This study analyzed the correlation between carcass traits of Hanwoo steers and feeding methods (concentrate feed and total mixed ration for ruminants). The results indicated that in the feeding system using concentrate feed, the variation in carcass weight and marbling score among individual animals within farms tended to affect the average carcass sale price, with both showing negative effects (p=0.057, p=0.053). The standardized regression coefficients were used to compare the influence of each variable, revealing that the coefficients for carcass weight variation and marbling score variation were –0.38 and –0.30, respectively, indicating a greater influence of carcass weight variation. Therefore, reducing the variations in carcass weight and marbling score among steers in farms using concentrate feed is likely to increase the average carcass sale price. In the case of farms using total mixed ration (TMR) for ruminants, the variation in marbling score among individual animals significantly affected the average carcass sale price, showing a negative effect (p=0.002). Thus, reducing the variation in marbling score among steers in TMR farms is likely to increase the average carcass sale price. In summary, the coefficient of variation of marbling score was found to have a significant impact on the average carcass sale price of the farm. In farms using concentrate feed, the variations in both carcass weight and marbling score tended to affect the average carcass sale price (0.05<p<0.1). Meanwhile, in farms using TMR, the variation in marbling score had a significant impact. In conclusion, the coefficient of variation for marbling score in carcass performance was found to have the most significant impact on the average carcass sale price for both feeding types (concentrate and TMR diets). Furthermore, reducing the variation along with carcass weight of Hanwoo steers on concentrate feed may be a way to increase farm income.

This study aimed to investigate the effects of amino acid complex additives, such as protected vitamin C (VC) or detoxified sulfur (DS), on the growth and metabolism of Hanwoo cattle under high-temperature conditions. Accordingly, farms in Temperature-Humidity Index (THI) regions ranging from 78 to 89 for over 100 days were selected. The experimental groups were control, T1 (lysine + methionine + VC, 50 g/head/day), and T2 (lysine + methionine + DS, 50 g/head/day) with 70, 77, and 71 animals each. The range of the THI for 115 days was 78-89, and this occurred in most of the experiment days. The results showed that there was no significant difference in rectal temperature among the groups. The body weight increased to 786.4 and 809.0kg in the T1 and T2 groups, respectively, compared to the control group (p<0.05). Linoleic acid showed a high result of 2.01% in the T1 group compared to the control group (p<0.05). Unsaturated fatty acids were higher at 55.70 and 56.54% in the T1 and T2 groups, respectively, compared to the control group (p<0.05), and the omega 6/3 ratio was reduced to 20.10% (p<0.05). These findings indicate that T1 has a positive impact on growth, meat quality, and fatty acid composition compared to the control group. In conclusion, amino acid complex with VC improved the body weight of Hanwoo steers and the unsaturated fatty acids and essential amino acids of their meat; however, further research is needed to clarify this impact on carcass performance.

γ-aminobutyric acid (GABA) is a natural stress-reducing substance and is actively used as a human health supplement. However, minimal research has been conducted on its use in cattle. This study was conducted to evaluate the effects of GABA on the growth performance, complete blood count, blood metabolites, and carcass characteristics of fattening Hanwoo steers. Twenty-one fattening steers were randomly assigned to one of three treatments: control (basal diet: concentrate feed + rice straw), T1 (basal diet + GABA supplement at 0.8% of feed/head/day), and T2 (basal diet + GABA supplement at 1.6% of feed/head/day). Feed intake and conversion ratio did not differ among the treatments. However, the average daily gain during the early fattening period increased linearly to 0.80 kg, 0.86 kg, and 0.92 kg in the control, T1, and T2 groups (p<0.05). Plasma γ-glutamyl transferase (37.5, 58.2, 42.8 U/ℓ) and creatinine (1.32, 1.34, 1.49 ㎎/㎗) levels in the GABA supplement group were increased compared to those in the control group. The carcass weight (422.7, 427.1, 454.1 kg), rib eye area (86.67, 92.57, 91.14 cm2), and marbling score (3.67, 4.29, 4.14) were numerically higher in the GABA supplement group than in the control group. Thus, GABA supplementation positively affected the average daily gain and carcass characteristics of Hanwoo steers. However, the effect of the GABA supplement level of GABA was small, and further research using rumen-protected coating technology on GABA is necessary.

본 연구에서는 미생물 첨가에 따라 거세한우 비육우 분의 이화 학적 특성, 미생물 성상, 가스발생량 및 퇴비 부숙도에 미치는 영 향을 규명하고자 수행하였다. 이상의 결과를 종합하면, 4주 후,미생물 첨가구에서 수분, 유기물, 총질소 함량 및 pH가 낮았으며, 나머지 이화학적 특성에서는 차이가 나타나지 않았다. 유산균과 효모균 수는 증가하였으며, 대장균 수는 감소하였다. 12주 후, 미 생물 첨가구에서 유산균과 고초균 수는 높았으나, 수분, 효모 및 대장균 수는 낮게 낮았다. 하지만 암모니아, 황화수소 발생량과 퇴비 부숙도는 미생물 첨가에 의한 효과가 나타나지 않았다. 따라 서, 거세한우 분에 미생물을 첨가하면 유익균은 증가하고, 병원성 미생물은 감소하여, 비육우의 생산성은 증진될 것으로 사료되지 만, 가스 발생량 및 퇴비 부숙도에 대한 추가적인 연구는 지속적 으로 수행되어야 할 것으로 사료된다.

본 연구에서는 거세방법에 따른 한우의 안심살(M. psoas major), 꽃등심살(M. longissimus thoracis) 및 우둔살(M. semimembranous)의 육질특 성과 지방산 조성을 조사하였다. 공시시료는 송아지가 7개월령에 도달하면, 외과적 수술방법을 통해 한쪽 고환을 제거한 반거세 한우(half-castration; HC) 9두와 양쪽 모두 제거한 완전거세 한우(complete-castration; CC) 8두를 이용하였다. 거세된 송아지는 24-26개월까지 동일한 조건에서 사육한 후 도축하고 3개 부위(안심살, 꽃등심살, 우둔살)를 채취하여 육질 분석하였다. 거세방법에 따른 그룹 간 지방함량은 HC 그룹이 2.97~11.06%로 CC 그룹보다 낮은 함량을 나타내었으며, 수분함량은 HC 그룹이 65.39~70.90%로 CC 그룹보다 높은 함량을 나타내었다(p<0.05). 3개 근육의 pH는 5.47~5.54 범위였으며, pH와 보수력은 거세방법에 따른 유의적인 차이는 나타나지 않았다(p>0.05). 육색은 L*값과 a*값에서 HC가 CC보다 낮게 나타났다(p<0.05). 가열감량과 전단력은 HC 그룹의 꽃등심살이 CC 그룹보다 높은 값을 나타내었다(p<0.05). 지방산 조성은 palmitic acid, palmitoleic acid, vaccenic acid, oleic acid, linoleic acid, linoleneic acid와 PUFA, n6에서 HC와 CC 그룹 간 유의적 차이가 나타났다(p<0.05). 특히, 지방산 조성에서 HC 그룹과 CC 그룹 모두 oleic acid가 가장 높은 함량을 나타내었다(p<0.05). 따라서 거세 방법은 한우육의 근육 내 지방, 육색, 연도와 같은 이화학적 특성과 지방산 조성에 영향을 미칠 수 있다고 사료된다.

The present study was conducted to examine the effect of soybean silage as a crude protein supplement for corn silage in the diet of Hanwoo steers. The first experiment was conducted to evaluate the effect of replacing corn silage with soybean silage at different levels on rumen fermentation characteristics in vitro. Commercially-purchased corn silage was replaced with 0, 4, 8, or 12% of soybean silage. Half gram of the substrate was added to 50 mL of buffer and rumen fluid from Hanwoo cows, and then incubated at 39°C for 0, 3, 6, 12, 24, and 48 h. At 24 h, the pH of the control (corn silage only) was lower (p<0.05) than that of soybeansupplemented silages, and the pH numerically increased along with increasing proportions of soybean silage. Other rumen parameters, including gas production, ammonia nitrogen, and total volatile fatty acids, were variable. However, they tended to increase with increasing proportions of soybean silage. In the second experiment, 60 Hanwoo steers were allocated to one of three dietary treatments, namely, CON (concentrate with Italian ryegrass), CS (concentrate with corn silage), CS4% (concentrate with corn silage and 4% of soybean silage). Animals were offered experimental diets for 110 days during the growing period and then finished with typified beef diets that were commercially available to evaluate the effect of soybean silage on animal performance and meat quality. With the soybean silage, the weight gain and feed efficiency of the animal were more significant than those of the other treatments during the growing period (p<0.05). However, the dietary treatments had little effect on meat quality except for meat color. In conclusion, corn silage mixed with soybean silage even at a lower level provided a greater ruminal environment and animal performances, particularly with increased carcass weight and feed efficiency during growing period.

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.

This study was conducted to investigate the effect of whole crop rice based TMR on the meat quality of Korean Native Cattle (Hanwoo). Sixteen Hanwoo steers (average 8 months old) were divided into the control group (commercially marketed TMR) and the WCR-TMR group (whole crop rice based TMR). Feeding trials were carried out up to 30 months of age, and after slaughter, the strip loin were collected and analyzed for meat quality. There were no significant differences in proximate compositions of Hanwoo (P>0.05), and crude protein, crude fat and crude ash were 19.51∼20.23 %, 11.53∼11.35 % and 1.10∼1.12 %, respectively. There was no significant difference in water holding capacity and cooking loss between treatments (P>0.05), but it was slightly lower in the control group. Among the various functional components in meat, β-carotene was not detected, but α-tocopherol was significantly higher in WCR-TMR group and vitamin A content in control (P<0.05). The a*-value in the meat color index decreased significantly with longer storage period in the control group, whereas the WCR-TMR fed group showed no significant difference (P>0.05) according to the storage period. There were no difference between the treatments in the TBARS (2-Thiobarbituric acid reactive substances) value used as an indicator of lipid oxidation and in fatty acid content. But the control group had high myristic acid content, whereas the WCR-TMR supplemented group showed higher oleic acid and linoleic acid content. In conclusion, feeding of WCR based-TMR increased the α-tocopherol content, which is a functional ingredient in meat, and the other components were not significantly different from the control. Therefore, it was judged that there was no significant difference between WCR based and conventional TMR in meat quality characteristics.

This study was carried out to investigate the effect of mountain grazing on growth performance and carcass characteristics of Hanwoo steers. Thirty two Hanwoo steers were randomly assigned. Control were fed concentrate + forage until 30 month of age. Treatment1 were fed concentrate + forage after mountain grazing from 8 to 13 months. Treatment2 and 3 were fed concentrate + forage after mountain grazing from 8 to 17 months. Hanwoo steers on Treatment 1 and 2 were slaughtered at the same age (30 months) as the control, and Hanwoo steers on Treatment 3 were slaughtered at 31 months. The average daily gain (ADG) were higher in the control than in the other treatments during the growing period (p<0.05). Carcass back fat thickness was thicker in the TRT 3 and marbling score was higher in the TRT 1 than in the other treatments; however, the differences were not statistically significant. There was no difference in the meat composition and shear force of the longissimus muscle according to the mountain grazing. However, the yellowness (b) of fat colors were significantly lower in the control than in the TRT 1 and TRT 2 (p<0.05). The effect of grazing on fatty acid composition was not constant. In conclusion, mountain grazing could reduce meat color without affecting the growth and meat quality of Hanwoo steers, and further research on the quality, yield and intake of grassland would be needed.

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.

This study was conducted to investigate the effects by supplementing concentrates during the late fattening phase in TMR (total mixed ration) feeding of Korean steer on the performance, carcass traits, physico-chemical characteristics and sensory test of the longissimus dorsi muscle. Eight Korean steers (24 months of age) averaging 604 kg in body weight were fed the TMR (Control) or the TMR supplemented with concentrates (TMR+conc.) until 30 months of age, then they were slaughtered. Steers fed the TMR supplemented with concentrates had a higher (p<0.05) intakes of dry matter and TDN (total digestible nutrient), carcass weight and marbling score compared to those fed TMR only, but carcass grade did not differ (p>0.05) between treatments. Amino acid concentration of the longissimus dorsi muscle did not differ between treatments, However, the highest concentrations were for glutamic acid and lowest for cystine; further, and the content of essential amino acids was highest for lysine, leucine, threonine, arginine, and isoleucine in that order. Cis-oleic acid and arachidonic acid of fatty acids in the longissimus dorsi muscle were higher (p<0.05) in the control condition compared to TMR+conc. The contents of oleic acids, palmitic acid, stearic acid constituted about 88% of the total fatty acids. Although the physico-chemical characteristics of the longissimus dorsi muscle did not significantly differ between treatments (p>0.05), but the sensory test results were lower for the TMR+conc. condition. These results suggest that supplementing concentrates during the late fattening phase of Korean steers resulted in increasing the carcass weight and marbling score. However, the cis-oleic acid content of the longissimus dorsi muscle was decreased as a result of supplementing concentrates, which could affect negatively in meat sensory evaluation.

This experiment was conducted to investigate the effect of whole crop rice (WCR) based TMR on growth performance and carcass characteristics of Hanwoo steers. WCR “Yeongwoo”was harvested at yellow ripen stage and ensiled for 60 days. The crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), in vitro dry matter digestibility (IVDMD) and total digestible nutrient (TDN) content was 8.4 %, 28.0 %, 53.8 %, 72.4 % and 66.8 %, respectively. For silage quality, pH was 4.37 and lactic and butyric acid content were 2.84 and 0.04 % in DM. Sixteen Hanwoo steers (8-mon-old) were allocated into either a control (commercial TMR) and WCR-TMR (WCR-based TMR) group. The TMR were fed according to the feeding stage phase: growing (Initiate∼14 month), early fattening (15 month∼21 month) and late fattening (22 month∼30 month). The body weight of control group increased (P<0.05) until early fattening stage, but late growing stage of WCR-TMR group was higher than that of control (P<0.05). Average daily gain (ADG) was significantly greater (P<0.05) in WCR-TMR group (total 0.78 kg/head) compared to control (total 0.66 kg/head) except for late fattening stage. The marketing weight and carcass weight were higher in WCR-TMR group (726 vs 765 kg; 417.8 vs 450.4 kg). The back fat thickness (11.75 vs 13.00 mm), Longissimus dorsi area (88.00 vs 89.88 ㎠) and yield index (65.87 vs 64.30) were not different between the two groups (P>0.05) and also no difference in meat yield grade (A : B : C = 2 : 4 : 2). Marbling score (4.00 vs 4.13), meat color (4.75 vs 4.75), fat color (3.13 vs 2.88), texture (1.25 vs 1.50) and maturity (2.00 vs 2.00) were not significant difference between the two groups and meat quality grade (1++:1+:1:2:3=0:2:4:2:0) was also not different. In conclusion, TMR feeding based on WCR silage showed superiority in carcass yield and ADG compared to control TMR. It is considered that the use of WCR for feed is a necessary option for the substitution of the imported forages and the government's policy for rice production adjustment.

This study was conducted to investigate whether dietary levels of copra and palm meals affect the growth performance, carcass characteristics, and meat properties of Hanwoo steers. Eighty-one Hanwoo steers were randomly assigned to one of three dietary groups: T1 (conventional level of palm and copra meals), T2 (20% copra meal and 15% palm meal), and T3 (30% copra meal and 20% palm meal). During the growing and early fattening periods, the average daily gains and formula feed intakes of T2 and T3 were higher than that of T1; however, those differences were not statistically significant. The dietary levels of copra and palm meals did not affect carcass weight, back fat thickness, and rib-eye areas. Marbling scores and meat quality grades were lower in T3 than in T1 and T2; however, those differences were not statistically significant. Meat color, fat color, texture, and maturity were similar among the treatment groups. In addition, dietary levels of copra and palm meals did not affect the chemical and fatty acid composition of longissimus dorsi muscles in Hanwoo steers. Thus, the present results indicate that high supplementation levels of copra and palm meals do not negatively affect the growth performance, carcass characteristics, and meat properties of Hanwoo steers.

본 연구는 경북지역 거세 한우의 출하체중에 따른 도체 특성 및 부분육 생산량을 조사하여 고기의 생 산성을 도체로부터 평가하기 위하여 실시하였다. 경북지역 거세 한우 51두를 도착체중 700kg미만, 701~750kg, 751~800kg, 801~850kg, 850kg초과 5그룹으로 나누어 가공단계별 중량변화, 도체규격, 대분할 부위 생산량 및 수율, 소분할 부위 생산량 및 수율, 부산물 생산량 및 수율을 조사하였다. 가공 단계별 중량변화는 한우의 출하체중이 증가함에 따라 온도체중, 냉도체중, 대분할육, 소분할육, 뼈량, 지방량이 증가하였다. 도체규격은 한우의 출하체중이 증가함에 따라 전장, 전사분체장, 흉장, 경폭, 흉 폭, 퇴폭, 흉위, 퇴위, 흉후가 증가하였다. 부산물 생산량은 한우의 출하체중이 증가함에 따라 머리, 앞 족, 뒷족, 가죽, 간, 소장, 배지방, 생식기, 신장, 기타지방량이 증가하였다. 도체부산물은 한우의 출하 체중이 증가함에 따라 사골, 꼬리반골, 도가니, 마구리, 잡뼈, 갈비뼈량이 증가하였다.

The purpose of this study was to investigate the effect of dietary addition of pegmatite for Hanwoo steers on the carcass characteristics. Based upon the findings yielded by the research referenced above, the results may be summed up as follows : Oleic acid was for the most part, higher as T2 plots (45.40%) and T3 plots (44.20%) compared with Con. plots (42.50%). As well, this study has shown that the treatment plots in unsaturated fatty acid (UFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) were largely higher than that of Con. plots, and of them all, T2 plots were highest. As for the melting point of fat, T2 plots (29℃) were largely lower than that of Con. plots (31.9℃). This study has shown that the treatment plots were significant higher as the content of total essential amino acid and total amino acid and inosine monophosphate in the nucleotide compound for the Hanwoo beef was treatment plots when compared with Con. plots.

This study was conducted to investigate the effects of fermented spent mushroom substrates (F-SMS) of Flammulina velutipes on growth performance, carcass traits, and economic characteristics of Hanwoo steers. A yeast strain (Saccharomyces sp. UJ14) and Bacillus strain (Bacillus sp. UJ03) isolated from fresh spent mushroom substrates of Flammulina velutipes were used as probiotics to prepare F-SMS. Twenty-four Hanwoo steers (14 months old) were allocated to three dietary treatments via a randomized block design and were slaughtered at 30 months of age. These treatment groups included Control (TMR), T1 (TMR containing 10% of F-SMS) group, and T2 (TMR containing 30% of F-SMS). Body weight gain was not influenced by the experimental diets. DM and TDN intakes in the finishing period were significantly (p < 0.05) greater in group T1 than in other groups. CP intake was significantly (p < 0.05) greater in group T2 than in other groups during the whole experimental period. Among carcass traits, rib-eye area and back fat thickness tended to increase with F-SMS supplementation. The appearance rate (%) of a meat yield more than grade A was the highest in group T1. The net profits increased by 1.2% and 13.3% in groups T1 and T2, respectively. In conclusion, if a proper feeding program (including feed safety) can be ensured, spent mushroom substrates of Flammulina velutipes can prove to be a highly profitable feed source for Hanwoo steers.