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 On the 3th administration of FSH, CIDR was withdrawn and 25 mg was administered.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.

In vivo embryo produced from Hanwoo donor cows were collected and transferred to Hanwoo recipients. Cows, at random stages of the estrous cycle, received Progesterone Releasing Intravaginal Device (CIDR-plus, InterAg, New Zealand) together with injection of 1 mg estradiol benzoate and 50 mg progesterone, and gonadotropin treatment began 4 day later. For superovulation, a total of 28 mg FSH was intramuscularly injected twice a day in the way of decreasing doses 4 day (5, 5, 4, 4, 3, 3, 2 and 2 mg). Twenty one Hanwoo donor cows were flushed on day 7 of estrus cycle with same FSH and artificial insemination by the same technicians. Embryos were recovered 7 days after the second insemination by flushing the uterus with Embryo Collection Medium. The results obtained were as follows: The rates of transferable embryos were 50.3%, and 78 fresh embryos at morulae and blastocysts stage were transferred into Hanwoo recipients on day 7 of estrus cycle. The pregnancy rates were first embryo transfer 55.6%, 2nd 62.9% and 3rd 57.9%, respectively. In conclusion, These results suggest that CIDR-based superovulation protocol may be effectively used for production of superior Hanwoo embryos. Also, since it seems the condition of recipient cows greatly affect pregnancy rate, it is very important to evaluate recipient for effective cattle production.

본 연구는 부산물 혼합 silage 사료 급여가 한우 비육전기 거세우의 채식 및 반추행동에 미치는 영향을 규명하기 위하여 실시하였다. 시험에 사용한 공시한우는 21개월령 총 12두를 3처리로 배치하였으며, 이 때 처리구는 관행구 (C구: 농후사료+ 볏짚 자유채식)와 부산물 혼합 silage 구를 2처리 (T1: 농후사료+부산물 혼합 silage 제한급여 (1 kg) + 볏짚 자유채식, T2: 농후사료+부산물 혼합 silage 자유채식)로 하여 48시간

본 연구는 반추위 및 십이지장 cannula를 동시장착한 거세한우 3두 (평균체중 )를 공시하여 in situ 기법으로 수확시기별 총체 벼 사일리지의 한우 생체 영양소 분해율 및 TDN을 분석하고자 실시하였다. 총체벼 사일리지의 조단백질 함량 (평균 4.81%)은 황숙기를 제외하고는 수확시기가 늦어질수록 감소하는 경향을 보였다. 총체벼 사일리지 건물의 반추 위 시간대별 분해율은 유숙기에서 배양 후 12시간 이후부터 다른 수확시기에 비해서 다소 낮은 경향

In this study, the analysis of meat quality grade was carried out on the DNA identity test samples of 452 Hanwoo (Korean cattle) raised in Gyeongnam region in the year 2009. Appearance rate of above 1st grade from cow (70%) and steer (93.16%) showed high quality grade. On the other hand, there were the difference between this study and slaughtered Hanwoo in Gyeongnam in the year 2009 - appearance rate of above 1st grade from cow (58.77%) and steer (82.99%). It expect considered influence of the samples for beef DNA identity test that collected mainly high quality meat. Quality grade by registry classification about collected samples showed correlation between pedigree classification and quality grade that appearance rate of above 1st grade highly observed pedigree registry more than advanced registry, advanced registry than fundamental registry. Although limited to DNA identity test samples, KPN (Korean Proven Bull's Number) 452 and KPN 407 was preferred for breeding in Gyeongnam. Also average appearance rate of above 1st grade in offsprings of the top 10 Korean Proven Bulls used mating is 95.35%. It means that Korean Proven Bulls influence meat quality of offsprings positively. Thus, this analysis is expected to be a base data for the improvement of meat quality of Hanwoo raised in Gyeongnam region.

In this study, genotyping was executed by using 11 microsatellite markers (BM1824, BM2113, ETH10, ETH225, ETH3, INRA23, SPS115, TGLA122, TGLA227, TGLA53, and TGLA126) for diversity of 214 Hanwoo cows in Hoengseong area. Each marker's size and number of allele, observed heterozygosity, expected total heterozygosity, and polymorphism information content were analyzed by 11 Microsatellite marker. The average of size range was detected from 150.9 to 174.9 in Hanwoo cows of Hoengseong. The number of average allele was 10.0 that is similar to the average of Kangwon Hanwoo, which is known as 10.5 in the previous report. The average were 0.751 for observed heterozygosity, 0.760 for expected total heterozygosity, 0.725 for polymorphism information content, respectively. These results were similar to previous studies in Kangwon Hanwoo, National Hanwoo and Korean Proven Bulls. This study is expected to contribute for genetic improvement of Hanwoo cows in Hoengseong as a popular brand.

This study aims to identify DNA marker related to health index which is derived from fatty acid composition of Hanwoo meat. We investigated a genetic association between two SNPs (-867G>C and 878C>T) of SCD gene and health indexes. Two health index values (index of atherogenicity and index of thrombogenicity) were derived from a combination of fatty acid composition. Phenotypic correlation indicated that oleic acid (C18:1) was negatively correlated to index of atherogenicity (-0.84) and index of thrombogenicity (-0.91), respectively. Statistical analysis revealed that 878T>C SNP was significantly associated with IA (index of atherogenicity, p=0.012) and IT (index of thrombogenicity, p=0.006). There was no association between the regulatory SNPs (-867G>C and -877Gdel) and health indexes. Haplotype analysis detected 4 main haplotype (GdelT; 0.004, GdelC; 0.344, CGT; 0.350 and CGC; 0.261) in Hanwoo. The GdelT haplotype was significant on IA and IT. The effect of GdelT haplotype showed increasing IA and IT values, while GdelC haplotype has a decreasing IA and IT value in Hanwoo. In conclusion, the 878C>T SNP in the SCD gene seems to have an effect on this health index and might be implemented into animal breeding program.

The conception rate of cow is a major factor in farm management. The environment of farm and management of cow are the best influencing factors on conception rate, and the fertility of bull is the second influencing factor. In Hanwoo bull, however, the informations limited to performance and carcass traits have been offered to Hanwoo farmer. Therefore, this study analysed the estimated relative conception rates (ERCR) for estimation of fertility of bulls, using the 8,892 mating data with 116 heads of prove bull to produce progeny. Mean of least square means of conception rate after first insemination was 50.95% in bull herds. On the standard of this mean, ERCRs after first insemination of each bull were analysed. Values ranged from -26.1% to +21.0%, the difference was 47.1%. Among 116 heads of bull analysed, KPN582 showed the highest ERCR as 21.0%, KPN550 (18.3%), KPN656 (16.7%), KPN632 (15.8%), KPN690 (14.9%) were gone behind, but KPN621 was the lowest as -26.1%, KPN680 (-21.3%), KPN674 (-16.2%), KPN569 (-15.9%), KPN699 (-14.9%) were succeeded. If ERCRs of Hanwoo bull will be offered to Hanwoo farmer, it will be worthwhile.

The relationships of scrotal circumference (SC) to semen characteristics and the conception rate (70 days-nonreturn rate) of artificial insemination in farm were studied with 137 heads of bull in Hanwoo. The average and range of SC were cm and 26.0~52.5 cm, respectively. Hanwoo bulls were classified with SC, divided into 34 cm below group, 34~39 cm group, and 39 cm over group. The 5,487 semen records of 43 heads of bull from July. 1. 2007 to June. 30. 2008. were used to determine the relationships between SC and semen characteristics. The semen concentration and total sperm number of each group were 11.18, 16.68, and , and 69.83, 101.64 and /ejaculate. The bulls with 34 cm or more SC were higher than the bulls with 34 cm below in semen concentration and total sperm number (p<0.01). But between SC and semen volume have no significant relationship (p>0.05). The 9,862 mating records of 44 farm with 137 heads of bull were used to determine the relationships between SC and conception rate. The conception rate of 1st artificial insemination were 73.31, 74.16, and 77.33 % in each group. Also SC was positively correlated with pregnancy rate (r=0.12, p=0.17). These results indicate that SC correlates positively with semen characteristics, and maybe with pregnancy rate in Hanwoo.

As a simple and economical method for in vitro produced embryos, we have used BSA instead of serum for the production and embryo transfer of Hanwoo in vitro fertilized (IVF) embryos and obtained the following results: 1) When using serum (FBS; fetal bovine serum) or BSA-containing culture media as the initial culture media for immature oocytes, it is regarded as inappropriate to add only BSA to the culture solutions from maturation of the immature oocytes to development stage culture, but serum still needs be added though there is no significant difference in the concentration, with a change from 5% to 10%. 2) The results of culturing IVF embryos after development (4 cell stage) in the Medium199 solutions containing BSA instead of serum (FBS) showed that 0.3% BSA concentration is not optimal and 0.5% or higher BSA concentration has no significant difference among 0.5%, 0.7%, 1% and 2% (p > 0.05). 3) The post-freezing survival ratio after development in 5% FBS-Medium199 showed that 1% BSA concentration of the culture solution is the most suitable in the BSA concentrations of 0.3% (51%), 0.5% (67%), 0.7% (69%), 1% (77%) and 2% (75%). 4) The pregnancy rates of the transplanted fresh(not frozen) blastocyst had no significant concentration dependency (p > 0.5), and the average pregnancy rate was 63.8%. 14% of overweight calves were found among the calves given birth to by the transfer of IVF blastocysts cultured in the serum-added culture solution, but none was found in the experimental groups in which BSA was added instead of serum.

The purpose of this study was to determine the effect of different feeding ratios of whole crop barley silage on the embryo production in Hanwoo donors. All donors were basically fed 2.5 kg concentrate daily. Donors were divided into three groups according to the different feeding of forage; hay 70% and rice straw 30% (control, n = 21), whole crop barley silage 80% and rice straw 20% (T1, n = 25), and whole crop barley silage 60% and rice straw 40% (T2, n = 23) fed based on TDN 6.70/ BW 500 kg. All Hanwoo donors received a CIDR together with injections of 1 mg estradiol benzoate and 50 mg progesterone (, Day 0). Four days later, they were superovulated with 28 mg FSH twice daily IM in decreasing doses over 4 days. Then donors received 2 doses of (25 and 15 mg) with the 5th and 6th injections of FSH on Day 6. CIDR were withdrawn at the 6th FSH injection and the donors received GnRH 36 h after the second injection. The donors were artificially inseminated twice, at 8 and 24 h after GnRH, and embryos were recovered 7 or 8 days after the 1st insemination. The flush rate of the donors following positive superovulation responses did not differ among groups (76.2~96.0%, p>0.05). The number of corpus luteum (CL) at embryo recovery also did not differ among groups (10.6~14.0, p>0.05). Furthermore, the mean numbers of total ova (9.4, 10.5 and 12.0) and transferable embryos (5.3, 12.0 and 6.5) did not significantly differ among the control, T1 and T2 groups, respectively (p>0.05). However, mean concentrations of serum of the T1 (64.2 ng/ml) and T2 groups (55.7 ng/ml) were higher than that of control group (43.3 ng/ml, p<0.01), while serum cholesterol concentrations in the control (105.8 mg/dl) and T2 groups () were significantly lower than in the T1 group (121.1 mg/dl, p<0.05). Conclusively, whole crop barley silage can be fed a good substitute for hay forage for Hanwoo donors. Furthermore the ratios of whole crop barley silage 60% and rice straw 40% might be more worthful for embryo production.

본 시험을 수행하기 위해서 6개월령 거세한 우 64두를 공시하여 주구는 조사료원으로 목건초와 볏짚 처리구를 배치하였으며, 세구는 출하시기로 24개월, 26개월, 28개월 및 30개월 배치하였다. 본 시험은 조사료원 및 출하시기별 발육 및 육질에 미치는 영향을 구명하기 위하여 수행하였다. 발육 및 사료이용성은 목건초 급여구가 볏짚 급여구에 비하여 동일 출하월령에서 10~12% 정도 더 발육이 향상되었으며(p<0.05), 배합사료 요구량에서도 목건초 급여

This study was conducted to test the effect different forages and feeding rates on generation of main greenhouse gases like carbon dioxide and methane in Hanwoo cows. Feeds were given twice per day at 09:00 and 17:00. Greenhouse gases were measured during 12 hours using Mamos-300 from 09:00 to 21:00. The results indicated that the generation of greenhouse gases under different forage categories and feeding rate were significantly different (p<0.05). Whole greenhouse gas tended to decrease in the high concentrate diets. The high timothy supplement ation group showed less amounts of carbon dioxide generation comparing with others group while high silage supplementation resulted more methane generation comparing with other treatments. On the afternoon test, carbon dioxide generation was significantly lower different (p<0.05) in timothy treatment comparing with others.