• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.149-159
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• 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
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• v.48 no.4
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• pp.975-985
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• 2021

The sufficient amount of protein supply is crucial for improving the growth performance of growing beef cattle. In addition, due to the improvement in the genetic potential of the carcass weight of Hanwoo steers, dietary protein requirements may be increased during the rapid growth period. Accordingly, the dietary crude protein (CP) level in growing Hanwoo steers has been increasing in the field. However, little scientific evidence is available in relation to this. Therefore, this study was conducted to test whether a higher dietary CP level than convention would improve the growth performance and body metabolism in growing Hanwoo steers. Fifty growing Hanwoo steers were randomly divided into two groups and fed either a commercial diet (CON) or a higher CP (HCP) concentrate mix, provided with a similar level of dietary energy. Tall fescue hay was provided ad libitum. The dietary CP level did not affect growth performance and blood metabolite. Nitrogen intake, predicted nitrogen excretion, and retained nitrogen were higher in the HCP group than in the CON group (p < 0.01). Although there was no difference in the nitrogen utilization efficiency, the growth efficiency per retained nitrogen decreased in the HCP group (p = 0.02). A higher dietary CP level may increase nitrogen retention in growing Hanwoo steers without improving growth performance, which leads to reduced growth efficiency per retained nitrogen. Furthermore, considering the high price of feed protein and increased nitrogen excretion to the environment, a further increase in the protein level may not be sustainable.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.3
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• pp.158-166
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• 2023

Background: Copy number variation (CNV) can be identified using next-generation sequencing and microarray technologies, the research on the analysis of its association with meat traits in livestock breeding has significantly increased in recent years. Hanwoo is an inherent species raised in the Republic of Korea. It is now considered one of the most economically important species and a major food source mainly used for meat (Hanwoo beef). Methods: In this study, CNVs and the relationship between the obtained CNV regions (CNVRs) can be identified in the Hanwoo steer samples (n = 473) using Illumina Hanwoo SNP 50K bead chip and bioinformatic tools, which were used to locate the required data and meat traits were investigated. The PennCNV software was used for the identification of CNVs, followed by the use of the CNV Ruler software for locating the different CNVRs. Furthermore, bioinformatics analysis was performed. Results: We found a total of 2,575 autosomal CNVs (933 losses, 1,642 gains) and 416 CNVRs (289 gains, 111 losses, and 16 mixed), which were established with ranged in size from 2,183 bp to 983,333 bp and 10,004 bp to 381,836 bp, respectively. Upon analyzing the restriction of minor alleles frequency > 0.05 for meat traits association, 6 CNVRs in the carcass weight, 2 CNVRs in the marbling score, 3 CNVRs in the backfat thickness, and 2 CNVRs in the longissimus muscle area were related to the meat traits. In addition, we identified an overlap of 347 CNVRs. Moreover, 3 CNVRs were determined to have a gene that affects meat quality. Conclusions: Our results confirmed the relationship between Hanwoo CNVR and meat traits, and the possibility of overlapping candidate genes, annotations, and quantitative trait loci that results depended on to contribute to the greater understanding of CNVs in Hanwoo and its role in genetic variation among cattle livestock.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.3
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• pp.257-266
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• 2010

This study was carried out to investigate the effect of feeding whole crop barley silage (WBS) on the growth performance, gain, feed requirement, carcass grade and beef quality of Hanwoo steers in 1999 to 2001. Twenty one steers were allocated, and divided into three treatment groups which fed rice straw only (control), WBS only, and fresh rice straw silage plus WBS during overall period ad libitum. Concentrates were fed at 1.5% level of live-body weight during growing stages, 4~12 months of age, at 1.8% level of live-body weight during early fattening stages, 13~18 months of age, and ad libitum after late fattening stages, 19~27months of age. The production yields of WBS were 17,135 kg as a silage, and 6,011 kg as a dry matter per ha, and the quality of WBS was 2~3 grade, while that of rice straw silage was 4grade. The daily gain with feeding of WBS (0.70 kg) during experimental period was higher than that of control group (0.65 kg), and the concentrate requirement (7.31 kg) per kg gain in WBS was lower than that of control (8.95 kg). The effects of gain and feed efficiency were very distinct during growing stage. i.e., the daily gain of WBS (0.84 kg) was increased by 65% compared to control (0.51 kg), and the concentrate requirement (4.16 kg) per kg gain in feeding of WBS was decreased by 35%, compared to control (6.39 kg). Meat quality with WBS was higher than that of control. Frequency rate of 1 and/or $1^+$ grade, and marbling score of feeding of WBS were 62.5% and 4.38, while those of control were 37.5% and 2.75, respectively. The results of the sensory evaluation showed that Hanwoo beef fed with WBS were better than that of control. In conclusion, feeding of WBS was desirable to improve daily gain, reduction of concentrates, feed efficiency and meat quality of Hanwoo steers.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.827-838
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• 2006

This experiment was carried out to investigate the effects of dietary vitamin E levels on carcass characteristics and vitamin E contents, fatty acid composition and lipid oxidation as indicated by thiobarbituric acid reactive substances(TBARS) of the longissimus muscle in Hanwoo steers. Forty Hanwoo steers were randomly assigned to one of four groups and fed the diet containing 200(control), 1000, 2000 or 2500 IU a(alpha)-tocopherol acetate/head/day for 3 months of last finishing period. Backfat thickness was thinner and beef fat color was whiter(P<0.05) in steers fed the vitamin E supplemented diets than those fed the control diet. But the longissimus muscle area and yield grade did not differ among treatments. Marbling score and quality grade were higher(P<0.05) in steers fed the diets containing 1000 and 2000 IU vitamin E than those fed the other diets. Vitamin E concentration in the longissimus muscle was higher(P<0.05) as the vitamin E content in diet was higher. The levels of oleic and linoleic acids in the longissimus muscle were not affected by dietary vitamin E levels. But linolenic and arachidonic acids were lower in steers fed the vitamin E supplemented diets than those fed the control diet. TBARS in the longissimus muscle was not affected by the vitamin E levels in diet until 5th day of storage but delayed muscle lipid oxidation in steers fed the vitamin E supplemented diets after 7th day of storage. Therefore according to this result, it may be concluded that steers have a higher quality grade and higher vitamin E concentration in muscle and lower in TBARS when diet contains 1000 or 2000 IU vitamin E per kg of diet.

• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.583-592
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• 2005

This experiment was conducted to determine the effects of dietary copper levels on performance, carcass characteristics, and economical analysis in Hanwoo steers. Fifteen Hanwoo steers weighing about 300kg were randomly allotted into one of three treatments. The three treatments consisted of Control(7mg Cu/kg feed), TI(12mg Cu/kg feed) and TII(17mg Cu/kg feed). Copper was formulated with concentrate from copper sulfate($CuSO_4$) and animals were fed the diets supplemented with copper from 300kg untill about 630 kg of body weight. Dietary copper levels did not affect daily weight gain, feed intake and feed efficiency during the whole feeding period. Dressing percentage, rib eye area and backfat thickness were not different between animals fed the diets supplemented with copper. Animals fed the diets supplemented with copper received the same B grade in yield grade. Animals fed the diets supplemented with copper received same marbling score. Beef color, fat color, texture and maturity were not affected by Cu supplementation in diet. Animals received the same first grade between treatments in quality grade. Animals fed the diet supplemented with 12mg of copper per kg diet was higher in profit by 13.3% than animals fed the control diet. According to these results, it may be concluded that performance, yield and quality grade were not affected by the Cu levels of 7 to 17mg per kg feed but crude income was enhanced when Hanwoo steers were fed the diet containing 12mg Cu/kg feed.

• Journal of Animal Science and Technology
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• v.48 no.3
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• pp.401-414
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• 2006

Twenty eight Holstein steers 12 months old and weighing about 300kg were andomly allotted into one of four groups being fed ammoniated rice straw(ARS) and substituted 30%, 40% and 50% crushed bamboo chip for ARS to determine the effects of different levels of bamboo chip on performance, digestibility and carcass characteristics. Daily weight gain was reduced as the substitution levels of bamboo chip for ARS as a roughage source increased but there were no differences in daily weight gain between steers fed ARS alone and 30% bamboo chip for ARS. Concentrates intakes were not different between treatments by the substitution levels of bamboo chip for the whole fattening period. Roughage intake tended to increase as the substitution levels of bamboo chip increased. Total feed intake was not affected by the substitution levels of bamboo chip. However, feed efficiency got worse with increasing levels of bamboo chip. Animals fed the roughage substituting 30% bamboo chip for ARS were higher in profit by 13% than animals fed ARS alone as a roughage source. Digestibilities of Dry matter(DDM) and crude fiber(DCF) were highest in animals fed ARS alone as a roughage source. DDM's were lower in higher substitution levels of crushed bamboo chip but there were no differences in DCF among animals fed different levels of bamboo chip as a roughage source. Crude protein digestibility was not affected by ammoniated rice straw or by the different levels of bamboo chip. Dressing percentage and backfat thickness were not affected by ammoniated rice straw or by the levels of bamboo chip but ribeye area was narrowed as the levels of bamboo chip increased. Beef color, fat color, texture, maturity and marbling score were not affected by feeding of ammoniated rice straw or by the levels of bamboo chip. According to these results, it may be concluded that profit can increase when Holstein bulls are castrated and roughage containing ammoniated rice straw plus 30% bamboo chip is offered.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.4
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• pp.281-289
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• 2013

This study was conducted to investigate the effects of feeding seleniferous whole crop barley silage (WCBS) on the growth performance, blood and carcass characteristics, and tissue selenium deposition infinishing Hanwoo steers. A total of 20 growing Hanwoo steers were selected and assigned to one of the following feed groups: control (0.1 ppm Se), T1 (0.3 ppm Se), T2 (0.9 ppm Se), and T3 (0.9 ppm of inorganic Se). Five steers were allocated to each treatment group, and the trial lasted for 90 days. All experimental diets combined seleniferous and/or non-seleniferous WCBS up to a ratio of 30%. For the T3 diet, 0.9 ppm Se in the form of sodium selenite was added to the control diet. Dietary level and type of selenium did not affect feed intake and body weight gain. Blood total lipid and triglyceride concentrations were significantly (p<0.05) lower in the T2 group than in control. Blood immunoglobulin G concentration increased significantly (p<0.05) with increasing levels of dietary selenium; concentrations were significantly (p<0.05) higher in T2 and T3 than in control. Blood selenium concentration was the highest (p<0.05) in T2. No significant difference was observed in dressing rate, ribeye area, marbling score, meat color and fat color. Further, no association was found between levels and chemical form of dietary selenium and quality and quantity of meat. To the contrary, tissue selenium content in kidney, liver, and hind leg increased significantly (p<0.05) with increasing levels of selenium; however, feeding inorganic selenium did not introduce a significant increase in tissue selenium content of finishing Hanwoo steers. The results indicated that the selenium present in seleniferous WCBS was an effectively absorbable selenium source, suitable for increasing tissue selenium content in beef. Approximately 100 g of hind leg muscle from steers fed on the T2 diet met approximately 69% of the recommended daily selenium requirements.

• Journal of Animal Science and Technology
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• v.55 no.5
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• pp.451-460
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• 2013

The feed value of sesame meal, a main agricultural by-product from the northern area of Gyeongsangbuk-do province, was assessed in Hanwoo steers. A total of twelve Hanwoo steers (average BW = 412.08 kg) were allocated into a Control (fed no sesame meal) or Treatment (fed sesame meal from 14.6 months of age) group, considering BW and ages, and the animals were fed for a total of 480 days. The final BW, total gain and ADG for the Control and Treatment groups were 741.17 kg and 762.67 kg, 331.84 kg and 347.84 kg, and 0.69 kg and 0.72 kg, respectively, showing better performances in sesame meal-fed animals. Feed requirements during the whole experimental period improved by feeding sesame meal (15.31 and 14.87 for Control and Treatment group, respectively). Hanwoo steers fed sesame meal also showed a 22.83 kg heavier cold carcass weight (424.17 kg and 447.00 kg in the Control and Treatment group, respectively), and 2.41% improved dressing percentages (58.60% and 57.22% for the Control and Treatment group, respectively). The area of the M. longissimus dorsi was $91.83cm^2$ and $88.33cm^2$ in the Control and Treatment group, respectively. The final yield of A and B grade meat were 50 : 50% and 33.3 : 66.7% from the Control and Treatment group, respectively. The average marbling score was 4.83 and 5.50, and the numeric values for quality grade was 2.17 and 2.67 for the Control and Treatment group, respectively, showing better beef quality in sesame meal-fed Hanwoo steers. In fact, there were two animals with beef quality $1^{{+}{+}}$ in the sesame meal-fed group. The melting point of lipid extracted from the M. longissimus dorsi of Hanwoo steers was significantly (p<0.05) lower in the Treatment group ($28.28^{\circ}C$) compared to the Control group ($30.65^{\circ}C$). The composition of saturated fatty acids, $C_{14:0}$ (myristic acid) and $C_{16:0}$ (palmitic acid), were significantly lower in sesame meal-fed animals, 4.70% and 2.20% for myristic acid, and 30.55% and 27.12% for palmitic acid, in the Control and Treatment group, respectively. In contrast, there were no significant differences in C18:0 (stearic acid) composition between the groups. The composition of a representative unsaturated fatty acid, $C_{18:1}$ (oleic acid), was significantly higher in Treatment animals (49.89%) than Control animals (44.29%) (p<0.05). The ratio of total monounsaturated fatty acids / saturated fatty acids; M/S) was 1.10 and 1.36 for the Control and Treatment groups, respectively, showing remarkably higher ratios in sesame meal-fed group. The content of glutamic acid, related to beef flavor, was significantly higher in the Treatment group (3.35 mg/100 g) compared to the Control group (1.88 mg/100g) (p<0.05). The tenderness score, evaluated by an eight-point scale in the panel test, and overall palatability (based on juiciness, flavor, oiliness, and umami) were significantly higher in the Treatment group (5.67 and 5.23, respectively) than the Control group (3.83 and 4.60, respectively) (p<0.05). In conclusion, the current results imply that sesame meal could serve as a good supplement for Hanwoo steers for producing high quality beef.

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.427-436
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• 2004

The current study was conducted to determine the effect of suspension method on satisfaction level of Korean consumers and objective meat quality traits in Hanwoo longissimus dorsi(LD), triceps brachii(TB) and semimembranosus(SM) muscles. Eighteen Hanwoo steers were slaughtered and alternative sides were hung either by pelvic bone(TS) or Achilles tendon(Al). Sensory characteristics, WB-shear force, sarcomere length, water-holding capacity, saroomere length and cooking loss were determined after a 7-d chiller ageing. Higher carcass quality grade received significantly(p < 0.05) greater eating quality for LD, but the grade did not affect eating quality for both TB and SM. TS did not influence objective and subjective meat quality for TB, but that significantly(P < 0.05) improved eating quality for LD and SM. The most noticeable result was that when SM was tenderstretehed, eating quality was equivalent to that of nonna1ly hung LD. In relationship between objective and subjective meat quality assessments, eating qualty for LD had a significant(P < 0.05) relationship with intramuscular fat content, while that for SM was greatly(P < 0.05) related to saroomere length. The current study indicated that pelvic hanging was an effective way to improve eating quality both LD and SM, and carcass quality grades did not greatly reflect eating quality of SM and TB. The data also implied that instnunental measurements poorly estimated the satisfaction level of Korean conswners.