The objective of this study was to determine the effect of different pregnancy stages on the eating and ruminating behavior of Hanwoo heifers (Bos taurus coreanae). A total of twelve Hanwoo heifers were divided into four groups depending on pregnancy stage: C: before pregnancy, 9 months old, T1: 3 months pregnant, 16 months old, T2: 6 months pregnant, 19 months old, T3: 9 months pregnant, 22 months old (3 replicates per group). Concentrate of 1% of the body weight was fed to them. Roughage was provided at ad libitum to all treatments. Our results revealed that the intake of roughage was the highest in the T3 group (at 3.68 kg) and the lowest in the C group (at 1.02 kg, p<0.05). Total intake in the order from high to low was: T3 > T2 > T1 > C (p<0.05). The rate of dry matter intake compared to body weight (DMI/BW, %) from high to low order was: T3 > T2 > T1 > C (p<0.05). Eating time, ruminating time, and chewing time were the highest in T3 group (p<0.05). Resting time was the highest in C group (p<0.05). The number of bolus and the number of total chews were significantly higher in T3 compared to those in other groups. However, ruminating time per bolus was not significantly difference among groups. The number of chews per bolus from high to low order was: C > T1 > T3 > T2 (p<0.05). The number of bolus per minute was not significantly different among groups. The number of drinking and the number of defecating were significantly higher in C and T1, respectively (p<0.05). However, the number of urinating had no effect according to pregnancy stage. Eating rate and chewing efficiency were significantly higher (p<0.05) in accordance with pregnancy stage (T3 > T2 > T1 > C). Ruminating efficiency was significantly (p<0.05) higher T1 than that in other groups.

The aim of this study was to compare ultrasonic measured traits (Eye muscle area : EMA, backfat thickness : BF and marbling score : MS) of Hanwoo cows by months of age and periods around 1st calving. The data used in this study were taken 2,636 cows which were measured from 20 months old to 28 months old and within 5 months around 1st calving. According to comparison of cows' month of age, ultrasonic measured EMA, BF and MS were not significantly different between 21 months old and 26 months old, 21 months old and 25 months old and 23 months old and 27 months old, respectively. According to comparison of periods around 1st calving, ultrasonic measured EMA, BF and MS were not significantly different between -45 days and 30 days, -15 days and 75 days, -105 days and 90 days around 1st calving, respectively. The selection of cows could be possible based on the phenotypic ultrasonic measurement performance if the traits are measured between 23-month old and 25-month old and between - 15 days and 30 days around 1st calving.

본 연구에서는 현재 국가단위 개량체계에서 이용하는 도체형질 및 12개월령 체중과 부분육간의 유전 모수추정을 통하여 각 형질별 상관관계를 조사하였다. 분석에 이용된 형질은 1996년도부터 2013년까지 당·후대 검정한 한우 수소 및 거세우 총 10,351두의 부분육 중량 및 수율, 도체형질 그리고 12개월령 체중측정 자료이다. 유전모수 추정을 위하여 부분육 형질에는 차수, 검정지, 도축일의 고정효과와 도체 중을 공변량으로 포함하였으며, 도체형질은 동일한 고정효과에 도축일령을 공변량으로 하였다. 유전모 수 추정 결과 부분육 수율(%)의 유전력은 안심, 등심 및 채끝이 각각 0.53, 0.58 및 0.65였다. 등심수 율은 12개월령 체중, 도체중, 등심단면적, 등지방두께 그리고 근내지방도와 유전상관이 각각 0.13, 0.15, 0.61, -0.44 그리고 0.37이었다. 따라서 등심단면적이 크면 10가지 대분할육 중 경제적가치가 가장 높은 형질인 등심의 비율이 증가 할 것으로 사료되며, 도체의 육질을 결정하는데 주요한 형질인 근내지방도의 등급도 다소 높아질 것으로 사료된다.

In this study, the texture, nucleotide-related compounds, and sensory characteristics of dry-aged beef, made from third quality grade Hanwoo beef (Korean native cattle), were investigated according to aging periods. Loin cuts obtained from three different Hanwoos were dry-aged under the specific conditions (controlled temperatures, humidity, and air flow) during 0-7 weeks. With increasing aging periods, textures were significantly decreased after 5 weeks (hardness: from 13,264±2,033 to 7,112±1,743 g; chewiness: from 4,107±1,467 to 2,334±780) and four sensory characteristics were significantly increased after 3 weeks (texture: from 2.2±1.0 to 6.2±1.1; flavor: from 3.9±0.7 to 6.2±1.5; whole preference: from 2.5±0.8 to 6.3±1.3; purchase intention: from 3.7±1.4 to 6.0±1.5) except for color (p<0.05). On the other hand, the concentrations of IMP which is related to the umami flavor of beef were significantly decreased with increasing aging periods (from 40.44±5.97 at 0-week to 7.44±2.43 μg/ mg at 7-week) (p<0.05). These results obtained in this study could provide an useful data base for the quality control of dry-aging.

The influence of aging on the flavor precursors and volatile compounds of top round beef was studied. The concentrations of free amino acids, nucleotides, creatine, dipeptides, and volatile compounds were measured after top round from Hanwoo was aged at 4℃ for 21 days. The amount of free amino acids in top round significantly increased with the increase of aging period. There was no effect of aging on the concentrations of adenosine monophosphate or inosine in top round. The inosine monophosphate content of top round significantly decreased with age, while the hypoxanthine content increased. The concentrations of creatine, carnosine, and anserine in top round were not influenced by aging. In total, 24 volatile compound were identified in aged, cooked top round. Of these, the quantities of aldehydes (propanal, pentanal, hexanal, heptanal, octanal, and nonanal), hydrocarbons (pentane and octane), 2-butanone, ethyl acetate, and pyridines (4-ethynyl-pyridine and 4-acetyl-pyridine) significantly increased after aging. We conclude that the flavor of top round can be improved by aging.

한우 사육두수는 한우 암소의 번식 정도가 어느 정도인지에 따라서 결정된다. 한우 암소의 번식 여부 는 산지가격에 대한 기대가격에 따라 결정된다. 이 논문은 한우 암소 번식농가의 의사결정 행위를 분석 한 것이다. 이를 위해 네 가지 기대모형이론을 적용하여 어느 모형이 보다 적합한 모형인지를 비교하였 다. 산지가격에 대한 기대가격을 형성함에 있어서 순수기대모형, 적응적기대모형, 부분조정모형, 합리적 기대모형 등 네 가지 모형을 적용하였다. 그리고 이들 네 가지 기대모형을 근거로 실제 암소도축과 송 아지공급함수를 추정하였다. 그 결과 한우 암소 번식농가의 의사결정은 상대적으로 복잡한 적응적기대 모형이나 부분조정모형보다는 순수기대모형이나 합리적기대모형으로 잘 설명되는 것으로 분석되었다. 또한, 모형 전체의 적합도에서는 합리적기대모형이 가장 우수한 것으로 나타났다.

본 연구에서는 2009년부터 2011년 까지 6년간 경남지방 도축장에서 도축한 한우 63,388두에 대한 도 축성적 자료를 근거로 하여 한우의 경락단가 결정에서 있어 가장 큰 영향을 미친다고 생각되는 등지방 두께, 등심단면적, 도체중 및 근내지방도가 경락가격에 영향을 미치는 기여도를 분석하기 위하여 최소 제곱 평균법으로 SAS @9.3 Package/PC를 이용하여 분석하였으며, 본 연구의 결과를 요약하면 다음과 같다. 각 요인에 대한 분산분석 즉, 유의성 검정 결과 조사한 형질에 대해 성, 도축계절, 도축년도의 효 과에 대해 고도의 유의성(p<0.01)을 나타내었다. 표현형 상관에서 모든 형질간의 정의상관을 확인 할 수 있었으며 경락단가에 대해서는 근내지방도가 가장 높은 0.70의 정의 상관을 나타내었으며, 총 가격 에서는 경락단가를 제외한 도체형질 중에서 도체중이 0.74로 가장 높은 정의 상관을 나타내었다. 요인 별 기여도 분석에서 경락단가에 대한 근내지방도의 기여도는 95.41%로 가장 높게 나타났고, 총가격에 서도 근내지방도가 52.57%로 가장 높았고 다음으로 도체중이 44.31%로 기여도가 높은 것으로 나타났 다. 이상의 연구결과를 통해 한우의 경락단가, 총가격에 대한 요인별 기여도를 산출해낼 수 있었다. 한 우의 경락단가를 높이기 위해서는 근내지방도 위주의 개량이 적합하고 총가격을 위해서는 도체중까지 고려한 개량 및 사양 방법이 필요할 것으로 사료된다. 본 연구는 분석 결과를 통해 경락단가와 총가격 의 기여도를 고려하여 가장 높은 수익을 얻도록 전략적으로 출하시기를 선택하는데 기초자료로 활용하 고자 하며 각 형질들의 환경요인에 따른 분산분석결과를 통해 한우농가 수입증대를 위한 한우 개량 방 향제시를 위한 기초자료로 활용하고자 한다.

The objective of this study was to investigate the effect of pen and group size on behavioral characteristics of Hanwoo steers. Forty-eight beef steers, all 15 months of age, were used in this study, and were assigned to 3 groups: control (4/35.28 ㎡), treatment 1 (8/70.56 ㎡), and treatment 2 (12/105.84 ㎡). In addition, behavioral characteristics were analyzed every 2 days in each month using CCTV cameras. Each behavior of the treatment group was observed significantly more frequently (p<0.05) than the corresponding behavior of the control group in summer, especially feeding behavior. In addition, no significant difference was observed between the treatment groups. Locomotion was observed for a significantly longer duration in the control group than in the treatment groups (p<0.05), and resting was observed for slightly longer in the treatment groups than in the control group. Fighting behavior, related to social status, was observed significantly more frequently in the control group than in the treatment groups (p<0.05). In winter, feeding behavior was observed for a significantly longer duration in the control group than in the treatment groups (p<0.05) On comparing the behavior of Hanwoo steers during different seasons, we found that the steers showed more resting behavior during summer and more feeding behavior and movement during winter. The above results suggest that the behavioral characteristics of Hanwoo steers depend on the pen and group size, based on the higher frequency of fighting, rubbing, and scratching observed in the treatment groups than in the control group. The results also suggest that the behavioral characteristics of Hanwoo steers depend on the environmental conditions, as shown by the seasonal differences in behavior. Under conditions of high temperature stress, Hanwoo steers showed increased lying down, drinking and grooming behavior to counter this stress. The findings of this study can be applied to management practices for animal welfare and producticon of cattle in both growing and fattening periods.

The aim of this study was to investigate the effects of different rearing spaces on growth performances, behavioral traits, and blood parameters in Hanwoo (Korean Native Cattle) heifers and steers. The average daily gain and feed conversion ratio were measured to assess the growth performance. A total of 54 Hanwoo heifers and steers at 18 months old, were housed separately in groups of 2, 3 or 4 heads in a pen (32 m2) for nine months. In the case of the heifers, the growth performances were significantly (p<0.05) improved by increasing the 2 head group size with the exception of the 18 month old heifers. However, among the steers the growth performances were significantly enhanced (p<0.05) after 18 months of age, by increasing the 3 heads group size. In addition, the heifers in groups of 2 heads spent less time standing and more time lying down or walking, and also had a significantly (p<0.05) lower frequency of self-grooming, scratching, and fighting. These findings are similar to the results obtained for steers housed in 2 or 3 heads per group. The steers housed in 2, 3 heads groups spent more time feeding and consequently had a significantly (p<0.05) lower frequency of pair-wise grooming and Leaning. The heifers and steers housed in groups of 4 heads showed lowest red blood cell counts, but highest cortisol content with statistical significance at p<0.05. The heifers in groups of 2 heads had the highest hemoglobin concentrations (p<0.05). On the other hand, white blood cell count was found to be the lowest in groups of 2 steers with statistical significance at p<0.05. We conclude that a large rearing space improved growth performances, behavioral characteristics, and blood parameters in Hanwoo heifers and steers. In the future, this data could be used to improve the welfare of rearing Hanwoo cattle.

본 연구는 지구온난화 시 예상되는 고온기를 대비하여 고온 및 사료 에너지 급여 수준이 한우 번식우 영양소 소화율에 미치는 영향을 규명하고 고온 스트레스 시 한우 번식우의 영양소 요구량을 설정하고자 수행하였다. 시험은 한우 번식우 4두(평균체중 491±85.6kg)를 공시하였고, 시험구는 고온 및 사료 에너지 급여 수준에 따라 4 시험구(한국가축사양표준 한우 번식우 유지요구량 TDN의 100%(대조구), 고온 처리 및 TDN 100%(T100), TDN 115%(T115), TDN 130%(T130))로 나누어 개체별 대사케이지에 4×4 Latin square design으로 배치하여, 각 period당 21일씩 대사시험을 실시하였다. 대조구는 온도 24℃, 습도 60%(온습도지수(THI)=71.46), 나머지 3개 처리구는 온도 30℃, 습도 70%(THI=81.38)로 설정하였다. 외관상 건물소화율은 대조구와 T100구가 각각 81.64와 81.39%로 T115(78.23%), T130구(78.15%)보다 유의적으로 높게 나타났다(p<0.05). 대조구 대비 혈중 thyroxine, glucose 및 BUN 함량은 T100구에서 수치적 감소가 나타났으나 T115 및 T130구에서 다시 증가하는 결과가 나타났다. 고온처리구의 일당증체량을 기준으로 한우 번식우 유지를 위한 TDN 요구량 산정식 (Y=0.2097X+111.2428)을 도출하였고, 이는 지구온난화(고온기) 시 유지를 위한 한우 번식우 TDN 요구량은 현재 한국가축사양표준에서 제시된 요구량 대비, 11.24%를 증량 급여해야 함을 의미한다.

본 연구는 한우 능력검정체계에 이용되는 선발형질에 따른 부분육 중량 및 수율의 간접선발반응을 파 악하고 부분육 형질을 선발형질로 포함하였을 경우 선호부위의 유전적 개량량 변화를 파악하기 위하여 시뮬레이션 프로그램인 ZPLAN+를 이용하였다. 분석에 이용한 자료는 1996년도부터 2013년까지 농협 중앙회 한우개량사업소, 도 축산연구센터, 국립축산과학원, 한우육종농가에서 당·후대 검정한 한우 수 소 및 거세우 총 10,351두의 자료를 이용하였다. 그 결과 후보 및 보증씨수소 선발가중치와 동일조건 하에서 등심단면적의 가중치를 각각 1, 3, 6으로 하였을 때 등심수율의 연간 유전적 개량량은 각각 0.222%, 0.282%, 0.328%로 증가하는 결과를 보였다. 현재 선발가중치와 동일한 조건에서 부분육 형질 을 선발형질로 포함하여 등심수율에만 가중치를 주었을 경우 갈비, 채끝수율은 등심수율과 함께 증가하 는 것으로 나타났으나 안심수율의 연간 유전적 개량량의 변화는 미미하였다. 또한 안심, 등심, 채끝 등 의 선호부위에 8가지의 경우의 수(가중치: 1 또는 2)로 그룹별 가중치를 주었을 경우, 가중치가 각각 2:2:2인 그룹에서 선호부위의 연간 유전적 개량량이 가장 높았다. 따라서 선호되는 부위의 생산량 증대 를 위해서는 이들 부위에 상대적으로 높은 가중치를 동일하게 적용하는 것이 한우의 선발에 효과적인 방법이라 사료된다.

Calculating break-even price of calf production is closely associated with reproductive efficiency. To determine the price, we need data from reproduction records including number of claves weaned, number of cows exposed for breeding, and annual cash coast per cow, and average weaning or market weight of claves sold and retained. Unfortunately, the data were not available in Korea native cow (Hanwoo). To evaluate the performance and the price, we collected calving interval from about 60,000 cows for last 10 years and estimated reproductive performance. Calving interval was increased 4.3% and pregnancy rate was decreased about 1.4∼2.8% year-on-year. Increases in growth rates of number of cow and semen per calf supported the low reproductive performance. Finally, break-even price was calculated using estimated percent calf crop and demonstrated that growth rate of break-even price is larger than that of annual cash per cow, suggesting cow-calf profitability and financial efficiency in Korea native cow (Hanwoo) is getting worse.

The objective of this study was to monitor health conditions of genetically identical somatic cells cloned Korean white cattle, endangered indigenous cattle (EIC) and indigenous cattle (IC) by analysis of hematologic characteristics. Naturally ovulated oocytes and donor cells were used for somatic cell nuclear transfer (SCNT). Donor cells and enucleated oocytes were followed by electric fusion, chemical activation and surgical embryo transfer into the oviducts of surrogate females. Two recipients became pregnant; two maintained pregnancy to term, and one live cattle were delivered by caesarean section. The cloned Korean white cattle were genetically identical to the nuclear donor cattle. As a result, the mean values of RBC and platelet of cloned cattle and white cattle were significantly decreased by age (P<0.05). The mean values of RBC, HCT, MCV and MCHC between cloned cattle and IC of the same age (1∼2 years) showed the statistical significance (P<0.05). Also, in the WBC of Korean white cattle, the estimated values were decreased according to the age from 12.0×103/μl under 1 year to 11.0×103/μl over 1 years respectively. Although clone-cattle had lower numbers of RBC than reference range, the most of RBC and WBC related heamatologic results of cloned cattle were not different when compared to reference range. This study suggests that cloned Korean white cattle derived from SCNT did not have remarkable health problems, at least in the growth pattern and hematological parameters. In addition, this study provides a valuable resource for further investigations of the preservation of rare genetic stocks underlying traits of interest in cattle.

These studies were conducted to establish the practical Hanwoo (Korean native cattle) improvement system through the combining of embryo transfer technology and confirming individual Hanwoo oocyte culture system and to investigate that correlation of Hanwoo carcass classification (intramuscular marbling) and oocyte donor for blastocyst production in vitro. In case of Hanwoo, the carcass meat quality grades were divided to grade 1⁺⁺, 1⁺, 1, 2, and 3 depends on fat distribution of longest muscle cross-sectional surface. As results, the numbers of follicular oocytes collected from individual fundamentally-registered Hanwoo yielded 1⁺⁺, 1⁺, 1, 2 and 3 meat quality were 9.5, 9.4, 8.5, 8.8 and 8.8 per ovary, respectively. The numbers of retrieval oocyte from follicles were significantly higher in the cattle yield 1⁺⁺, 1⁺ meat quality than in the cattle yield 1, 2 and 3 meat quality (p<0.05). The rates of blastocyst formation were 18.2, 21.3, 29.4, 30.9, and 31.5% in the cattle yield 1⁺⁺, 1⁺, 1, 2 and 3 meat quality of after in vitro maturation, respectively. It was significantly lower in the cattle yield 1⁺⁺ and 1⁺ meat quality than in the cattle yield 1, 2 and 3 meat quality (p<0.05). In order to evaluate embryos quality, TUNNEL assay was conducted for each meat quality grade using blastocyst stage embryo on day 8. The results showed that apoptosis cell number was higher tendency in the cattle yield 1⁺⁺and 1⁺ meat quality (81 and 79, respectively) than in the cattle yield 1, 2 and 3 meat quality (51, 48 and 50, respectively) but there was no statistical significance in each group. After embryo transfer, the conception rate of recipient was 53.5 (23 out of 43), 52.1 (38 out of 73) and 58.0% (58 out of 100) in the meat quality of 1, 1+ and 1++, respectively. These results showed that the conception rate was significantly higher in the cattle yield 1 meat quality than in the cattle yield 1⁺⁺, 1⁺ , 2, and 3 meat quality (p<0.05). In summary, these results indicate that the application of confirming Hanwoo individual oocyte culture system and embryo transfer technology can make good use of the genetic resources conservation and improvement of Hanwoo. Relevance of the meat quality grade and reproductive ability of carcasses of Hanwoo will be considered to be one of the effective means for the associated research with obesity and reproduction.

본 시험은 맥섬석과 한약제재 첨가급여가 한우거세우의 비육능력 및 혈액성상에 미치는 영향을 구명하기 위해 생후 13개월령의 거세한우 40두(4처리×5두×2반복)를 공시하여 사료용 첨가제로 1일 사료급여량의 0.5∼1.0% 수준으로 26개월령까지 시험하였다. 시험구 배치는 C(무첨가), T1구(맥섬석 0.5% 첨가), T2구(한약제재 0.5% 첨가), T3구(맥섬석 0.5%+한약제재 0.5% 첨가)로 구분하였다. 증체량의 경우 비육전기때 T1구(226.2kg)가, 비육후기 때는 T3구(162.1kg)가 가장 높게 나타났다(p<0.05). 혈중 총콜레스테롤 함량은 T3구가 다른 처리구보다 유의적으로 높았다(p<0.05). 또한 도체중은 T3구(439.00kg) > T2(425.80kg) > T1(420.50kg) > Control(413.00kg) 순으로 낮아졌다. 배최장근 단면적은 T3구가 107.00㎠로 다른 처리구보다 높았고(p<0.05), 도체등급에서 육질등급은 T2구와 T3구가 공히 3.25로서 크게 높았다(p<0.05). 한편 등심육의 지방산 조성에서 oleic acid 함량이 48.55∼50.90%로서 가장 많은 비율을 나타내었고, 불포화지방산은 T3구(57.94%)가 다른 처리구보다 유의적으로 높게 나타났다(p<0.05). 따라서 거세한우에게 각각 맥섬석과 한방제재를 혼합하여 첨가급여하면 도체등급, 관능검사 및 불포화지방산의 개선에 도움이 될 것으로 판단된다.

The purpose of this study was to perform a functional component analysis to optimize the recipes for Korean beef main bone area. To optimize the recipes for beef leg bone broth, beef feet broth and tail broth, the quality and physiochemical properties of the dishes were comparatived and investigated. Crude protein, crude fat and moisture showed significant differences among the beef leg bone broth, Beef feet broth and tail broth (p<0.001). All free amino acids showed significant differences, with the exception of cystine and tryptophan (p<0.05). All minerals showed significant differences (p<0.01). Na content was highest in the beef leg bone broth (211.77 mg/kg), followed by beef feet broth (254.40 mg/kg), and tail broth (134.93 mg/kg). Collagen was significantly different each dish (p<0.001), but chondroitin sulfate was not. And all nucleic acids showed significant differences.