Effects of gender and slaughter age on physicochemical and quality traits of Korean Hanwoo striploin.

Hanwoo beef is in high demand because of its unique flavor, freshness, and high-fat content. However, the longer rearing period required to enhance marbling in Hanwoo cattle has adverse environmental consequences, such as greenhouse gas emissions and overall rearing costs. To address consumer preferences for leaner and healthier meat, the Korean meat industry has recently introduced Hanwoo heifer meat as an alternative source, but its quality traits are still unclear. Nevertheless, there is a limited body of research exploring the impact of Hanwoo gender (steer, heifer, and cow) and their corresponding slaughter ages on meat quality traits. This study looked into how gender affected the physicochemical and qualitative features of Hanwoo striploin at their respective slaughter ages. Results revealed that cow striploin has higher levels of moisture (66.81%) and protein (20.76%), whereas it contains lower levels of fat (10.66%) and cholesterol (34.66 mg/100 g). Regarding the physicochemical properties, cow striploin exhibited significantly lower shear force, color indexes, and soluble collagen (p < 0.05). However, chondroitin (1.19%) and muscle fiber area (1,545.23 µm2) were significantly higher in steer striploin than in heifer and cow (p < 0.05). Cow striploin exhibited significantly higher levels of oleic acid, unsaturated fatty acids (UFAs), and monounsaturated fatty acids (MUFAs) while having lower levels of eicosadienoic acid and atherogenic index compared to the other two groups. Cows and heifers had higher concentrations of amino acid metabolites than striploin from steers. Furthermore, bioactive metabolites such as carnitine and carnosine content were found higher in cow and heifer respectively. Overall, Hanwoo cattle gender influences the qualitative attributes of striploin; nevertheless, compared to steer and heifer striploin, cow striploin is a relatively good source of protein, fatty acid content, and metabolites conducive to a healthy diet.

Molecular signatures diversity unveiled through a comparative transcriptome analysis of longissimus dorsi and psoas major muscles in Hanwoo cattle.

This study investigates the transcriptome-level alterations that influence production traits and early fattening stage myogenesis in Hanwoo cattle, specifically focusing on the highly prized Longissimus dorsi (LD) and Psoas major (PM) skeletal muscles, which hold significant commercial value. We conducted RNA sequencing analysis on LD and PM muscles from 14 Hanwoo steers (n = 7, each group) at the age of 10 months, all fed the same diet. Our results unveiled a total of 374 and 206 up-regulated differentially expressed genes (DEGs) in LD and PM muscles, respectively, with statistical significance (p < 0.05) and a log2fold change ≥ 1. Genes governing muscle development processes, such as PAX3, MYL3, COL11A1, and MYL6B, were found to be expressed at higher levels in both tissues. Conversely, genes regulating lipid metabolism, including FABP3, FABP4, LEP, ADIPOQ, and PLIN1, exhibited higher expression in the PM muscle. Functional enrichment analysis revealed a tissue-specific response, as PM muscle showed increased lipid metabolism allied pathways, including the PPAR signaling pathway and regulation of lipolysis in adipocytes, while LD was characterized by growth and proliferative processes. Our findings validate the presence of a muscle-dependent transcription and co-expression pattern that elucidates the transcriptional landscape of bovine skeletal muscle.

Transcriptomic Analysis of Newborn Hanwoo Calves: Effects of Maternal Overnutrition during Mid- to Late Pregnancy on Subcutaneous Adipose Tissue and Liver.

This study investigated the transcriptomic responses of subcutaneous adipose tissue (SAT) and liver in newborn Hanwoo calves subjected to maternal overnutrition during mid- to late gestation. Eight Hanwoo cows were randomly assigned to control and treatment groups. The treatment group received a diet of 4.5 kg of concentrate and 6.5 kg of rice straw daily, resulting in intake levels of 8.42 kg DMI, 5.69 kg TDN, and 0.93 kg CP-higher than the control group (6.07 kg DMI, 4.07 kg TDN, and 0.65 kg CP), with respective NEm values of 9.56 Mcal and 6.68 Mcal. Following birth, newly born calves were euthanized humanely as per ethical guidelines, and SAT and liver samples from newborn calves were collected for RNA extraction and analysis. RNA sequencing identified 192 genes that were differentially expressed in the SAT (17 downregulated and 175 upregulated); notably, HSPA6 emerged as the most significantly upregulated gene in the SAT and as the singular upregulated gene in the liver (adj-p value < 0.05). Additionally, differential gene expression analysis highlighted extensive changes across genes associated with adipogenesis, fibrogenesis, and stress response. The functional enrichment pathway and protein-protein interaction (PPI) unraveled the intricate networks and biological processes impacted by overnutrition, including extracellular matrix organization, cell surface receptor signaling, and the PI3K-Akt signaling pathway. These findings underscore maternal overnutrition's substantial influence on developmental pathways, suggesting profound cellular modifications with potential lasting effects on health and productivity. Despite the robust insights that are provided, the study's limitations (sample size) underscore the necessity for further research.

Genome-wide association study comparison analysis based on Hanwoo full-sib family.

Objective: The improvement of carcass traits is essential for the Hanwoo industry because of the Hanwoo grade determination system, and Genome-Wide Association Study (GWAS) analysis is an instrumental tool for identifying the genetic factors that impact these traits. While GWAS analysis utilizing family data offers advantages in minimizing genetic bias, research on family-based GWAS in Hanwoo is currently lacking. Methods: This study classified Group A using both parental and offspring genetic information, and Group B based solely on offspring genetic information, to compare GWAS analysis results of Hanwoo carcass traits. Results: 16 significant SNP markers (carcass weight (CWT) 7, back fat thickness (BFT) 3, marbling score (MS) 6) were identified in Group A, and 7 significant SNP markers (CWT 3, eye muscle area (EMA) 1, BFT 1, MS 2) were identified in Group B. Functional annotation analysis revealed only one common function related to carcass traits between the groups, while Protein-protein interaction (PPI) analysis indicated more gene interactions in Group A. The reliability of estimated values for common SNP markers identified between the groups was higher in Group A. Conclusion: GWAS analysis utilizing parental genetic information holds greater potential for application, owing to its higher reliability of estimated values and the ability to explore numerous candidate genes.

Evaluation of non-additive genetic effects on carcass and meat quality traits in Korean Hanwoo cattle using genomic models.

The traditional genetic evaluation methods generally consider additive genetic effects only and often ignore non-additive (dominance and epistasis) effects that may have contributed to genetic variation of complex traits of livestock species. The available dense single nucleotide polymorphisms (SNPs) panels offer to investigate the potential benefits of including non-additive genetic effects in the genomic evaluation models. Data from 16 971 genotyped (Illumina Bovine 50 K SNP chip) Korean Hanwoo cattle were used to estimate genetic variance components and prediction accuracy of genomic breeding values (GEBVs) for four carcass and meat quality traits: carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT) and marbling score (MS). Five different genetic models were evaluated through including additive, dominance and epistatic interactions (additive by additive, A × A; additive by dominance, A × D and dominance by dominance, D × D) successively in the models. The estimates of additive genetic variances and narrow sense heritabilities (ha2) were found similar across the evaluated models and traits except when additive interaction (A × A) was included. The dominance variance estimates relative to phenotypic variance ranged from 1.7-3.4% for CWT and MS traits, whereas, they were close to zero for EMA and BFT traits. The magnitude of A × A epistatic heritability (haa2) ranged between 14.8 and 27.7% in all traits. However, heritability estimates for A × D and D × D epistatic interactions (had2 and hdd2) were quite low compared to haa2 and were contributed only 0.0-9.7% of the total phenotypic variation. In general, broad sense heritability (hG2) estimates were almost twice (ranging between 0.54 and 0.68) the ha2 for all of the investigated traits. The inclusion of dominance effects did not improve the prediction accuracy of GEBV but improved 2.0-3.0% when epistatic effects were included in the model. More importantly, rank correlation revealed that partitioning of variance components considering dominance and epistatic effects in the model would enable to re-rank of top animals with better prediction of GEBV. The present result suggests that dominance and epistatic effects could be included in the genomic evaluation model for better estimates of variance components and more accurate prediction of GEBV for carcass and meat quality traits in Korean Hanwoo cattle.

Genome-wide association study identifies genomic regions associated with key reproductive traits in Korean Hanwoo cows.

BACKGROUND: Conducting genome-wide association studies (GWAS) for reproductive traits in Hanwoo cattle, including age at first calving (AFC), calving interval (CI), gestation length (GL), and number of artificial inseminations per conception (NAIPC), is of paramount significance. These analyses provided a thorough exploration of the genetic basis of these traits, facilitating the identification of key markers for targeted trait improvement. Breeders can optimize their selection strategies, leading to more efficient and sustainable breeding programs, by incorporating genetic insights. This impact extends beyond individual traits and contributes to the overall productivity and profitability of the Hanwoo beef cattle industry. Ultimately, GWAS is essential in ensuring the long-term genetic resilience and adaptability of Hanwoo cattle populations. The primary goal of this study was to identify significant single nucleotide polymorphisms (SNPs) or quantitative trait loci (QTLs) associated with the studied reproductive traits and subsequently map the underlying genes that hold promise for trait improvement. RESULTS: A genome-wide association study of reproductive traits identified 68 significant single nucleotide polymorphisms (SNPs) distributed across 29 Bos taurus autosomes (BTA). Among them, BTA14 exhibited the highest number of identified SNPs (25), whereas BTA6, BTA7, BTA8, BTA10, BTA13, BTA17, and BTA20 exhibited 8, 5, 5, 3, 8, 2, and 12 significant SNPs, respectively. Annotation of candidate genes within a 500 kb region surrounding the significant SNPs led to the identification of ten candidate genes relevant to age at first calving. These genes were: FANCG, UNC13B, TESK1, TLN1, and CREB3 on BTA8; FAM110B, UBXN2B, SDCBP, and TOX on BTA14; and MAP3K1 on BTA20. Additionally, APBA3, TCF12, and ZFR2, located on BTA7 and BTA10, were associated with the calving interval; PAX1, SGCD, and HAND1, located on BTA7 and BTA13, were linked to gestation length; and RBM47, UBE2K, and GPX8, located on BTA6 and BTA20, were linked to the number of artificial inseminations per conception in Hanwoo cows. CONCLUSIONS: The findings of this study enhance our knowledge of the genetic factors that influence reproductive traits in Hanwoo cattle populations and provide a foundation for future breeding strategies focused on improving desirable traits in beef cattle. This research offers new evidence and insights into the genetic variants and genome regions associated with reproductive traits and contributes valuable information to guide future efforts in cattle breeding.

Dietary effects of protected fat, glycerol, and soybean meal on performance, physiological parameters, carcass characteristics, and behavioral measurements of late-fattening Hanwoo steers under heat stress conditions.

OBJECTIVE: This study aimed to determine the effects of increasing energy and protein levels in diets by including protected fat (PF), glycerol (GL), and soybean meal (SBM) on growth performance, physiological parameters, carcass characteristics, and behavioral measurements of late-fattening Hanwoo steers under heat stress conditions. METHODS: Thirty-six steers (initial body weight, 724.9±58.3 kg; age, 25.5±0.4 month) were assigned into control (total digestible nutrient [TDN] 76%, crude protein [CP] 15%), PF (TDN 83.6%, CP 15%), PF+GL (TDN 83.6%, CP 15%) and PF+GL+SBM (TDN 83.6%, CP 16.5%) by randomized complete block design for a total of 16 weeks with division of 4-week periods. The average temperature-humidity index was 87.0 (1st period; severe), 82.8 (2nd; moderate), 71.4 (3rd; comfort), and 68.1 (4th; comfort). RESULTS: The dry matter intake (DMI) showed no treatments differences during the whole experiment. However, DMI in 1st and 2nd period decreased by approximately 30% and 10% compared to 4th period, respectively. Higher average daily gain and feed conversion ratio were noted for treatments compared to control at both 1st and 2nd period (p<0.05). There were no treatment effects on rectal temperature (RT), cortisol, and behaviors during the entire experiment. However, both RT and cortisol in 0, 1st and 2nd period were higher than those of 3rd and 4th period (p<0.05). Carcass yield and grade remained unaffected by increasing TDN and CP levels. Behavioral changes in the hot season (1st period) included reduced lying (43%), increased standing (48%), decreased walking (62%), and decreased eating (38%) (p<0.05), with an increase in drinking by 54%. Rumination during standing was 53% higher, while rumination during lying was about 33% lower compared to the post-hot season (3rd period) (p<0.05). CONCLUSION: Dietary supplementation of protected fat in late-fattening Hanwoo steers under heat stress had a positive effect on preventing a reduction in performance.

Repeatability of feed efficiency and its relationship with carcass traits in Hanwoo steers during their entire growing and fattening period.

Objective: This study investigated the repeatability of feed efficiency and its association with carcass traits in Hanwoo steers during the entire growing and fattening periods. Methods: The growth and intake of thirty-six Hanwoo steers (259 ± 19.7 kg; nine months) were monitored throughout five periods, including two growing periods (GP) and three fattening periods (FP). The steers were fed two types of concentrate mixes with varying nutrient compositions until they reached a target weight of 800 kg for slaughter. For each period, steers were categorized into three classes based on their feed efficiency rankings using residual feed intake (RFI) and feed conversion ratio (FCR). Feed efficiency repeatability was assessed using the Spearman correlation coefficient, decomposition of random errors, and the Theil segregation index (TSI). The Pearson correlation coefficient was used to examine the relationship between feed efficiency and carcass traits. Results: The results demonstrated a significant and high correlation with RFI, but not FCR, during the growing or fattening stages (r > 0.5; P < 0.01). When steers were classified according to their feed efficiency rankings, 58% of the animals in the high RFI class (low efficient) initially (GP 1) remained in the same class by the last period (FP 3), whereas steers were randomly distributed based on FCR. The repeatability, assessed by the decomposition of random errors, was higher for RFI (0.61) than for FCR (0.15). The TSI also indicated that RFI rankings, rather than FCR rankings, are more likely to be maintained. Moreover, a weak association was observed between feed efficiency and carcass traits. Conclusion: In conclusion, RFI repeatability throughout the growing and fattening periods surpassed that of the FCR, with steers classified as high RFI during the GP more likely to remain in the same class during the FP. Feed efficiency was weakly correlated with carcass traits.

Impact of rumen cannulation surgery on rumen microbiota composition in Hanwoo steers.

Rumen cannulation is a surgical technique used to collect rumen contents from ruminants. However, rumen cannulation surgery may potentially impact the composition of the rumen microbiota. This study aimed to examine the longitudinal alterations in the rumen microbiota composition of Hanwoo steers after cannulation surgery. In this study, eight Hanwoo steers were used; four steers underwent rumen cannulation surgery (cannulation group), while the remaining four were left intact (control group). Rumen samples were collected from all eight steers using the stomach tubing method on the day before surgery (day 0) and on postoperative days 1, 4, 7, 10, 14, 17, 21, 24, and 28, resulting in 80 samples (10 timepoints × 8 animals). The microbiota of all 80 samples were analyzed using 16S rRNA gene amplicon sequencing with Quantitative Insights into Microbial Ecology version 2 (QIIME2). There were no significant differences (p > 0.05) in all major phyla and most major genera representing at least 0.5% of total sequences across all 80 samples between the control and cannulation groups on the preoperative and postoperative days. However, while the alpha diversity indices did not differ (p > 0.05) between the two groups on the preoperative day, they significantly differed (p < 0.05) between the two groups on the postoperative days. Further, the overall microbial distribution based on both unweighted and weighted principal coordinate analysis plots significantly differed (p < 0.05) between the two groups on both the preoperative and postoperative days. Orthogonal polynomial contrasts indicated that major genera and microbial diversity in the cannulation group decreased following surgery but returned to their initial states by postoperative day 28. In conclusion, this study demonstrates that rumen cannulation surgery affects some major taxa and microbial diversity, suggesting that the rumen cannulation method can alter the composition of rumen microbiota in Hanwoo steers.

Effect of Crude Polysaccharides from Ecklonia cava Hydrolysate on Cell Proliferation and Differentiation of Hanwoo Muscle Stem Cells for Cultured Meat Production.

Ecklonia cava, a brown seaweed native to the East Asian coast, is known for its unique composition, including polysaccharides, polyphenols, and phlorotannins. Fucoidan is a sulfated polysaccharide widely used as a functional ingredient in foods. This study obtained crude polysaccharides (ECC_CPS) from E. cava celluclast enzymatic hydrolysate using ethanol precipitation. ECC_CPS increased cell viability during the proliferation of Hanwoo muscle satellite cells (HMSCs). The effect of ECC_CPS on the expression of proliferation-related markers was confirmed as MYF5 and MYOD expression significantly increased, whereas PAX7 expression was maintained. The evaluation of cell migration activity has a major impact on cell proliferation and differentiation, and the cell migration index significantly increased with ECC_CPS treatment (p < 0.01). This was related to the HGF/MET pathway and FAK pathway. Treatment with ECC_CPS promoted differentiation at the cell differentiation stage, thereby increasing the expression of differentiation markers, such as MYH2, MYH7, and MYOG (p < 0.001 or p < 0.01). Therefore, our findings imply that crude polysaccharide obtained from E. cava can be an additive ingredient that enhances the proliferation and differentiation of muscle satellite cells used in the manufacture of cultured meat products.

Effects of Dietary Crude Protein Level of Concentrate Mix on Growth Performance, Rumen Characteristics, Blood Metabolites, and Methane Emissions in Fattening Hanwoo Steers.

This study aimed to investigate the effect of varying levels of dietary crude protein (CP) on growth performance, rumen characteristics, blood metabolites, and methane emissions in fattening Hanwoo steers. Twenty-four steers, weighing 504 ± 33.0 kg (16 months old), were assigned to four dietary treatments with different CP concentrations (15, 18, 19, and 21% of CP on a dry matter (DM) basis). A linear increasing trend in the average daily gain (ADG) was observed (p = 0.066). With increased dietary CP levels, the rumen ammonia concentration significantly increased (p < 0.001), while the propionate proportion linearly decreased (p = 0.004) and the proportions of butyrate and valerate linearly increased (p ≤ 0.003). The blood urea exhibited a linear increase (p < 0.001), whereas the blood non-esterified fatty acids and cholesterol showed a linear decrease (p ≤ 0.003) with increasing dietary CP. The methane concentration from eructation per intake (ppm/kg), forage neutral detergent fiber (NDF) intake, total NDF intake, and ADG exhibited linear decreases (p ≤ 0.014) across the treatments. In conclusion, increasing the dietary CP up to 21% in concentrates demonstrated a tendency to linearly increase the ADG and significantly decrease the propionate while increasing the butyrate. The methane concentration from eructation exhibited a tendency to linearly decrease with increasing dietary CP.

Effect of Lupin Supplementation on the Growth, Carcass, and Meat Characteristics of Late-Fattening Hanwoo Steers.

This study aimed to investigate the effects of lupin flake supplementation on the growth, plasma parameters, carcass characteristics, and meat composition of late-fattening Hanwoo steers. The steers (n = 40) were randomly divided into the four groups with 10 steers each: LP0 (lupin flake 0%), LP3 (lupin flake 3%), LP6 (lupin flake 6%), and LP9 (lupin flake 9%). The total digestible nutriant intake increased as the concentration of lupin increased (linear and quadratic effects; p < 0.05). The thiobarbituric acid-reactive substance content in the strip loins decreased as lupin flake supplementation levels increased (linear and quadratic effects; p < 0.05), while carnosine levels increased linearly (p < 0.05). As the lupin flake supplementation level increased, anserine and creatinine contents increased linearly and quadratically (p < 0.05). Similarly, adenosine triphosphate (ATP) and adenosine monophosphate (AMP) content increased with increasing lupin flake supplementation levels in linear and quadratic effects (p < 0.001). Palmitoleic acid content increased significantly with increasing lupin flake supplementation level (linear and quadratic effects; p < 0.05). The content of oleic acid in the strip loin was not significant, but the unsaturated fatty acid (UFA) (p < 0.05) and n-6/n-3 ratio (p < 0.05) increased. The results of this study indicated that although lupin flake supplementation did not markedly affect the growth, carcass characteristics, or meat composition of late-fattening Hanwoo steers, it exerted a positive effect on the flavor, taste profiles (anserine, creatinine, ATP, and AMP), hypotonicity (TBARS), and healthy meat production (UFA and n-6/n-3 ratio) related to beef.

Effects of heat stress on performance, physiological parameters, and blood profiles of early-fattening Hanwoo steers in climate chambers.

OBJECTIVE: This study was conducted to assess effects of heat stress on growth performance, physiological parameters, and blood profiles of Hanwoo steers during early-fattening period in climate chambers. METHODS: Four Hanwoo steers (body weight, 454.3±10.9 kg; age, 14±0.1 month) were allocated into four levels of temperature-humidity index (THI) in a 4×4 Latin square design for 21 days (pre-adaptation, 7 d; heat stress, 7 d; post-adaptation, 7 d) per period. Experimental treatments were assigned according to THI chart based on National Institute Animal Science (NIAS, 2022): Comfort (25.5°C to 26.5°C, 60%; THI 73 to 75), Mild (28°C to 29°C, 60%; THI 77 to 79), Moderate (29.5°C to 30.5°C, 80%; THI 82 to 84), and Severe (31°C to 32°C, 80%; THI 85 to 86) in separate climatic controlled chambers. RESULTS: The dry matter intake (DMI) of the formula feed was lower in Severe compared to Mild and Comfort (p<0.05). The DMI of rice straw was the lowest in Severe and lower in Moderate than Comfort and Mild (p<0.05). Both average daily gain and feed conversion ratio of Severe and Moderate were lower than those of Mild and Comfort (p<0.05). Water intake was the highest in Severe and lower in Moderate compared with Comfort and Mild (p<0.05). Heart rate and rectal temperature increased as THI level increased (p<0.05). Glucose was the lowest in Severe and lower in Moderate compared to Comfort (p<0.05). On the contrary, non-esterified fatty acid was the highest in Severe and lower in Moderate compared with Comfort (p<0.05). Blood urea nitrogen of Moderate and Severe were higher than those of Comfort and Mild (p<0.05). Cortisol increased as THI increased (p<0.05). CONCLUSION: This study demonstrated the negative effects of heat stress on the performance and physiological responses of Hanwoo steers during the early-fattening period. In addition, it is judged that the THI chart for Hanwoo steers of National Institute of Animal Science (2022) was properly calculated.

Effects of mid-to-late prepartum feed supplementation in Hanwoo beef cows on their performance, blood metabolites, and the carcass characteristics and metabolites of their neonatal calves.

Introduction: This study aimed to evaluate the implications of supplementary nutrition during the mid-to-late pregnancy on various parameters in Hanwoo cows and their subsequent neonatal calves. Materials and methods: Eight Hanwoo cows in their first parity were divided into two groups. The control group (C, 100%) received 3kg of concentrate and 5kg of rice straw throughout the pregnancy period, while the treatment group (T, 150%) increased their diet during mid-to-late pregnancy. Both performance assessments and blood metabolite analyses were performed for the pregnant cows. Neonatal calves were subjected to morphometric evaluations, blood sampling, and detailed morphometric analyses of carcasses and gastrointestinal components. Results: Performance indices of the cows showed that both Pregnancy Period (PregP) and Body Condition Score (BCS) were significantly improved with supplemental feeding (p <0.05). Improvements in Body Weight (BW) and Feed Conversion Ratio (FCR) were not statistically significant. Blood metabolite analysis for the cows revealed decreased levels of triglycerides (TGLate), non-esterified fatty acids (NEFALate), and progesterone (P4Late), with a notable increase in glucose (GluLate) levels (p <0.01). In the neonatal calves, anatomical metrics of the gastrointestinal tissues showed increased Omasum Width (OmasWdth) values in the supplemented group (p =0.053). There was significant increase of papillae and villus lengths in the rumen and small intestine (p <0.01 and p <0.05, respectively). Morphometric evaluations displayed longer body lengths (BLnth) and larger chest width (ChestWdth) in the treated calves (p <0.05 and p <0.01, respectively). Carcass characteristics showed no substantial variations between the groups, while blood analysis in the calves revealed decreased GPT levels in the nutritionally supplemented group (p<0.05). Discussion: The findings indicate that supplementing the diets of Hanwoo cows during mid-to-late pregnancy leads to significant changes in select maternal blood metabolites and influences specific anatomical and morphometric features in neonatal calves, all without significant shifts in carcass attributes.

Evaluation of umami taste in Hanwoo with different feed sources by chemical analysis, electronic tongue analysis, and sensory evaluation.

This study aimed to evaluate umami taste in Hanwoo with different feed by chemical analysis, sensory evaluation and an electronic tongue system. Hanwoo cattle were divided into three groups: control group (fed only total mixed ration [TMR]), T1 (fed soybean meal + TMR), and T2 (fed soybean meal + corn-dried distiller's grain with solubles [Corn DDGS] + TMR). The three most abundant fatty acids (C18:1n-9, C16:0, and C18:0) in the T1, T2, and control groups accounted for 83.63%, 86.07%, and 85.52% of the total fatty acid content, respectively. Umami taste-related glutamic acid levels were significantly high in T1 (109.89 mg/kg), followed by T2 (66.66 mg/kg) and control (47.27 mg/kg). Fatty acid levels showed a high correlation with umami taste. The results of this study showed that the amino acid and fatty acid levels had been affected by feed types and soybean- or Corn DDGS-based feed potentially enhanced Hanwoo's umami flavor.

The First Identification of Cryptosporidium parvum Virus-1 (CSpV1) in Hanwoo (Bos taurus coreanae) Calves in Korea.

Cryptosporidium is an obligate coccidian parasite that causes enteric diseases in bovine species. A double-stranded RNA virus associated with C. parvum oocysts, Cryptosporidium parvum virus-1 (CSpV1), has been characterized. However, the relationship between the abovementioned coccidian parasite and the virus has not been studied in the context of the known clinical outcomes. This study aimed to characterize the prevalence and molecular traits of CSpV1 in diarrheal feces of Hanwoo (Korean indigenous cattle) calves. Of the 140 fecal samples previously tested for C. parvum, which were obtained from Hanwoo calves aged 60 days, 70 tested positive and 70 tested negative. These samples were included in this study. By using the polymerase chain reaction (PCR) analysis targeting the RdRp gene of CSpV1, we detected CSpV1 in 28 samples (20.0%), with infection rates of 31.4% (22/70) in C. parvum-positive and 8.6% (6/70) in C. parvum-negative samples. CSpV1 samples detected in the same farm were clustered together. To the best of our knowledge, this is the first study to report the prevalence and molecular characteristics of CSpV1 in Hanwoo calves in the Republic of Korea, providing important insights into the relationship between C. parvum and CSpV1 in bovine hosts.

Complete genome sequence of probiotic Lactobacillus johnsonii 7409N31 isolated from a healthy Hanwoo calf.

Lactobacillus johnsonii 7409N31 was isolated from the feces of a healthy 11-day-old Hanwoo calf from a farm in Geochang-gun, Gyeongsangnam-do, Korea. The genome of the strain was completely sequenced using the PacBio RSII sequencing system, and it was confirmed that it was composed of one circular chromosome. The size of the entire genome was 2,198,442 bp, and it had 35.01 mol% guanine + cytosine (G + C) content and 2,222 protein-coding sequences, 24 rRNA, 3 ncRNA, and 112 tRNA genes. Strain 7409N31 possessed genes encoding enzymes involved in the hydrolysis of both fibrous and non-fibrous carbohydrates. These data provide a comprehensive theoretical understanding for developing industrial probiotic feed additives that improve nutrient digestibility.

Improved pregnancy rate and sex ratio in fresh/frozen in vivo derived embryo transfer of Hanwoo (Bos taurus coreanae) cows.

This study aimed to assess the effects of embryonic developmental stage, quality grade, and fresh or frozen/thawed conditions on the pregnancy rate and sex ratio of live offspring in Hanwoo (Bos taurus coreanae) cows. The quality and developmental stage of in vivo-derived (IVD) transferred embryos were evaluated using the standard criteria of the International Embryo Technology Society. The recipient cows were synchronized using conventional (estradiol benzoate and progesterone) protocols before embryo transfer. Embryos were transferred to 297 cows, and pregnancy was monitored for 60-70 days after embryo transfer. The pregnancy rates of fresh and frozen/thawed embryos were 56.90% and 52.49%, respectively. Pregnancy rates varied according to embryo quality (56.18% for grade 1 vs. 36.67% for grade 2). Pregnancy rates also varied by developmental stage and cryopreservation (67.86% vs. 63.49% for stage 4-1, 64.00% vs. 54.72% for 5-1, and 50.00% vs. 47.83% for 6-1, in fresh embryos vs. frozen/thawed embryos, respectively). For stage 7-1, the pregnancy rates were 72.73% for fresh embryos and 20.00% for frozen/thawed embryos. In 66 fresh embryos, the sex ratio of live offspring was 5:5, whereas it was 4(female):6(male) for frozen/thawed embryos among the 95 frozen/thawed embryos. The miscarriage rate was approximately 3% higher for frozen/thawed embryos than for fresh embryos (18.1% for fresh vs. 21.1% for frozen). Seasonal fertility rates were 33.3% in spring, 55.67% in summer, 52.8% in autumn, 60.0% in winter. The following male-to-female ratios were observed in different seasons: 6.7:3.3 in spring, 4.0:6.0 in summer, 5.5:4.5 in autumn, and 3.3:6.7 in winter. The current data revealed no significant differences in pregnancy rates between fresh and frozen/thawed IVD embryos. However, there was a lower pregnancy rate with advanced-stage frozen/thawed embryos (stage 7-1). The current study provides comprehensive results for the better optimization of embryo transfer in Hanwoo cattle to obtain the desired fertility rate, pregnancy rate, and sex ratio of calves. These results provide important insights into the factors that influence the viability and success of IVD embryo transfer in Hanwoo cows and may have practical applications for improving breeding programs and reducing production costs.

Increased accuracy of estrus prediction using ruminoreticular biocapsule sensors in Hanwoo (Bos taurus coreanae) cows.

Visual estrus observation can only be confirmed at a rate of 50%-60%, which is lower than that obtained using a biosensor. Thus, the use of biosensors provides more opportunities for artificial insemination because it is easier to confirm estrus than by visual observation. This study determines the accuracy of estrus prediction using a ruminoreticular biosensor by analyzing ruminoreticular temperature during the estrus cycle and measuring changes in body activity. One hundred and twenty-five Hanwoo cows (64 with a ruminal biosensor in the test group and 61 without biosensors in the control group) were studied. Ruminoreticular temperatures and body activities were measured every 10 min. The first service of artificial insemination used gonadotropin-releasing hormone (GnRH)-based fixed-time artificial insemination protocol in the control and test groups. The test group received artificial insemination based on the estrus prediction made by the biosensor, and the control group received artificial insemination according to visual estrus observation. Before artificial insemination, the ruminoreticular temperature was maintained at an average of 38.95 ± 0.05°C for 13 h (-21 to -9 h), 0.73°C higher than the average temperature observed at -48 h (38.22 ± 0.06°C). The body activity, measured using an indwelling 3-axis accelerometer, averaged 1502.57 ± 27.35 for approximately 21 h from -4 to -24 h before artificial insemination, showing 203 indexes higher body activity than -48 hours (1299 ± 9.72). Therefore, using an information and communication techonology (ICT)-based biosensor is highly effective because it can reduce the reproductive cost of a farm by accurately detecting estrus and increasing the rate of estrus confirmation in cattle.

Peri-estrus activity and mounting behavior and its application to estrus detection in Hanwoo (Korea Native Cattle).

This study was conducted to investigate the change in activity and mounting behavior in Hanwoo (Korean Native Cattle) during the peri-estrus period and its application to estrus detection. A total of 20 Hanwoo cows were fitted with a neck-collar accelerometer device, which measured the location and acceleration of cow movements and recorded the number of instances of mounting behavior by the altitude data. The data were analyzed in three periods (24-, 6-, and 2-h periods). Blood samples were collected for 5 days after the prostaglandin F2α (PGF2α) injection, and the concentrations of estradiol, progesterone, follicle-stimulating hormone, and luteinizing hormone were determined by enzyme-linked immunosorbent assays. Activity and mounting behavior recorded over 2-h periods significantly increased as estrus approached and were more efficient at detecting estrus than over 24- and 6-h periods (p < 0.05). Endocrine patterns did not differ with the variation of individual cows during the peri-estrus period (p > 0.05). Activity was selected as the best predictor through stepwise discriminant analysis. However, activity alone is not enough to detect estrus. We suggest that a combination of activity and mounting behavior may improve estrus detection efficiency in Hanwoo. Further research is necessary to validate the findings on a larger sample size.