• 한국가축번식학회지
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• 제8권2호
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• pp.87-91
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• 1984

This study was conducted to determine the optimum time and the insemination site of frozen in Cheju native cows, and 660 cows first service inseminated with rectovaginal methods by 3 skillful technicians as 3 districts near Cheju City and Sogwipo City areas obtained the following results. Optimum time for insemination was 16-20 hours after the onset of estrus and 80.6% of 67 conceived to first insemination. In the rectovaginal technique used widely at present conception rate for the palpation of ovaries showed 6.6% (index) higher than that of non-palpation. Conception rate of the insemination site; the intra-uterine horn, intra-uterus, just inside the cervix and depositing in mid-cervix were 62.5, 78.4, 74.6, and 80.9% respectively, however, there was no difference in conception rate between cervical and uterine deposition of forzon semen except for the intra-uterine horn.

• 대한수의학회지
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• 제26권1호
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• pp.163-174
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• 1986

The 587 Holstein cows which calved from January 1983 to December 1984 at an integrated dairy farm in Chung-nom province were examined for the incidence of reproductive disorders and their conception rate after treatment. The results obtained were as follows; 1. The incidence of reproductive disorders was 47.9% (281 heads) among 587 heads which calved. 1) As number of calvings increased, the incidence of reproductive disorders decreased. 2) The cows which calved in spring and summer showed significantly higher incidence of reproductive disorders than those which calved in autumn and winter (p<0.05). 3) Among reproductive disorders, ovarian, uterine, cervical and vaginal diseases figured 54.3%, 43.7%, 0.9% and 0.6%, respectively. 4) Among individual genital diseases, endometritis (40.3%) occurred most frequently. 2. Among 281 heads with reproductive disorders, 216 heads(76.9%) conceived after treatment. 1) After treatment of reproductive disorders, the conception rate by number of calvings was in range from 69.6% to 87.5%. 2) The cows which calved in summer and winter showed significantly higher conception rate after treatment of reproductive disorders than those which calved in spring and autumn (P<0.05). 3) The conception rates after treatment of the cows with ovarian, uterine, cervical and vaginal diseases were 66.5%, 81.2%, 33.3% and 50.0% respectively. 4) The cows with endometritis showed the highest conception rate after treatment (85.9%).

• 한국수정란이식학회지
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• 제25권1호
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• pp.51-55
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• 2010

The relationships of scrotal circumference (SC) to semen characteristics and the conception rate (70 days-nonreturn rate) of artificial insemination in farm were studied with 137 heads of bull in Hanwoo. The average and range of SC were $38.27{\pm}3.90$ cm and 26.0~52.5 cm, respectively. Hanwoo bulls were classified with SC, divided into 34 cm below group, 34~39 cm group, and 39 cm over group. The 5,487 semen records of 43 heads of bull from July. 1. 2007 to June. 30. 2008. were used to determine the relationships between SC and semen characteristics. The semen concentration and total sperm number of each group were 11.18, 16.68, and $17.4{\times}10^8/ml$, and 69.83, 101.64 and $114.40{\times}10^8$/ejaculate. The bulls with 34 cm or more SC were higher than the bulls with 34 cm below in semen concentration and total sperm number (p<0.01). But between SC and semen volume have no significant relationship (p>0.05). The 9,862 mating records of 44 farm with 137 heads of bull were used to determine the relationships between SC and conception rate. The conception rate of 1st artificial insemination were 73.31, 74.16, and 77.33 % in each group. Also SC was positively correlated with pregnancy rate (r=0.12, p=0.17). These results indicate that SC correlates positively with semen characteristics, and maybe with pregnancy rate in Hanwoo.

• 한국수정란이식학회지
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• 제27권3호
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• pp.133-139
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• 2012

This study was carried out to develop the useful inducing method of estrus for Korean native cows. Under the condition of estrus induction by administering $PGF_{2{\alpha}}$ for the cows in which corpus luteum (CL) in ovaries was detected by ultrasonography, ovarian responses and the changes of progesterone ($P_4$) concentration against $PGF_{2{\alpha}}$ compared with conception rate were observed in cows and heifers. In inducing estrus administering $PGF_{2{\alpha}}$. to the cows which has corpus luteum in ovaries, ovarian reponses, the changes of progesterone concentration, and conception rate were identified and compared. The results attained from the studies were as follows. Significant decreases of CL in size over time after $PGF_{2{\alpha}}$ administration were detected in both cow and heifer groups (p<0.001), but not different between groups in the CL regression rate (p>0.05). In addition, the percentage changes relative to the plasma $P_4$ concentration on day 1 after $PGF_{2{\alpha}}$ treatment were decreased to below 1ng/ml. The growth rate of follicle was observed as 31% on day 1 and 42% on day 2 in cows, and 34% on day 1 and 97% on day 2 in heifers, resulting that growth of heifers are faster than that of cows (p<0.05). The conception rate after $PGF_{2{\alpha}}$ treatment were 60.5% and 64.2% in cows and heifers, respectively. It also indicated that the conception rate after estrus observation with $PGF_{2{\alpha}}$ injection was as high as 66.6% while that with timed-artificial insemination (TAI) regardless of the estrus observation was 56%, which means the pregnancy rate of artificial insemination after estrus observation was higher than that of TAI (p<0.05). In the result of all above, there were significant decreases in CL size and the plasma $P_4$ concentration by days but rapid growth in follicles, which has no differences in cows and heifers. The conception rate was commonly high after estrus observation and more than 50% under TAI.

• Animal Bioscience
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• 제34권12호
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• pp.1879-1885
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• 2021

Objective: Owing to the lack of a breeding index for efficient and quick fertility evaluations of Holstein bulls when using traditional or genome-wide detection methods, this study aimed to determine whether in vitro fertilization (IVF) could be used as an indicator of conception rate of artificial insemination (AI). Methods: Conventional and sexed frozen semen from nine bulls were used for IVF and AI. Results: The IVF and AI conception rates of each bull were confirmed to be positively correlated between the conventional frozen and sexed frozen semen. The correlation coefficient R values of nine bulls between IVF and AI methods were 0.73 and 0.97 for the conventional frozen and sexed frozen semen, respectively. The average conception rate of three bulls undergoing AI was 69.5% and 64.2%, 61.8% and 58.8%, and 48.2% and 46.2% in first-, second-, and third-born cows when conventional frozen and sexed frozen semen were used, respectively, which showed a positive correlation with the fertilization rate in the same parity. We propose an evaluation standard to assess the fertilization ability of bulls based on their IVF test results, which is categorized into three grades: grade one, normal fertility bull with an AI conception rate of 40%±5% and IVF rate of 45% to 60%; grade two, higher fertility bull with an AI conception rate of 50%±5% and IVF rate of 61% to 80%; and grade three, highest fertility bull with an AI conception rate of 60%±5% and IVF rate of >80%. Conclusion: These findings reveal that IVF results can be used as a breeding index for bulls to evaluate their AI conception ability, which may shorten the time required to select bulls for breeding.

• 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.

• 한국수정란이식학회지
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• 제26권2호
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• pp.91-96
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• 2011

The purpose of this study was to evaluate the effects of days open on subsequent reproductive performance following to estrus synchronization in the 114 lactating dairy cows. The animals were divided into two groups according to the time of estrus synchronization; viz, ${\leq}$ 85 days, and > 85 days postpartum, respectively. The estrus synchronization protocol consisted of insertion of a controlled internal drug release (CIDR) device containing 1.9 g progesterone with an injection of 250 ${\mu}g$ gonadorelin (Day 0), an injection of $PGF_2{\alpha}$ and removal of the device on Day 7, an injection of 250 ${\mu}g$ GnRH on Day 9, and TAI 17 h later. Pregnancy diagnosis was determined at 30 to 60 days after TAI using both ultrasonography and rectal palpation. The body condition score (BCS) gradually increased over the postpartum period. In estrus synchronized cows until 85 days, conception rate on first service, number of service per conception, interval from estrus synchronization to conception, and interval from calving to conception were not significantly different among two farms (P>0.05). In estrus synchronized cows after 85 days postpartum, conception rate on first service, number of service per conception and interval from calving to conception were significantly different ($P{\leq}0.05$) between herds A and B (26.8 vs 50.0%; $2.1{\pm}1.35$ vs $1.37{\pm}0.54$ times, $237.3{\pm}97.8$ vs $164.7{\pm}69.3$ days, respectively). In estrus synchronized cows after 85 days postpartum interval from estrus synchronization to conception was greater (P<0.01) in herd B than in herd A ($63.6{\pm}57.4$ vs $26.1{\pm}24.9$). These results indicate that the time of estrus synchronization for maximized the reproductive performance is before 85 days postpartum and feeding and management is important factor for high reproductive performance.

• Reproductive and Developmental Biology
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• 제30권3호
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• pp.225-228
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• 2006

본 연구는 유우 사육 농가에서 배란동기화법(OVSYNCH)의 활용시 수태율에 미치는 영향을 검토하였다. 그 결과, 유우의 정상 번식우(15/23, 63%)와 번식 장애우(5/10, 50%)의 수태율 비교에서는 정상번식우가 수태율이 높게 나타났지만 유의차는 인정되지 않았다. 그러나 유우 경산우의 산유량에 따른 수태율 비교에서는 1일 산유량이 $30{\sim}35kg$ 이상인 유우군에서 배란동기화 처리시 $20{\sim}25kg$인 유우군에 비해 유의적으로 높은 수태율을 나타냈다(p<0.05). 또한 유우 경산우의 산차수에 따른 수태율 비교에서는 1산차의 시험우군이 3산차군에 비해 유의적으로 높은 수태율을 나타냈지만(p<0.05) 산차수 증가에 따른 수태율은 일정한 경향을 나타내지 않았다. 본 연구의 결과로부터, 배란동기화 방법을 유우의 다두사육 농가에서 실제로 이용할 경우 우유 생산이 가능한 정상번식우에서 효과적이었으며, 특히 1일 산유량이 많은 유우에서 높은 수태율을 얻을 수 있었다. 한편 앞으로의 연구를 통해 개선된 배란동기화법을 이용한다면 호르몬 불균형으로 초래된 번식 장애우의 번식 능력 회복과 함께 향상된 수태율을 얻을 수 있는 효과적인 방법으로 농가에서도 간편하게 이용될 수 있을 것으로 평가된다.

• 한국수정란이식학회지
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• 제18권3호
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• pp.187-193
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• 2003

본 연구는 한우에 GnRH ＋ PGF$_2$$\alpha$＋GnRH (Ov-synch)를 처리하여 배란동기화를 시켰으며, 2차 GnRH 투여후 배란시간, 수태율, 계절별 수태율, 산차별 수태율을 조사하였으며, 시험축은 2산 이상의 개체를 무작위로 선발하여 실험에 공시하였으며, 배란동기화 처리후 1회 인공수정을 실시하고 수태율을 환산하였다. 호르몬 처리방법으로는 GnRH ＋ PGF$_2$$\alpha$ ＋ Gn-RH(Ov-synch)법을 이용하였으며, 배란시간의 조사는 초음파를 이용하여 2차 GnRH 투여 후 24시간부터 31시간까지 2시간 간격으로 난소를 촬영하여 배란 여부를 조사하였다. 1. 배란동기화 처리후 24시간부터 31시간까지 2시간 간격으로 난소의 상태를 확인한 결과 28∼30시간 사이에 80%(20/25)로 가장 많이 배란된 것으로 나타났다. 2. 수태율에 있어서는 계통별 1회 수정 수태율은 고급육 계통이 48.1%(38/79)로 다소 높게 나타났다. 3. 산차에 따른 수태율은 1∼2, 3∼4산차에서 각각 44.3, 55%로 나타났다. 4. 계절별로는 여름보다는 봄과 가을에서 47.3%로 다소 높은 경향이였다.

• 대한간호학회지
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• 제21권3호
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• pp.307-322
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• 1991

The purpose of this exploratory study was to analyze nursing role conceptions and test the relationships between nursing role conceptions and professional commitment among selected Korean nurses. Data were obtained from a convenience sample of 262 practising nurses of varying positions, education, and experience. The total sample represents a response rate of 93 percent. Subscales of Nursing Role Conceptions (Pieta, 1976) were used to measure professional, service, and bureaucratic role conceptions 1 the tool to measure professional commitment was developed by the investigator. The results of this study were as follows. 1. Professional role conception and service role conception were positively related(normative r＝ .61 : categorical r＝ .64). Bureaucratic role conception scores(32.6$\pm$4.97) were higher than professional and service role conception scores. 2. Experience was positively related to bureaucratic professional categorical role conception(r＝ .17, p＜ .01), and negatively related to bureaucratic professional role discrepancy(r＝- .12, p＜ .01). There was no relationship between experience and service role conception. This study also showed that nurses who had longer experience tended to have higher role conceptions on all three subscales. 3. Nurses with a master's degree had significantly higher professional and bureaucratic role conceptions scores. Bacealaureates graduates had the lowest bureaucratic categorical role conception scores ; associate nurses had the lowest professional categorical role conception scores. 4. Nursing supervisors and head nurses had significantly higher bureaucratic categorical role coneption scores, whereas they had lower bureaucratic normative and professional role conception scores. 5. Age and experience were positively related to professional commitment (r＝ .24, r＝ .28). Hierarchical multiple regression analyses showed that the combination of nursing role conceptions explained greater variance in professional commitment pair of the variables alone. Further research employing dynamic designs is needed to execute rigorous tests of causal models of nursing role conceptions and professional commitment. The findings of this study suggest that antecedents and moderating variables of nursing role conception and professional commitment need to be explored for further theoretical. specification and empirical evaluation.