• Journal of Animal Science and Technology
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• v.55 no.5
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• pp.405-416
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• 2013

This aim of this study was to estimate the most reasonable slaughter month for Hanwoo steers according to carcass traits. Carcass trait data on Hanwoo steers (17,249 head) were collected from October 2008 to September 2011. To measure the regression coefficients, Hanwoo steers were divided into two groups according to slaughter age: early (25 to 31 months) and late (32 to 38 months) groups. Regression coefficients of carcass traits according to slaughter age were significantly different (p<0.001) with the exception of PPKG (estimated auction price per 1 kg of carcass weight) in the early slaughter age group and MAR (marbling score, p<0.05) and PPKG (p<0.05) in the late slaughter age group. To obtain a positive gross margin, Hanwoo should be slaughtered at around 28 months of age.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.4
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• pp.397-404
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• 2012

This study was carried out to investigate the effects of stocking density on eating and ruminating behavior of Hanwoo steers (Bos taurus coreanae) in the finishing period. A total of 30 finishing Hanwoo steers ($631.3{\pm}11.4$ kg, 25 months old) were allocated to one of four stocking density groups comprising 1, 2, 3, and 4 steers per 32 $m^2$ pen [G1 (32 $m^2$), G2 (16 $m^2$), G3 (10.7 $m^2$) and G4 (8 $m^2$), respectively] in triplicate. Eating, rumination behaviors, as well as dry matter intake of steers were measured, and the results were subjected to analysis of variance with stocking density as the main effect. The results of eating behaviors over 48 hours are summarized as follows: Total intake was significantly (p<0.01) higher in G1, G2, and G3 compared to G4. Eating time was not different among the treatments, whereas ruminating time increased in the order of G1 > G2 > G3 > G4 (p<0.01). However, resting time and chewing time (sum of eating and ruminating) were not significantly different among the treatments. Number of boluses and number of total chews were highest in G1 (p<0.01), whereas number of chews per bolus was highest in G3 (p<0.01). Ruminating time per bolus as well as number of boluses per minute was not significantly different among the treatments. Number of defecations was higher in G1 and G2 animals compared to G3 and G4 animals (p<0.01). However, stocking density had no effect on drinking or urination. In conclusion, increasing stocking density (i.e. G4) per pen decreased voluntary intake, ruminating time, and total chewing number in the finishing period of Hanwoo steers. However, care must be taken in discussing stocking density in the present study as the space allowance per animal was satisfactory to meet the current animal welfare regulation in Korea and in Europe, although the beef production system in Korea is more intensive than in Europe.

• 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.

• Food Science of Animal Resources
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• v.26 no.3
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• pp.284-289
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• 2006

Effects of feeding timothy hay roughage in the growing period on the beef quality with during 24 month(5 month from 28 month to) in twenty Hanwoo steers were investigated. Hanwoo steers were randomly assigned to 2 groups (10 heads/treatment), the control group (C) and the treatment group (T). Cooking loss and the shear force value of m. longissimus tended to be higher in the control group, and the panel test scores of juiciness and flavor were higher in the treatment group. However the tenderness was significantly higher in the treatment group (5.10 points) relative to the control group (4.30 points) (p<0.05). The proportion of fatty acids that were saturated ranged from $42.83{\sim}40.75%$. The unsaturated fatty acid, mono-unsaturated fatty acid and poly-unsaturated fatty acid contents in the two groups were not significantly different (59.25%, 55.61% and 3.40%, respectively, for T; 57.17%, 54.40% and 2.77%, respectively, for C) (p>0.05).

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

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.7
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• pp.952-959
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• 2010

This study was conducted to evaluate growth, behavior and carcass traits of fattening Hanwoo (Korean native cattle) steers managed in different group sizes. A total of 48 animals, 6 months of age, were allocated to one of three group sizes and the experiment was conducted from 12 to 30 months of age. Groups were balanced for weight and the group sizes consisted of 4, 8, or 12 steers which were named 4sG, 8sG and 12sG, respectively. When animals were 12 months of age, initial fasted body weight (BW, $304.51{\pm}12.40\;kg$) was measured. All animals were housed at a constant space allowance of $8.82\;m^2$ per animal, and a feeder and drinker were provided per 4 animals. The whole fattening stage was divided into three phases: phase I (from 12 to 18 month of age), phase II (from 19 to 24 month of age), and phase III (from 25 to 30 month of age). Steers managed in 12sG showed low (p<0.05) growth rate and feed conversion rate (FCR) in phase I and phase II when compared to other treatment groups. However, this difference was not observed for the whole fattening phase (p>0.05). Steers managed in 4sG had a thick (p<0.05) ultrasound back fat thickness at 15 and 18 months of age. However, group size had no effect on meat yield and quality traits of area and marbling score. Animals managed in 8sG yielded a better meat grade of "A" than the "B" grade in other treatment group sizes. Lean color, fat color, firmness and maturity scores did not differ among group sizes. Hanwoo steers housed under 12sG spent less time on eating concentrate, relevant higher eating rate, less frequency of allogrooming, and more time on walking (p<0.05). It could be concluded that a large group size retarded growth rate and back fat thickness in the fattening stage, which was mainly focused on 15 and 18 months of age.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.10
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• pp.1486-1494
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• 2017

Objective: This research analyzed behavioral characteristics of Hanwoo (Bos taurus coreanae) steers during each season and growth stage to enable measurement of the animals' welfare level for precision livestock farming. Methods: A hundred-eight beef steers were divided into three equal groups at a Hanwoo farm according to their growth stage: growing stage (GS), 8 months; early-fattening stage (EFS), 19 months; and late-fattening stage (LFS), 30 months. Twelve behavioral categories were continuously recorded for 13 day-time hours in each four seasons with three replications. Results: Time spent standing was found to be significantly longer in summer at all growth stages (p<0.05). Hanwoos at the GS spent significantly longer standing time in spring and summer than those at the EFS and LFS (p<0.05). Lying time in summer was the shortest for all growth stages (p<0.05). Steers at the LFS spent significantly longer lying time than that at the GS (p<0.05) in summer. For GS and EFS, time spent eating in spring and autumn were longer than in summer and winter (p<0.05). Eating time was the longest for the GS in spring, autumn, and winter, excluding for the LFS in winter (p<0.05). Regarding ruminating, steers at the LFS spent significantly shorter time than those at other stages in all seasons (p<0.05). GS and EFS steers showed the longest walking time in summer compared with other seasons (p<0.05). At GS and LFS, drinking time in summer was the longest of all seasons (p<0.05). Sleeping time was significantly shorter in summer compared with the other seasons (p<0.05). Self-grooming time was the longest in winter for all growth stages (p<0.05). Conclusion: Steers were found to have more variable behavioral patterns during summer and the GS and less active behaviors during the LFS, thus extra care seems necessary during the GS, LFS, and summer period.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1560-1563
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• 2001

An ability to utilize the substrates (acetate, glucose and lactate) in the lipid synthesis was measured in vitro with the adipose tissues of 4 locations (subcutaneous, SUBC; intramuscular, INTR; tail and kidney, KIDN) in 12 Hanwoo (Korean native cattle) steers (26 and 28 months of ages, mean body weight 638.6 kg). The rates of lipid synthesis from acetate were higher than those from glucose in SUBC and ITRA adipose tissues, respectively. In contrast, the rates of lipid synthesis from glucose were higher than those from acetate in the adipose tissues of tail and KIDN, respectively. Lactate utilization was lowest in all the locations while that of acetate or glucose had the different trends of utilization in the lipogenesis. The rate of lipid synthesis from acetate was highest in the SUBC adipose tissue but was lowest in the KIDN while that from glucose was also higher in the SUBC adipose tissue than in the other tissue locations. The rate of lipid synthesis from lactate, however, was highest in the tail adipose tissue among the locations.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.4
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• pp.457-462
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• 2011

The purpose of this study was to detect QTL for carcass quality on bovine chromosome (BTA) 6 using a high density SNP map in a Hanwoo population. The data set comprised 45 sires and their 427 Hanwoo steers that were born between spring of 2005 and fall of 2007. The steers that were used for progeny testing in the Hanwoo Improvement Center in Seosan, Korea, were genotyped with the 2,535SNPs on BTA6 that were embedded in the Illumina bovine SNP 50K chip. Four different linkage disequilibrium (LD) mapping models were applied to detect significant SNPs for carcass quality traits; the fixed model with a single marker, the random model with a single marker, the random model with haplotype effects using two adjacent markers, and the random model at hidden state. A total of twelve QTL were detected, for which four, one, three and four SNPs were detected on BTA6 under the respective models (p<0.001). Among the detected QTL, four, two, five and one QTL were associated with carcass weight, backfat thickness, longissimus dorsi muscle area, and marbling score, respectively (p<0.001). Our results suggest that the use of multiple LD mapping approaches may be beneficial in increasing power to detect QTL given a limited sample size and magnitude of QTL effect.