본 연구는 젖소(Holstein종)의 mtDNA D-loop 영역 염기변이 다형성과 경제형질간의 관련성을 분석하기 위하여 수행하였다. 젖소의 mtDNA D-loop 영역에서 단일염기의 치환에 의해 총 35개의 polymorphic site가 확인되었다. 그중 주요 Polymorphic site의 염기변이 빈도는 106, 169, 16057, 16231 및 16255 지역에서 높은 빈도의 염기치환이 검출되었다. 169 지역은 A가 G로 염기치환이 일어났고 그 빈도는 0.555로 높게 나타났으며 염기치환에 의한 산유량 효과는 1259.6 kg(P<0.05)로 나타났다. 유지방과의 관계를 분석한 결과 16118 지역은 A가 G로 치환되는 빈도가 0.02로 검출되었으며, 16135 지역은 T가 C로 치환되는 빈도가 0.02로 검출되었고, 16302 지역은 G가 A로 치환되는 빈도가 0.04로 검출되었다. 이 지역들이 유지방에 미치는 변이 효과는 - 156, - 118.15 및 - 67.77 kg(P<0.1)으로 나타났다. 본 연구에서 검출한 젖소 mtDNA내 D-loop 영역의 염기서열 변이 빈도와 유량, 유지방과의 연관성 분석 결과 등은 젖소집단의 유전적 변이성 추정과 좀 더 다양한 경제형질과의 관련성 분석으로 다양한 유전적 지표인자 발굴에 도움이 될 것이며 이를 통해 분자유전학적 기법을 이용한 젖소의 육종전략을 확립하는데 기초 자료가 되는 것은 물론 분자육종학적인 연구에 기초 자료로서 유용하게 활용할 수 있을 것으로 기대된다.

가축에서 생산성을 높이기 위해 사용되는 수정란이식술의 실용성을 알아보기 위하여 한우 및 젖소 36두로부터 과배란 처리를 하여 신선수정란은 25두에, 동결수정란은 17두에, 쌍태 생산을 위한 수정란 두 개 이식은 13두 수란우에 이식되어 그 생산 결과를 조사하였다. 1 과배란을 위한 호르몬 처리후 반응을 나타낸 공란우는 75.0％이었다. 2. 황체수와 비교하여 채란된 수정란 율은 91.8％ 이었다. 3. 비외과적으로 채란된 전체 난자 중 생존성이 있는 배

한우 태아 섬유아세포 유래 체세포복제수정란 이식으로 임신된 수란우가 분만예정일이 도래하였으나 분만징후가 없어 수정란이식 후 272일째에 dexamethasone 20 mg을 근육주사하고 24시간후 PG 25 mg과 estradiol 20 mg을 근육주사하여 분만유도를 실시하였다. dexamethasone 투여후 48시간만 분만징후를 나타내었으며, dexamethasone 투여후 50시간째에 40 kg의 수송아지를 견인에 의해 정상적으로 분만시켰다. 그러

유전적으로 우수한 능력을 보유하고 있으나 정상적으로 번식이 불가능한 젖소 16두를 간이 난자 체취기를 이용하거나 장기공태 젖소 5두를 초음파 난자체취기를 이용하여 미성숙난자를 채취하므로서 체외수정란을 안정적으로 생산하기 위해 채취기기의 효율성과 반복채란에 미치는 영향을 조사한 결과는 다음과 같다. 1 공란우당 채취회수는 간이 난자 체취기 8.8회였고, 초음파기기는 8.8회였으며, 공란우당 평균 회수된 난포란은 각각 4.39개와 4.14개로 채취기기간에

This study was conducted to develop an improved method for oocyte pick-up(OPU) with finger-sensibility using ultrasound-guidance from ovarian follicles in Holstein heifers. Oocytes were aspirated from ovarian follicles of clear-outline (>2mm), obscure-outline and invisible( 2mm) on ultrasound images with 3 different vacuum pressure(40, 80, 120mmHg). Total number of oocytes recovered/follicles were 309/237(130.4%). 113/80(141.3%) and 107/74(144.6%) with 40, 80 and 120 mmHg of vacuum pressure, respectively. Mean number of oocytes recovered was higher in 2 OPU/week (18.35.3) than 1 OPU/week(14.54.1), but this difference was not statistical1y significant. The recovery rates were not affected by the number of OPU as 135.6%(282 oocytes/208 follicles) in 1~20 OPU, 137.7% (168/122) in 21~40 OPU and 148.4%(92/62) in 41~60 OPU, respectively. The proportions of good oocytes (Grades I) recovered were not significantly different by the number of OPU until 40 OPU(12.4% in 1~20 OPU vs 16.7% in 21~40 OPU). However, a significantly(P<0.05) lower recovery rate resulted from more than 40 OPU compared to less than 40 OPU(7.6%). These results imply that more fertilizable oocytes can be produced from invisible-immature follicles by transvaginal aspiration with finger-sensibility from Holstein heifers.

The objective of this study was to produce calves by transfer of embryos derived from slaughter house(SHD) and ultrasound-guided ovum pick-up (OPU). At 60 hrs after injection of 400 mg FSH dissolved in 25% polyvinylpyrrolidone(PVP) by single dose, ultrasound-guided follicular oocyte aspiration was ferformed. Day-7 and day-8 blastocysts produced by in vitro maturation (IVM), fertilization (IVF) and culture(IVC) of the oocytes derived from SHD and OPU were nonsurgically transferred into recipients. The results obtained were as follows. The cleavage rate and the development rate to blastocysts were not significantly (P<0.05) different between the oocytes obtained by SHD (72.9% vs. 34.1%) and OPU (75.9% vs. 38.4%). The oocyte recovery rate from the number of follicles by ultrasound-guided aspiration were not significantly (P<0.05) different between Holstein (61.7%) and Hanwoo (60.1%), but the rate of oocytes useful for IVF was significantly (P<0.05) higher in Hanwoo (69.3%) than Holstein (59.6%). The cleavage rate and the development rate to blastocysts was not significantly (P<0.05) different between Holstein (74.9% vs. 39.2%) and recipients on day 8 of estrus cycle resulted in 13 pregnancies (34.2%). One of them was sacrificed during gestation period due to mastitis and another was aborted spontaneous. The resulting 14 calves were morphologically normal at birth. Seventy eight fresh OPU-IVF embryos were transferred into 21 recipients on day 8 of estrus cycles, resulting in pregnancy of 12 recipients (41.4%). Two of them were sacrificed during gestation period due to mastitis and the other two were aborted. Nevertheless, the 11 OPU-calves have been born normally.

Recently there has been an increasing amount of foreign livestock products distributed in the domestic market due to the market opening. Some vicious dealers sell the foreign beef in the trade name of the native beef during the final distribution step to arouse the social criticism frequently. In this report, we investigated a method to distinguish the native beef from the foreign one scientifically using the PCR-RAPD, a recent gene technique. Hygienical safety was also examined using a microbiological test for toxicity of Escherichia coli O157:H7 and the food poisoning bacteria. The conditions of DNA amplification for the PCR analysis were 1 × Taq polymerise buffer, 1.5 mM MgCl₂, 50 uM dNTP, 100 ng primers, 2.5 unit Taq polymerise and 5-20 ng template DNA, with the final volume of 50 Etl. The size of the amplified product was detected mostly in the range of 0.5-2.0 kbp. The size of DNA, gene marking factor, which could be a criterion distinguishing the native beef from the foreign one, appeared approximately 1.2 kbp. The native beef was distinguished from the foreign beef with more than 90% of confidence by the gene marking factor. This method was expected to be useful in the breed discrimination between the native beef and the foreign one. The hygienical test results showed that, fortunately, neither Salmonella spp. and Listeria monocytogenes which form a principal cause of the food poisoning nor Enterohemorrhagic Escherichia coli : EHEC which have provoked a recent social disturbance, were detected at all.

본 시험은 Holstein종 수소를 조기에 외과적 거세 후 SR-rbST 투여시 사육 단계별 건물 및 영양분 섭취량 변화에 미치는 영향을 구명하기 위하여 Holstein 수소 32두를 공시 하여 얻어진 주요 결과를 요약하면 다음과 같다. 1. 건물 섭취량은 비거세구와 거세구는 큰 차이 가 없었지만 rbSTl구와 rbST2구는 각각 7.88kg과 7.65kg으로 비거세구와 거세구에 비해 6~9% 정도 건물 섭취량이 적었다. 2. NRC 비육우 요구량 대비

This study was carried out to investigate the reproduction efficiency and disease of Holstein heifer grazed on mixed pasture desighed with association of tall fescue and white clover cultivar (3 treatments = TI : Tall fescue Fawn + White clover Regal + Or

The present study was carried out to produce in vitro fertilized embryos with immature follicular oocytes collected by transvaginal aspiration from Holstein cows. A simple aspiration apparatus consists of two stainless steel tubes, an inner tube (needle holder; 1.2cmdiameter, 55cm long) and an outer tube (1.5cm diameter, 4Scm long), and a hand-operated vacuum pump was used. Under epidural anesthesia, the needle guide was passed into the vagina of the cow to a point next to the cervix. An ovary was placed against the wall of the vagina over the end of the aspiration needle by rectal manipulation. As the needlepassed into the ovary, an assistant was asked to apply vacuum(l00mrnHg) and the ovary was manipulated back and forth in all directions over the needle. When all sites of the ovary was aspirated, the needle was withdrawn and the needle guide was moved to the other side of ovary and the procedure was repeated. When the oocyte aspiration procedure was finished, collected fluid was transported to laboratory. Oocytes surrounded with at least 1 layer of cumulus cells were matured, fertilized and cultured in vitro. The results were as follows; Ninety seven oocytes were collected by transvaginal aspiration from seventeen Holstein cows(5.7 /head). The number of oocytes surrounded with at least 1 layer of cumulus cells were 60(61.9%). Following in vitro maturation, fertilization and culture, the cleavage and development rate to morula+blastocyst were 83.3% and 30.0%, respectively. From this study, transferable in vitro fertilized embryos could be produced with imma- ture follicular oocytes collected by transvaginal aspiration from Holstein cows using a simple aspiration apparatus

This experiment was carried out to clarify the pedigree identification from blood typing of 301 Hoisteins in National Animal Breeding Institute(N.A.B.I.). Twenty kinds of standard reagent standardized by Insternational Society for Animal Blood Group Research provied from KNC improvement center, N, L, C, F. were used as the reference reagents in this study. The highest frequency of antigenic facfors was obtained from Xin blood typing of 301 Holsteins. The frequency of X was 0.714.In A blood system, four kinds of phenogroups were observed. The gene frequencies of Al and Z' phenogroups were equally 0.027.This frequency was greatly lower than those of breeds of Southern European and Zebu cattle. In B blood Systern, nineteen kinds of blood type were appeared. The appearance frequency of Gx blood type was 0.259, whish was higher than the others. In C blood system, thirty kinds of blood type were observed. The appearance frequency of X blood type was the highest(0.189). In F blood system, three kinds of alleles were detected. The gene frequency of F allele was higher than that of V(0.105). However, the frequency of F allele(0.327) was greatly lower than that of "- /- " allele. In S blood system, twelve kinds of blood type were appeared and showed sirnilar appearance frequencies except " - / - " allele. From the results of the pedigree identification from 8 sires and 28 progenies of them, the accuracy of pedigree identification was 92.9%.ification was 92.9%.

홀스타인 암소 육성우에 옥수수사일리지와 볏짚을 급여하면서 영양수준을 80, 100 그리고 12%(NRC 요구량 대비)로 급여할때 육성우의 중체량 및 영양소 섭취량을 조사하기 위하여 육성우 30두를 각 처리당 5두씩 완전임의 배치로 공시히여 체중 400kg까지 시험을 수행한 결과는 다음과 같다. 1. 옥수수사일리지 및 볏짚급여시 육성기 최대 일당중체량은 각각 체중 200과 250kg 일때였다. 2. 체중이 증가할수록 DM, CP 및 TDN 요구량은 증가되