These findings revealed that secondary behavioral signs exhibit distinct quantitative and temporal patterns between TE and FE, suggesting potential criteria that could be integrated into automated detection algorithms to reduce false-positive rates. Full article

This study aims to characterize tissue-specific expression patterns in Hanwoo steers by identifying co-expression modules, functional pathways, and hub genes related to fat and muscle traits using Weighted Gene Co-expression Network analysis (WGCNA). RNA-Seq data were generated from three muscle tissues (longissimus muscle, tenderloin, and rump) and two fat tissues (back fat and abdominal fat) collected from six 30-month-old Hanwoo steers. Quality control of raw sequencing reads was performed using FastQC, and trimmed reads were aligned to the bovine reference genome (ARS-UCD1.3) using HISAT2. We also identified a gene co-expression network via WGCNA using normalized gene expression values. Modules were defined based on topological overlap and correlated with tissue-specific expression patterns. Modules with a significant association (p < 0.05) were used for functional enrichment based on Gene Ontology (GO) and KEGG pathways, as well as Protein–Protein Interaction Network analysis. A total of seven co-expression modules were identified by WGCNA and labeled in distinct colors (yellow, blue, red, brown, turquoise, green, black). Among them, the yellow and blue modules were positively associated with back fat, while the turquoise and green modules showed a negative correlation with abdominal fat. Additionally, the turquoise or green module was positively correlated with longissimus and rump tissues, indicating distinct gene expression patterns between fat and muscle. This study identified key co-expression modules and hub genes associated with muscle and fat metabolism. Notably, ARPC5 (blue module) was involved in lipid metabolism and energy storage, whereas AGPAT5 (turquoise module) was linked to maintaining muscle cell structure and function. These findings reveal biological mechanisms for tissue-specific gene regulation, providing targets for enhancing meat quality in Hanwoo. Full article

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

Reproductive outcomes following synchronized ovulation protocol in beef cattle are influenced by multiple factors, making protocol selection based on farm-specific conditions essential. This retrospective study analyzed the relationship between pregnancy rates and associated factors under the CIDR (GnRH with CIDR insertion–PGF_2α with CIDR removal–GnRH), GPG (GnRH–PGF_2α–GnRH), and GPPG (GnRH–PGF_2α–PGF_2α–GnRH) protocols in Hanwoo cattle. The highest pregnancy rate was observed with the CIDR protocol (58.3%), whereas the GPG protocol yielded the lowest (47.5%). The CIDR protocol demonstrated superior suitability compared with the GPG protocol in first service (61.0% vs. 47.0%) and young breeding cattle (parity: 0–2; 61.6–70.0% vs. 47.5–48.6%). The dominant follicle size strongly associated with pregnancy success was 13–16 mm, and the CIDR protocol induced these follicles more frequently than the GPG protocol (50.2% vs. 35.5%). Although interpretive bias may exist from data collected from pregnant animals only, CIDR protocol significantly increased luteinizing hormone levels compared to GPG. The GPPG protocol produced outcomes that were improved relative to the GPG protocol and statistically comparable to the CIDR protocol. These findings addressed the study’s objective, identifying optimal synchronized ovulation strategies and underscoring reproductive management importance for Korean Hanwoo operations. 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

A healthy gut microbiota in calves is necessary for optimal performance and development. Considering that probiotics have been shown to improve gut microbiota, the aim of this study was to investigate the effects of Clostridium butyricum on growth performance, blood parameters, and gut microbiota in Hanwoo calves. In total, 92 calves from two farms were randomly assigned to four groups: a control and three treatment groups that received increasing doses of C. butyricum (CB1, CB2, and CB3) during the first 5 days after birth. Independent experiments were conducted at each farm with different measurements, where body weight was monitored and blood, rumen, and fecal samples were collected to assess physiological responses and microbial profiles. Notably, significant differences were observed in blood amylase and acid–base parameters, suggesting that C. butyricum supplementation may enhance metabolic stability and buffering capacity. Microbial profiling revealed preserved alpha diversity and compositional shifts in both the rumen and fecal microbiota. Particularly, there was an increase in the relative abundances of Prevotella and Muribaculaceae and a decrease in the abundances of the pathogenic genera Escherichia and Shigella in calves fed C. butyricum-supplemented diets. These changes, along with a trend toward a reduced frequency and severity of diarrhea, suggest that C. butyricum supplementation may support gut health and promote stable early growth in neonatal calves. Full article

This study evaluated the effects of early-life creep feeding with a high-protein, high-energy diet on growth performance, ruminal fermentation, and gut microbiota in Hanwoo calves (n = 10). Calves were assigned to control or treatment groups from birth to 6 months of age. No significant differences were observed in body weight, average daily gain (ADG), or feed conversion ratio (FCR), but ADG and dry matter intake (DMI) tended to be higher in the treatment group. Ruminal pH, NH₃-N, and volatile fatty acid (VFA) concentrations showed no significant differences. Fecal VFA profiles exhibited numerical trends suggesting higher propionate at 3 months and lower acetate, butyrate, and total VFA at 6 months in the treatment group, potentially reflecting altered substrate availability or absorption capacity, though these mechanisms were not directly measured. Microbiota analysis indicated stable ruminal alpha diversity, with numerical increases in fecal Bacteroidetes and genera such as Fournierella and Flavonifractor in the treatment group. These results suggest that early creep feeding with high-nutrition diets can support intake and promote potential shifts in hindgut microbiota composition without compromising overall microbial stability. Further research with larger sample sizes is needed to confirm these trends and assess long-term impacts on calf health and productivity. Full article

Weight is the most basic and important indicator in cattle management, and automation of its measurement serves as a fundamental step toward modern smart livestock farming. Automated weighing systems (AWS) capable of continuously measuring cattle weight, even during movement, have been explored as key monitoring components in smart livestock farming. However, owing to the high measurement variability caused by environmental factors, the accuracy of AWSs has been questioned. These factors include real-time fluctuations due to animal activities (e.g., feeding and locomotion), as well as measurement errors caused by residual feed or excreta within the AWS. Therefore, this study aimed to develop an algorithm to enhance the reliability of steer weight measurements using an AWS, ensuring close alignment with actual cattle body weight. Accordingly, daily weight data from 36 Hanwoo steers were processed using a three-stage approach consisting of outlier detection and removal, weight estimation, and post-processing for weight adjustment. The best-performing algorithm that combined Tukey’s fences for outlier detection, mean-based estimation, and post-processing based on daily weight gain recommended by the National Institute of Animal Science achieved a root mean square error of 12.35 kg, along with an error margin of less than 10% for individual steers. Overall, the study concluded that the AWS measured steer weight with high reliability through the developed algorithm, thereby contributing to data-driven intelligent precision feeding. Full article