An abnormal female Korean native calf at five months age with five legs was observed macroscopically and radiographically. External features included two normal forelimbs, and hindlimbs, and an abnormal forelimb which was underdeveloped. A rudimentary forelimb, which was attached to the pectoral region, was observed at the right axillary part. The extra forelimb was scapural and humeral meromelia. It consisted of an underdeveloped forearm (antebrachium), several carpal bones (three bones), large metacarpal bone (Mc. 3 + 4), and two digits with two hoofs. The proximal, middle and distal phalanges, proximal and distal sesamoid bones are normal.

The morphogenesis of the stifle joint in Korean cattle embryos and fetuses was observed by radiography, alizarin red S stain and light microscopy. Fourty-eight(48) embryos and fetuses, ranging from 11mm to 160mm in crown-rump length (C-R L), were used for this study. The experimental samples were divided into twelve separate groups according to their C-R L. The first to the nineth group ranged from 11-100mm in C-R L, spaced at 10mm intervals. The tenth to the twelfth group ranged in C-R L from 101mm to 160mm, and were spaced at 20mm intervals. The results were as follows; 1. The first appearance of the interzone between the femur and tibia was formed in the second experimental group. The patellar ligament and cruciate ligament appeared in the third group and the patella, menisci and synovial cavity appeared in the fourth group. 2. The lateral and medial menisci were first obseved in the fourth group, and these structures showed crescent shape in the fifth group of the fetuses. 3. The first appearance of the femoro-tibial joint cavity was in the third group. The fifth group contained the first appearance of the patello-femoral cavity. Also, the femoro-tibial cavity was divided into two cavities by the anterior and posterior cruciate ligament.

To investigate the cycle and relative frequences and the fine structure of seminiferous epithelia in mature Jindo dogs, histologic study was performed. The results obtained were summarized as follows; 1. Type A spermatogonia appeared approximately 1.6 times as many at stage II as compared to stage I while type In spermatogonia appeared small amount in stage III, IV and V. type B spermatogonia were found during the stage VI to VIII, though not detectable during stage I to V. The type B spermatogonia divided at stage VII to produce the preleptotene primary spermatocytes at stage VIII. The number of primary spermatocytes of the leptotene phase markedly increased during stage I to II, and the primary spermatocytes of the pachytene phase were shown the least in number at stage IV. The secondary spermatocytes could be seen only at stage IV. 2. The relative frequencies of each stage from stages I to VIII of the cycle of seminiferous epithelia were 31.6, 11.9, 10.0, 3.2, 8.2, 10.1, 11.7 and 13.2% respectively. 3. On electron microscopic observations, acrosomal vesicle of spermatids appeared larger though the bulk of germ cells were the morphologically same as those of the other animal species. Thread line structures light microscopically observed in the cytoplasm of Sertoli cell were the longitudinal orientation of mitochondria.

The purpose of this study was to examine the effect of growth hormone(GH) on the division and migration of the small intestinal epithelium in mice. Twenty mice(ICR), weighing initially about 10 g, aged 18 days were randomly subdivided in two groups of control and GH-treated group. Control group was sacrificied at 2 hr, 2, 3, 4 and 5 day after intraperitoneal injection of $^3H$-thymidine($^3H$-TdR, $4{\mu}$ Ci/gm of BW/day for 2 days). GH-treated group was injected subcutaneously with somatotropin(10 IU/mouse/day for 4 days) from 2 day ago of first $^3H$-TdR injection and then was sacrificied at 2 hr, 2, 3, 4 and 5 day after intraperitoneal injection of $^3H$-TdR($4{\mu}$ Ci/g of BW/day for 2 days). The small intestines were collected for autoradiogrophy and Hematoxylin counterstain. The location of the labeled epithelial cells(LEC) in villi of the small intestine was invested with light microscope. 1. In the control group, the LEC regions in the small intestine were located at crypts on 1 dsy, at $0%{\sim}15.9{\pm}3.6%$ of villus high value(VHV) on 2 day, at $0%{\sim}49.8{\pm}16.5%$ of VHV on 3 day, at $0%{\sim}95.3{\pm}6.9%$ of VHV on 4 day and $62.9{\pm}16.7{\sim}100%$ of VHV on 5 day, respectively. 2. In the GH-treated group, the LEC regions in the small intestine were located at crypts on 1 day, at $0%{\sim}39.2{\pm}9.5%$ of VHV on 2 day, at $0%{\sim}81.5{\pm}18.2%$ of VHV on 3 day, at $45.2{\pm}11.5%{\sim}100%$ of VHV on 4 day, at 85%~100% of VHV on 5 day, respectively. 3. VHV of tops in the LEC regions appeared to be 23.3% and 31.7% higher on 2 and 3 day, and VHV of the LEC region bases appeared to be 45.2%, 22.1% higher on 4 and 5 day, respectively in the GH-treated group than those observed in the control group. These difference was very highly significant(p<0.01).

Mitochondrial DNA(mt DNA) of Mammalian is the circular one which the 16.5K base pairs and show the maternal inheritance. Evolutional speed of nucleotide sequence is very fast. So that polymorphic analysis of mt DNA provide the useful informations to investigate the genetic relations of interspecies. Authors trials were focussed to compare with the polymorphic differences of mitochondrial DNA between Jindo and Japanese mongrel dogs. DNA was extracted from bloods of 21 head of Jindo dogs and 20 head of Japanese dogs and isolated using 10 kinds of restriction endonucleases(Apa I, BamH I, Bgl II, EcoR I, EcoR V, Hinc II. Hind III, Pst I, Sty I, Xba I) and then separated by the agarose gel electrophoresis. After sourthern blotting hybridization was completed using the mtDNA of Japanese mongrel dogs as a probe. Autoradiography was used to compare the polymorphism of mtDNA both dogs. The results obtained were as follows; 1. mt DNA of Jindo dog showed polymorphism resulting cleavage with four kinds of restriction endonuclease, Apa I, EcoR V, Hinc II, Sty I. While in the Japanese mongrel dogs observed the polymorphism in the five kinds of restriction endonuclease supplemented with EcoR I. 2. Compared with both dogs the frequency differences of DNA polymorphism were recognized in the specific restriction endonuclease Apa I. Consequently in the restriction endonuclease Apa I both dogs classified with three types as A, B, C however in the Jindo dogs frequency of C type was 71.5 percent but in Japanese mongrel dogs observed 45 percent in the A type. 3. DNA polymorphism obtained from the use of five kinds of restriction endonuclease were classified with seven types. In Jindo dogs frequency was highest in the type 6 as 71.4 percent but in the Japanese mongrel dogs showed 35 percent in the type 5. 4. Genetic distances calculated by NEI method showed 0.0089 in Jindo dogs and was 0.0094 in the Japanese mongrel dogs.

Anaerobic bacteria are suggested to be potential source for new antibiotics. In order to search for antibiotics from domestic origin, we collected 800 soil samples across Korean locations and could isolate as many as 989 anaerobic strains. Among them 10, strains were found to have good producing capacity of antibiotics. An anaerobe was finally selected due to secreting antibiotics having high antimicrobial activity towards multiple resistant microorganism(E coli JM 83) transformed by genetic engineering technique. Its morphological, physiological and biochemical charateristics were investigated, together with antimicrobial spectrum therefrom. On antimicrobial spectrum study, substance secreted from this strain, had no activities to fungus and yeast. The selected strain showed G(+) and coccal shape, on Gram, staining and electron scanning microscopy, respectively. Biochemically this strain utilized glucose, fructose lactose, sucrose, but did not arabinose, cellulose, rhamnose, sorbitol, trehalose, mannitol. Catalase test showed negative property. Optimal growth temperature was $37^{\circ}C$. The results obtained above suggest this strain Streptococcus faecium subspp. and we named it Streptococcus sp. An-21-1.

In order to search for new antibiotics from anaerobic bacteria, a large number of samples from domestic soil were collected and processed by apropriate methods. A potential strain, Streptococcus sp. An-21-1, was found to produce antimicrobial compounds. The Results were as follows; 1. During fermentation, the bacteria grew rapidly up to 20hr, thereafter entered the death phase. The optimal temperature and pH for the bacterial growth were $37^{\circ}C$ and pH 7.0, respectively. 2. Antibiotics were purified from culture broth by solvent extraction, silica gel column chromatography and Sepadex L.H 20 column. 3. Physicochemical properties of Ap-1 and Ap-2 were similar ; Their melting points were between $234-237^{\circ}C$. Color reactions of ninhydrin, 2,7-dichlorofluorescein, 4-dimethylaminobenzaldehyde, Dragendroffs reagent and 20% $H_2SO_4$, were positive. Therefore, we assumed that these antibiotics have amine group, immine group, alkaloid, and lipid components. These were stable to heat. UV spectrophotometry showed two peaks at 210 nm and 260 nm. From above results, we assumed these antibiotics are belong to the peptide antibiotic family.

The central nervous system depressant effect of xylazine and xylazine-ketamine was studied in chicken and mice. Intraperitoneal injection of xylazine(1~30 mg/kg) and xylazine(1~30 mg/kg)-ketamine(100 mg/kg) induced a loss of the righting reflex in chicken and mice, respectively. These effects of xylazine were dose-dependent. The results obtained were as follows; 1. The effect of xylazine-induced depression was antagonized by adrenergic antagonists having ${\alpha}_2$-blocking activity(yohimbine, tolazoline, piperoxan and phentolamine). 2. Yohimbine was most effective in the reduction of the CNS depression by xylazine. 3. Phenoxybenzamine and prazosin did not reduced CNS depression by xylazine in both species. 4. Labetalol (${\alpha}_1$, ${\beta}_1$-adrenergic antagonist) and propranolol(${\beta}$-adrenergic blocking agent) were not effective in reducing xylazine induced depression. 5. Cholinergic blocking agents (atropine and mecamylamine), a dopaminergic antagonist (Haloperidol), a histamine $H_1$-antagonist(chlorpheniramine), a histamine $H_2$-antagonist(cimetidine), a serotonergic-histamine $H_1$ antagonist(cyproheptadine) were not effective in reducing xylazine-induced depression. 6. Xylazine-induced depression is mediated by ${\alpha}_2$-adrenergic receptors and appears not to be involved in cholinergic, dopaminergic, serotonergic or histaminergic pathways.

Gel electrophoresis has proven to be one of the most useful of DNA separation and purification. The new technique of pulsed field gel electrophoresis (PFGE) is high resolution separation of large size DNA moleculs. Conventional continuous gel electrophresis can not be separation of large DNA fragments(20~50 k base). Field inversion gel electrophoresis(FIGE) is very useful for large DNA molecules. We have found that a pulse ratio ; 2 : 1, time ; 24hrs., volts ; $10^{volts}/_{cm}$, start ; 0.45sec, end ; 1sec, is most effectively resolves DNA fragment in the 6~50k base.

The morphological hetergeneity of lipopolysaccharides(LPSs) and variation in the O-side chain lengths of LPSs of Salmonella pullorum, which was serially subcultured on the brain heart infusion agar containing $100{\mu}g/m{\ell}$ of acridine orange, was analyzed in Sephadex G-50 column chromatography and silver-stained polyacrylamide gels. The biochemical differences in LPS W and LPS A0150 were identified. Increases in the contents of O-polysaccharides of LPS A0150 than those of LPS W were reflected in the profiles of chromatography and silver-stained polyacrylamide gels. In summary, LPS molecules of S pullorum A0150 appeared to be enriched in the molecules with long O-polysaccharide chains than those of LPS W.

This study was conducted to investigate the cause of a new duck disease occured in southern part of Korea. A meat type duck farm located in Kangjin, Chonnam Province had experienced outbreaks of septicemic disease at around 20 days of age in nearly every batch of ducklings from early spring to early summer in 1989. Main symptoms of the birds were eye and nasal discharge, depression, inappetence, diarrhea and nervous signs such as tremor and ataxia. Some birds died suddenly without any signs. Mortality reached from 20% to 80% in severe cases. The autopsy findings of the affected ducklings revealed consistantly severe airsacculitis, fibropericarditis, perihepatitis and occasionaly enteritis and distended ureter with urate deposit. A rod shaped gram-negative bacterium was isolated purely from brain and liver of the diseased ducks by culturing the specimens on blood agar for 48 hours in candle jar. The isolate neither produced hemolysis nor grew on MacConKey Agar. It formed colony relatively slowly being recognizable at least 36 hours after culturing, reaching colony size of about 1mm in diameter at 48 hours culture. The colony looked iridescent under oblique light and had muddy odor. The isolate did not ferment carbohydrates tested but produced gelatinase, hippuricase and oxidase which were considered as characteristics of P anatipestifer. The isolate induced similar signs and lesions when infected experimentally into ducks of 3 to 38 days age via intraperitoneum or intratrachea. However it did not produce any clinical signs wen inoculated via intranasal route. It produced only mild signs in chicken just injected with a very large dose. The bacteria did not produce any signas or lesions in mice. It was concluded through biochemical and physiological tests and animal inoculation tests that the new disease was caused by P anatipestifer.

To examine the effects of vaccination against Babesia gibsoni(B gibsoni) infection in dogs, 15 normal mixed-breed dogs(5 months to 1 year old) were divided into 3 groups with 5 dogs in each group. One of them was selected as control group(group A) and other were selected as experimental groups(group B and C). The group B was vaccinated with antigen which were mixed 0.2% of formalin treated B gibsoni and sonicated one. The group C was inoculated Theileria sergenti as a non-specific antigen. The results obtained in this experiment were summarized as follows; 1. After first vaccination, antibody titers of group B and C were increased 5 times(1:200) than those of control group(1 : 40). The antibody titers of group C were increased more than that of group B after second vaccination. When challenged with the living protozoa(Babesia gibsoni), the antibody titers of C group were elevated higher than that of B group and maintained steadly. Those were not exceeded over 1 : 5,000 for 4 weeks in all 3 groups. 2. After challenge, the peak time of the parasitemia appeared nearly on the 15th day(12~18 days) in all groups. During this period, the rate of parasitized erythrocytes in control group was $55.0{\pm}5.4$‰. But that of group B and C were $41.3{\pm}38.8$‰ and $15.2{\pm}16.3$‰, respectively. 3. After challenge with B gibsoni, all of the values of PCV, Hb, RBC and total leukocytes counts were decreased in both of the experimental and the control. 4. In all groups, there were increased lymphocytes and monocytes after challenge with the protozoa.

This paper dealt with the situation and the hatch rate of bot's eggs on the equine hairs in Cheju horse with the species grouping of the bot flies of equine(genus Gasterophilus). The prevalence and infection dynamics of Gasterophilus spp. larvae was also evaluated in the equine alimentary canal submitted in this laboratory for the necropsy or from the abattoir. Samples including Gasterophilus spp. larvae, bot's flies and its eggs, which were collected from the alimentary canal and equine hairs, respectively, were studied and classified by morphology. The morphologic feature of the spines of Gasterophilus larvae were studied by scanning electron microscope. 1. Gasterophilus intestinalis larvae concentrated in the nonglandular portions of the stomach. The infection of second-, and third stage larvae were common in November, and from January to October, respectively. Gasterophilus nasalis larvae were commonly identified on the gastric pylorus and upper portion of duodenum. Second stage larvae were found from October to December, and 3rd stage larvae, from January to September. 2. The hatch rate of laid eggs of Gasterophilus intestinalis was 28.4%, and that of Gasterophilus nasalis was 79.5%. The hatch rate of Gasterophilus intestinalis eggs was highest(62.5%) in December. The hatch rate of laid eggs were higher in the region of scapula(64.0%) and limbs(62.5%) than on the maned hairs. The eggs of Gasterophilus nasalis were completely hatched by October. 3. Eight hundred five Cheju horses examined in this study were infected with the eggs of Gasterophilus spp. Gasterophilus intestinalis eggs on the body regions from sixty horses were recognized in phalangeal (14.4%), in abdominal(13.8%), metacarpal, brachial and cervical regions. Gasterophilus nasalis eggs were uncommon and recognized in submandibular regions(1.4%). 4. In conclusion, the infection of imago, larvae and eggs of both Gasterophilus intestinalis and Gasterophilus nasalis were indentified in cheju horse.

The present study was intended to use the avidin-biotin-peroxidase-antiperoxidase complex (ABPAP) method for the identification of Mycobacterium bovis in the tissue sections of infected cattle. Antibodies and linksera for ABPAP procedure used in incubated order were rabbit anti-Mycobacterium polyvalent antibodies, goat anti-rabbit IgG, rabbit peroxidase-antiperoxidase complex, biotinyl-horse anti-rabbit IgG, and avidin-biotin-peroxidase complex. Where the bacterial antigen was localized by ABPAP, a dark brown deposit occurred in the cytoplasms of macrophages and Langerhans' giant cells of the granulomatous lesions. The method approved to be highly specific for the identification of the bacteria and allowed a precise localization of the bacterial antigen in infected cells.

An acute fatal infectious disease in rabbits has been outbroken in Korea since 1985. This disease has been characterized as an acute hepatitis caused by viruses. However, viral pathogenesis in rabbit viral hepatitis leading to sudden death remain unclear. This report dealt with the electron microscopic findings on the spleen of experimentally infected rabbits, because spleen is one of the affected organs which have high titer of virus by a haemagglutination test. A typical crystalline array of virus was not found in the splenic cells of infected rabbits with acute hepatitis. Virus-like particles were seen within the phagosome of macrophages of the spleen. Ultrastructural changes in the spleen were severe with the lapse of time after inoculation. From these results, virus-like particles in the spleen were supposed to be phagocytosed by macrophage during viremia, while active replication of virus occurred in the liver. It was concluded that sudden death in this viral disease was caused by hepatic coma and/or circulatory disturbance.

Enzyme-linked Immuno sorbent Assay (ELISA) for the serological diagnosis of Brucella abortus was developed and compared with plate agglutination test. Cell wall antigen was extracted from Brucella abortus 1119-3 by sonication and with a sodium deoxychlate solution. Optimum protein concentration of coating antigen were $0.4{\mu}g/100{\mu}{\ell}$ protein on each microtiter plate well. Horse radish peroxidase (HRP) labeled protein-G was used as a tracer of reacted antibodies. ELISA confirmed the agreeable results of 40 cases out of 43 cases by plate aggulutination test. ELISA diagnosed positive cases(10 out of 12) and negative cases (1 out of 12) with dubious sera by plate agglutination test. From this results ELISA could be used for the early diagnostic tools of Brucellosis in cattle.

This study was carried out to completelycure the experimental bovine theileriasis with small unilamella vesicle liposome incorporated buparvaquone which was effective both to schizonts in lymphocyte of lymph nodes and piroplasmic stage in erythrocytes. Small unilamella vesicle liposome incorporated buparvaquone was prepared by French pressure cell method using egg phosphatidylcholine. The diameter of the vesicles was ranged from 5 to 220 nm, but the most vesicles were ranged from 10 to 50 nm in diameter. The incorporation rate for buparvaquone was 100%. Parasitaemia of the 10 calves inoculated with $5{\times}10^8$ erythrocytes infected with Theileria sergenti were first detected from on day 16 to day 23 after inoculation. In calves treated with a dose rate 2.5 mg/kg BW of free buparvaquone, a gradual decrease in piroplasmic parasitaemia was observed following treatment to day 5. However parasitaemia levels returned to near pretreatment values after approximately 60 days. In calves treated with a dose rate 5.0mg/kg BW of free buparvaquone, parasitaemia were disappeared on day 3 after treatment, but there was a mild recrudescence of infection on day 28 after treatment. In calves treated intraavenously with a dose rate 2.5 mg/kg BW of buparvaquone incorporated in liposome, the calves were all cured on day 2 or day 3 after treatment. In calves treated subcutaneously and intraperiotoneally with a dose rate 2.5 mg/kg BW of buparvaquone incorporated in liposome, parasitaemia were disappeared on day 3 or day 4 after treatment, but there was a mild recrudescence of infection on day 40 or day 45 after treatment.

실험대상(實驗對象)으로서 유우(乳牛) 5두(頭)에게 50% 포도당(葡萄糖) $500m{\ell}$를 생리적식염수(生理的食鹽水)에 혼합(混合) 13~15회(回) 반복(反復) 경정맥(jugular vein)을 통해 주입후(注入後) 혈중(血中) insulin수준(水準)과 Langerhans islets의 조직화학(組織化學)을 관찰(觀察)한바, 혈중(血中) insulin의 수준(水準)은 포도당(葡萄糖)의 투여전(投與前)에 비(比)하여 4~11배(倍)나 증가(增加)됨이 관찰(觀察)되었다. 한편, Langerhans islet의 B cell도 포도당(葡萄糖)의 투여회수(投與回數)에 따라 특이(特異)하게 주름이 관찰(觀察)되었는데 이는 B cell에서의 insulin 합성능(合成能)을 높이는데 그 원인(原因)이 있었다고 본다.

The present study was carried out to investigate the best condition for nuclear-cytoplasm fusion and in vitro culture of nuclear transplanted embryos and to investigate the production of nuclear transplanted offsprings. The nuclei from 2-, 4- and 8-cell mouse embryos were transferred into enucleated 2-cell embryos, and the reconstituted embryos were submitted to direct current(DC) pulses at output voltage of 1.0, 1.5 and 2.0 kV/cm for 100, 150 and $200{\mu}$ sec to induce cell fusion. 1. The culture of intact or zona cut 2-cell embryos in the medium supplemented with cytochalasin B($5{\mu}g/m{\ell}$) and colcemide($0.1{\mu}g/m{\ell}$)for 30 and 60 minutes did not affect the development to later stage. 2. The in vitro developmental rates of group A(a nucleus from one of the blastomeres was removed) and B(electrofusion of group A) were significantly lower than that of control group(p<0.01). 3. When nuclear transplanted embryos were submitted to electrofusion, the significantly higher fusion rates of 2-cell donor nuclei were achieved at the electric field strength of DC 1.5kV/cm for 100 and $150{\mu}$ sec, DC 2.0 kV/cm for $100{\sim}200{\mu}$ sec than DC 1.0 kV/cm for 100 and $150{\mu}$ sec(p<0.01). The significantly higher fusion rates of 4-cell donor nuclei were achieved at DC 2.0 kV/cm for 100 and $150{\mu}$ sec than DC 1.0kV/cm for $100{\sim}200{\mu}$ sec(p<0.01). These fusion rates in 8-cell donor nuclei were 88.7~99.3%. 4. The developmental potency to blastocyst in 2- and 4-cell donor nuclei was significantly higher in DC 1.0 and 2.0 kV/cm for $100{\sim}200{\mu}$ sec treated group and DC 2.0 kV/cm for 150 and $200{\mu}$ sec treated group (p<0.01). The developmental potency to blastocyst in 8-cell donor nuclei was significantly higher in DC 2.0 kV/cm for $100{\mu}$ sec treated group than in DC 1.0 kV/cm for $100{\mu}$ sec treated group and DC 2.0 kV/cm for 150 and $200{\mu}$ sec treated group(p<001). 5. The developmental potency to blastocyst after nuclear transplantation was significantly higher in 2-cell donor nuclei than in 8-cell donor nuclei(p<0.01). 6. The success rate of nuclear injection into enucleated 2-cell embryos was significantly higher in 2-cell donor nuclei than in 4- or 8-cell donor nuclei(p<0.01). 7. The culture time taken for the nuclear transplanted 2-cell embryos to blastocyst stage was significantly longer in 2-cell donor nuclei than in 8-cell donor nuclei(p<0.01). 8. There was no significant difference in the developmental potency of nuclear transplanted embryos within the concentration of EGF at 0 to 15 ng per $m{\ell}$ of BMOC-3 solution. 9. The production rates of offspring after transfer of nuclear transplanted embryos to recipient mouse were significantly higher in 2-cell donor nuclei than in 8-cell donor nuclei(p<0.01).

The present study was carried out to investigate the developmental potency to blastocyst after freezing and thawing of nuclear transplanted 2-cell embryos. The nuclei from 2-, 4- and 8-cell mouse embryos were transferred into enucleated 2-cell embryos, and the reconstituted embryos were submitted to direct current(DC) pulse at output voltage of 2.0 kV/cm for $100{\mu}$ sec to induce cell fusion. The recovery rate and developmental potency to blastocyst after freezing and thawing of nuclear transplanted 2-cell embryos was investigated. 1. The recovery rate of nuclear transplanted 2-cell embryos in normal morphology after freezing and thawing was significantly higher in rapid freezing(DMSO 4.5M) than in slow cooling(p<0.01). 2. When the recovered embryos in normal morphology were cultured in vitro, there were no significant differences in the developmental potency to blastocyst between the freezing methods and the concentrations of cryoprotectant. In summary, these experiments have proved that rapid freezing method(DMSO 4.5M) is effective in nuclear transplanted 2-cell mouse embryos. If improved micromanipulation techniques and freezing are combined, nuclear transplantation technique will contribute to the improvement of productivity in livestock animals.

The developmental capacity of bovine oocytes under three different culture systems was investigated in this experiment ; One was culture in TCM199 with bovine oviductal epithelial cells(BOEC) for in vitro culture, another was culture in TCM199 with BOEC for 2 days and then transfer of 4~8cell embryos to rabbit oviduct(RO) and the other was transfer of 1 or 2cell embryos to RO for in vivo culture. And the other concern of this experiment was to investigate the effect of culture period and transfer site on recovery. Immature bovine oocytes were cultured in TCM199 with granulosa cells for 22-24hrs and then fertilized in vitro using frozen-thawed semen treated with BO-caffine and BO-BSA. Fifteen to 18hrs after in vitro fertilization oocytes were cultured in TCM199 with BOEC or transferred to RO for 5 days. The rate of development to the morula or blastocyst was higher in transfer of 1 or 2cell embryos to RO(23.1%) than culture in TCM199 with BOEC(11.7%). But, there was no difference between transfer of 1 or 2cell embryos and transfer of 4~8cell embryos to RO(12.8%). Recovery under different culture periods in RO was significantly higher in 90~95hrs(70.1%) than 122~125hrs(50.9%, p<0.05) and recovery significantly increased when oocytes were transferred deeper in RO(2.5cm>, 47.7% ; 2.5~4.5cm, 63.9% ; 4.5cm<, 77.3%, p<0.05). The results show that transfer of 1 or 2cell embryos to RO is an effective means of supporting the further development of in vitro matured and fertilized bovine oocytes than culture in TCM199 with BOEC or transfer of 4~8cell embryos to RO, and recovery from RO increases when oocytes are transferred deeper and incubated shorter in RO.