일반적으로 혈통 정보가 검증된 송아지의 경우 부모로부터 전달받은 유전능력을 통해 비육 후 출하 시에 우수한 도체 성적을 나타낼 확률이 상대적으로 높다고 알려져 있고, 이를 근거로 경매 시장에서 높은 가격대를 형성하고 있으나 이에 대한 과학적인 검증이 미비한 실정이다. 그러나 최근 친자확인 사업을 통해 과학적 검증을 위한 자료 수집이 가능한 상황이다. 따라서 본 연구는 2014년부터 2019년까지 경남 ‘ㄱ’지역 송아지를 대상으로 친자확인을 실시한 결과와 송아지의 경매 낙찰가 자료를 활용하여, 친자확인이 송아지 경매 낙찰가에 미치는 영향에 대해 분석하였다. 그 결과 2014년 친자 일치율이 64.6%였으나 6년간 지속적인 친자확인을 통해 2019년도에는 91.4%로 친자 일치율이 26.8% 상승하였음을 확인하였고, 이는 경남 ‘ㄱ’지역 농가의 혈통관리에 대한 인식이 높아진 결과로 한우의 자연적 개량이 이루어지는데 친자확인이 긍정적인 영향을 미쳤다고 판단된다. 또한 친자확인 일치 여부에 따른 송아지 경매 낙찰가의 경우 친자 일치된 송아지가 불일치된 송아지에 비해 경매 낙찰가가 약 34만원 높게 낙찰 되었고, 친자 일치된 송아지 내 성별에 따라 수송아지와 암송아지가 친자 불일치된 송아지 보다 각각 약 37만원, 22만원 높은 가격에 낙찰되었다. 따라서 본 연구와 추가적인 연구를 진행한다면 추후 농장별 계획 교배와 정확한 혈통관리를 통한 신뢰도를 높이는 것이 수익에 긍정적인 효과와 지역 단위로 지속적인 친자확인의 관리가 한우산업에 긍정적인 효과를 유발할 수 있다는 것으로 사료된다.

번식효율은 농가수입에 직접적으로 영향을 미치는 요인으로 암소뿐 만 아니라 씨수소의 번식효율은 중요한 경제형질로 여겨지고 있다. 본 연구에서 는 한우 씨수소에 대한 번식효율을 분석하기 위하여 2010~2017년에 전북지역 분만기록 62,284개와 이에 사용된 132두의 KPN에 따른 인공수정 수태율을 분석하였다. 종부차수(NAIPC)가 증가함에 따라 분만간격(CI), 공태기간(CCI)이 유의적으로 증가하였으며(P<0.05), 임신율은 낮아졌다. 첫 종부 임신율은 62.365%로 나타났으나, 3차 이후에는 48.147 이하로 급격히 낮아졌으며, 6차 이후에는 15.664% 이하로 낮아졌다. KPN과 인공수정사 모두 수태율에 크게 영향을 미치는 것으로 나타났다. KPN에 따른 수태율은 39.154~70.621%로 분석되었으며, 인공수정사에 따른 수태율 은 22.237~85.517%로 나타났다. 인공수정 실패 시 같은 KPN의 재사용율은 20% 내외로 특별한 경향은 보이지 않았다. 첫 종부 기록만을 이용하여 상대적 추정 수태율(ESCR)을 분석한 결과 KPN1041이 가장 높은 11.107%로 나타났으며, KPN1112는 가장 낮은 -20.591%로 나타나 31.698%의 차이를 보였다. 본 연구결과 인공수정사 뿐 만 아니라 전북지역에서 사용되고 있는 KPN에 따라 번식효율이 크게 영향 받을 수 있는 것으로 나타났다.

This study was performed to evaluate the effect of heat stress on the status of physiological responses, blood parameter, serum T3 and cortisol, and heat shock proteins (HSP 27, 70, and 90) of Hanwoo cattle. Six Hanwoo steers (242.8 ± 7.2 kg of BW) were housed in the climate-controlled respiration chambers. The experiment consisted of 7 days (control; 0 day) at thermoneutral (air temperature (Ta) of 15oC and relative humidity (RH) of 60%; temperature-humidity index (THI) = 64), and by 3 and 6 days (treatment groups) at heat stress (Ta of 35oC and RH of 60%; THI = 87). Body temperature of each parts (frank, rump, perineum and foot) and rectal temperature elevated in heat stress groups (3 days and 6 days) than the control group (0 day). Respiration rates increased in 3 days and 6 days (88.5 ± 0.96 bpm and 86.3 ± 0.63 bpm, respectively) from 0 days (39.5 ± 0.65 bpm). Feed intake significantly decreased in heat stress groups (3 days and 6 days, 3.7 ± 0.14 kg and 4.0 ± 0.15 kg, respectively) than the control group (0 day, 5.0 ± 0.00 kg). In addition, final BW significantly decreased in heat stress groups (3 days and 6 days, 211.8 ± 4.75 kg and 215.5 ± 3.50 kg, respectively) than the control group (0 day, 240.0 ± 25.00 kg). However, heat stress has no significant effect on blood parameter, serum T3 and cortisol. Nevertheless, heat stress increased HSPs mRNA expression in liver tissue, and serum concentration of HSPs. Despite Hanwoo cattle may have high adaptive ability to heat stress, our results suggested that heat stress directly effect on body temperature and respiration rate as well as serum and tissue HSPs. Therefore, we are recommended that HSPs could be the most appropriate indicators of Hanwoo cattle response to heat stress.

한국에 있어서 한우는 경제 동물일 뿐 만 아니라 중요한 유전자원 중 하나이다. 그러나 현재 한우의 번식 능력 개량을 위한 연구는 매우 미흡한 실정이다. 한우의 번식 능력에 대한 기초 자료를 확보하기 위해 전북지역(정읍시)에서 인공수정 된 암소 총 33,281두에 대한 105,017개의 번식기록(2010-2017)을 이용하여 임신기간(GP), 분만 후 첫 종부기간(CFSI), 분만 후 임신간격(CCI), 수태당 종부회수(NAIPC), 첫 종부 임신율 (FSCR)을 계산하여 분석에 활용하였다. 전체적으로 GP 는 287.602±4.797일, CFSI와 CCI는 각각 77.513±34.417 및 88.433±42.194일 이였다. 또한 FSCR는 62.365%였으며, NAIPC 는 1.411회로 나타났다. 2017년의 FSCR과 NAIPC는 각각 67.497% 및 1.344회로 2013년 62.366% 및 1.402에 비해 유의적으로 증가하였다(p<0.05). 가을과 겨울에는 번식기간이 더 길었으며, NAIPC는 봄과 여름에 비해 유의적으로 증가하는 것으로 나타났다(p<0.05). 3~7산차 암소의 경우 NAIPC가 1.323±0.669~1.339±0.689회로 다른 그룹에의 1.401±0.772~1.446±0.854회 보다 우수한 것으로 나타났다. 반면, 1산차 암소의 경우 FSCR와 NAIPC가 각각 60.217% 및 1.506±0.937회로 가장 저조한 것으로 나타났다. 본 연구 결과 한우의 번식효율은 산차에 따라, NAIPC는 계절에 따라 영향 받는 것으로 나타났으며, 전체적인 번식효율은 과거에 비해 지속적으로 향상되고 있는 것으로 나타났다.

This study was conducted to investigate the optimal artificial insemination (AI) time with diagnostic kit at ovulation time. We already applied the patent about the protein in the cow heat mucose in external reproductive tract. And we would examine the accuracy for detection of cow heat by the kit produced with the protein. Evaluation of optimal heat detection was tried two time at 12 hrs and 24 hrs after the heat. And then, AI service also performed two times with no relation to the results of heat diagnosis by heat detection kit and pregnancy rates were checked with rectal palpation on 60th day after AI. Heat diagnostic results by kit in natural heat after 12 hrs in Hanwoo cows were showed 31.3~75.0% on positive in first heat detection and 33.3~100.0% on positve in second heat detection. In the 1st positive results were significant different (p<0.05), but 2nd positive were not. The results of heat detection showed different result on regional influence and individual cow effects. The pregnancy rates of first trial of heat detection were showed 34.4~78.7% on positive and 21.3~68.8% on negative after the diagnosis by heat detection kit. And the pregnancy rates of next trial of heat detection were showed 33.3~85.7% on positive and 14.3~66.6% on negative after the heat diagnosis. Both positive results of first trial and next trial also were showed significant different (p<0.05), but negative results were not. In positive result, first trial of total pregnancy rates was higher than the next trial of pregnancy, but there showed opposite results on negative results. In conclusion, the optimal heat detection kit is suitable to ordinary Hanwoo cows and it suggested that we have to improve the kit’s accuracy by detecting the materials like proteins related optimal AI time.

Cryopreservation of germ cells from genetically proven animals could be a source of restoration tools from the risk of extinction or disappearance of wanted characteristics. Using frozen semen, the genetic gains of Korean native cattle have been increased greatly for 70 years. The preservation of genetic resources as a form of frozen semen straw has limited availability due to the numbers. To circumvent this weakness of frozen semen, we tested two re-freezing methods with different initial thawing temperatures using frozen Korean proven semen and rare breed semen from albino, black and chikso breeders. It has been known that human sperm could resist to cryo-damages by repeated freeze-thaw cycles, but not for Korean proven bulls number (KPN) or for rare breeds. Total 7 frozen semem from brindled(2), black(1), Korean Albino(2) and KPN(1) bulls were used for our research. After thawing straws under 5°C/2min or 37°C/40sec with low temperature water bath and thermo jug, spermatozoa were re-diluted with triladyl diluents after first thawing and re-frozen. Sperm motilities were compared between animals and treated groups after re-thawing. Mean values of motility and viability of refrozen/thawed sperm for expansion of the number of straws were significantly higher in 5°C than in 37°C (P< < 0.05). However, the activity of viable sperm thawed at 5°C was significantly decreased after first and second thawing. It is estimated that re-freezing of frozen semen from rare Korean native cattle is possible with resistant properties of survived spermatozoa.

This study aimed to indentify single nucleotide polymorphisms (SNPs) in exon region of the glycerol-3-phosphate dehydrogenase 1 (GPD1) gene and to evaluate their associations with meat yield and quality traits in Hanwoo (Korean cattle). Two SNP markers, g.2766C>T and g.5105A>G were identified in the exons 5 and 8, respectively. Genotyping of the two SNPs was carried out using PCR-RFLP analysis in 309 Hanwoo steers to evaluate their associations with meat yield and quality traits. As a result, g.2766C>T in exon 5 was significantly associated with carcass weight (CW) and marbling score (MS). Animals with the CC genotype of g.2766C>T had heavier CW than those with the CA or AA genotype. Animals with the CC genotype of g.2766C>T also had higher MS than those with the CA or AA genotype. Additive effect was also observed with CW and MS traits. We constructed haplotypes by linkage disequilibrium analysis and analyzed association between haplotypes and meat yield and quality traits. Haplotype of GPD1 gene was associated with CW. As a result, animals with CA haplotype had heavier CW than TG haplotype. These findings suggest that the SNPs of bovine GPD1 gene may be a useful molecular marker for selection of meat yield and quality traits in Hanwoo.

The Korean native cattle, Hanwoo, is the most popular breed of beef cattle in Korea. However, the reproductive performance data are limited although reproduction is one of the most economically and biologically important in beef production. Therefore, this study was undertaken to investigate reproductive performance parameters including calving interval, parity for life time production. Data collected from 206,827 calvings were analyzed. There were no significant differences in calving interval and gestation days as parity increased from 2nd and 13rd parity cow, from spring to winter. However, we found a dramatic increase in calving interval after year 2000. About 1 month were increased per year ( y = 30.578x + 344.45 R² = 0.9157). Interestingly, we observed that parities for life time can be affected by birth weight. Calves with 23 kg at birth showed highest parities, 3.4±2.0 times. In summary, this study provides valuable data on reproductive performance of Hanwoo and the data presented here can be used as a standard target for optimising and enhancing reproductive performance.

Wholesale beef price is the critical factor for determining Korean native cattle, Hanwoo, farm’s income in short-term. Wholesale beef price has seasonality due to high demand in Korean traditional holidays such as Korean thanksgiving day and lunar new year’s day. Therefore, it is important to make reproduction and marketing plans for Korean Hanwoo farmers, in order to increase their farm income. However, there is no study available on changes in the expected farm income depending on reproduction and marketing schedules. This study analyzed the expected farm income per head depending on the monthly-based marketing schedules. The analysis was conducted based on the seasonality of wholesale beef price, reproduction efficiency, operating costs, relationship between carcass grade and slaughter age. The result shows that slaughter Hanwoo at the age of 29 months-old in August and January generating the highest expected farm income per head.

The aim of the present study was to evaluate and estimate timing of artificial insemination (AI) in Hanwoo heifer (Korean native cattle) that is the most popular breed of beef cattle in Korea. To determine changes in body weight of heifers around AI, body weight were measured at different stages either before or after AI. We found that daily body weight gain was higher in the pregnant cows after AI. We also investigate correlation between body mass measured by shoulder height and body length, and conception rates, used (body length+ height)2 instead of height2 for body mass index (BMI), and found that relatively more BMI heifers (>55) showed higher conception rates. Finally, we estimated body weight by measuring should height (SH), heart girth (HG), and body length (BL); BW=3.93372*HG-2.90985*SH-0.021*BL. In addition, we observed that HG is most closely correlated with BW; y(BW) = 1.77355*x(HG), R² = 0.98881. In summary, we can determine the best timing of AI using body measurement and its application including BMI.

The objective of this study was to investigate the effect of amino acid and vitamin C supplementation on the quality attributes of top round (TR) muscle from Korean cattle (Hanwoo). Sixteen-month-old steers were divided into three different feeding groups and raised until they were 28 months old. A control group (9 heads) was fed a basal diet and rice straw, whereas two experimental groups (8 heads/group) were fed a basal diet and rice straw supplemented with rumen-protected amino acids (≥16.0% L-lysine monohydrochloride, ≥8.0% DL-methionine) and vitamin C at a dose of 100 g/head/day (AA+VC group) or only vitamin C at 100 g/head/day (VC group). After slaughter, TR muscle (M. semimembranosus) was collected from carcasses and used to measure the quality attributes. Crude fat content was significantly higher (p<0.05) in the AA+VC group than in the VC group. No significant difference was observed for water-holding capacity and shear force value between the control, AA+VC, and VC groups. Contents of the free amino acids (FAAs) glycine, aspartate, and glutamate were significantly higher (p<0.05) in the VC group than in the control group. Sensory evaluation of tenderness and flavor preference revealed significantly higher scores (p<0.05) in the AA+VC group than in the control group. These findings suggest that vitamin C supplementation increases the contents of some FAAs, and the combined supplementation of amino acids and vitamin C improves the marbling and sensory attributes of TR muscle in Hanwoo.

The KLF(Kruppel-like factors) are transcriptional regulators that including the C2H2 zinc-finger motif and regulation of cell growth, cell differentiation, and development. In this study, mRNA and total DNA was extracted from the meat around the backbone of 130 cattle that has economic traits score. The KLF11 gene was act on the center of the main pathway in associated with the development and growth of cells and the fat metabolism. Genetic polymorphism was detected by DNA sequencing. A total of four SNPs(G9047A, C9104G, G9131A, C9170T) were identified in exon 4 regions, statistical association analysis revealed that the G9131A polymorphism were significantly associated with marbling score. The real time quantitative PCR to investigated gene and miRNA expression patterns and identify the relation of economic trait in Korean Native Beef Cattle. Gene expression level linked to KLF11 genes was investigated by determining its association and variation with the economic traits in Korean Native Beef Cattle. The increment of KLF11 gene expresstion level is resulted in increasing marbling score(MS). We found that expression profile of KLF gene and mir-494 was contrast tendency because the lower expression ratio of gene was the higher marbling score rating was when we analyzed expression profile ofKLF gene and mir-494. Therefore, this result has useful in improvement of livestock in Korean cattle.

In experiment dealt with 240 Hanwoo (172 steers and 68 heifers) among the 456 cattle during growing and fattening period were used from 2004 to 2015. Growth period was divided into 6, 12, 18, and 24 months for steers and 6, 12, 18, and 43 months for heifers. The results showed that lying down, feeding, and drinking behavior increased according to the growth. In contrary, the time of locomotion behavior including standing and walking behavior were reduced. Aggressive behavior was observed to be mostly generated in the first 6-months. Thus the results showed that different growth period of Hanwoo steers can be used as management systems for breeding and disease management. It conclude that providing a comfortable living space is a useful management systems suppress stress to the minimum extent without giving unnecessary stress to the animals.

농장동물복지형 한우 사양관리를 통한 고품질의 쇠고기 생산을 목표로 세계적인 트랜드에 부합하는 축산선진국으로 나아가기 위하여 본 시험으로 우방내 사육공간의 넓이차이에 따른 한우의 사양성적, 행 동특성 및 혈액성상에 미치는 영향을 비교·분석해 보았다. 16개월령의 한우 54두(암소 미경산공태우 및 거세우 각각 27두)를 공시하여 성별에 따라 사육공간의 넓이차이를 주기 위해 4두(8m2), 3두 (10.67m2) 및 2두(16m2)로 처리하여 9개월간 각각 3반복으로 완전 임의배치 후 실시하였으며, 한우 사 양관리 프로그램에 따라 사료급여를 하였다. 데이터 수집방법으로 증체량, 사료요구율 및 혈액분석은 2 개월 간격으로 반복하여 측정하였으며, 행동패턴 수집은 복수개체 추적방법 및 선택적 행동관찰법으로 기상청에서 제공한 맑은 날을 선정하여 15일간 녹화 후 분석에 이용하였다. 본 시험의 결과로, 사양성 적(체중, 일당증체량 및 사료요구율)의 경우 미경산공태우와 거세우 각각 20개월령과 18개월령 이후부 터 2두와 3두 처리구에서 모두 유의적(p<0.05)으로 향상되었다. 행동특성으로는 미경산공태우의 2두 처 리구에서 행동시간으로 기립행동은 유의적(p<0.05)으로 낮고, 횡와 및 걷기행동은 유의적(p<0.05)으로 높았다. 행동빈도에서는 음수, 자기몸핥기, 긁기, 몸비비기, 투쟁행동에서 유의적(p<0.05)으로 적게 나 타났다. 거세우의 2두 및 3두 처리구에서는 미경산공태우와 유사한 경향을 나타냈으나 유의적(p<0.05) 으로 섭식시간은 증가하고, 다른소핥기 및 몸기대기의 빈도는 유의적(p<0.05)으로 적게 나타났다. 혈액 성상으로 미경산공태우와 거세우의 4두 처리구에서 적혈구가 유의적(p<0.05)으로 낮았고, 콜티졸은 유 의적(p<0.05)으로 높게 나타났다. 또한, 미경산공태우의 헤모글로빈과 거세우의 백혈구 수치에서는 모 두 2두 처리구에서 유의적(p<0.05)으로 각각 높고 낮은 것으로 분석되었다. 이상의 결과를 종합하면 사 양성적, 행동특성 및 혈액성상 등의 전체적인 내용을 토대로 우사의 여유 및 표준우사의 우방크기를 고 려할 때 한우의 사육공간에서 관행사육인 4두 처리구(두당 8m2) 보다 미경산공태우는 2두 처리구(두당 16m2), 거세우는 3두 처리구(두당 10.67m2)로 사육하는 것이 적절하다고 판단되며, 본 시험결과는 추후 복지형 한우의 사양관리를 위한 기초자료로 활용할 수 있을 것으로 판단된다.

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 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.

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.