• Journal of Animal Science and Technology
• /
• v.65 no.1
• /
• pp.149-159
• /
• 2023

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.

• Korean Journal of Agricultural Science
• /
• v.38 no.2
• /
• pp.263-268
• /
• 2011

This experiment was conducted to investigate the effect of feeding TMR with or without Yukmijihwangtang meal silage on the growth performance, meat yield and quality of Hanwoo steers. Sixteen male Hanwoo steers in the late fattening period were randomly assigned to a control diet and Yukmijihwangtang meal diet, with eight heads per treatment. The supplementation of Yukmijihwangtang meal silage did not affect the feed conversion rate, ribeye area, and meat yield index of cold carcass of Hanwoo. Fat thickness of Hanwoo s loin obtained from silage supplementation was significantly lower than that of non-supplemented. Total grade in meat yield of Hanwoo from silage supplementation were higher than that of non-supplemented control. The supplementation of Yukmijihwangtang meal silage to Hanwoo decreased the marbling score significantly, but did not affect fat color, firmness, and maturity. Total grade of meat quality of Hanwoo with Yukmijihwangtang meal supplementation was lower than that of non-supplemented control. In conclusion, Yukmijihwangtang meal could be used as partial substitution (10%) in TMR for fattening cattle. However, it is considered that Yukmijihwangtang meal can be a useful feed for the periods of growing or early fattening than that of late fattening since it improved meat yield but decreased meat quality grade of Hanwoo steers.

• Korean Journal of Agricultural Science
• /
• v.43 no.5
• /
• pp.810-817
• /
• 2016

The aim of this experiment was to determine the effect of a high-energy diet on the level of serum metabolites and on carcass characteristics of Hanwoo steers. High energy diets have been used for enhancing intramuscular adipose tissue in high quality beef cattle. However, there is not much information about the physiological reactions to this diet. We hypothesized that a high energy diet would increase blood metabolites and the meat quality of Hanwoo steers during the early and final fattening periods. A $2{\times}2$ factorial arrangement (High, Control, and Early, Final) in a completely randomized design was used to feed 24 Hanwoo steers. Two steers were kept in the same pen and 12 pens were used for the experiment. Blood was drawn from each steer on the first week of every other month from 11 to 28 months. Overall Average Daily Gain (ADG) and feed efficiency were not different between high energy and control diets (p > 0.05). However, Dry Matter Intake (DMI greater with the control diet than DMI with the high energy diet during the final fattening period (p < 0.05). Serum non-esterified fatty acid (NEFA) concentrations were greater in the control diet group than in the high energy diet group during the final fattening period (p < 0.05). However, serum albumin, glucose, total protein, triglyceride, and phosphorus were greater in the high energy group than those of the control group (p < 0.05). Carcass traits or physico-chemical characteristics were not different between high energy diet treatment and the control. These data indicated that a high energy diet (+ 3% TDN) increased serum triglyceride during early fattening periods and decreased non-esterified fatty acids during final fattening periods in Hanwoo steers.

• Korean Journal of Agricultural Science
• /
• v.45 no.1
• /
• pp.74-83
• /
• 2018

Four early-fattening Hanwoo steers weighing $247{\pm}13.5kg$ were used within a $4{\times}4$ Latin square design to establish a nutrient requirement for maintenance and to investigate nutritional changes in the steers under heat stress condition. The steers were fed four different energy level diets: 100% (control) and 100%, 115% and 130% of total digestible nutrients (TDN) requirement of the early-fattening Hanwoo steers for maintenance based on the Korean Feeding Standard for Hanwoo. The steers in the control were housed with no stress (temperature $24^{\circ}C$ and humidity 60%), whereas the steers in the other groups were under heat stress (temperature $30^{\circ}C$ and humidity 70%). True digestibilities of dry matter (DM) and other nutrients were not significantly (p > 0.05) affected by heat stress (i.e., control vs T100). This may be the result of a lower DM intake than that of the Korean feeding standard due to the establishment of the nutrients requirement under heat stress. Heat stress and different energy intake levels did not affect the blood metabolite concentrations. Average daily gain (ADG) for T100 (-69.6 g) was lower than that of the control (-44.6 g, numerically), T115 (44.6 g, p < 0.05) and T130 (83.3 g, p < 0.05), respectively. Based on the ADG and TDN intake, the equation (Y = 0.1814X + 111.5) for the TDN requirement of the early fattening Hanwoo steers for maintenance was calculated, indicating that 11.5% of TDN requirement for maintenance under heat stress may be additionally supplied.

• Journal of Animal Science and Technology
• /
• v.63 no.5
• /
• pp.1086-1097
• /
• 2021

This study examined the impact of using total mixed ration (TMR) and concentrate on feed intake, daily gain, carcass yield grade, and carcass quality grade of Hanwoo steers and its subsequent economic efficiency. Thirty six 7-month-old Hanwoo steers were assigned to one of the four treatment groups, and each group was divided into three repeated pens, with each repeated pen comprising three steers. The treatment groups were: 1) separate feeding with commercial concentrate and forage (namely, SCF) for the entire experimental period; 2) TMR feeding for a growing period followed by SCF for the early and late fattening period (namely, TMRGSCF); 3) TMR feeding for growing and an early fattening period followed by SCF for the late fattening period (namely, TMREFSCF); and 4) TMR feeding for the entire experimental period (namely, TMRW). The results showed that the SCF treatment had significantly (p < 0.05) higher feed intake during the growing period than other treatments. In contrast, the total feed intake had little difference during early and late fattening as well as the whole period regardless of feeding strategies. Daily gain showed no difference during the growing period. However, it was significantly higher in SCF and TMREFSCF treatments for the early and late fattening period, respectively (p < 0.05). The daily gain during the total raising period is in the order of TMREFSCF > TMRGSCF > SCF > TMRW. Carcass characteristics, including carcass weight, loin eye muscle area, and carcass yield grade, did not significantly differ among different treatments. However, TMRW treatment, wherein TMR was fed for a long time, showed that the cold carcass weight was less compared with other treatments, but carcass yield grade was higher with thinner backfat. Backfat thickness was in the order of SCF > TMRGSCF > TMREFSCF > TMRW, showing that the thickness reduced with longer TMR feeding (p < 0.05). TMRGSCF, which numerically had a higher carcass quality grade, showed higher economic efficiency, whereas SCF showed low economic efficiency. In conclusion, it was more feasible to apply TMR strategy in the growing and early fattening period and then SCF for the early or late fattening period to improve carcass yield, quality grade, and economic efficiency.

• Journal of Animal Science and Technology
• /
• v.64 no.5
• /
• pp.897-910
• /
• 2022

Bovine fecal microbiota is important for host health and its composition can be affected by various factors, such as diet, age, species, breed, regions, and environments. The objective of this study was to evaluate the impact of diet and gender on fecal microbiota in Korean native Hanwoo cattle. The 16S rRNA gene amplicon sequencing of fecal microbiota was conducted from 44 Hanwoo cattle divided into four groups: (1) 11 heifers fed an oat hay plus total mixed ration (TMR) diet for breeding (HOTB), (2) 11 heifers fed an early fattening TMR diet (HEFT), (3) 11 steers fed the early fattening TMR diet (SEFT), and (4) 11 steers fed the late fattening TMR diet (SLFT). Firmicutes and Bacteroidota were the first and second most dominant phyla in all the samples, respectively. The Firmicutes/Bacteroidota (F/B) ratio associated with feed efficiency was significantly greater in the SLFT group than in the other groups. At the genus level, Romboutsia, Paeniclostridium, and Turicibacter were the most abundant in the SLFT while Akkermansia, Bacteroides, and Monoglobus were the most abundant in the HOTB group. Although the same early fattening TMR diet was fed to Hanwoo heifers and steers, Marvinbryantia and Coprococcus were the most abundant in the HEFT group while Alistipes and Ruminococcus were the most abundant in the SEFT group. Shannon and Simpson diversity indices were significantly lower in the SLFT group than in the other groups. Distribution of fecal microbiota and functional genetic profiles were significantly different among the four treatment groups. The present study demonstrates that different diets and genders can affect fecal microbiota and the F/B ratio may be associated with feed efficiency in Hanwoo cattle. Our results may help develop strategies to improve gut health and productivity through manipulation of fecal microbiota using the appropriate diet considering Hanwoo cattle gender.

• Korean Journal of Organic Agriculture
• /
• v.31 no.4
• /
• pp.327-341
• /
• 2023

The Ministry of Agriculture, Food and Rural Affairs, Hanwoo Association and Nonghyup have discussed proactive reduction measures for cows in response to concerns about an oversupply of hanwoo to ensure supply stability. This study aims to empirically analyze whether the cow fattening support program is being implemented in line with its objectives. Based on the analysis of beef traceability data, the slaughter age of participating cows was reduced by 7.6 to 14.7 months compared to non-participating cows. And heifer was reduced 1.5 months in their slaughter age. In case of parity, participating cows showed a reduction of 1.4 compared to non-participating cows. Through the SUR model, an analysis was conducted to examine the effect of the cow fattening support program on the suppression of calf production numbers. The analysis results showed that the calf production numbers are positively influenced by the number of fertile cow and the quantity of semen sales. Furthermore, it is estimated that calf production decreased as the fat index increased, and during the period when the cow fattening support program was implemented, an average monthly suppression of 3,558 calves was observed.

• Korean Journal of Agricultural Science
• /
• v.45 no.1
• /
• pp.84-93
• /
• 2018

This study was conducted to develop a pasture feeding program for reducing the Hanwoo feeding cost. Italian ryegrass (IRG) is a major plant which is abundantly produced in the southern area of South Korea. Locally produced Italian ryegrass has a 30 - 50% reduced pasture cost compared to imported pasture grasses. We hypothesized that Italian ryegrass feed could reduce the feeding cost but not change the physiological characteristics of the Hanwoo steers in the feedlot. Four treatments (Control, short fed IRG silage, long fed IRG silage, and IRG hay) in a completely random design were used to feed 27 Hanwoo steers. Three or four steers were fed in the same pen, and 8 pens were used for the treatments. Blood was drawn from each steer on the first week of every month from 11 to 30 months. Overall, the average daily gain and feed efficiency were not different among the treatments (p < 0.05) except for the final fattening diets (p < 0.05). The long fed IRG silage group had a low ADG compared to the other groups (p < 0.05). The serum non-esterified fatty acid and glucose concentrations were reduced during the fattening periods (p < 0.05); however, the serum albumin, total proteins, triglycerides, and phosphorus were increased during the fattening periods (p < 0.05). The carcass weight, longissimus muscle area and back-fat thickness were low in the long fed IRG silage group (p < 0.05). The IRG diet induced saturated fatty acids in the longissimus dorsi (p < 0.05). These results show that the IRG diet increased the serum triglycerides but reduced the glucose level at the final fattening diet and decreased the meat yield score in Hanwoo steers.

• Animal Bioscience
• /
• v.37 no.1
• /
• pp.142-150
• /
• 2024

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℃ to 26.5℃, 60%; THI 73 to 75), Mild (28℃ to 29℃, 60%; THI 77 to 79), Moderate (29.5℃ to 30.5℃, 80%; THI 82 to 84), and Severe (31℃ to 32℃, 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.

• Journal of Animal Science and Technology
• /
• v.48 no.3
• /
• pp.345-352
• /
• 2006

Korean native cattle (Hanwoo) have a good capacity to produce heavily marbled meat of high value. The intramuscular fat in Hanwoo is known to be deposit from 12 months of age by degree of slightly visible and significantly developed in 28 months of age. Lipogenesis gene expression profiling in longissimus dorsi at early and late fattening stage will be helpful to understand the mechanism of intramuscular fat deposition in skeletal muscle. Therefore, we analysed the gene expression patterns of six genes related lipid metabolism (FABP4, GLUT4, LPL, ACC, ACL and SCD) between early and late fattening stage. The mRNA expression of FABP4 at late fattening stage (27 months old) was higher about 3.0 fold than at early fattening stage (12 months old) in each three individuals of Hanwoo. However, GLUT4 mRNA expression was not different at late fattening stage compared with at early fattening stage. On the other hand, The expression patterns of LPL, ACC, ACL and SCD genes related lipid metabolism were significantly over-expressed about 3.5 fold, 2.7 fold, 3.7 fold and 7.5 fold at late fattening stage, respectively. Thus, these results suggested that lipogenesis in skeletal muscle at late fattening stage is due to increasing uptake of fatty acid by FABP4 and lipogenesis gene expression such as LPL, ACC, ACL and SCD.