This study was conducted to investigate the effect of age on the oxidative stability of Hanwoo (Korean cattle) cow beef. The samples of M. longissimus dorsi from 65 and 133 months-old-Hanwoo cows (4 and 3 heads, respectively) were stored at 4±0.2℃ for 9 days. The proximate composition, total myoglobin content, pH value, water-holding capacity and drip loss were not significantly affected by age. At day 9 of storage, the lipid oxidation (2-thiobarbituric acid reactive substances) was significantly (p<0.05) higher in beef from 133 months-old-cows than 65 months-old-cows. Lower (p<0.05) oxymyoglobin concentration and R630-R580 value and higher (p<0.05) metmyoglobin concentration were observed in beef from 133 months-old-cows at day 9 of storage than 65 months-old-cows. The CIE a*, b* and C* values were significantly (p<0.05) lowered in beef from 133 months-old-cows at day 9 of storage than 65 months-old-cows. It could be concluded that old age decreased the lipid oxidation stability and myoglobin oxidation stability in Hanwoo cow beef.

The objective of this study was to investigate the influence of parity on chemical composition and meat quality of Hanwoo cows (n=74, 2-15 years old). The beef loin and top round muscle samples were obtained and divided by 3 groups of parity numbers (G1, 0; G2, 1-3; G3, 4-9 times). Loin and top round from G1 had significantly higher intramuscular fat contents and lower protein contents than those from G3 (p<0.05). There was no significant difference in collagen contents among 3 parity groups (p>0.05). In meat color, G1 was higher in a* values for loin and higher in L* and a* values for top round muscle (p<0.05). The loin from G1 had significantly lower cooking loss (%) than G3, however, there was no significant difference in water holding capacity among 3 parity groups. For top round muscle, G3 had significantly higher Warner-Bratzler shear force values and lower water holding capacity values than G1 (p<0.05). In fatty acid composition, G1 had significantly higher C18:1n7 and C18:1n9 contents for loin, and it had significantly higher C16:1n7 and C18:1n7 contents for top round than those of the other groups (p<0.05). In free amino acid composition, alanine was highest and followed by glutamine, phenylalanine, isoleucine, proline, glycine, methionine. In conclusion, the parity conditions influenced on chemical composition and meat quality depending on different cut of Hanwoo cows, and the parity numbers were related with the age of cows.

The gene encoding an esterase enzyme was cloned from a metagenomic library of cow rumen bacteria. The esterase gene (est2R) was 2,120 bp in length, encoding a protein of 516 amino acid residues with a calculated molecular weight of 57,286 Da. The molecular weight of the enzyme was estimated to be 57,000 Da by SDS-PAGE. Est2R shared 35.6% amino acid identity with esterase (CAH19079) of uncultured prokaryote. The Est2R was most active at 20-40°C, and showed optimum at 30°C and pH 8.0. The most activity of Est2R for the different chain length of p-nitrophenyl ester group as substrate was p-nitrophenyl acetate. Moreover, the enzyme was found to be most active without organic solvent, followed by 98% active with ethanol, and the enzyme activity was highly affected by the acetonitrile. The enzyme was significantly inhibited by Zn2+ but stimulated by Ca2+. So, novel esterase gene est2R is likely to obtain from cow rumen metagenome and supposed to use for industrial purpose.

A carboxymethyl cellulase gene, cel5B, was cloned, sequenced, and expressed in Escherichia coli. pRCS20 in E. coli was identified from metagenomic cosmid library of cow rumen for cellulase activity on a carboxymethyl cellulose agar plates. Cosmid clone (RCS20) was partially digested with Sau3AI, ligated into BamHI site of pBluescript II SK+ vector, and transformed into E. coli DH5α. The insert DNA of 1.3 kb was obtained, designated cel5B, which has the activity of hydrolyzation of CMC. The cel5B gene had an open reading frame (ORF) of 1,059 bp encoding 352 amino acids with a signal peptide of 48 amino acids and the conserved region, VIYEIYNEPL, belongs to the glycosyl hydrolase family 5. The molecular mass of Cel5B protein expressed from E. coli DH5α exhibited to be about 34 kDa by CMC-SDS-PAGE. The optimal pH was 8.0, and the optimal temperature was about 50℃ for its enzymatic activity.

This study was carried out to investigate artificial insemination (AI) failure status and frozen semen characteristics in Korean proven bulls‘ number (KPN) semen used for AI of Hanwoo cows in Gangwon East region (Gangneung, Donghae, Taebaek, Samcheok, Sokcho, Yangyang, Goseong). Among semen used for AI, AI failure rate showed lowest at KPN506 (27.6%), whereas highest at KPN593 (77.2%). Correlations of AI failure in between Korean proven bulls semen and cows was 0.2941, which means that AI failure rate of Korean proven bulls semen may have respectable effect on reproduction of Hanwoo cow. In addition, present study was conducted to investigate spermatozoal viability rate, ruptured acrosome rate and active mitochondria in frozen Korean proven bulls semen with flow cytometry. The semen of KPN593 showed significantly (p<0.05) higher viability rate in KPN593 (30.49%) than that in KPN637 (37.34%). Furthermore, percentage of ruptured acrosome was lower in KPN637 as 21.37% than in KPN637 (21.37%), but it was not statistically significant. In conclusion, these results indicate that choice of Korean proven bulls semen may correlate positively with conception rate in Hanwoo cow. Therefore, KPN with high AI failure rate might be avoid to increase conception rate and characteristics of frozen semen might be evaluated before its use for AI.

The present research was carried out to evaluate the possibility of increasing female offspring production ratios using artificial insemination buffer (AIB) before artificial insemination (AI). In this experiment, we optimized AIB composition, made an AIB gun and analyze factors affecting AI non-return rate after AIB treatment. The AIB was made with the base of Tris-buffer supplemented with L-arginine and several other chemicals that might reduce the motility of male sperm compared to the female counterpart, therefore, increasing the possibility of fertilization by female sperm. AIB must be deposited into to cervix by AIB gun. After 15 min of AIB deposition, frozen semen was deposited into the same place. A total of 348 cattle were inseminated with AIB insemination, and there were no significant differences between AIB and traditional AI non-return rates (56.8% vs. 55.7%). The AI non-return rate in AIB group, however, differed significantly among 7 Hanwoo farms. The parturition numbers ( to ) of cows did not affect AIB AI rate. The proportion of AIB AI success rates was significantly higher in Hanwoo cows than in dairy cows (61.0% vs. 48.7%), but the average AI success rate did not differ significantly between AIB and conventional AI (56.8% vs. 55.7%). The female offspring production rate in to cervix deposition place was significantly higher than that in the uterus body (77.7% vs. 59.6%, p<0.05). The injection volume of AIB in 5 and 10 ml was significantly higher than that in 2 ml (77.7%, 78.7% vs. 51.8%, p<0.05), but there were no differences in AIB injection volume between 5 and 10 ml. The best exposure time of AIB in the cervix was 10 to 15 min rather than 5 min (79.2%, 77.2% vs. 52.6%, p<0.05). AIB therefore needs to have an exposure time of at least over 10 min for a higher production rate of female offspring. In conclusion, AIB could be used in AI industry to increase the female offspring ratio and AIB AI can increase the AI success rate.

This study was carried out to investigate the effect of muscle part and aging period on free amino acids and aroma compounds of Hanwoo (Korean cattle) cow beef. The M. longissimus (ML) and M. semitendinosus (MS) from 101 mon-old-cows were aged at 2℃ for 14 d. The free amino acids concentration increased in both ML and MS on 14 d of aging. In ML, asparagine, glutamine, histidine, glycine, threonine, arginine, tyrosine, phenylalanine, isoleucine, leucine and lysine were significantly (p<0.05) higher than those in MS. Varieties of aldehydes, ketones, alcohols, hydrocarbons, nitrogen and sulfur compounds were detected in both ML and MS and majority of these compounds showed increasing trend on aging. The ML had higher 14 aldehydes (acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2- methylbutanal, pentanal, hexanal, heptanal, E-2-heptanal, octanal, 2-octenal, 2-nonenal, E-2-decenal, E,E-2,4-decadienal and 2-undecenal), 5 ketones (2-propanone, 2,3-butanedione, 2-butanone, 2-heptanone and 2,3-octanedione), 4 alcohols (ethanol, 1-pentanol, 1-hexanol and 1-octanol), 3 hydrocarbons (3-ethyl-2-methyl-1,3-hexadiene, 3- methyldecane and 2,2-dimethyloctane) significantly (p<0.05) compared with MS. However, the MS had higher 5 nitrogen and sulfur compounds (methanethiol, dimethyldisulfide, fufural, 2,5-dimethylpyrazine and 2-octylfuran) significantly (p<0.05) compared with ML.

The aim of this study was to evaluate the changes of protein patterns in granulosa cells and corpus luteum during the estrus cycle in bovine ovary by proteomics ^techniques. Our study was devided into five steps for follicular, ovulatory, early-lteal, midluteal and late-luteal. The protein was extracted from glanulosa cell and corpus luteum proteins by using M-PER Mammalian Protein Extraction Reagent. Proteins were refined by clean-up kit and quantified by Bradford method until total protein was 700 μg. Immobilized pH gradient (IPG) strip was used 18 cm and 3 11 NL. SDS-PAGE was used 10% acrylamide gel. The protein spots were visualized by Coomassie Brilliant Blue (CBB) staining, analyzed by MALDI mass spectrometry and searched on NCIBlnr. As the result, 61 spots of total 85 spots were repeated on follicular stage and 51 spots of total 114 spots were repeated on ovulatory stage. 40 spots of total 129 were repeated on early-luteal and 49 spots of total 104 spots were repeated on mid-luteal stage. Also 41 spots of total 60 spots were repeated on last-luteal stage. There were differences in the ovulation (follicular∼ovultory stage) in which the spots of follicular stage 19 was only and in ovulation stage was 10 spots. The difference between the luteinization (ovultory∼mid-luteal stage) was the spots counted in each stage. The spots of ovulatory stage was 1, early-luteal stage was 1 and in mid-luteal stage was 2. Eleven spots were found in mid-luteal stage and 2 spots were found in last-luteal stage. In conclusion, we confirmed that there were 7 spots in ovulation, 4 spots in luteinization and 2 spots in luteolysis. Spot No. 89-93 from ovulation were transferrin, and spot No.94 and 95 were HSP60. Spot No. 103 were Dusty PK, spot No. 135 were OGDC-E2, and spot No. 175, 176 were Rab GDI beta from luteinization. Spot No. 178 and 179 from luteolysis were vimentin.

The present research was carried out to evaluate the possibility of female offspring production using artificial insemination buffer (AIB) before artificial insemination (AI). To do it, we carried out the optimization of AIB, making of AIB gun and analysis of affecting AI rate after AIB treatment. AIB made with the base of Tris‐buffer supplemented with L‐arginine and several materials that could be reduced the motility of male sperm compared with female one. This mean that female sperm could be increased the possibility of fertilization with ovum compared with male one. AIB must be deposited into 2nd to 4th cervix by the guide of AIB gun. After 15 min of AIB insertion, frozen semen was deposited into same place after. Total 352 cattle were inseminated with AIB insemination and was not significant difference between AIB and traditional AI rate (56.8 vs. 55.7%). However, AIB AI rate was significantly differs among 12 different farms. The parturition number of cows did not effect on AIB AI rate among 1st to 7th parturition number of cows. The proportion of AIB AI success rates in hanwoo cows was significantly higher than in dairy cows (61.0% vs. 48.7%), but the average AI success rate was not different between AIB and conventional AI (56.8% vs. 55.7%). The female offspring production rate in 2nd to 4th cervix deposition place was significantly higher than in uterus body (77.7% vs. 59.6%, p<0.05). The injection volume of AIB in 5 and 10 ml was significantly higher than in 2 ml (77.7, 78.7 vs. 51.8%, p<0.05), but not different between 5 and 10 ml ABI volume. The best exposure time of AIB in the cervix was 10 and 15 min rather than that of 5 min (79.2%, 77.2% vs. 63.2%, p< 0.05), and so AIB have to expose at least 10 min to get higher female offspring. In conclusion, AIB could be used in AI industry to produce female offspring and also AIB AI can be increased the AI success rate compared with traditional AI rate.

The objective of this study was to compare the accuracy analysis and the effect of field application of a newly developed automatic heat detector in dairy cows. From 2009 to 2010, we used 48 Holstein cows (mounting cows : 38 heads, standing cows : 10 heads) raised in experimental barn of National Livestock Research Institute (RDA) for the accuracy analysis of automatic heat detector, and 14 Holstein cows raised in three commercial dairy farms of Cheonan and Pochun area for comparison of the effect of field application. The accuracy of response in cows attached with automatic heat detector was 86.8% (33/38) displayed on board when mounting activity observed, and 100% (10/10) when standing activity observed, and on average, 90.0% (43/48) displayed on board. The accuracy of automatic heat detector in on-farm test was 85.7% (12/14), and conception rate was 75.0% (9/12).

희소 한우인 칡소의 정액 동결을 위해서 레시딘을 기본 희석제로 하는 AndroMed와 Tris-egg yolk extender를 사용하여 정자의 생존율과 활력 조사를 위해서 본 연구를 수행하였다. AndroMed 희석제를 사용하였을 때 생존율과 활력은 와 의 결과를 보였다. 그리고 Tris-egg yolk extender의 경우는 각각 와 결과를 보여 생존율에서는 Tris-egg yolk 희석제가 AndroMed 희석제를 사용하였을 때보다 유의적으로(p

The objective of this study was to investigate the effects of abnormal ovarian cycles after superovulation treatment of Hanwoo donors. Thirty six, at random stages of the estrous cycle, received a CIDR. Four days later, the animals were superovulated with a total of 28AU FSH (Antorin, 2AU=1 ml) administered twice daily in constant doses over 4 days. On the 3th administration of FSH, CIDR was withdrawn and 25 mg was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received GnRH at the time of Ind insemination. Embryos were recovered 7 or 8 days after the 1st insemination. The cows were considered to have resumed ovarian cyclicity on the day of ovulation if followed by regular ovarian cycles. 50.0 percentage of the cows (18/36) had normal resumption of ovarian cyclicity (resumption within 40 days after superovulation), and 50.0% (18/36) had delayed resumption(resumption did not occur until>40 days after superovulation). Delayed resumption Type II (first ovulation did not occur until 40 days after superovulation, i.e. delayed first ovulation 33.3%) were the most common types of delayed resumptions. The mean numbers of total ova from < 10 and 10 of corpora lutea (CL) was 7.3 and 13.9, respectively. The number of transferable embryos differed between < 10 and 10 CL was 4.2 and 5.1, respectively. 11.1 percentage of the cows (4/36) did not resumption their ovarian cyclicity until 60 days after superovulation treatment.

The aim of present experiment was to examine commercial synthetic extender(AndroMed) for semen cryopreservation of Korean Black Bull. Semen was collected from a Korean Black Bull using an artificial vagina and transported to the laboratory. The semen was diluted 1:1 by AndroMed. The pellect was diluted to final sperm concentration of by doubling in every 10 minutes at cold chamber. The semen was equilibrated for 1 hr at cold chamber and packed to 0.5 ml straw. The semen straws were located above 5 cm of liquid nitrogen for 5 minutes, above 5 cm for 10 minutes and above 10 cm for 10 min. And then the frozen straw was plunged to . The presented straws were examined the viability and motility after thawed at water bath. Hanwoo semen was used as KPN (Korea Proven Bull Number) in this experiment. The survival rates was significantly higher in fresh semen than frozen semen (). However, the motility rates was similar (80.7% and 66.4%). The survival and motility rates were higher in 5cm, 10 min treatment group than the other two groups in straw-located height and duration above ( and 70.7% vs, 33.18% and vs, 30.14% and 65.7%, respectively). The development rates to cleavage was higher in Black Cow than Hanwoo semen (62.2%, 64.4%), However, The development rates to blastocyst was higher in Hanwoo than Black cow semen (25.9%, 23.0%). In conclusion. The present results that acceptable fertilization and cryopreservation could be obtained by in vitro fertilization with frozen-thawed semen using a synthetic semen extender (AndroMed).

Ultrasonographic examination was performed to observe the ultrasonographic image of Korean native cows' normal uterus in condition of in vitro and in vivo. The experiment was done 28 slaughtered cows' uterus using immersed in water in vitro, and 41 healthy breeding cows taken rectal ultrasonography in vivo. Ultrasonographic examination of uterine was taken on the reference of cross section of intercornual ligaments' cranial. Each uterus on the experiments was compared by estrous cycle and ultrasonographic frequency. The uterine structure using ultrasonography was 5 layers of uterine horn in vivo as well as in vitro. Uterine horn was observed to be distinguished from inside to outside as endometrium to inner echogenic layer, circular muscle layer to slightly echogenic elliptical layer, stratum vasculare to central echogenic layer, longitudinal muscle layer to slightly echogenic arched layer, and perimetrium to outer echogenic layer, respectively. According to the observation of uterus related to estrous cycle and ultrasonographic examination, uterine endometrium in vitro was constantly founded irrespective of estrous cycle and ultrasonographic frequency. On the low frequency, endometrium and circular muscle layer in estrus were prone to distinguished than in diestrus. On the high frequency, endometrium and circular muscle layer were always distinguished regardless of estrous cycle. In vivo, uterine endometrium and circular muscle layer were observed regardless of estrus and ultrasonographic frequency. On the low frequency, stratum vasculare and longitudinal muscle layer were not likely to be distinguished in diestrus, but estrus. On the high frequency, stratum vasculare and longitudinal muscle layer were observed regardless of estrous cycle. Also, every uterine structure was easily distinguished on high frequency than low frequency owing to precision of distinction in layers. The difference of results followed by the experiments conditions between in vitro and in vivo was that uterine endometrium and circular muscle layer in diestrus in vitro were difficult to be distinguished and uterine lumen was observed during whole estrous cycle. In vivo, It was founded that the distinction of stratum vasculare and logitudinal muscle layer in diestrus was complicated and uterine lumen was observed during only estrus. In view of the result so far achieved, normal uterine structure divided in 5 layers on ultrasonography was accorded with microscopic organization, uterine structure was likely to be observed during estrus than diestrus, high frequency checkup than low frequency, and uterine endometrium, circular muscle, stratum vasculare was easily observed regardless of estrous cycle and ultrasonographic frequency.

젖소의 분만 전․후기는 일반적으로 전환기라고 칭하며 분만후 유생산을 준비하기 위해 동물체내 대사 및 생리적 상태가 급격히 변화하는 시기라 할 수 있다. 젖소는 이 시기에 간조직에서 당신합성을 통해 유당합성을 위한 glucose의 생산을 촉진하고, 지방조직에서는 분만 전부터 지질을 축적하고 비유개시에 맞추어 혈중 NEFA (nonesterified fatty acid)의 농도를 증가시켜 유지방 합성을 준비한다. 이러한 대사조절에 epinephrine 및 insulin이 조절 호르몬으로 작용하여 유생산을 위한 탄수화물 및 지질대사를 변화시키고 사료 섭취량의 부족에 기인한 전체 에너지의 감소를 체내 영양소의 재분배로 충족시킨다.