• Korean Journal of Animal Reproduction
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• v.24 no.2
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• pp.209-216
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• 2000

This study was carried out to investigate the effects of breed, age of boar, season, parity and mating system on boar semen characteristics and fertilizing capacity. A total of 4181 sows and 199 boars of Durocs (D), Landraces (L), and Yorkshires (Y) were used for this experiment at Darby Artificicial Insemination Center from 1996 through 1999. Semen volume per ejaculate was largest in Landrace (266.8 $m\ell$), followed by Yorkshire, and was smallest in Duroc. Sperm motility did not show significant differences among the above breeds. Sperm concentration was lowest in Landrace (4.7$\times$10$^{9}$ sperm/$m\ell$) and was highest in Duroc (5.7$\times$10$^{9}$ sperm/$m\ell$). Semen volume per ejaculate according to the age of boars was largest at the age of 2 years, followed by the age of 4 and 3 years, and was smallest at the age of I year. Semen volume per ejaculate according to the season in boars was largest in winter (228.6 $m\ell$), followed by autumn and summer, and was smallest in spring. Sperm concentration was highest in spring (5.9$\times$10$^{9}$ sperm/$m\ell$), followed by summer and winter, and was lowest in autumn. The average litter weight at birth did not show any differences according to the mating type. But the number of pigs born alive per litter was largest (9.5 pigs) in the natural mating ＋ artificial insemination group, followed by the artificial insemination group (9.2 pigs), and was smallest (8.9 pigs) in the natural mating group (P＜0.01). The average litter weight at birth and number of pigs born alive per litter did not show any differences between the natural mating and artificial insemination. The L (♀)$\times$Y (♂) and L (♀)$\times$L (♂) matings show $\varepsilon$ d higher average litter weight at birth and number of pigs born alive per litter than the Y (♀) $\times$ Y (♂) and Y (♀) $\times$ L (♂) matings. The pigs in the 2~6th parities had higher average litter weight at birth and number of pigs born alive per litter than those in the 1 st and 7~9th parities.

• Korean Journal of Poultry Science
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• v.45 no.4
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• pp.245-252
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• 2018

This study investigated the effect of LED light wavelength (color) on reproductive hormones and egg production of brown laying hens raised on floor. Red, blue, green and white colors of LED light were four treatments with four pens per treatment. One hundred forty four Hy-line brown laying hens (47 wks old) were allocated in a floor pen for six weeks trial. Egg production, egg quality, yolk cholesterol and hormones ($17{\beta}$-estradiol, progesterone) concentrations in plasma and oviduct were analyzed. Egg production of red group was higher (P<0.01) than that of green group. Haugh unit of eggs from red group was higher (P<0.01) than that of blue and green groups. Egg weight of green group was heavier (P<0.05) than that of red group. Shell of blue group was stronger (P<0.05) than that of red and white groups. Shell color of white group was browner (P<0.01) than that of blue and green groups. Yolk cholesterol of red group was higher (P<0.01) than that of others. Plasma $17{\beta}$-estradiol of red group was higher (P<0.05) than that of others at $3^{rd}$ week, but that of white group was highest (P<0.05) at $6^{th}$ week. Oviduct progesterone of green group was higher (P<0.01) than that of others. The result showed that the LED colors affect the reproductive hormone concentrations, egg production, egg weight and egg quality. This study suggested that red LED would be the most appropriate color for floor raising brown laying hens to sustain the egg production when it begins to decline with aging.

• Journal of Animal Science and Technology
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• v.44 no.2
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• pp.191-200
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• 2002

This study was conducted to estimate the effects of environmental factors on certain reproductive traits in Korean cattle on the basis of data from Korean Cattle Improvement Areas which were surveyed from 1986 to 1995. Results obtained were summarized as follows ; 1. Least square means of the reproductive traits estimated were 466.11${\pm}$5.72 days for age at 1st service, 480.10${\pm}$6.15 days for age at 1st conception, 742.79${\pm}$7.48 days for age at 1st calving, 64.97${\pm}$1.42 days for days at 1st service postpartum, 72.06${\pm}$1.73 days for days open, 355.93${\pm}$1.92days for calving interval, 285.38${\pm}$0.42 days for gestation length and 1.21${\pm}$0.02 days for number of services for conception, respectively. 2. The ranges of the least squares means for the districts were 447.62${\pm}$5.94-490.72${\pm}$5.94 days for age at 1st service, 464.27${\pm}$6.38-505.20${\pm}$6.39 days for age at 1st conception, 721.91${\pm}$7.85-772.75${\pm}$7.80 days for age at 1st calving, 62.27${\pm}$1.55-68.97${\pm}$1.74days for days at 1st service postpartum, 69.74${\pm}$1.97-74.36${\pm}$2.27days for days open, 352.71${\pm}$2.18-359.64${\pm}$2.09 days for calving interval, 284.52${\pm}$0.42-286.04${\pm}$0.47days for gestation length and 1.11${\pm}$0.02-1.30${\pm}$0.02 days for number of services for conception, respectively. 3. Age at 1st service was latest in the cows with Basic Register and tended to be earlier for the more advanced registers. The number of services per conception tended to increase for the more advanced registers. 4. Days at 1st service postpartum was longest in the 2nd parity and tended to be shorter with the advancement of parity. The number of services per conception tended to decrease with the advancement of parity. 5. As the calving year advances from 1987 to 1995, days at 1st service postpartum, days open and calving interval tended to be longer, and number of service per conception tended to increase. 6. Days at 1st service postpartum, days open and calving interval were shorter in the cows that calved in spring and summer than in the cows that calved in fall and winter. The number of services per conception was larger in the cows that cocalved in fall and winter than the cows that calved in spring and summer.

• Journal of Veterinary Clinics
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• v.30 no.3
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• pp.178-185
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• 2013

This study evaluated the effects of milk yield on the postpartum health and reproductive performance of dairy cows. In total, data were collected from 1,060 cows on six dairy farms, including their milk production, body condition score (BCS), postpartum disorders, and reproductive performance. The lactation data were grouped based on the 305-day milk yield into control (< 10,000 kg, n = 445) and high milk yield (${\geq}$ 10,000 kg, n = 615) groups. The milk fat and protein, and BCS were lower during the first 5 months postpartum in the high milk yield group compared with the control group (p < 0.01). Ovarian cysts were more frequent (p < 0.0001) in the high milk yield group (28.6%) than in the control group (15.3%), whereas endometritis tended to be less frequent in the high milk yield group (29.6%) than in the control group (35.1%, p = 0.06). A higher proportion of cows tended to receive reproductive hormones (p = 0.06) in the high milk yield group (62.4%) than in the control group (56.6%). The probability of a pregnancy after first insemination tended to be lower (odds ratio = 0.78, p = 0.07) in the high milk yield group (30.2%) than in the control group (35.2%). Furthermore, the hazard of pregnancy by 210 days in milk was lower in the high milk yield group (hazard ratio = 0.84, p = 0.04) than in the control group, which resulted in a 20-day increase in the median interval to pregnancy. In conclusion, high milk yield was related to lower milk fat and protein, lower BCS, an increased incidence of ovarian cysts, and increased use of reproductive hormones, which resulted in decreased reproductive performance of dairy cows.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.120-120
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• 2003

고능력 젖소와 보통능력 젖소의 번식능력을 비교하기 위하여 progesterone을 분석하여 분만후 초발정일을 추정하였고, 번식자료를 통하여 분만 후 번식성적을 조사하였으며, 또한 비유능력 및 Body condition score(BCS) 에 따른 $PGF_2a + PGF_2a+CIDR$ program 투입 효과를 구명하기 위하여 분만 후 40일째에 $PGF_2a$를 1차 처리한 후 발정이 발현되지 않은 개체에 대하여 1 차 처리후 14일째에 다시 2차 $PGF_2a$를 처리하였고 2차 $PGF_2a$ 처리후에도 발정이 발현되지 않은 개체에 대하여 2차 $PGF_2a$ 처리후 5일째에 CIDR plus를 처리하여 발정유기율을 조사분석하였던 바, 그 결과를 요약하면 다음과 같다. 가. 보통능력우와 고능력우의 분만후 progesterone peak를 나타내는 일수는 각각 $38.8 \pm 11.1$ 및 $39.6 \pm 9.7$일로 거의 비슷한 경향을 나타내었음 나. 보통능력우와 고능력우의 분만후 발정재귀일수는 각각 $99.4 \pm 71.6$ 및 $117 7 \pm 78.6$일로 고능력우에서 18.3일 늦어지는 경향이었음 다 보통능력우와 고능력우의 분만후 수태일수에 있어서 각각 $145.9 \pm 102.8$및 $165.9 \pm 100.8$일로 고능력우에서 20일 늦어지는 경향이었음 라. 보통능력우와 고능력우의 분만간격에 있어서 각각 421.5 \pm 107.2$ 및 $448.4 \pm 108.7$일로 고능력우에서 26.9일 늦어지는 경향을 나타내었음 마 보통능력우와 고능력우에 있어서 1차 $PGF_2a$ 처리시 각각 39.1% 및 60.0%, 2차 $PGF_2a$ 처리시 각각 42.9% 및 70.0%, CIDR plus 처리시 50.0% 및 66.7%의 발정 유기율을 나타내었음 바. BCS에 따라 $PGF_2a + PGF_2a+CIDR$ plus program을 투입한 결과 BCS 2.5 이하와 BCS 2.75-3.50에 있어서 1차 $PGF_2a$ 처리시 각각 47.4% 및 48.3%, 2차 $PGF_2a$ 처리시 각각 40.0% 및 66.7%, CIDR plus 처리시 각 각 50.0% 및 80.0%의 발정 유기율을 나타내었음

• Journal of Animal Science and Technology
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• v.51 no.3
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• pp.255-262
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• 2009

Current study was conducted to investigate the influence of parity and region variation in ultrasound live carcass traits of Hanwoo cows. A total of 1,386 heads of Hanwoo cows, spreading over six regions in Gangwon province of South Korea, were measured for longissimus muscle area, back fat thickness, marbling score and rump fat thickness by using real-time ultrasound method. The results revealed that, positive correlations were found in all ultrasound live carcass traits. All live carcass traits were increased in accordance with parity until the sixth, and then decreased thereafter. Statistical significant differences (p<0.01) were found among regions in ultrasound live carcass traits, e.g. Hanwoo cows showed highest longissimus muscle area and marbling score in Hwacheon, while the lowest back fat thickness and rump fat thickness were observed in Yanggu. Greater longissimus muscle area and marbling scores were found in Hanwoo cows which were born during autumn, 2000. Moreover, individuals born during autumn, 2005 and 2006 showed a thicker back fat and rump fat thickness. Back fat thickness had the highest positive correlation with rump fat thickness, while rib eye area and rump fat thickness had the lowest correlation.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.76-76
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• 2002

본 연구는 Se과 Vit. E 투여수준이 한우 종빈우 번식효율에 미치는 영향을 규명하기 위하여, 한우 종빈우의 임신말기에 적정량의 Se와 Vit .E를 투여하여, 종빈우의 혈액화학치 변화 및 혈중 Vit. E 농도변화를 규명하였다. 1. 분만 1개월 전 Se 과 Vit. E 투여가 한우 종빈우의 혈액성분에 미치는 영향을 검토한 결과, 평균 혈중 albumin 과 calcium 함량은 각각 투여구가 대조구보다 유의적으로 높았으며 (P＜0.05), 평균 혈중 IP 함량은 각각 Se 과 Vit. E 혼합투여구가 여타구보다 높은 성적을 나타냈다 (P＜0.05). 그러나 평균 혈중 BUN, creatinine, glucose, cholesterol 및 triglycerides 의 함량은 처리구간 유의적인 차이가 인정되지 않았다 (P＞0.05). 2. 분만 2개월 전 Se과 Vit. E 투여가 한우 종빈우의 혈액성분에 미치는 영향을 검토한 결과, 혈중 평균 albumin, BUN, cholesterol, creatinine, glucose, IP, TP, triglycerides 및 Ca 함량은 처리구간 유의적인 차이는 인정되지 않았다 (P＞0.05). 3. 한우 종빈우의 분만 l 개월전 Se 및 Vit. E 투여가 한우 종빈우의 혈중 Vit. E 농도에 미치는 영향을 검토한 결과, 평균 혈중 Vit. E 농도는 투여구가 대조구보다 다소 높은 농도를 나타냈으나, 처리구간 유의적인 차이는 인정되지 않았다 (P＞0.05). 4. 한우 종빈우에서 분만 2 개월전 Se 및 Vit. E 투여가 혈중 Vit. E 농도에 미치는 영향을 검토한 결과, 평균 혈중 Vit. E 농도는 처리구간 유의적인 차이가 없었으며 (P＞0.05), 처리구간 투여횟수의 증가에도 불구하고 혈중 Vit. E 농도는 커다란 차이가 없었다.atform by investigating current and future e-business services platforms involved in domestic and global international banks. Several financial interchange standards which are involved in B2B business of e-procurement, e-placement, e-payment are also investigated.. monocytogenes, E. coli 및 S. enteritidis에 대한 키토산의 최소저해농도는 각각 0.1461 mg/mL, 0.2419 mg/mL, 0.0980 mg/mL 및 0.0490 mg/mL로 측정되었다. 또한 2%(v/v) 초산 자체의 최소저해농도를 측정한 결과, B. cereus, L. mosocytogenes, E. eoli에 대해서는 control과 비교시 유의적인 항균효과는 나타나지 않았다. 반면에 S. enteritidis의 경우는 배양시간 4시간까지는 항균활성을 나타내었지만, 8시간 이후부터는 S. enteritidis의 성장이 control 보다 높아져 배양시간 20시간에서는 control 보다 약 2배 이상 균주의 성장을 촉진시켰다.차에 따른 개별화 학습을 가능하게 할 뿐만 아니라 능동적인 참여를 유도하여 학습효율을 높일 수 있을 것으로 기대된다.향은 패션마케팅의 정의와 적용범위를 축소시킬 수 있는 위험을 내재한 것으로 보여진다. 그런가 하면, 많이 다루어진 주제라 할지라도 개념이나 용어가 통일되지 않고 사용되며 검증되어 통용되는 측정도구의 부재로 인하여 연구결과의 축적이 미비한 상태이다. 따라서, 이에 대한 재고와 새로운 방향 모색이 필요하다고 사료된다.로 사료되며, 임신관련 cytokine에 대한 다양한

• Korean Journal of Animal Reproduction
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• v.26 no.1
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• pp.53-59
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• 2002

This study were performed to investigate the effect of magnetic field exposure on semen characteristic and the weights of body, reproductive organs and liver, kidney and spleen in mice. In magnetic field exposure for 15 days, sperm concentrations and viability were significantly lower in magnetic field(15.7$\times$10$^{6}$ $m\ell$, 29.3%) than that in control group(25.1$\times$10$^{6}$ $m\ell$, 34.4%)(P＜0.05). The proportion of sperm abnormality were significantly increased in magnetic field exposure groups for 15 days than that in control group(P＜0.05). The exposure of magnetic field in mice didn't affect the body and reproductive organ weight such as testis, epididymis, vasicular gland and coagulatin gland. The weight in liver and kidney were not affect in magnetic field exposure groups. However, the spleen weight were significantly higher(P＜0.05) in group exposed with than without magnetic field. This studies indicate the short or long term magnetic field exposure in mice were noxious effects on the sperm characteristics and spleen weight, but didn't affect body, reproductive organs, and liver and kidney weight.

• Korean Journal of Psychosomatic Medicine
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• v.30 no.2
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• pp.99-111
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• 2022

Akey factor in evolution is reproduction, which is also a major concern in medicine. Evolutionists have proposed many theories and hypotheses to explain the low fertility rates of modern industrial societies, which are contrary to maximization of biological fitness. Given that childbirth is the most significant factor affecting reproductive fitness, it is likely that a variety of psychological modules related to childbirth behavior and intention evolved over time. Several evolutionary psychological modules have been proposed in relation to reproduction, including sexual desire, status-seeking, a need for nurturing, and the desire for children. Previously adaptive psychological modules may now be expressed maladaptively due to the discrepancy between the Environment of Evolutionary Adaptedness (EEA) and the environment of modern industrial society. Several evolutionary ecological factors influence childbirth intention in modern society, including individual personality factors, childhood life history experiences, and socioecological factors throughout reproductive life. By focusing on mental, social, and ecological factors, this review examines several hypothetical models relating to evolutionary psychological factors and childbirth decisions in modern industrial society, as well as a possible explanation for the low birth rate.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.185-188
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• 1997

전남대학교 수의과대학에서는 조류 blue-green algae를 먹이로 하여 간질의 중간숙주인 애기물달팽이를 실험실에서 유지시켜 왔으나 조류의 배양에 어려움이 많아서 보다 간편하면서 달팽이의 번식에도 좋은 방법을 고안하고자 노력하였다. $28.5{\times}17{\times}18cm$ 크기의 유리수조에 모래를 1.5cm 높이로 깔고 10개의 꼬막껍질을 그 위에 올려놓은 다음 4리터의 증류수를 부어넣었다. 야외에서 채집한 달팽이의 난괴를 부화시켜 얻은 0.63cm 크기의 어린 달팽이 45마리를 세 그룹으로 나누어 세 개의 수조에서 $20^{\circ}C$의 온도를 유지하면서 사육하였고 먹이로 상추잎을 넣어주었다. 매주 수조바닥의 물 $2{\ell}$를 흡인하여 갈아주면서 상추잎을 바꿔넣었고, 계속해서 공기를 통과시켜 산소를 공급하였다. 이와 동일한 방법으로 실험실에서 조류로 사육하던 17대의 달팽이를 사육하여 그 성적을 비교하였던 바 야외에서 채집한 달팽이의 성장률이 실험실에 적응된 것들에 비하여 약간 떨어졌으나 생존율이나 산란율에서는 큰 차이가 인정되지 않았다. 그래서 1년이 넘도록 이 방법으로 달팽이를 사육하면서 간질의 피낭유충을 생산하고 있다. 꼬막껍질은 서서히 분해하면서 달팽이의 각을 형성하는 물질을 제공하여 생존율을 높게 한 것으로 생각된다. 그리고 수조를 햇볕이 드는 창문 가까이에 놓아두었기 때문에 조류가 자생하여 적은 양이나마 달팽이의 먹이가 되었을 것으로 보인다.