• Asian-Australasian Journal of Animal Sciences
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• 제23권11호
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• pp.1427-1435
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• 2010

The present study was conducted to examine the effect of a stair-stepped feed intake pattern on growth, feed efficiency, and meat quality of Hanwoo steers. Twenty-seven 11-month-old Hanwoo steers were randomly divided into three groups. The control group was fed according to the Korean steer feeding program, and the other two groups were fed according to an alternated feeding schedule of 3-2-4-2 months. During the first three months of the experiment, treatment group 1 (T1) and treatment group 2 (T2) were fed 20% and 30% less than the control group, respectively. For the following two months, the T1 group was fed 20% more than the control group while the T2 group was fed 20% less than the control group. In the third step, T1 and T2 groups were fed 20% and 10% less, respectively, than the control group for four months. In the last two months, T1 and T2 groups were fed 20% more than the control group. After the stair-step feeding trial, steers were fed concentrated feed ad libitum for five months. The altered feed intake pattern did not affect daily body weight gain. However, daily feed intake tended to decrease and growth efficiency tended to increase in the two treatment groups compared to the control group. Altered feed intake also affected blood metabolite levels. The serum glucose and BUN level of the T1 group increased in the first re-fed period compared to the T2 and control groups. The serum cholesterol level of the T2 group decreased in the first restricted-re-fed growth period compared to the T1 and control groups. The serum NEFA levels of the two treatment groups increased from the first restricted period compared to the controls. The serum insulin level of the T2 group increased in the last period compared to the T1 and control groups. Regarding meat yield index, the control group was significantly higher than the T2 group (p<0.05). Regarding meat yield grade, the carcass back fat thickness of the T2 group was significantly higher than the control group (p<0.05). In marbling score, the T1 group was the highest (4.9), followed by the control group (4.1) and the T2 group (4.0). These results indicate that using a stair-stepped growth pattern (T1) can contribute to improvements in growth efficiency and muscle marbling.

• Asian-Australasian Journal of Animal Sciences
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• 제31권2호
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• pp.293-300
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• 2018

Objective: This study observed the effects of cooking method and final core temperature on cooking loss, lipid oxidation, aroma volatiles, nucleotide-related compounds and aroma volatiles of Hanwoo brisket (deep pectoralis). Methods: Deep pectoralis muscles (8.65% of crude fat) were obtained from three Hanwoo steer carcasses with $1^+$ quality grade. Samples were either oven-roasted at $180^{\circ}C$ (dry heat) or cooked in boiling water (moist heat) to final core temperature of $70^{\circ}C$ (medium) or $77^{\circ}C$ (well-done). Results: Boiling method reduced more fat but retained more moisture than did the oven roasting method (p<0.001), thus no significant differences were found on cooking loss. However, samples lost more weight as final core temperature increased (p<0.01). Further, total saturated fatty acid increased (p = 0.02) while total monounsaturated fatty acid decreased (p = 0.03) as final core temperature increased. Regardless the method used for cooking, malondialdehyde (p<0.01) and free iron contents (p<0.001) were observed higher in samples cooked to $77^{\circ}C$. Oven roasting retained more inosinic acid, inosine and hypoxanthine in samples than did the boiling method (p<0.001), of which the concentration decreased as final core temperature increased except for hypoxanthine. Samples cooked to $77^{\circ}C$ using oven roasting method released more intense aroma than did the others and the aroma pattern was discriminated based on the intensity. Most of aldehydes and pyrazines were more abundant in oven-roasted samples than in boiled samples. Among identified volatiles, hexanal had the highest area unit in both boiled and oven-roasted samples, of which the abundance increased as the final core temperature increased. Conclusion: The boiling method extracted inosinic acid and rendered fat from beef brisket, whereas oven roasting intensified aroma derived from aldehydes and pyrazines and prevented the extreme loss of inosinic acid.

• Asian-Australasian Journal of Animal Sciences
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• 제19권10호
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• pp.1464-1469
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• 2006

The present study was conducted with twenty-four Korean native (Hanwoo) steers to observe the effect of mixed oil and monensin supplementation and duration of feeding on c9,t11-CLA content in plasma and fat tissues. The steers were randomly assigned to three groups of eight animals each according to body weight. Hanwoo steers in the control group were fed the commercial concentrate for the late fattening stage. The other groups of steers were fed the same diet as control steers, but the concentrate was supplemented with high-$C_{18:2}$ oil mixture (soybean oil, sunflower oil, safflower oil) and fish oil at 6% level of concentrate (DM basis), and monensin (20 ppm). The second and third group of steers was fed the oil mixture supplemented diet with monensin for the last 10 weeks and 20 weeks, respectively, prior to being slaughtered. The oil mixture consisted of 45% soybean oil, 20% sunflower oil, 20% safflower oil and 15% fish oil. Average daily gain (p<0.049) and feed efficiency (p<0.018) of the steers fed the diet supplemented with oil mixture and monensin (OM-M) for 20 weeks were higher than those of the other groups of steers. Dressing percent, fat thickness and longissimus muscle area were not affected by the OM-M supplementation and duration of its feeding. The OM-M supplementation increased the content of total-cholesterol (p<0.0001-0.0007) and HDL-cholesterol (p<0.0001) in the plasma of steers compared to the control diet. The steers fed the OM-M diet had a higher proportion of c9,t11-CLA in plasma (p<0.048-0.044) than the control steers. Feeding the OM-M diet for 20 weeks increased the proportion of CLA in intramuscular (p<0.015), intermuscular (p<0.039) and subcutaneous (p<0.001) fat tissues compared with both steers fed the control diet and the OM-M diet for 10 weeks. Increased (p<0.007) proportion of total unsaturated fatty acids in steers fed the OM-M diet for 20 weeks compared to those in control steers was related to the increased (p<0.001) $C_{18:2}$ and decreased (p<0.001) $C_{18:0}$ proportions in subcutaneous tissue.

• Asian-Australasian Journal of Animal Sciences
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• 제30권10호
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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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• 제30권10호
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• pp.1388-1395
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• 2017

Objective: Using medicinal plant by-products (MPBP) as feed additives may be an eco-friendly option as substitutes for feedstuffs and may assist in reducing the improper disposal of MPBP. Therefore, this study was conducted to evaluate the influences of MPBP on the meat quality of Hanwoo steers fed a total mixed ration (TMR). Methods: Twenty seven steers (body weight = $573{\pm}57kg$) were randomly divided into three treatments with a control group and two tested groups as follows: control, 1,000 g/kg TMR; treatment 1 (MPBP30), 970 g/kg TMR and 30 g/kg MPBP; treatment 2 (MPBP50), 950 g/kg TMR and 50 g/kg MPBP. Results: Average daily gain, feed conversion ratio and the Commission Internationale de l'Eclairage $L^*$ of muscle were improved (p<0.05, respectively) by MPBP30. Stearic acid ($C_{18:0}$) was decreased (linear effect, p = 0.012), while oleic acid ($C_{18:1}$) was increased (linear effect, p = 0.055) by MPBP level. Saturated fatty acid (SFA) and polyunsaturated fatty acid (PUFA) were decreased for MPBP50 while unsaturated fatty acid (USFA) and monounsaturated fatty acid (MUFA) were increased for MPBP 50. USFA and SFA ratio was increased for MPBP50 as well. Conclusion: These results indicated that MPBP supplementation in Hanwoo steers fed a TMR increased feed efficiency and meat color (lightness) with altering fatty acid proportions. Therefore, MPBP may be successfully used in ruminant feeding.

• 한국축산식품학회지
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• 제26권2호
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• pp.212-217
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• 2006

본 연구는 거세 한우에 대한 육성기의 양질 조사료(티머시 건초)의 급여 효과를 구명하기 위하여 거세우 20두를 공시하여 대조구, 시험구로 2개 처리구를 두고 생후 5개월령부터 28개월령까지 24개월간 비육시험를 실시한 결과는 다음과 같다. 28개월령 시험종료 시기의 체중은 대조구가 669.70kg, 시험구가 681.75 kg이었고, 일당 증체량은 시험구가 (0.83 kg) 대조구(0.81 kg)보다 다소 높은 경향이었다. 육성기의 두당 1일 조사료섭취 량은 시험구(4.27 kg)가 대조구(3.80kg)보다 크게 높은 경향이었다. 도축후 배최장근 단면적과 육량등급, 육질등급은 시험구(각 $85.62 cm^2$, 2.20 점, 2.20점)가 대조구(각 $81.29 cm^2$, 2.00점, 1.60 점)보다 크게 높아 통계적인 유의차 인정되었고(p<0.05), 육성기때의 양질 조사료 급여가 영향을 미친 것으로 사료된다.

• 농업생명과학연구
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• 제45권4호
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• pp.95-103
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• 2011

본 연구는 한우 거세우 95두 (평균체중 226 kg)를 이용하여 농후사료와 조사료 분리급여구, TMR구 그리고 TMR을 발효시킨 F-TMR구로 나누어 22개월동안 사육하여 도축하였을 때, 사료효율, 도체성적 및 경제성분석에 미치는 영향을 조사하기 위하여 실시되었다. 건물 및 TDN 섭취량은 육 비육 각 단계별로 F-TMR구에서 가장 많았다 (p<0.05). F-TMR구의 경우, 일일증체량은 육성기에는 처리구중 가장 적었으나, 비육후기에는 타 처리구에 비해 약 48%나 높았다 (p<0.05), 사료효율은 전 육성비육기간 동안 비슷한 수준으로 유지되었다. 도체중과 배최장근단면적에서는 F-TMR 급여구에서 가장 높았으나 (p<0.05), 등지방두께가 가장 얇았던 (p<0.05) 분리급여구에서 육량지수와 육량 A등급 비율이 높았다. F-TMR구의 근내지방도가 타구에 비해 현저히 (p<0.05) 증가되어 육질 1+등급이상 출현율이 96%에 달하였다. 경제성 분석에서 사료비는 F-TMR구가 분리급여구에 비해 40%가 증가되었으나 증체량과 육질등급의 향상으로 인하여 순수익은 29%나 증가되었다.

• Journal of Animal Science and Technology
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• 제62권6호
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• pp.812-823
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• 2020

The aim of this study was to investigate the effects of Korean rice wine residue (RWR) on the growth performance and blood profiles of Hanwoo steers in the fattening stage. In situ and in vivo experiments were conducted to analyze rumen fermentation characteristics and total tract digestibility, respectively. Three cannulated Hanwoo steers (mean body weight: 448 ± 30 kg) were used in both analyses. The growth performance of 27 experimental animals in the fattening stage (initial body weight: 353.58 ± 9.76 kg) was evaluated after 13 months of feeding. The animals were divided into three treatment groups (n = 9/group). The treatments comprised total mixed ration (TMR) only (CON), TMR + 10% RWR (10% RWR), and TMR + 15% RWR (15% RWR). The diets of equal proportions were fed daily at 08:00 and 18:00 h based on 2% of the body weight. The animals had free access to water and trace mineral salts throughout the experiment. Supplementation of 15% RWR significantly decreased (p < 0.05) the rumen fluid pH compared with the control treatment, but there was no significant difference in the total volatile fatty acid concentration. It also significantly increased (p < 0.05) dry matter digestibility compared with the other treatments. The total weight gain and average daily gain of the animals in the RWR-supplemented groups were significantly higher (p < 0.05) than those in the control group. Furthermore, the feed intake and feed efficiency of the RWR-supplemented groups were higher than those of the control group. Supplementation of RWR did not affect the alcohol, albumin, glucose, total cholesterol, triglyceride, and low-density lipoprotein concentrations, and aspartate aminotransferase and alanine transaminase activities in the blood; these parameters were within the normal range. The high-density lipoprotein and creatinine concentrations were significantly higher in the 15% RWR group, whereas the blood urea nitrogen concentration was significantly higher in the 10% RWR group than in the other groups. These results suggest that TMR with 15% RWR can serve as an alternate feed resource for ruminants.

• 현장농수산연구지
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• 제23권1호
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• pp.117-128
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• 2021

한우의 성장단계별 부위 근육발달을 이해하는 것은 도체율 개선에 따른 소득증대와 증체율 증가에 따른 생산효율 향상에 긍정적인 영향을 미친다. 본 연구에서는 한우의 등심과 사태 유래 근육위성세포를 분리 후 세포단위의 발달 및 분화를 비교하여 transcriptome 단위의 작용기전을 제시하였다. 한우의 부위별 근육 유래 근육위성세포의 근섬유의 양은 4일에 가장 높게 나타났고 이후 감소하였다. 한우의 근육위성세포의 발달 단계에 따라 발현되는 총 전사체 유전자의 종류는 사태근육 위성세포에서 높게 나타났다. 등심과 사태 근육 유래 위성세포의 발달단계에 따라 유의적인 차등 유전자 453개를 찾아냈고 이를 이용한 기능유 전체 분석이 필요하다. 등심과 사태유래 근육위성세포를 이용한 동일조건 분화 비교에서 사태유래 근육 위성세포의 분화 시 myosin complex, skeletal muscle contraction, troponin complex, skeletal muscle tissue development 와 같은 근섬유 형성관련 유전자의 발현이 높게 나타나는 것으로 보아 같은 개체의 근육조직에서도 부위별로 차등 발달이 되고 있다는 것을 알 수 있다. 기존 연구에서는 근육의 성장에 대한 이해를 위해 사양과 영양관련 시험이 많이 이루어졌다. 향후 세포단위의 연구들이 많이 이루어져 작용기작에 대한 생물정보 자료를 추가로 적용한다면 한우의 정밀사양을 적용할수 있는 바탕이 마련될 것이다. 또한 근육위성세포의 연구는 추후 동물실험 윤리제도 강화에 따른 비동물 전임상 screening 시험 활용과 대체단백질 산업의 주요 이슈인 배양육 소재 개발 연구와 같이 축산시험연구의 지속적인 확장성에 많은 영향을 미칠 것으로 생각된다.

• Journal of Animal Science and Technology
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• 제64권6호
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• pp.1046-1062
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• 2022

This study investigated the effects of L-glutamine (Gln) supplementation on growth performance, physiological traits, heat shock proteins (HSPs), and gene expression related to muscle and adipose tissue development in Hanwoo steers under heat stress (HS) conditions. Eight Hanwoo steers (initial body weight [BW] 570.7 ± 43.6 kg, months of age 22.3 ± 0.88) were randomly separated into two groups, control and treatment, and supplied with the concentration (1.5% of BW kg/day/head) and rice straw (1.5 kg/day/head). The treatment group were fed the Gln supplementation (0.5% of concentration, as-fed basis) once a day at 08:00 h. Blood samples for the assessment of haematological and biochemical parameters and the separation of peripheral blood mononuclear cells (PBMCs) were collected four times, at 0, 3, 6, and 10 weeks of the experiment. Feed intake was measured daily. BW to analyze growth performance and hair follicle collection to analyze the expression of HSPs were executed four times at 0, 3, 6, and 10 weeks. To analyze gene expression, longissimus dorsi muscle samples were collected by biopsy at the end of the study. As a result, growing performance, including final BW, average daily gain, and gain-to-feed ratio, were not different between the two groups. Leukocytes including lymphocytes and granulocytes, tended to increase in the Gln supplementation group (p = 0.058). There were also no differences in biochemical parameters shown between the two groups, except total protein and albumin, both of which were lower in the Gln supplementation group (p < 0.05). Gene expressions related to muscle and adipose tissue development were not different between the two groups. As temperature-humidity index (THI) increased, HSP70 and HSP90 expression in the hair follicle showed a high correlation. HSP90 in the hair follicle was decreased in the treatment group compared with the control group at 10 weeks (p < 0.05). Collectively, dietary Gln supplementation (0.5% of concentration, as-fed basis) may not be influential enough to affect growth performance and gene expression related to muscle and adipose tissue development in steers. However, Gln supplementation increased the number of immune cells and decreased HSP90 in the hair follicle implying HS reduction in the corresponding group.