• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.478-489
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• 2010

Penthiopyrad is a fungicide agent in types of pyrazole which is showing the effect of prevention in fungal disease and powdery mildew. In order to register this new pesticide, reports of acute toxicity and chronic toxicity by animal study were examined to set acceptable daily intake to evaluate hazards of consumers. Acute toxicity was low in toxic, and it did not have the effect of acute dermal toxicity, acute eye irritation, or skin sensitization. As the result of the study in chronic toxicity, the common effect of chemical appeared in the liver and thyroid which was proven as a toxic effect. Two-generation reproduction toxicity, genotoxicity, and prenatal development toxicity were not proven. As the result of carcinogenic study, increase of thyiroid follicular adenoma in the rat and the frequency of liver hepatocellar adenoma in mice were also increased. However, it was decided that the threshold value on the effect in chemicals could be controlled through study liver enzyme induction. Therefore, the ADI for penthiopyrad is 0.081 mg/kg/ bw/day, based on the NOAEL of 8.10 mg/kg bw/day of twelve-months dogs study and applying an uncertainty factor of 100.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.160-168
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• 2021

This study was undertaken to determine the effect of different cooling systems on the performance and hair cortisol of sows under heat stress. During a 21-day experiment, a total of 40 multiparous sows (Landrace×Yorkshire; 242.84±2.89 kg) were allotted to 4 treatments, each with 10 replicates (1 sow per pen). The experimental treatments were CP (Cooling pad), AC (Air conditioner), SC (Snout cooling), and MS (Mist spray). We observed an increase in the average daily feed intake during lactation (p<0.05) in the CP and AC treatment groups. AC treatment had the highest (p<0.05) and SC treatment had the lowest (p<0.05) piglet weight at weaning. During lactation, sows administered SC and MS treatments had higher (p<0.05) hair cortisol accumulation, as compared with the AC and CP treatments. Hair cortisol accumulation in piglets during lactation was highest with MS treatment (p<0.05), and lowest after CP treatment (p<0.05). MS treatment had the highest (p<0.05), and AC treatment had the lowest (p<0.05) respiratory rate and rectal temperature during lactation. In conclusion, our results indicate that a cooling pad and air conditioning cooling system increases the productivity of a sow, as compared to snout cooling and mist spray cooling systems.

• Reproductive and Developmental Biology
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• v.28 no.2
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• pp.83-87
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• 2004

The objective of this study was performed to establish the in vitro culture system of porcine in vitro maturation and in vitro fertilization(IVM/IVF) embryo. These studies was to determine the effects of melatonin, nitric oxide donor(SNP), and the combination effects of SNP and melatonin in porcine IVM/IVF embryos. In routine porcine IVM/IVF procedure, oocytes were cultured for 40∼44h incubation, and the zygotes were cultured for 40∼44h in NCSU 23 medium. Then 2 to 8 cell embryos were removed cumulus cell and were allotted randomly to NCSU 23 containing different concentration of melatonin, SNP and SNP plus melatonin in 5% $O_2$, 5% $CO_2$ and 90% $N_2$ at 38.5$^{\circ}C$. Cell numbers of blastocyst were also counted using double fluorescence stain method. In NCSU 23 medium treated with melatonin 0, 1, 5 and 10 nM, the developmental rate of morula plus blastocysts were 33.3%, 39.1%, 33.3% and 27.9%, respectivly. This result show that the developmental rate of morula and blascytocys treated with 1 nM melatonin was higher than in any other groups(P<0.05). The developmental rates of morula plus blastocysts were 41.9% in 0 uM SNP, 25.6% in 50 uM and 28.4% in 100 uM, respectively. The developmental rate of morula plus blastocysts were decreased treated with SNP in NCSU 23. In combined effects of SNP plus melatonin (0, SNP 50 uM, SNP 50 uM plus melatonin 1 nM, SNP 50 uM plus melatonin 5 nM and SNP 50 uM plus melatonin 10 nM), the developmental rates beyond morula stage of porcine embryos were 31.3%, 34.1%, 39.5%, 29.4% and 39.5%, respectively. The addition of SNP 50 uM plus maltonin 1 nM, developmental rates of blastocyst was higher rate than in any other groups. Cell numbers of blastocyst in NCSU 23 treated with melatonin 0, 1, 5 and 10 nM were 41.0, 42.6, 39.6 and 33.0, respectively. In combined effects of SNP plus melatonin (0, SNP 50 uM, SNP 50 uM plus melatonin 1 nM , SNP 50 uM plus melatonin 5 nM and SNP 50 uM plus melatonin 10 nM), cell numbers of developed blastocyst were 36.3, 34.6, 39.0, 39.9 and 39.0, respectively. These result show that the cell numbers of blastocyst treated with 0, 1 and 5 nM melatonin were higher than in 10 nM group(P<0.05), but cell numbers of blatocyst produced by SNP plus melatonin were not significantly difference in all experimental groups.

• Journal of Animal Science and Technology
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• v.52 no.2
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• pp.83-90
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• 2010

Hanwoo proven bulls have been selected since 1987 and consequently contributed to farmers for the improvement of beef cattle in Korea. The demand for the quality beef production as well as higher production efficiency was erupted after early 2000 as relatively cheap imported beef released. Therefore the pressure on the reformation of selection index for Hanwoo proven bulls have been piled up to furnish with Hanwoo's competitive. A total of 734 progeny test data were analyzed to select traits and their weights in the selection index to meet the beef market requirement. Regression analysis with stepwise selection method was used to select proper trait and its weight for selection index. A series of computer simulation was carried out to compare the currently using selection index with the alternate two selection indices proposed in this study. New selection index using standardized breeding values of Loin eye Muscle Area (LMA), Backfat Thickness (BFT) and Marbling Score (MS) with weight ratio 1:-1:6 was proposed. Results showed higher performance in improving MS and BFT gain by 22% and 31% still holding 86%~89% of genetic gain achieved by current index in Carcass Weight (CW) and LMA when new selection index was fitted. Because, new index has little consideration for production cost, further research should be performed to build selection index including cost and income simultaneously.

• Reproductive and Developmental Biology
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• v.37 no.3
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• pp.135-141
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• 2013

This study aimed to improve the reproductive efficiency of dairy herds by comparison and analyzing estrous appearance rate, conception and non-conception rate according to the stage of lactation using the lactation and reproductive records of average (less than 10,000 liters milk in 305 days) and high yielding (more than 10,000 liters milk in 305 days) Holstein cows (n=102). Milk production and reproduction data were collected between January 2010 and December 2012 from Holstein cows kept in the commercial dairy farms. Average (n=32) and high yielding (n=24) Holstein cows used to analyze the relationship between milk yield and reproductive performance. Our results showed that estrous appearance rate according to the stage of lactation was 25.0% (30~59d), 40.6% (60~89d), 25% (90~110d) and 9.4% (>111d) in average yielding cows and 16.7% (30~59d), 20.8% (60~89d), 12.5% (90~110d) and 50.0% (>111d) in high yielding cows, respectively. Conception rate according to the stage of lactation was 87.5% (30~59d), 61.5% (60~89d), 75.0% (90~110d) and 66.7% (>111d) in average yielding cows and 25.0% (30~59d), 0% (60~89d), 33.3% (90~110d) and 50.0% (>111d) in high yielding cows, respectively. Days between parturition and conception was 23.7% (<149d), 0% (150~209d) and 0% (>210 d) in average yielding cows and 69.0% (<149 d), 77.8% (150~209d) and 38.9% (>210d) in high yielding cows, respectively. Conception rate from 110 days postpartum in high yielding cows was 41.7% (110~150d), 50.0% (151~180d) and 50.0% (>181d). Body condition score (BCS) in 120 days postpartum was $2.64{\pm}0.1$ in average yielding cows and $2.28{\pm}0.1$ in high yielding cows, respectively.

• Reproductive and Developmental Biology
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• v.37 no.3
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• pp.117-122
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• 2013

The aim of this study was to investigate the effects of dietary supplementation of pelleted-Italian Ryegrass (IRG) as a source of fiber on reproduction performance in pregnant sows. A total of 24 pregnant sows were randomly assigned to four dietary treatments, which was given a corn-soybean diet with 0%, 10%, 20%, and 30% pelleted-IRG from 105 days prepartum to 7 days postpartum. During experimental period, the sows fed the IRG supplemented diet showed the lower feed intake than the sows fed the control diet (p<0.05). The changes of body weight in sows from initial to pre- and/or post-partum was significantly smaller in sows fed the IRG supplemented diet than control group. It is thought that the lower weight gain in IRG supplemented groups is caused by low feed intake. Although there was no significant difference, sows fed the IRG supplemented diet tended to increase the litter size and birth weight in piglets compared with sows fed the control diet. This result suggests that the dietary supplementation of IRG has the positive effects to improve the reproductive performance in sows. But, the excessive feeding of IRG to sows might cause to retard the days of return to estrus, and decrease the contents of solid, milk protein, and milk fat in colostrum. Thus, the addition of about 10% IRG is desirable to increase the reproductive performance. Meanwhile, the feeding energy diet is better effective than feeding the fiber diets to improve overall productivity in sows after postpartum.

• Journal of Embryo Transfer
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• v.20 no.1
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• pp.49-53
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• 2005

This study was conducted to investigate the effects of repetition usage of various estrus synchronization and seasonal breeding in Hanwoo. Body weight(kg) at birth and weaning in calves produced by seasonal breeding are 24.0kg, 75.6kg in female, 24.9kg, 78.3kg in male, respectively. Changes of birth weight(kg) by parity in Hanwoo increased gradually. Raising rates of calves by raising experience of farmer higher than in more 10 years as $88.4\%$ and in more 6 years as $84.0\%$. Delivering rates by induced estrus methods in $PGF_{2}{\alpha}$, PRID, CIDR and $GnRH-PGF_{2}{\alpha}-GnRH$ were $87.0\%$, $87.3\%$, $91.6\%$ and $96.0\%$, respectively. Conception days of post-partum following to induced estrus methods in Control, $PGF_{2}{\alpha}$ PRID, CIDR and $GnRH-PGF_{2}{\alpha}-GnRH$ were 137.1, 147.6, 141.3, 116.6 and 118.0 days, respectively. The results show that repetition usage of various estrus synchronization were not effective on postpartum reproduction in Hanwoo.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1393-1397
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• 2005

홍수유출을 저감시키기 위해서 유역의 저류기능을 강화시킬 수 있는 댐 건설은 이수적인 측면에서 안정적인 용수공급을 보장해주는 수단으로 겸용되어 왔으며, 특히 다목적댐이 건설되면서 하도의 첨두홍수유출량을 줄이는데 크게 기여해 왔다. 하지만 그로 인해 물의 흐름이 막히는 정체수역이 증가하고 있으며, 생활오수, 산업폐수의 발생은 정체수역에서의 영양염류 부하량을 증가시켜 부영양화를 초래하고 있다. 수생식물은 태양빛을 받아 광합성 작용을 하여 수중에서 성장하면서 수중의 유$\cdot$무기물질을 영양소로 섭취함으로써 수질을 정화시키는 작용을 하게 된다. 영양염류 부하량이 큰 정체수역의 오염된 물은 식물의 성장활동에 의해서 어느 정도 정화시킬 수 있으며, 이와 같이 수중에 식물을 식재하기 위해서는 식물이 하상에 쉽게 그리고 지속적으로 성장하고 번식활동을 할 수 있는 여건이 필요하다. 따라서 본 연구에서는 Mattress/Filter를 정체수역에 설치함으로써 이러한 식물의 성장과 번식을 도와줄 수 있는 환경조건을 제안하였다. 연구결과, Mattress에 식재한 갈대, 줄 및 애기부들의 피도는 $60-80\%$ 정도로 나타났다. 각 Mattress의 식물군집에는 초기 식재한 식물의 우점도가 가장 높았으나 갈대와 줄 군락의 경우 다른 종이 많이 출현하는 것으로 나타났다. 갈대 군락에서는 갈대가 크게 우점하였으나 그 외에 돌피, 하늘지기, 여뀌바늘 등이 우점하는 것으로 나타났다. 또한 줄 군락에서는 역시 줄이 크게 우점하였으나 방동사니, 돌피, 조개풀 등이 출현하였다. 애기부들 군락에서는 애기부들외에 세모고랭이와 미국가막사리 두가지 종만 출현한 것으로 나타났다. 갈대와 줄 군락의 출현 종수는 각각 7과 11이었으며, 다양도지수가 1.67, 2.18로 식물다양성이 크게 증가한 것으로 나타났다. 수질은 BOD 10mg/L, TN 15mg/L, TP 2.0mg/L이하로 이를 유등천 상류부에 공급할 경우 유등천의 수질은 BOD 6.7mg/L, TN 9.80mg/L, TP 0.90mg/L를 나타낼 것으로 예측된다. 고도처리시설의 도입 후 금강 합류점에서 갑천의 예측 BOD는 7.4mg/L로 현재 9.0mg/L에 비하여 개선되지만 이는 금강수계 오염총량 관리계획의 시$\cdot$도 경계지점 목표수질인 5.9mg/L를 만족시키지 못하므로, 이를 만족시키기 위해서는 방류수 BOD 7.2mg/L이하로 처리해야 할 것으로 판단된다.which support only concepts or image features.방하는 것이 선계기준에 적합한 것으로 나타났다. 밸브 개폐에 따른 수압 변화를 모의한 결과 밸브 개폐도를 적절히 유지하여 필요수량의 확보 및 누수방지대책에 활용할 수 있을 것으로 판단된다.8R(mm)(r^2=0.84)$로 지수적으로 증가하는 경향을 나타내었다. 유거수량은 토성별로 양토를 1.0으로 기준할 때 사양토가 0.86으로 가장 작았고, 식양토 1.09, 식토 1.15로 평가되어 침투수에 비해 토성별 차이가 크게 나타났다. 이는 토성이 세립질일 수록 유거수의 저항이 작기 때문으로 생각된다. 경사에 따라서는 경사도가 증가할수록 증가하였으며 $10\% 경사일 때를 기준으로 $Ro(mm)=Ro_{10}{\times}0.797{\times}e^{-0.021s(\%)}$로 나타났다.천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다. 그러나 진단 즉시 직접 좌관상동맥-대동맥 이식술로 수술적 교정을 해줌으로써 좋은 성적을 기대할 수 있음을 보여주었다.특히 교사들이 중요하게 인식하는 해방적 행동에 대한 목표를 강조하여 적용할 필요가 있음을 시사하고

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.247-252
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• 2010

This study was carried out between 2008 and 2009 in four dairy farms to investigate the effect of feeding of whole crop barley silage on the reproductive performance of Holstein heifers. Two diets, mixed hay or whole crop barley silage separately from concentrate were fed 6-month old Holstein heifers (=37). In control group (=CON), heifers (n=16) were fed 6 kg (/head) mixed hay and 4 kg (/head) commercial diet. In whole crop barley silage group (=WBS), heifers (n=21) were fed 10 kg (/head) whole crop barley silage, 4 kg (/head) mixed hay and 2 kg (/head) commercial diet. To manage body weight gain, the body condition score of heifers were measured every month. The results obtained were as follows: 1. Body weight in CON and WBS heifers at 13-, 14-, 15- and 17-month old were $340{\pm}17.9$ and $342{\pm}13.6\;kg$, $356{\pm}15.7$ and $366{\pm}14.7\;kg$, $382{\pm}13.1$ and $387{\pm}14.4\;kg$, and $429{\pm}15.0$ and $417{\pm}10.3\;kg$, respectively. 2. Body condition score in CON and WBS heifers at 9-, 12-, 15- and 17-month old were $2.88{\pm}0.04$ and $2.80{\pm}0.04$, $2.88{\pm}0.04$ and $2.80{\pm}0.04$, $2.89{\pm}0.08$ and $3.00{\pm}0.07$, and $2.89{\pm}0.08$ and $3.00{\pm}0.07$, respectively. 3. Average age of sexual maturity in CON and WBS heifers were $437.3{\pm}9.9$days and $939.6{\pm}12.5$days, WBS group heifers were significantly shorter (p<0.05) than CON group heifers. 4. First-service conception rates in CON or WBS group were 81.3% (13/16) and 66.7% (14121), respectively, and cumulative conception rate to 2nd artificial insemination were 87.5% for CON and 85.7% for WBS group. Conception rate was not different between treatments.

• Korean Journal of Animal Reproduction
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• v.18 no.2
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• pp.87-94
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• 1994

The objective of this study is to evaluate the developmental ability of mouse embryo in the presence of human amniotic fluid (hAF), The highest development rate was found in the culture media supplemented with 20% mid-term hAF but this rate was concomitantly reduced with more than 20% hAF. Furthermore, mouse two-cell embryos cultured in 20% mid-term hAF were developed more consistently to the expanded and hatched blastocyst stages compared to those cultured in simple medium. However, no significant differences in the embryo development rates were observed among the supplemented effects of 20% mid-term hAF, 0.3% bovine serum albumin (BSA), and 10% fetal calf serum (FCS), Development rates of two-ceiI mouse embryos cultured in 20% full-term hAF were declined compared to 20% mid-term hAF. Outgrowth of hatched blastocysts were observed when the embryos were cultured in medium containing 20% mid-term hAF or 10% FCS. But two-cell mouse embryos cultured in the presence of 20% full-term hAF or O.3% BSA was not observed their outgrowth. The kinetics of outgrowth processes in the presence of hAF were similar to those with 10% FCS. However, embryos with FCS showed a considerably greater extents of trophetodermal cell proliferation and outgrowth. Taken together, these data suggest that mid-term hAF may have a suitability for the mammalian embryos and induce embryonic outgrowth.