• Korean Journal of Organic Agriculture
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• v.17 no.3
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• pp.393-403
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• 2009

This study was conducted to investigate the productivity of Hanwoo steers by feeding self-product organic rice straw and concentrates(conventional, T1 and organic T2). Sixteen Hanwoo steers(8 months on the average) were randomly assigned to two treatment groups. Feeding trail was carried out in 2 treatment(8 heads/ treatment) by Hanwoo steers for 600 days form 8 to 28 months in age. The range of average daily gains of T1 and T2 were 0.76 to 0.77kg in the growing stage, 0.93 to 0.90kg in the first fattening stage, 0.99 to 0.84kg in the middle fattening stage, and 0.59 to 0.64kg in the latter fattening, respectively, and the gains for overall period was higher in T1 than in T2. Concentrates and total digestive nutrients(TDN)(T1) intakes per unit of kg gains were higher than T2 without significant difference. In carcass characteristics, the carcass weight in T1 were higher about 5% than in T2. According to the above results, it may be concluded that dry matter(DM) intakes, crude protein(CP) and TDN contents of feedstuff between treatments was no significant difference. but marbling in T2 score was higher than in T1 about 20%. There were no significant differences rib-eye area, back fat thickness and fat color(p>0.05).

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.731-744
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• 2005

Ninety Hanwoo steers(initial BW=167.2$\pm$13.4kg) were used to determine the effect of energy concentrations in concentrates and slaughter age on performance, carcass characteristics. Steers were allotted by BW to one of eighteen pens. Eighteen pens were randomly allotted to a low(70-70-71-72% for the growing, the early, the middle or the late fattening periods), medium(70-71-72-73%) or high(70-72- 73-74%) TDN level of concentrates. Five steers for each treatment of energy level were slaughtered every one month from 26 month of age to 31 month of age. Concentrates was fed restrictedly to achieve a predicted gain of 0.7-0.9kg from growing stage to middle fattening stage. All steers were fed orchard grass(Dactylis glomerata L.) hay as roughage during the growing period, fed rice straw gradually substituted for orchard grass hay during the early fattening period, and fed rice straw only thereafter. Overall body weight and feed intake were not affected by TDN levels of concentrates. Average daily gain for all treatments was higher than 0.9kg/d during the 19-21 month of age and decrease thereafter, but sustained above 0.7kg/d. Mean concentrates intake for all treatments was 1.0-1.3% of live BW during the growing period and 1.5% during the early fattening. Thereafter, it decreased up to 1.4% during the middle fattening and 1.0% during late fattening period. Delay of slaughter end point resulted in a gradual increase of rib-eye area, back fat thickness and marbling score, especially after slaughter age of 29 month there was significant increases(P<0.05). The appearance rate of 1+ and 1 grade related to the slaughter ages was 100% at 29, 30 and 31 months of age, whereas those at 26, 27 and 28 months were 93, 86 and 80%, respectively. Dressing rate was significantly(P<0.05) increased and rate of retailed cut weight significantly(P<0.05) decreased when slaughter age increased. In economic analysis, there was pronounced increase in net income up to 32-46% after slaughter age of 29 months. Under the conditions of this study, high TDN intake is not necessarily required for high quality Hanwoo meat production and slaughter age of 29 month might be the optimum for Hanwoo steers.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.11
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• pp.1575-1581
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• 2012

This study evaluated the effect of dietary supplementation of microbially-fermented spent mushroom substrates (MFSMS) on weight gain, carcass characteristics, and economic efficiency of Hanwoo steers. Highly cellulolytic bacteria (Enterobacter spp. and Bacillus spp.) isolated from spent mushroom substrates (SMS) stacks were inoculated (1% v/v) into the SMS, which was anaerobically fermented and fed to the steers for 12.6 months during the growing and fattening periods. Growing Hanwoo steers were assigned to the control group without supplementation of Microbially-fermented SMS (MFSMS), to a treatment group with 50% of MFSMS (1/2 of the ad libitum group), and to a treatment group with ad libitum access to SMS (the ad libitum group). All the groups were fed the formulated feed and rice straw. The voluntary intake (DM basis) of MFSMS was 1.6 kg/d during the growing period and 1.4 kg/d during the fattening period. The voluntary rice straw intake decreased by 6 to 11%, but the total voluntary DMI increased by 7 to 15% with MFSMS fed. The increased DMI with MFSMS supplementation resulted in a tendency of increased (p = 0.055) live weight gain by 8 to 12% compared with the control group. At slaughtering, the supplementation of MFSMS increased (p<0.05) the ribeye area by an average of 10 cm2. In conclusion, feeding MFSMS improved growth performance and carcass traits of Hanwoo steers and could successfully replace a part of conventional roughage such as rice straw commonly used in Asian countries.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.832-838
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• 2012

This study was conducted to evaluate the effects of dietary supplementation of catechins and wheat bran on growth performance, carcass characteristics and meat color using forty-eight Hanwoo steers. Each steer was randomly assigned to one of four treatments. Treatments were as follows: control, catechins, wheat bran, and catechins+wheat bran (CW). At the end of the feeding trial, blood samples were collected for analysis of hemoglobin and iron concentration, and then steers were slaughtered at a commercial abattoir. Catechins, wheat bran, and CW had no effect on growth performance and carcass characteristics. Percentage of myoglobin in M. longissimus dorsi was not affected by treatments. Percentage of oxymyoglobin was increased (p<0.05) by CW and maintained at the highest level (p<0.05) for CW during meat display time up to 24 h. Percentage of metmyoglobin was the lowest (p<0.05) for CW between 5 and 24 h during display time. Although blood iron concentration was not affected by treatments, total concentration of muscle iron was the lowest (p<0.05) for CW compared with that of other treatments. Therefore, the results of the present study suggest that CW may provide good protection against oxidation of myoglobin, and might be an effective dietary supplement for improving meat color in the late fattening period of Hanwoo steers.

• Journal of Animal Science and Technology
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• v.51 no.5
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• pp.395-406
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• 2009

Fifty four Hanwoo steers in final fattening period were assigned to 3 groups control, top dressed $PROSOL^{(R)}$ as an emulsifier (TP) and DSP group (experimental diet made to down spec of nutrients with $PROSOL^{(R)}$, which is sodium stearoyl-2-lactylate), based on the body weight (647.96${\pm}$41.31 kg) and months of age (27.3${\pm}$0.8 mo), and the experiment was conducted to establish the reasonable fattening method of Hanwoo steers for 91 days. Average daily body gains during trial were 0.94, 0.84 and 0.98 kg in control, TP and DSP, respectively (P=0.011). DDMI/ADG of TP group tend to lightly improving compared to control and DSP group (P=0.692). There was no effect of supplementation of the $PROSOL^{(R)}$ in concentrates on growth rate, feed efficiency and shrinkage in Hanwoo steers during the short final fattening period. MQI from TP and DSP was not different based on the rib-eye area and carcass weight in carcass than that from control. Back fat thickness tended to be thicker than control (P>0.05). Marbling score, texture and maturity for TP and DSP was abundantly to increase compared to control (P<0.003). There was significantly increment in supplemented $PROSOL^{(R)}$ (P<0.0001). The meat quality grade of control, TP and DSP were 2.94, 3.78 and 4.50, respectively. Related to this result, the auction price (carcass/kg) were gained significantly (P<0.003) from control (17,560), TP (18,586) and DSP (19,266 won) so which the monetary return was the highest in DSP and the differences was recognized between TP and DSP. Percentage over 1st grade appeared in control, TP and DSP were 55.4, 88.9 and 100.0%, respectively. These results supported the hypothesis that supplementation of emulsifier improve the marbling score and the carcass quality grade by increased digestibilities of the feed fat in Hanwoo steers in fattening period.

• Journal of Life Science
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• v.21 no.9
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• pp.1251-1258
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• 2011

Multiparous Hanwoo cull cows have been generally regarded to have poor meat quality compared to young and primiparous Hanwoo in Korea, and there have been few studies attempting to understand various feeding programs for the multiparous Hanwoo cull cow. In this study, the effects of a feeding program consisting of two different diets for multiparous Hanwoo cull cows on meat production and quality were tested in comparison to a commercially used diet. Diets for treatment consisted of two levels of crude protein contents, 14.28% and 12.70% for early fattening and finishing, respectively. For a control, commercially used fattening feed (12.39% crude protein) was used. Feeding trials were performed at three different farms. In farm A, 29 herds of multiparous Hanwoo cull cows were used for the treatment group and 3 herds for the control. In farms B and C, the number of animal herds for treatment and control were 8 vs. 3 and 11 vs. 4 herds, respectively. Experiment diets were fed for an average of 211 days and in treatment, early fattening diet was fed for 4 months and then finishing feed was fed until slaughter. Average daily gains, thickness of back fat, area of Longissimus dorsi, carcass weight, index of carcass weight, intramuscular fat, meat color and texture were analyzed after slaughter. Random effect model [8] was employed in effect analysis. Positive effects of treatment were found in terms of average daily gain, back fat thickness, Longissimus dorsi area, carcass weight, and intramuscular fat. Carcass yield index, meat color and texture showed a negative effect. In this study, significant results were not found in all factors analyzed because the variance between experiment farms was large, however the 90% confidence interval of summary effects of ADG, back fat thickness, Longissimus dorsi area and carcass weight were significant and that of carcass yield index, intramuscular fat, meat color and texture were less so. Conclusively, a high protein diet fed early during the fattening period in multiparous Hanwoo cull cows could have positive effects on meat production.

• Journal of Animal Science and Technology
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• v.55 no.1
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• pp.61-66
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• 2013

The purpose of this study was to determine the effects of different crude protein levels in the concentrates on carcass and meat quality of Hanwoo steers. A total of thirty 5.3-month-old castrated Hanwoo calves ($135.6{\pm}10.52$ kg) were randomly allocated into either control or treatment group. The animals were separately housed to 5 heads per group. Crude protein levels in concentrates for growing, fattening, and finishing phases were 14, 13, and 11% for control group and 16, 15, and 14% for treatment group respectively. Comparative analysis of carcass characteristics, physico-chemical characteristics, and fatty acid composition in M. longissimus dorsi of Hanwoo steers were carried out. There was no statistical difference in average cold carcass weight between control (411.9 kg) and treatment (419.9 kg) group. Also, dietary crude protein level in concentrates did not affect M. longissimus dorsi area, backfat thickness, and meat yield index. In contrast, the marbling score in treatment group was higher (p<0.05) than the control group. Also, treatment group showed significantly higher (p<0.05) values than control group for CIE L-value, Mono-unsaturated fatty acids and oleic acid composition. Therefore increasing crude protein levels of concentrates in Hanwoo steers during growing and fattening phases might be beneficial for the improvement of meat quality.

• Journal of Animal Science and Technology
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• v.65 no.3
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• pp.596-610
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• 2023

Focusing high marble deposition, Hanwoo feedlot system uses high-energy diet over the prolonged fattening period. However, due to the individual genetic variation, around 40% of them are graded into inferior quality grades (QG), despite they utilized the same resources. Therefore, focusing on development of a nutrigenomic based precision management model, this study was to evaluated the response to the divergent selection on genetic merit for marbling score (MS), under different dietary total digestible nutrient (TDN) levels. Total of 111 calves were genotyped and initially grouped according to estimated breeding value (high and low) for marbling score (MS-EBV). Subsequently, managed under two levels of feed TDN%, over the calf period, early, middle, and final fattening periods following 2 × 2 factorial arrangement. Carcasses were evaluated for MS, Back fat thickness (BFT) and Korean beef quality grading standard. As the direct response to the selection was significant, the results confirmed the importance of initial genetic grouping of Hanwoo steers for MS-EBV. However, dietary TDN level did not show an effect (p > 0.05) on the MS. Furthermore, no genetic-by-nutrition interaction for MS (p > 0.05) was also observed. The present results showed no correlation response on BFT (p > 0.05), which indicates that the selection based on MS-EBV can be used to enhance the MS without undesirable effect on BFT. Ultimate turnover of the Hanwoo feedlot operation is primarily determined by the QGs. The present model shows that the initial grouping for MS-EBV increased the proportion of carcasses graded for higher QGs (QG1⁺⁺ and QG1⁺) by approximately 20%. Moreover, there appear to be a potential to increase the proportion of QG 1⁺⁺ animals among the high-genetic group by further increasing the dietary energy content. Overall, this precision management strategy suggests the importance of adopting an MS based initial genetic grouping system for Hanwoo steers with a subsequent divergent management based on dietary energy level.

• Korean Journal of Agricultural Science
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• v.48 no.3
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• pp.387-396
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• 2021

This study was conducted to provide basic data for efficient Hanwoo beef production by conducting a comparison of growth performance, blood metabolites, testosterone, and carcass characteristics of Hanwoo according to complete and hemi-castration. Twelve Hanwoo calves were allotted to two treatment groups as follows: CC = complete-castration and HC = hemi-castration method of removing only one testicle. At the end of the test, the body weight was 66 kg higher in HC than in CC, and the average daily gain increased by 12.6% (p < 0.05). The feed conversion ratio was significantly improved in HC compared to CC (p < 0.05). Serum cholesterol and triglyceride concentrations were significantly higher in CC than HC in both the growing and fattening periods (p < 0.05), and serum testosterone concentrations before castration were similar between HC and CC, but steadily increasing in HC after castration. Back fat thickness and marbling score were significantly higher in CC than HC in the entire period (p < 0.01). In the results of this study, hemi-castration can improve body weight gain and feed conversion ratio due to the influence of male hormones compared to complete castration, but it is considered that there will be difficulties in producing high-quality meat with a high marbling score.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.12
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• pp.1729-1735
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• 2015

This study was conducted to evaluate the effect of medicinal plant by-products (MPB) supplementation to a total mixed ration (TMR) on growth, carcass characteristics and economic efficacy in the late fattening period of Hanwoo steers. Twenty seven steers (body weight [BW], $573{\pm}57kg$) were assigned to 3 treatment groups so that each treatment based on BW contained 9 animals. All groups received ad libitum TMR throughout the feeding trial until slaughter (from 24 to 30 months of age) and treatments were as follows: control, 1,000 g/kg TMR; treatment 1 (T1), 970 g/kg TMR and 30 g/kg MPB; treatment 2 (T2), 950 g/kg TMR and 50 g/kg MPB. Initial and final BW were not different among treatments. Resultant data were analyzed using general linear models of SAS. Average daily gain and feed efficiency were higher (p<0.05) for T1 than control, but there was no difference between control and T2. Plasma albumin showed low-, intermediate- and high-level (p<0.05) for control, T1 and T2, whereas non-esterified fatty acid was high-, intermediate- and high-level (p<0.05) for control, T1 and T2, respectively. Carcass weight, carcass rate, backfat thickness and rib eye muscle area were not affected by MPB supplementation, whereas quality and yield grades were highest (p<0.05) for T1 and T2, respectively. Daily feed costs were decreased by 0.5% and 0.8% and carcass prices were increased by 18.1% and 7.6% for T1 and T2 compared to control, resulting from substituting TMR with 30 and 50 g/kg MPB, respectively. In conclusion, the substituting TMR by 30 g/kg MPB may be a potential feed supplement approach to improve economic efficacy in the late fattening period of Hanwoo steers.