• 한국가축번식학회지
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• 제22권2호
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• pp.145-152
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• 1998

Many trials have been made to produce transgenic animals using sperm cells as a vector transferring foreign DNA into eggs, but reliable results are yet to be obtained (Brinster et al., 1989; Lavitrano et al., 1989; Bachiller et al., 1991; Sato et al., 1994). Recently, one of author(SO) demonstrated that mouse blastocysts derived from eggs fertilized by spermatozoa of male mice single injected with liposome-DNA complexes within the testis expressed thegene (Ogawa et al., 1995.) Here we report that a single injection of liposome-encapsulated DNAs into the testis of either male rats or mice resulted in successfully gene transfer to the postpartum progeny. The expression of mRNA derived from transgenes was also demonstrated in transgenic animals thus obtained. Further, the transmission of the exogenous gene to the descedants was confirmed in one line of transgenic rat up to F4 generation, indicating that the gene was stably incorporated into the germ line. Thus, direct single injection of foreign DNA into the testis provides a novel and convenient means to generate transgenic animals.

• 한국임상수의학회지
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• 제28권4호
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• pp.339-343
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• 2011

젖소에서 쌍태분만이 이후의 산후질병 발생, 도태, 번식능력에 대한 영향과 쌍태분만에 대한 위험요인을 조사하였다. 9개 목장 1,717 분만축의 번식, 위생 및 분만관련 상세 자료가 분석에 이용되었다. 쌍태 분만율은 3.4%였으며, 임신기간은 쌍태분만 시에 단태분만 시에 비해 9일 단축되었다($270.6{\pm}2.0$ vs. $279.5{\pm}0.2$일, P < 0.01). 쌍태분만 시가 후산정체(47.5 vs. 16.0%), 대사성질병(18.6 vs. 3.8%) 및 자궁내막염의 발생(62.7 vs. 28.2%)뿐만 아니라 도태율(32.2 vs. 16.5%)이 단태분만 시에 비해 현저하게 증가되었다(P < 0.01). 쌍태분만은 분만으로부터 임신까지의 간격에 유의적인 영향을 미치지 않았으나, 분만계절이 영향을 미쳤는데, 즉 봄에 분만 시가 겨울에 분만 시에 비해 임신율이 감소되었으며(AHR = 0.80; P = 0.01), 또한 자궁내막염의 발생이 임신율의 감소를 초래하였다(AHR = 0.46, P < 0.01). 로지스틱 분석은 산차의 증가(P < 0.01)와 수태 전 번식호르몬의 사용(OR = 1.84, P < 0.05)이 쌍태분만의 위험요인임을 나타내었다. 결론적으로, 젖소에서 쌍태분만은 산후질병 발생과 도태의 증가에 의한 심한 경제적 손실을 초래하므로, 쌍태분만에 대한 적절한 관리 및 고산차 소 및 번식호르몬 사용에 대한 적절한 통제를 통한 위험요인을 감소시키는 것이 요구된다.

• 한국동물생명공학회지
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• 제36권4호
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• pp.194-202
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• 2021

In this study the effect of vitamin C administration on pregnancy rates during summer heat stress in dairy cows was examined. A total of 80 Holstein-Friesian cows were divided into control and treatment groups (n = 40 each). Control group animals were given 10 mL isotonic normal saline, and treatment group, Vitamin C (4 mg/kg) on artificial insemination day (day 0) and 4^th, 8^th and 12^th day post insemination. Pregnancy diagnosis was performed on 30^th day post insemination by ultrasonography. Blood samples were randomly taken from 11 animals from each group. Serum P₄, GSH, MDA and plasma 8-OHdG levels were determined by using ELISA method. Results showed that 8-OHdG levels were lower in treatment group on day 4, 8 and 12 (p < 0.05) compared with the control group. Similarly, pregnancy rate was higher in treatment group (32.5%) than control (22.5%), respectively. However, MDA, P₄ and GSH levels were similar in both groups at 4^th, 8^th and 12^th day. A gradual increase in P₄, and MDA levels, and a strong positive correlation between 0, 4^th (r = 0.54), 4, 8^th (r = 0.59) and 8, 12^th (r = 0.51) day was found. Similarly, GSH levels also showed positive correlation at days 0, 4^th (r = 0.47) and 4, 8^th (r = 0.56). However, a strong negative correlation (r = -0.56) between MDA day 0, and GSH day 8 was found. In conclusion, vitamin C application during insemination period in postpartum cows increases pregnancy rate, and reduces oxidative stress metabolite 8-OHdG levels.

• Asian-Australasian Journal of Animal Sciences
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• 제20권1호
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• pp.124-131
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• 2007

There is worldwide interest in buffalo as an animal for meeting the growing demands of meat, milk and work in the developing countries. One of the major constraints to full exploitation of the productive potential of buffalo has been its inherently low reproductive efficiency as reflected by late maturity, poor expression of oestrus, silent oestrus, irregular oestrous cyclicity, seasonality in breeding, anoestrus, low conception rate, long postpartum interval, repeat breeding etc. Ovarian cyclicity is regulated by endocrine and neuroendocrine mechanisms namely hypothalamic hormones, gonadotropins and ovarian steroids. Detailed endocrine investigations are suggested with special reference to the hypothalamo-hypophysial-ovarian axis to gain a better understanding of reproduction in buffalo and to modify it to derive the maximum benefit from this animal.

• Asian-Australasian Journal of Animal Sciences
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• 제16권9호
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• pp.1268-1273
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• 2003

Sixty postpartum lactating Friesian cows in 3 treatments at a commercial dairy farm were used to study the effect of using progesterone supplementation with GnRH and PGF2$\alpha$ synchronization with and without timed AI on fertility during summer. Cows in treatment1($Tr_1$) and treatment2 ($Tr_1$) were fitted with progesterone releasing intravaginal device (PRID) device and injected with 10 g GnRH agonist on $51{\pm}3$ d postpartum (pp). Seven days later, PRID was removed and cows received 25 mg PGF2$\alpha$. Two days later, $Tr_1$ cows received another injection of 10 g GnRH and timed AI 16-20 h later. Control cows received only 25 mg PGF2$\alpha$ $58{\pm}3d\;pp$. $Tr_2$ and control cows were AI at detected estrus. Serum progesterone for all cows was determined on days of injection, AI and 21, 23 and 28 d postinsemination. Pregnancy rates from first AI based on serum P4 concentrations on d 21, 23 and 28 postinsemination (50, 40 and 35%) and that based on rectal palpation 40-45 d postinsemination (30, 15 and 15% for $Tr_1$, $Tr_2$ and control cows, respectively) did not differ among the three groups. Whereas, pregnancy rate at 120 d pp for $Tr_1$ (65%) was higher (p<0.05) than that in $Tr_2$ (30%) or control (30%). The overall pregnancy rate was not significantly different (90, 90 and 75% for $Tr_1$, $Tr_2$ and control, respectively). Days open for cows in $Tr_1$ ($100.3{\pm}9$) was less (p<0.03) than that in $Tr_2$ ($130.9{\pm}9$) or control ($135.1{\pm}10$). Results indicate that using PRID device with Ovsynch program had significantly increased pregnancy rate and decreased days open compared to AI at detected estrus after synchronization with GnRH, PRID and PGF2$\alpha$ or synchronization with one injection of PGF2$\alpha$.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.637-642
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• 2005

The objective of this study was to evaluate the effect of dietary undegradable protein (UP) level on body weight change, nutrient intake, milk production and postpartum reproductive performance of Awassi ewes. Twenty-seven multiparous Awassi ewes (initial body weight = 53.3${\pm}$1.6 kg) were randomly assigned to three dietary treatments (9 ewes/treatment) for 62 days using a completely randomized design. Experimental diets were isonitrogenous (15.5% CP), isocaloric, and were formulated to contain 17.9 (LUP), 27.1 (MUP), and 34.0% (HUP) of the dietary CP as UP. On day 10${\pm}$3 (day 0 = parturition) ewes were housed in individual pens for 5 weeks. Feed offered and refused was recorded daily. At the end of this period, animals were removed from their pens and combined into 3 separate groups (LUP, MUP and HUP). One fertile, harnessed ram was allowed with each group for 34 days. Rams were rotated every 2 days among the three groups. Each group was offered the corresponding experimental diet. Organic matter, CP, UP and metabolizable energy intakes were higher (p<0.05) for ewes fed the HUP diet compared with ewes fed the LUP and MUP diets. Ewes fed the HUP diet gained more (p<0.05) weight compared with ewes fed the MUP diet (7.3 vs. 2.1 kg), while ewes fed the LUP diet lost an average of 2.1 kg. Pregnancy rate of ewes fed the HUP diet was 100%, compared with 66 and 33% for ewes fed the MUP and LUP diets, respectively. Lambing rate was greater (p<0.05) for ewes fed HUP (8/9) diet compared with ewes fed the MUP (4/9) and LUP (3/9) diets. These results indicate that Awassi ewes receiving adequate dietary UP level consume more feed and are capable of returning to estrus shortly after parturition and are capable of producing two lamb crops per year.

• Asian-Australasian Journal of Animal Sciences
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• 제19권1호
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• pp.19-25
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• 2006

The effect of vitamin E supplementation on plasma ${\alpha}$-tocopherol level, total antioxidant level and reproductive performance in Murrah buffaloes was studied during periparturient period. Twenty-four advance pregnant buffaloes were randomly divided into four equal groups as $T_1$, $T_2$, $T_3$ and $T_4$ and were supplemented with 0, 1,000, 1,500 and 2,000 IU of ${\alpha}$-tocopheryl acetate (Merck) from 60 days prepartum to 30 days postpartum and 0, 500, 750 and 1,000 IU from 30 to 60 days postpartum, respectively. Blood samples were collected at -60, -45, -30, -15, -7, 0, 7, 15, 30 and 60 days of parturition and were analyzed for plasma ${\alpha}$-tocopherol and total antioxidant activity (TAA). The intake of DM, CP and TDN did not vary among different groups. Plasma ${\alpha}$-tocopherol and TAA around parturition (-7 to 15 day) in $T_3$ and $T_4$ were significantly higher than the control group. There was 17% reduction in retention of fetal membranes (RFM) and metritis in $T_4$ than control. The post partum estrus interval averaged 58.00, 55.33, 51.83 and 43.00 days in $T_1$, $T_2$, $T_3$ and $T_4$ respectively. There was significant reduction in days open in both $T_3$ and $T_4$ in comparison to $T_1$ group (127,130 Vs.146). All the vitamin E supplemented groups showed reduction in days open than their previous lactation performance. Supplementation of vitamin E at $1,500IU\;d^{-1}$ from 60 day prepartum to 30 day post partum to buffaloes exhibited beneficial effect on plasma ${\alpha}$-tocopherol level and TAA around parturition and continuation of its supplementation at $1,000IU\;d^{-1}$ from 30 to 60 days of lactation improved post partum reproductive performance of buffaloes.

• 한국발생생물학회지:발생과생식
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• 제13권1호
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• pp.51-57
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• 2009

큰포식세포나 혈관의 내피세포 등에서 분비되는 monocyte chemoattractant protein-1(MCP-1)은 큰포식세포의 활성을 조절하고 황체의 용해시기에는 용해를 개시, 촉진시키는 작용을 하는 것으로 알려져 있다. 그러나 아직 임신 황체나 출산 후의 황체의 발달과 유지에 대한 MCP-1의 작용기전은 확실히 알려져 있지 않다. 난포발달과정에서 큰포식세포의 역할을 알아보기 위해서 흰쥐를 실험동물로 임신시기별, 출산 후 황체에서 TUNEL 염색, ED1, ED2 및 MCP-1에 대한 면역조직화학을 실시하였다. 출산 후 황체에서 큰포식세포의 수가 의미 있게 증가하였으며, 큰포식세포에 대한 ED1, ED2의 면역반응성이 증가하였고, MCP-1의 면역반응성도 크게 증가하였다. 본 연구의 결과 출산 후 황체에서는 큰포식세포가 주로 탐식작용을 하게 되지만, 임신 황체에서는 황체의 구조와 기능을 유지하는데 주로 관여할 것으로 생각된다.

• Reproductive and Developmental Biology
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• 제37권3호
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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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• 제37권3호
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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.