• 한국수정란이식학회지
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• 제33권3호
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• pp.169-175
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• 2018

It has been claimed that artificial insemination (AI) of cows with frozen-thawed semen treated with commercially produced kits, Wholemom (in favour of female gender) increases the birth chance of calves with desired sex ratio by approximately 85% without decrease of pregnancy rates. Hence, this study was conducted to investigate the efficacy of wholemom kits as combined with frozen-thawed bovine semen during in vitro fertilization on the in vitro fertilization and developmental efficiency and sex ratios such as some reproductive parameters in bovine. For this, 1,737 oocytes were in vitro fertilized and developed. Agglutination effects on bovine after treatment of Wholemom kit were observed by time passage and dose respectively. To determine sex of embryos, Bovine embryo Y-specific gene primers(ConEY) and Bovine specific universal primer(ConBV) were used as multiple PCR method. Fertilization rate of wholemom-treated group was significantly lower than its of control group[66.9% (1,156/1,737) in Wholemom-treated group; 75.0% (610/813) in control group]. However, developmental rate after fertilization of both wholemom-treated and control groups were not significantly different [26.1% (404/1,156) in Wholemom-treated group; 27.4% (224/610) in control group]. Sex ratio of in vitro fertilized embryo with frozen-thawed semen treated with wholemom kit was determined by multi PCR. Female ratio in wholemom-treated group [85.4% (173/201)] was significantly higher than its of control group [47.2% (66/141)]. In conclusion, wholemom treatments of semen used in the in vitro fertilization and development of bovine oocytes provided increase in female ratio with decrease of fertilization rate.

• 한국작물학회지
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• 제51권6호
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• pp.505-512
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• 2006

In Korea, silicate fertilization (SF) is being practiced every four years to enhance rice production. However, the relationship between nitrogen (N) and SF in view of growth characteristics and grain yield of rice has not been examined after watermelon cropping in plastic film house. This study was carried out to identify useful critical N and Si fertilizer levels to sustain grain yield and to improve N use efficiency for rice. The watermelon-rice cropping system has maintained for three seasons in each year from 1998 to 2001 by farmer before this experiment. Experiments on N and Si fertilization levels were evaluated with Hwayoungbyeo (Oryza sativa L.) in 2002 and 2003 at Uiryeong, Korea. The goal of this experiment was to find out the optimum N and Si levels to sustain rice yield by reducing excessive N fertilizer in watermelon-rice cropping system. Nitrogen fertilization (NF) levels were three ($0,\;57,\;114kg\;ha^{-1};0,\;50,\;100%$ of conventional NF amount) and five (0, 25, 50, 75, 100%) in 2002 and 2003, respectively, and combined with three SF levels ($70,\;130,\;180mg\;kg^{-1};100,\;150,\;200%$ which were adjusted with Si fertilizer in soil) were evaluated for the improvement of N and Si fertilization level in both years. Rice yielded 3.98-5.95 and 2.84-4.02 t/ha in 2002 and 2003, respectively. Our results showed the combinations of 50% and 100% of N with 200% level of Si produced the highest grain yield in both years, respectably. The grain yield was greatly improved in plot of N25% level when compared to conventional NF (Nl00%) in 2003. In conclusion, NF amount could be reduced about 50% compared to recommended level by specific fertilization of N and Si combination levels for rice growing and grain yield after cultivation watermelon in paddy field.

• 한국수정란이식학회지
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• 제14권3호
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• pp.185-193
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• 1999

To improve the efficiency of in vitro production of embryos with follicular oocytes in pig, the recovery rates, in vitro fertilization and development. The results obtained were as fellows: The number of oocytes recovered 37 ovary was 1,365 by aspiration, 1,884 by slicing and 3,830 aspiration post slicing, per ovary was averaged 103.5 aspiration post slicing than 30.7 by aspiration and 50.8 by slicing (P<0.05). The percentage of grade I and II oocytes recovered was 0.05∼0.2% and 1.7∼2.3% respectively(p<0.05). The fertilization rates of ejaculate and epididymis sperm was 83.0 and 83.1%. And cleavaged rate was 60.8 and 69.0% respectively(P<0.05). However, there were no significant differences between sperm sources. The clevage rates of fertilized oocyte was significantly(P<0.05) higher as B.O(92.8%) than TALP (90.1%) or mTBM (80.1%). And in vitro developed to blastocyst rates of mTBM media used for fertilization was significantly (P<0.05) higher as 12.4%, compared with the results using the media of TALP(1.6%) or B.O (0.0%). The embryos developed 2-cell stage after in vitro fertilization were co-cultured with or without POEC and BOEC in NCSU-23 and TCM-199 media. In vitro developed to blastocyst rates was NCSU-23 with POEC(2.3%) or BOEC(1.2%), but in vitro cultured in TCM-199 medium with POEC or BOEC was not developed to blastocyst. The percentage of embryos that developed to morula stage in 0, 50, 100, 200 and 250uM was 16.6, 22.0, 13.5, 19.0 and 22.0%, respectively.

• 한국동물생명공학회지
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• 제38권2호
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• pp.70-76
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• 2023

Background: Despite considerable technological advancements, polyspermy remains a significant challenge in in vitro fertilization (IVF) procedures in pigs, disrupting normal embryonic development. Here, we aimed to determine whether optimal fertilization conditions reduce the polyspermy incidence in pigs. Methods: In vitro-matured oocytes were co-incubated with sperm according to a modified two-step culture system. Results: In the first experiment, oocytes were briefly co-incubated with sperm, washed in IVF medium, and then moved to fresh IVF medium for 5 or 6 h. Although the 6 h sperm-free cultured group had a higher penetration rate than the 5 h cultured group, the polyspermy rate significantly increased in the 6 h sperm-free cultured group. The gamete co-incubation period was either 20 or 40 min. The 40 min cultured group had a higher rate of blastocyst formation and number of total cells in blastocysts than the 20 min cultured group. In experiment 2, oocytes were inseminated with sperm separated by Pecroll treatment. Percoll treatment increased the rate of oocyte penetration and blastocyst formation compared to the control. In experiment 3, fertilized oocytes were cultured in 25 µL microdroplets (10 gametes/drop) or 500 µL (100 gametes/well) of culture medium in 4-well plates. The large volume of medium significantly reduced the number of dead oocytes and increased the rate of blastocyst formation compared to the small volume. Conclusions: Collectively, these results demonstrate that various fertilization conditions, including modified co-culture period, active sperm separation, and culture medium volume, enhance fertilization efficiency and subsequent embryonic development by decreasing polyspermy occurrence.

• 한국초지조사료학회지
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• 제11권3호
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• pp.189-194
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• 1991

This experiment was carried out to investigate the effect of pure mineral nitrogen fertilization on dry matter yield and to determine the amounts of advisable mineral nitrogen according to difference of annual precipitations in permanent grassland. The results obtained were as follows: 1. Only PK-fertilizing without additional mineral nitrogen application produced 6. 9 tonlha of annual dry matter yields on average in relatively wet years that was higher than in rel. dry and normal years under 3-cut system by 0. 7 and 0.6 ton DMIha, respectively. 2. Due to the lesser rainfall the nitrogen-efficiency was substantially higher with heavy dressing of nitrogen fertilizer. The absolute differences in yield between rel. dry and wet years were 0.4 and 0.7 ton DMIhalyear respectively when dressed with 90 and 120 kgN/ha/cut at 4-, 5- and 6-cut systems, whereas at 3-cut system differences around 1.3 and 1.1 ton Dhllhalyear respectively were recorded. 3. In rel. dry years the most efficient N-dressing rates per ha and year tended to be slightly higher than in rel. wet and normal years. Particularly at 5-cut system 4-7 kg/ha/cut of more nitrogen fertilization was required in order to obtain the highest overyields. 4. The N-dressing rates needed to maintain a nitrogen-efficiency of 8 to 16 kg DM/kg N tended to be stronger particularly at high cut system, and also in rel. dry years higher dressing rates were required that in rel. wet and normal years.

• 한국작물학회지
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• 제37권2호
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• pp.209-215
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• 1992

도전의 분양법은 세역위양이었던 중국의 고대농법에서와 달리, 이미 우리나라는 여말에 상경화하였으며, 두과작물의 녹비이용법과 함께 분전법의 실현에 앞서 분종법이나 분과법이 순차적으로 진전되고 있었다. 이러한 상태에서 15세기에 이르러 $\ulcorner$직설$\lrcorner$의 도전분전법은 재료를 객토류, 초본류, 분류로 확대분화시켰고 초경과 재경 사이에 시비토록 하되 토양조건이 특수한 도전에는 각각 적의한 시비법을 별도를 기술하였다. 또한 묘종법의 도전에서는 분묘처(못자리)와 묘종처(본답)의 시비술로 나누어 전문화시켰고, 개간지에서는 기경작업과 병행시키는 유기물 환원방식이 체계화 되어 있었다. 17세기에 이르러서는 $\ulcorner$직설보$\lrcorner$를 통하여 경상도의 속방을 체계화시켜 조도앙기처의 분양술을 완성시켰다. 여기에서 특기할 것은 분회, 요회 및 퇴비제조술과 사용법이었다. 18-19세기에는 황지회복과 수전이모작 확대를 지원하기 위한 지방보강법으로 시비재료를 최대한 확대하고 저분법과 추비법을 강조하였으며, 시비이론과 함께 작업능률을 높이기 위한 수레 이용이 강조되기도 하였다. 이상으로 보아 도전분양에 있어서는 분원재료상의 제약을 타파하고 추비체계를 확립시켰으며, 저분법과 함께 다비의 필요성에 대한 이론과 인식을 새롭게 하는 방향으로 발전되어 왔다.

• 생물환경조절학회지
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• 제20권2호
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• pp.123-133
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• 2011

본 연구에서는 E. pellita와 A. mangium 용기묘를 대상으로 시비 처리에 따른 광합성, 엽록소 형광반응, 엽록소 함량 등의 생리적 특성 및 생장 특성 변화를 조사 분석하여 열대림 두 수종에 대한 시설양묘과정에서의 최적 시비 조건을 구명하고자 연구를 실시하였으며, 다음과 같은 결론을 얻을 수 있었다. 시비처리에 따른 E. pellita의 광합성 능력, 광화학 효율 및 엽록소 함량은 $1g{\cdot}l^{-1}$ 처리구에서 가장 우수하였으며, $2g{\cdot}l^{-1}$에서는 과량 시비로 인한 생육저하 현상으로 오히려 감소하는 경향을 나타냈다. A. mangium은 $2g{\cdot}l^{-1}$ 처리구에서 가장 우수한 광합성 능력, 광화학 효율 및 엽록소 함량을 보이면서 시비수준이 높을수록 우수한 능력을 나타냈다. 두 수종 모두 적정 시비 조건에서 높은 엽록소 함량과 광화학 효율에 의해 활발한 광합성 활동이 이루어졌다. 즉, 양분 조건에 따라 광합성 기구가 유동적으로 변하는 것을 알 수 있다. 근원경과 간장 생장 및 물질생산량 또한 E. pellita는 $1g{\cdot}l^{-1}$, A. mangium은 $2g{\cdot}l^{-1}$ 처리구에서 가장 우수하였으며, 생리적 특성과 같은 경향을 보였다. H/D율과 T/R율은 시비 처리구가 무시비 처리구보다 높은 값을 보였지만, 시비 처리 간 유의적 차이는 나타나지 않았다. 묘목품질지수는 두 수종 모두 위 결과와 같이 수종별로 적정 시비 처리구에서 가장 높았으며, 적정 시비 처리에 의해 생산 된 묘목 우수한 형질을 나타낸 것이다. 본 연구 결과를 종합해 보면, 열대 수종인 E. pellita와 A. mangium의 용기묘 양묘 시 시비 처리에 따른 양분 조건에 의한 생리 및 생장 특성의 변화를 볼 수 있었다. 양분 부족은 광합성 기구의 활동 감소에 의한 생장 저하가 초래되어 불량한 묘목이 생산되는 과정을 볼 수 있다. 즉, 양묘과정에서 수종별 양분 요구도에 맞는 생육환경조절은 시설양묘시업에 의한 건전한 묘목을 대량 생산함과 동시에 조림과정에서도 높은 활착과 생장으로 우수한 조림성과를 기대할 수 있을 것으로 판단된다. 또한 일률적인 시비를 실시하는 것이 아니라, 기간별 상대생장량을 조사하여 수종별 생장패턴에 따라 기간별로 양분 요구량에 맞는 집중, 효율적인 시비를 실시할 수 있을 것으로 기대된다. 이에 띠라 양묘과정에서의 환경적 측면과 함께, 비용 측면에서 이점이 있어 경제적으로도 묘목 생산비를 절감할 수 있을 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제9권6호
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• pp.737-741
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• 1996

Dry matter yield of reed canarygrass was investigated in uncultivated rice paddy in Korea, and an attempt was made to estimate the most economic and efficient cutting frequency and rates of nitrogen (N) fertilization, for increased production of reed canarygrass. Total dry matter yields of reed canarygrass per year were 7.4-15.7, 8.5-16.1, and 7.5-13.4 tons/ha in 3, 4, and 5 cutting frequencies, respectively, and over the N treatments of 0-120 kg N/ha/cut. When cut 3 or 5 times annually, the 2nd cut produced the highest proportion of total yield at 38.4 and 33.0%, respectively, when cut 4 times the 3rd cut was highest (38.3%). The ranges of economic N level, limiting N level and efficiency of dry matter production were 243.3-293.0, 387.2, and 14.6 kg DM/kg N, respectively. These indicators were particularly low for the 5 cutting frequency possibly because of the unusually high temperature in the summer season. The best cutting frequency for the dry matter production of reed canarygrass in 1994 was 3 per year because of the higher efficiency of dry matter production.

• Reproductive and Developmental Biology
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• 제39권2호
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• pp.29-36
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• 2015

Pigs are considered an ideal source of human disease model due to their physiological similarities to humans. However, the low efficiency of in vitro embryo production (IVP) is still a major barrier in the production of pig offspring with gene manipulation. Despite ongoing advances in the associated technologies, the developmental capacity of IVP pig embryos is still lower than that of their in vivo counterparts, as well as IVP embryos of other species (e.g., cattle and mice). The efficiency of IVP can be influenced by many factors that affect various critical steps in the process. The previous relevant reviews have focused on the in vitro maturation system, in vitro culture conditions, in vitro fertilization medium, issues with polyspermy, the utilized technologies, etc. In this review, we concentrate on factors that have not been fully detailed in prior reviews, such as the oocyte morphology, oocyte recovery methods, denuding procedures, first polar body morphology and embryo quality.

• Reproductive and Developmental Biology
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• 제28권4호
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• pp.257-260
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• 2004

Efficiency of somatic cell nuclear transfer was investigated in mice. First, oocyte activation was induced by SrCl₂, and the rate of development was compared with embryos from normal fertilization. Although more than one half of SrCl₂-treated oocytes developed to blastocysts (146/262, 55.7%), the rate of blastocyst formation was significantly lower than normal fertilization controls (59/79, 74.6%). Second, enucleation of oocytes was performed using Polscope that enables non-invasive visualization of metaphase spindles. Such approach could not only avoid damage of oocytes during an exposure to UV light often employed in conventional enucleation procedures, but could also assure the removal of nuclei from all oocytes operated because of monitoring the location of spindles during an entire process of enucleation. Morphologically normal blastocysts were obtained from the transfer of cumulus cell nuclei into enucleated oocytes. However, the rate of development into the blastocyst stage was still low (4/93, 4.3%). This reflects that the nuclear transfer procedure used in this study was not sufficiently optimized, and other factors may also impact greatly the efficiency of nuclear transfer. Including an induction of oocyte activation and method of enucleation tested in this study, a lot more elements are remained to be optimized to improve the efficiency of somatic cell nuclear transfer in mice.