Understanding adipocyte development in fetus during bovine pregnancy is important for strengthening fattening technology. Additionally, nutritional level of dams during pregnancy has the potential to improve offspring growth and fat development. The purpose of this study is to evaluate the intramuscular adipocyte development and expression level of related genes in bovine fetus, and the effect of increased crude protein (CP) intake during pregnancy on the growth performance and carcass characteristics of male offspring. Eighty six pregnant Hanwoo cows (average body weight, 551.5 ± 51.3 kg, age 5.29 ± 0.61 y) were used. Fetuses were collected at 90, 180 and 270 d of gestation from 18 pregnant Hanwoo cows. The remaining 68 pregnant cows were randomly assigned to 2 feeding groups. The control (CON) group was provided the standard protein diet (n = 34), and treatment (TRT) group was provided a diet with a 5% increase in CP intake (n = 34). Male offspring were divided into two groups according to protein treatment of the pregnant cows: CON male offspring (CON-O) and TRT male offspring (TRT-O). Intramuscular adipocytes were found in the fetal skeletal muscle after 180 days of gestation. Male calf's birth weight increased in the TRT group compared to that in the CON group (p < 0.002). The final body weight (p < 0.003) and average daily gain (p < 0.019) of male offspring were significantly higher in TRT-O than in CON-O. The feed conversion ratio was also improved by 10.5% in TRT-O compared to that in CON-O (p < 0.026). Carcass weight was significantly higher in the TRT-O group than that in the CON-O group (p < 0.003), and back fat was thicker in the TRT-O group (p = 0.07). The gross receipts and net income were higher in TRT-O than in CON-O (p < 0.04). Thus, fetal intramuscular fat can be formed from the mid-gestation period, and increased CP intake during pregnancy can increase net income by improving the growth and carcass weight of male offspring rather than intramuscular fat.

The purpose of this study was to evaluate the effects of castration method and short-term fattening periods on Hanwoo cattle. Thirty-two Hanwoo calves (average body weight: 148.4 ± 19.8 kg) were used. The calves were randomly assigned in a 2 × 2 factor according to two castration methods (castration or hemi-castration) and two short-term finishing periods (24 months or 26 months). The final body weight increased significantly as the fattening period increased (p < 0.05), and the average daily weight gain was higher in the hemi-castration groups than in the castration groups (p < 0.05). After surgical castration, testosterone concentration was higher in the hemi-castration group than in the castration group during the entire experimental period (p < 0.05). The rib eye area was wider in the hemi-castration group than in the castration group (p < 0.01).An interaction effect was observed between the castration method and short-term fattening period (p < 0.05). Marbling and auction price scores differed between castration methods and were higher in the castration group than in the hemi-castration group (p < 0.01). Gross receipts and net income increased in the castration group compared to the hemi-castration group (p < 0.01) and showed a tendency to increase with the short-term fattening period, but there was no significant difference. Thus, castration to remove both testicles is essential for economic profit through producing high-quality Korean beef meat, and short-term fattening for 26 months, rather than 24 months, can benefit more by increasing carcass weight and meat quality.

We evaluated the growth performance, serum testosterone, carcass traits, histological characteristics, and economic efficacy of castrated and hemi-castrated Korean beef cattle. Thirty-two Hanwoo calves (Initial body weight: 148.4 ± 19.8 kg) were randomly assigned into the castrated Hanwoo (CH) and hemi-castrated Hanwoo (HH) group. The experiment lasted 18 months; the animals were all slaughtered on the same day. Final body weight and average daily gain (ADG) tended to increase in the HH group compared to the CH group. Testosterone concentration was higher in HH group (5.27–14.27 ng/dL) than in the CH group (0.47–0.70 ng/dL) during the whole experimental period after castration (p < 0.05). Rib eye area was 17.08 cm2 wider in HH group than in CH group, but marbling score was improved by 3.33 in CH group compared to HH group (p < 0.01). Deposition area of adipocytes in Longissimus dorsi were higher in CH group than in HH group (p < 0.001). Net income per head was 1760 US dollar higher in the CH group than in the HH group (p < 0.04). Thus, our findings suggest that hemi-castration had positive effects on the increase in ADG and meat yield traits, with negative effects on marbling and profitability.

This study was conducted to investigate the mRNA expression of adipogenic makers in Hanwoo fetus during the pregnancy periods. Eighteen Hanwoo cows (Average body weight: 561 ± 90.1kg, Parity: 4.4 ± 2.6) were used for experimental animals. Artificial insemination was performed on all the experimental animals after estrus synchronization. Pregnant cows were slaughtered at 3 gestation periods. Three cows were harvested at 3 months of gestation, 6 cows at 6 months of gestation, and 9 cows at 9 months of gestation. After exsanguination, fetus was removed immediately by collecting the gravid uterus. After measuring the body weight and length of the fetus, sample of fetal longissimus dorsi (LD) were collected for mRNA expression and histological analysis. The relative level of mRNA expression for peroxisome proliferator-activated receptor γ (PPARγ), stearoyl-CoA desaturase (SCD), CCAAT/ enhancer-binding proteins β (C/EBPβ) were measured by real-time quantitative PCR. Data were analyzed using the GLM procedure, and compared using Tukey’s method at α = 0.05. The body weight and length of the fetus continued to increase as the fetus grew (P < 0.01), and it was confirmed that the growth rate progressed rapidly between the 6 and 9 months of the fetus. The adipocyte were observed from the age of 6 months of fetus, and were mainly formed around blood vessels. The level of PPARγ (P < 0.02) and SCD (P < 0.01) mRNA expression in LD were highest at 6 months of fetus, and the C/EBPβ expression was significantly increased as the fetus grew (P < 0.01). As a result of this study, it was confirmed that not only the adipocyte in LD of the fetus was formed at least after 3 months of gestation, but also the adipogenic makers was differentially expressed during the growth stage of the fetus.

This study was conducted to investigate the effects of rumen-protected methionine and α-tocopherol (RPMT) on growth performance, carcass characteristics, and meat composition of late fattening Hanwoo steers in high-temperature seasons. Fourteen steers were randomly assigned to one of two diets; control (commercial concentrate) and treatment (commercial concentrate + 20 g of RPMT). Average daily gain was 34% higher in the treatment group than in the control group; however, there was no significant difference due to the small number under investigation. Feed conversion ratio was lower in the treatment group than in the control group (p < 0.05). Supplementation of RPMT had little effect on the fatty acid composition of longissimus muscle. Metmyoglobin in the longissimus muscle was significantly lower in treatment group compared to the control group at the ninth day of storage (p < 0.05). The redness of the longissimus muscle was higher in the treatment group than in the control group on day 9 of storage (p < 0.01). Thus, the results suggest that RPMT have positive effects on growth performance, and Commission Internationale de l’Eclairage color stability in the longissimus muscle of late fattening Hanwoo steers in high-temperature seasons.

This study was conducted to compare the mRNA expression levels of myogenic-adipogenic makers in the skeletal muscle and adipocytes formation, body weight, rumen weight, and papilla length on Hanwoo calves at newborn and 6 months of age. Animals used three newborn Hanwoo calves (NC) and three Hanwoo calves 6 months of age (SC). Body weight and rumen weight were significantly increased in SC compared to NC (p < 0.01), and papilla length was longer about 10-fold in SC than NC. Adipocytes was possible to visually identify more adipocytes in SC compared to NC, and were mainly formed around the blood vessels. mRNA expression of myogenin, myosin heavy chain 1 and myosin heavy chain 2A in both longissimus dorsi (LD) and semimembranosus (SM) was found to increase with calves growth (p < 0.01), and it was confirmed that have higher levels of mRNA expression in SM than LD. In LD tissues, the mRNA expression of stearoyl-CoA desaturase (SCD, p < 0.03) and peroxisome proliferator activated receptor γ (PPARγ, p < 0.04) was significantly higher in SC than NC. In SM tissues, mRNA expression levels of SCD (p < 0.02) and CCAAT/enhancer binding protein β (C/EBPβ, p < 0.01) were higher in SC than NC, and also mRNA expression levels of PPARγ increased, but there was no significant difference. Thus, the calves period suggests that it is an important step in the development of the rumen and the myogenesis and adipogenesis.

This study was conducted to evaluate the effect of the thickness of corn flakes produced by pressurized steam chamber (PSC) on rumen fermentation characteristics and nutrient degradability in Hanwoo and Holstein cows. Corn flakes were treated by PSC, in three groups based on corn flake thickness: < 2.5 mm (T1), 2.5-3.0 mm (T2), and > 3.0 mm (T3). Corn flake thickness significantly influenced pH (p < 0.01) and propionate concentration (p < 0.05) and slightly but not significantly influenced acetate, butyrate, and total-volatile fatty acids (T-VFA) concentrations. The dry matter (DM) degradability increased significantly with a reduction in corn flake thickness (p < 0.01), being significantly greater in T1 and T2 than T3 groups (p < 0.01) and similar between T1 and T2 groups throughout whole incubation time. Also, starch degradability was the lowest in T3 groups than others (p < 0.01). Thus, the present results showed that considering the production efficiency and economic feasibility, the optimal thickness of corn flakes produced in a PSC is recommended to be 2.5-3.0 mm.

This study was carried out to investigate the effect of the feeding method of total mixed fermentation (TMF) and concentrate feed on the growth performance, carcass and meat characteristics of late fattening Hanwoo steers. Twenty-four Hanwoo steers were used in this study. The control group was fed with concentrate feed + rice straw from the growing to the late fattening period, while the T1 group was fed with TMF from the growing to the early fattening period and concentrate feed + rice straw for the late fattening period. The T2 group was fed with TMF from the growing to the late fattening period. The average daily gain (ADG) and feed conversion ratio (FCR) were not different between the treatment and control group. Serum cholesterol and high density lipoprotein (HDL) cholesterol concentrations were higher in the T2 groups than in the control group (p<0.05). The yield grade and quality grade were not different between the treatment and control group. The lightness of longissimus muscle was higher in the T1 group than in the control and T2 groups (p<0.05). Poly-unsaturated fatty acid (PUFA) of longissimus muscle was increased in the T2 groups than in the control group. Therefore, the method of feeding TMF and concentrate feed could have a positive effect on the lightness and fatty acid composition of longissimus muscle without affecting the growth and carcass grades of Hanwoo steers.

The carcass traits, meat quality traits, and fatty acid profile of two muscles, longissimus thoracis (LT) and semimembranosus (SM), in Hanwoo steers were investigated against the Korean beef quality grade (QG) and yield grade (YG) standards. Back fat thickness and carcass weight most affect the YGs, while the marbling score is the primary determinant of the QGs. The muscle type greatly influenced the meat qualities, sensory properties, and fatty acid profiles of Hanwoo meat. In terms of sensory aspects, the muscle type affected the QG for tenderness and juiciness, with the LT being more desirable than the SM for all the sensory attributes. SM meat is potentially beneficial for human health because it has a lower amount of unhealthy saturated fatty acids and a greater amount of healthier polyunsaturated fatty acids, especially essential fatty acids, than the LT. The present study indicates that carcass based common grading system does not reflect the real value of SM meat.

In this study, we prepared stabilized vitamin A and C nanoemulsions, and investigated their efficacy on milk-specific proteins in bovine mammary epithelial cells (MAC-T). Emulsions of vitamin A (vit-A) and C (vit-C) were prepared using Lipoid S 75 and microfluidization. The particle size and polydispersity index (PDI) of nanoemulsified vit-A and vit-C were studied. The cytotoxic effect of nanoemulsion-free and nanoemulsified vit-A and vit-C was determined by an MTT assay. In addition, the efficacy of nanoemulsified vit-A and vit-C on the in vitro expression pattern of milk-specific proteins in MAC-T cells was investigated by quantitative RT-PCR. The results showed that the efficacies of stabilized nanoemulsions of vit-A and vit-C were 100% and 92.7%, respectively. The particle sizes were around 475.7 and 225.4 nm, and the zeta potentials were around −33.5 and −21.3 mV, respectively. The expression changes of αs2-, β- and κ-casein were higher in the presence of a stabilized nanoemulsion of vit-A, compared with nanoemulsion-free vit-A. Furthermore, the expression changes of αs2- and β-casein were lower and that of κ-casein was higher in the presence of a stabilized nanoemulsion of vit-C, compared with nanoemulsion-free vit-C. Thus, our findings demonstrate the efficacy of nanoemulsified vit-A and vit-C in changing the expression of milk-specific proteins in MAC-T cells.

This study aimed to investigate the effects of temperature and retention time of the pressurized steam chamber on the ruminal fermentation characteristics and nutrient degradability of corn flakes in three Korean native Hanwoo cows and three Holstein cows implanted with a ruminal fistula.Corn kernels were categorized into 13 groups based on the chamber temperature (range, 100°C-116°C) and retention time (range, 700-950 s).The pH value was lowest in T1 regardless of breed.Propionate concentration was the highest in T2 (p < 0.05).Total-volatile fatty acid (VFA) concentration was slightly but not significantly greater in T2 than in other conditions.Dry matter (p < 0.05), starch, and crude protein (p < 0.05) degradability were the highest in T1.At different incubation times and with different breeds, dry matter, starch, and crude protein degradability of corn flakes were the highest in T1.Thus, the present results indicate that the optimal temperature and retention time of the pressurized steam chamber should be 100°C-105°C and 700-720 s.

Abstract Hanwoo, Korean native cattle, have been known for high intramuscular adipose tissue compare to other beef cattle. Bovine satellite cells (BSC) of longissimus dorsi (LD) and semimembranosus (SM) tissues differentiated from myoblast into multinucleated myotubes has different characteristics under cell culture system. Differentially expressed genes (DEG) of the two muscle tissues were compared based on 24, 48, 96, and 168 hours. Difference in the index between LD and SM BSC at each time point were tested with an analysis of variance for a model fitting time (day), tissue and the interaction between time and tissue. P-values < 0.05 were considered significantly different. There were 640 genes difference in 4 Day with the lowest DEG, 442 in Up and 198 in Down. There were 2,755 genes difference in 7 Day and 879 genes in Up and 1876 genes in Down. The differential expression of actin alpha 1 (ACTA1), actin alpha cardiac muscle 1 (ACTC1), matrix metallopeptidase 2 (MMP2), and myosin light chain phosphorylated fast skeletal muscle (MYLPF) genes (P < 0.05) were involved in the differentiation of SM greater than those of LD muscle. However, we found the same pattern in the transcription levels of myogenine (MYOG), myogenic differentiation 1(MYOD), and myogenic regulatory factors 6 (MYF6) for both muscles. There were more difference in the enriched Gene ontology terms cell cycle, proliferation and G2/M transition of mitotic during the end of proliferation compare to myoblast differentiation. Our finding provide evidence that the differential expression in of ACTA1, ACTC1, MMP2, and MYLPF genes could be involved in the differentiation of LD and SM muscles. This data indicated that the origin of the BSC were epigenetically improved during the myogenic development of LD and SM

α-chaconine is a steroidal glycoalkaloid compound found in leaves, fruit and tubers of the solanaceae family such as potato, tomato, and eggplant. α-chaconine poisoning was reported in various animal models such as mice, rabbit, and chicken. However, previous study indicated that it is used to induce performance of beef cattle. We hypothesized that α-chaconine may affect myogenesis of bovine satellite cells but less affect adipogenesis of bovine adipocytes. Bovine satellite cells (BSC) were pronase-liberated from semimembranosus (SM) and longissimus dorsi (LD) muscle tissues of three new-born Hanwoo calves. Bovine preadipocytes were isolated from perirenal (PR) adipose tissues. BSC and preadipocytes were incubated with dulbecco modified eagle medium (DMEM) with 10% fetal bovine serum for proliferation. BSC induced differentiation with DMEM with 3% horse serum and preadipocytes induced differentiation with DMEM with insulin, dexamethasone, and ciglitazone. Cells were treated with various levels of α-chaconine (control, 0.001, 0.01, 0.1, 1, and 10μM). mRNA abundance for myosin heavy chain 2X (MHC2X), glucose transportor 4 (GLUT4), β2-adrenergic receptor (β2-AR), peroxisome proliferator-activated receptor γ (PPARγ), stearoyl-CoA desaturase (SCD) were measured by real-time quantitative PCR. Data were analyzed as a completely randomized design using the MIXED model, each treatment performed in triplicated. Means were considered different at P < 0.05. Relative MHC2X mRNA abundance was greater in BSC with dose-titrated chaconine treatments compared to the control (P < 0.05). Relative levels of β2-AR were greater in both BSC and adipocytes based on dose-dependent treatements (P < 0.05). The levels of PPARγ and SCD have no dose-titrated treatments in bovine PR adipocytes (P > 0.05). These result indicated that α-chaconine have a dose-dependent effect on MHC2X and β2-AR mRNA BSC and adipocytes but did not affect to adipogenesis in bovine PR adipocytes.

This study was conducted to investigate the effect of the total digestible nutrients (TDN) level of commercial concentrates on growth performance, carcass characteristics, and meat composition of late fattening Hanwoo steers. A total of 28 steers were randomly assigned to one of four dietary groups; T1 (73.30% TDN), T2 (74.50% TDN), T3 (76.40% TDN), and T4 (77.10% TDN). Average daily gain (ADG) was slightly but not significantly higher in the T2 than in the other treatments. Dry matter intake (DMI) and feed conversion ratio (FCR) were higher in the T2 than in the other treatments; however, the differences were not statistically significant. Carcass back fat thickness was thicker in the T4 and marbling score was higher in the T2 than in the other treatments; however, the differences were not statistically significant. The TDN level of concentrates had no effect on the physicochemical characteristics and fatty acid composition of the longissimus muscle. The finding of this study indicate that less than 74% or greater than 75% TDN in the commercial concentrate did not contribute to improve ADG, FCR, marbling score; therefore, in the present study, the recommendable TDN level in the commercial concentrate for late fattening period was 74% to 75% in terms of growth performance and marbling score of Hanwoo steer.

The purpose of this study was to investigate the proper feeding level and duration of fermented barley grain feed before harvesting to improve the availability of barley for feed. Trial 1 was to investigate the proper feeding amount of fermented barley grain fermented feed, and we prepared 32 heads (603.4 ± 42.7kg) of 22-month-old Hanwoo steer (603.4 ± 42.7kg) for 8 heads in 4 treatment groups. 48 heads (625.8 ± 13.1kg) for Trial 2 were used for 12heads per 4 treatments, and were reared for about 9 months until 30 months of age. Trial 1 is treated a Control group that feed 10㎏ of concentrate, replaces 10% fermented barley grain feed(FBGF) of the control by (TRT 1) and 20% (TRT 2) and 30%(TRT 3). Concentrate and FBGF fed 9, 2.1 kg, 8, 4.2 kg, 7 and 7, 6.3 kg on each treatments respectively and 1.5 kg of rice straw for forage. In Trial 2, 10% of alternative diets were judged to be appropriate, and the control of 9kg of diets and barley grain fermented feeds were used to determine the appropriate feeding period. The treatments were 3 months before shipment (TRT 1), 6 months (TRT 2) and 9 months (TRT32). Each treatment group had 8 and 2.1 kg of concentrate and barley grain fermentation, respectively. As a feed, rice straw was fed to 1.5 kg. The daily gains per treatment were higher in TRT 1 and TRT 3 was similar to the Control. Body weight and daily gain during the test period were higher in TRT 1 fed 10% barley grain fermented feed. TRT 2 was the highest at 6.13, and TRT 3 was 6.0, which was higher than 5.63 of TRT 1 and 5.5 of Control.