The nudear changes of bovine oocytes during 24 hrs. of culture for mejotic maturation were examined. Bovine oocytes were collected from small(<2 mm), medium(2~6 mm) and large(>6mm) follicles and classified into three grades by their morphological characteristics. A total of 242 oocytes collected were obtained:from 184 small, 157 medium and 1 large follicles, respectively and were classified into 95 grade I, 155 grade H and 92 grade III oocytes. All the bovine oocytes collected and graded were washed with a basal medium and incubated in groups of 10 for 24 hrs in 5% and 39. The basal medium used was composed of TCM-199 supplemented with sodium bicarbonate, sodium pyruvate, streptomycin, penicillin G and 10% FCS. The oocytes were cultured in drops of 50,l basal medium supplemented with 35g /ml FSH, 10g /ml LH and 1g /ml estradiol-17. The oocytes were fixed and examined on their chromosomal status by 1% acetorcein staining in the interval of 3 hrs. Most of the grade I oocytes developed to germinal vesicule stage at 0 to 3 hrs., germinal vesicle breakdown at 6 hrs., metaphase I at 9 to 15 hrs., anaphase I and telophase I at 18 hrs., and metaphase II and the first polar body at 24 hrs. after culture for meiotic maturation. However, it was found that compared to grade I oocytes, grade H and W oocytes reached earlier to germinal vesicle breakdown and most of them developed earlier to M II stage at 21 hrs. after culture.
본 실험은 성선(性腺)자극호르몬과 우태아혈청(牛胎兒血淸) 첨가가 돼지 난포란(卵胞卵)의 체외성숙(體外成熟) 및 체외수정(體外受精)에 미치는 영향을 조사하기 위하여 실시하였다. 미경산돈(未經産豚)(체중 80~90kg)의 난소(卵巢)를 도살된 직후에 절취하여 의 보온병에 담아 실험실로 운반하여 난포(卵胞)직경이 3~5mm되는 것만을 골라 난포(卵胞)를 찔러서 난포란(卵胞卵)을 채취하였다. 성숙모돈(成熟牡豚)(체중 130~150kg)의 정소상체미부정자(精巢上體尾部精子)를 농도로 희석하여 체외수정(體外受精)에 이용하였다. 본 실험의 경과를 요약하면 다음과 같다. 1. m-KRB와 10% FCS를 m-KRB에 첨가한 경우 성숙율(成熟率)은 82.37%이며, 10% FCS가 첨가된 배양액에 PMSG, hCG 그리고 PMSG와 hCG를 각각 첨가한 경우 66, 58, 68%로서 성숙율(成熟率)이 향상되었다. 2. 난구세포(卵丘細胞)의 팽화(膨化)는 m-KRB와 10% FCS가 첨가된 배양액에서 일어나지 않았으나 10% FCS가 첨가된 배양액에 PMSG, hCG 그리고 PMSG와 hCG를 각각 첨가시 92, 13, 91%로서 팽화율(膨化率)이 향상되었다. 3. m-KRB에서 성숙된 난포란(卵胞卵)의 체외수정(體外受精)에서 정자침입율과 웅성전핵(雄性前核) 형성율은 각각 93.7%였으나 FCS와 성선(性腺)자극호르몬을 첨가한 경우 각각 100, 80%로서 웅성전핵(雄性前核) 형성율이 향상되었다.
Total thirty of flushing were attempted on day 4 to 15 of estrus cycle with S heifers and 9 cows by nonsurgical method. The flushed or recovered rate among flushings was 86.7% (26/30) or 88.5% (23/26), respectively. There was no difference in the recovered rate between heifers (85.7%,6/7) and cows (89.5%, 17119). The embryo was recovered on day 4 to 15 of estrus cycle from the donors in natural heat without any technical difficulties.The I2FG Foley catheter used for pubertal heifers had sometimes plug in it with uterine mucus during flushing of uterine horn. But the problem could be overcomed by pumping the catherter with fluthing solution or by changing the catheter. Three normal embryos were recovered from 3 pubertal (10-11 month old) heifers. The rate of normal and abnormal eggs was 60.9% (14123) and 39.1% (9/23), respectively. The abnormal eggs were on degenerating except one unfertilized egg and were mostly recovered from heifers or cows flushed consecutively during the estrus cycle. The developmental states of normal embryos were l6-cells on day 5, 32-cells on day 6, compacted-morula on day 7, early-to expanded-blastocyst on day 8-to 9, and hatching-to hatched-blastocyst on day 10 to 11 of estrus cycle. The stage of embryos on day 8 to 10 showed varities among donors. On day 8 to 9 of estrus cycle hatching-blas tocyst was recovered from some donors.
This paper aims at finding out the optimum operating condition to reduce fuel consumption for the training ship Pusan 402 with controllable pitch propeller. For this purpose, this paper examints the variation of ship speed and fuel consumption in accordance with the change of engine revolution and propeller pitch. The results obtained are as follows: 1. When engine revolution is constant, the ship speed sluggishly increases according to the increase of propeller pitch but fuel consumption extremely increases. The higher revolution the engine is, the more remarkable this tendency is. 2. As the engine revolution becomes lower, the fuel consumption per mile decreases. Howt.er = the fuel consumption under the same engine revolution differs according to the propeller pitch. 3. Specific fuel consumption is uniformed about 180g/ps.h at any case of load. 4. Among the various operating conditions which yield the same ship speed, fuel consumption lowers in the case of lower engine revolution and larger propeller pitch.