• 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.

• 한국수정란이식학회지
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• 제26권1호
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• pp.37-43
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• 2011

A total 5,946 cows from 24 dairy farms were carried out for the improvement of reproductive performance. Dairy cows in post-parturition 30 day were performed periodic reproductive examination to check for recovery of post-parturition ovary and uterus and for the early diagnosis of reproductive disease. The results obtained from this studies were as follow. The result of 1,126 cows with ovario-uterine disease were 579 slient heat and error of estrus detection (51.4%), 296 ovarian disease (26.3%), 248 uterine disease (22%), mummification and freematin were each 1 head (0.1%), respectively. Hormonal therapeutic effects were follicular cyst 81.5%, luteal cyst 90.7%, endometritis 86.9%, mucometra 90.1%, pyometra 60.9%, respectively. In cows, even if the 1st treatment fails, 2nd, 3rd treatment were performed. Therapeutic effect of 2nd, 3rd were reduced, but the number of cured cows were gradually increased. The cured cows after hormonal treatment were performed service repeatedly and the cumulative conception rate were increased. The cows treated with hormones at first service, the conception rate were follicular cyst 26%, luteal cyst 64.1%, endometritis 38.7%, mucometra 40%, pyometra 20.5%, respectively. The cumulative conception rates were increased by repeated service follicular cyst 57.3%, luteal cyst 84.6%, endometritis 67%, mucometra 75%, pyometra 64.1%, respectively.

• 대한수의학회지
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• 제30권3호
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• pp.349-354
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• 1990

The effects of $PGF2{\alpha}$ on the conception rate and the plasma levels of estradiol-$17{\beta}$ and progesterone of anestrus Cheju mares were investigated at the breeding and non-breeding seasons. The results obtained from this studies are as follows; 1. The durations of the estrus and diestrus after $PGF_2{\alpha}$ treatment persisted shorter than control cycle (p<0.05), but ovulation time was fast. 2. The levels of estradiol-$17{\beta}$ and progesteron before $PGF_2{\alpha}$ treatment showed 103.8pg/ml, 8.0ng/ml in breeding season and 72.8pg/ml, 4.7ng/ml in non-breeding season, respectively. 3. The levels of estradiol-$17{\beta}$ rose to 115.4~154.0pg/ml, and 90.8~27.0pg/ml from 2nd to 6th day after the treatment of $PGF_2{\alpha}$, in breeding and non-breeding seasons, respectively, while progesterone level dropped to 1ng/ml with the sign of estrus and at 8th day rose in breeding season (p<0.05). 4. Of thirty anestrus mares investigated for $PGF_2{\alpha}$ administration, 87.5% showed estrus on an average of 3.8 days after treatment and the conception rate was 62.5% in breeding season, but the estrus and conception rates dropped 40% and 20% in non-breeding season, respectively.

• 한국임상수의학회지
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• 제24권3호
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• pp.337-341
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• 2007

This study determined the effect of postpartum intrauterine infusion of povidone-iodine solution on the subsequent reproductive performance in dairy cows. Six hundred and fifty-eight dairy cows that were around week 4 postpartum were randomly divided into two groups: (1) Cows in treated group received an intrauterine infusion of 100 to 150 ml 2% povidone-iodine solution (treated group, n=269), or (2) Cows that received no treatment were served as the controls (control group, n=389). The cows were bred at observed estrus more than 50 days after calving. Artificial insemination (AI) was done according to the a.m.-p.m. rule. The conception to AI was determined per rectum 60 days after AI by both ultrasonographical observation and manual palpation. The intervals from calving to first service and conception ($94.2{\pm}2.7$ and $144.1{\pm}4.1$ days vs. $88.0{\pm,}2.1$ and $143.5{\pm}4.6$ days, respectively), number of services per conception ($2.0{\pm}0.1$ vs. $2.1{\pm}0.1$), and cumulative pregnancy rates within 90 and 150 days postpartum (31.9 and 61.7% vs. 29.7 and 62.1%) did not differ between the control and treated groups (P>0.05), while conception rate at first service was lower (P<0.05) in the treated group (40.5%) than in the control group (49.4%). Additionally, we could not find any effect of intrauterine infusion of povidone-iodine solution according to cow parity or calving season on the reproductive performance. These results indicate that intrauterine infusion of povidone-iodine solution at week 4 postpartum does not affect the subsequent reproductive performance in dairy cows.

• 대한수의학회지
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• 제40권2호
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• pp.383-391
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• 2000

Milk urea nitrogen (MUN) determination is being used an indicator of the protein-energy balance in dairy herds. A faulty balance can be corrected to optimize milk production and animal health. This parameter is regarded as a potential tool to evaluate suboptimal feeding practices and reproductive disorders. Therefore, the purpose of this study was to investigate the response of milk composition by regular feeding analysis and to compared the relationship between MUN and milk protein(MP) and fertility at the insemination period in Holstein dairy cows. Total of 355 artificial insemination (AI) for 150 Holstein cows in the herd were used to examine the relationship between MUN and MP content and conception rate. The AI occured for the cows 50 to 150 day in milk, and MUN and MP concentration were determined using automated infrared procedures. The mean${\pm}$standard deviation of MUN and MP concentration in the herd were $15.6{\pm}2.1mg/dl$ and $3.23{\pm}0.38%$, respectively. MUN contents of bulk milk were increase by elevated crude protein intake. The conception rate was lower in the cows in which the level of MUN was lower than > 8.0mg/dl (10.0%) or > higher than 25mg/dl (15.4%) relative to the cows in MUN content of 12.0~17.9 mg/dl (36.7%) at the time of insemination. Also, lower MP than 3.0% or higher MP than 3.25% were associated with a lower conception rates. Consequently, MUN and MP analyses may be used serve as a monitoring tool of protein and energy nutritional balance to improve reproduction efficiency in Holstein dairy cows.

• 한국수정란이식학회지
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• 제31권3호
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• pp.261-265
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• 2016

The aim of the present study was to evaluate and estimate timing of artificial insemination (AI) in Hanwoo heifer (Korean native cattle) that is the most popular breed of beef cattle in Korea. To determine changes in body weight of heifers around AI, body weight were measured at different stages either before or after AI. We found that daily body weight gain was higher in the pregnant cows after AI. We also investigate correlation between body mass measured by shoulder height and body length, and conception rates, used (body length+ height)2 instead of height2 for body mass index (BMI), and found that relatively more BMI heifers (>55) showed higher conception rates. Finally, we estimated body weight by measuring should height (SH), heart girth (HG), and body length (BL); $BW=3.93372^*HG-2.90985^*SH-0.021^*BL$. In addition, we observed that HG is most closely correlated with BW; $y(BW)=1.77355^*x(HG)$, $R^2=0.98881$. In summary, we can determine the best timing of AI using body measurement and its application including BMI.

• Animal Bioscience
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• 제35권10호
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• pp.1524-1534
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• 2022

Objective: The objective was to test if creep feeding (CF) improves the average daily gain (ADG) and weaning weight of calves submitted to temporary weaning (TW) and if the combination of CF and TW improves conception and pregnancy rates of cows. Methods: Primiparous (n = 74) and primiparous and multiparous (n = 104) cows grazing native grasslands were used in experiment 1 and 2; respectively. The experimental design was in plots divided into complete random blocks with two replications. The CF was the big plot and TW the small plot, thus four experimental groups were formed: i) -CF-TW (n = 21 and 27); ii) -CF+TW (n = 16 and 24); iii) +CF-TW (n = 20 and 26); iv) +CF+TW (n = 17 and 27) with cow-calf pairs for experiments 1 and 2; respectively. Nose plate application for TW had a duration of 14 and 15 days for experiment 1 and 2: respectively. In experiment 1, calves were fed at 1% of live weight for 112 days using a commercial supplement with 18.4% crude protein. In experiment 2, the supplementation lasted 98 days, and was carried out with corn dried distillers grains with soluble (DDGS) at 40% of the potential intake on a daily basis. Results: The TW reduced ADG during the TW period and the following 14 days, but the negative effect of TW was maintained until the final weaning only in experiment 2. The CF increased ADG during TW period in both experiments. The TW promoted an earlier conception of the dams (12 days in -CF treatment and 19 days in +CF treatment, p<0.01) and CF increased pregnancy rate in experiment 1, being the effects not consistent between experiments. Conclusion: The CF consistently promoted an increase in ADG during the period of TW and increased final weaning weight of calves, therefore it is economically viable.

• 한국가축번식학회지
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• 제3권1호
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• pp.56-60
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• 1979

This study was carried out to find the difference between the naturaly born sex rtio among 1,242 head of pigs(120 litters) at Swine Farm, Cheil Sugar Co. and B-body a, pp.arance from their semen, and to find the conception rates which were inseminated to 40 sows with sperm from the anode and cathode after electrophoresis of boar semen. In order to the electrophoretic separation, the semen was placed into the platimum loop electrodes(105 cc) at room temperature for 30 minutes with D.C. 3V. and 350${\mu}$A. constant. The sperm fluorescent staining method was performed in accordance with Bhattacharya's(1970) method. The spermatozoa were observed through a Olympus Vanox microscope(made in Japan) using exciter filter with I heat barrier HPO 120. The results obtained were summarized as follows: 1. The natural sex ratio of 1,242 piglets(120 litters) which were born at Swine Farm, Cheil Sugar Co. was 50%, and B-body a, pp.arance of its boar semen were 49.24%. 2. With electrophoretic separation, the anode and cathode attracted 65.5${\pm}$5.03% and 29.89${\pm}$4.29% of B-body bearing sperm, respectively. 3. After electrophoresis of boar sperm, they were inseminated to 40 sows with sperm from anode and cathode. The conception rate was 92.5%.

• 한국수정란이식학회지
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• 제32권3호
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• pp.171-176
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• 2017

본 연구는 한우 송아지 생산효율 향상을 위한 농가 번식 실태를 조사하였다. 한우 사육 규모별, 지역별로 나누어 45개 농가의 가임암소를 대상으로 조사를 실시하여 다음과 같은 결과를 얻었다. 한우의 최초 분만월령은 평균 28.7개월령이었다. 수태당 인공수정 횟수는 $1.45{\pm}0.32$회였으며, 분만 후 인공수정 일수는 119.8일이었다. 수태율은 소규모 농가가 $75.2{\pm}16.93%$로 중규모($70.6{\pm}17.46%$) 및 대규모 농가($71.4{\pm}11.03%$)보다 높은 것으로 나타났다. 번식률 상위 농가의 사육 방식을 보면, '발정관찰 보조기구를 사용하는 농가'가 '그렇지 않은 농가'보다 송아지 생산율이 10.42% 높았다. 번식소에 대해 IBR과 BVDV 예방접종을 실시한 농가는 유사산 폐사율이 4.41% 감소한 것으로 나타났다. 또한 농가여건에 따라 방목과 운동을 한 경우, 수태율과 분만율이 각각 3.47%, 18.29% 향상되는 것으로 나타났다. 본 조사 결과를 통해 발정관찰, 예방접종, 방목이 한우농가에서 송아지 생산 효율을 높이는데 중요한 지표로 나타났다. 한우 사육 농가의 번식실태 조사를 통해 농가 현장의 번식률 향상을 위한 연구 자료로 활용이 가능할 것이다.

• 한국수정란이식학회지
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• 제29권1호
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• pp.7-12
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• 2014

본 연구는 한우 번식 기록이 잘 유지되고 있는 4개 농장의 2007년 1월부터 2010년 10월까지의 번식 자료 수집하여 분석하였다. 수태 당 평균 수정 횟수와 평균 공태일은 A농장 $1.7{\pm}0.1$회와 $77.4{\pm}4.8$일, B농장 $1.5{\pm}0.1$회와 $150.8{\pm}11.2$일, C농장 $1.5{\pm}0.1$회와 $90.4{\pm}4.5$일, D농장 $1.4{\pm}0.1$회와 $71.4{\pm}2.5$일이었다. 호르몬으로 발정을 유도하는 D농장을 제외한 3개 농장 531두의 번식 기록으로 분만 후 첫 수정 시기에 따른 평균 수정 횟수와 평균 공태일을 분석한 결과, 총 5개의 수정 시기에 따른 수정 횟수는 30일 이전 첫 수정이 $2.1{\pm}0.2$회로 31일 이후 첫 수정보다 유의적으로 높았다. 번식 장애우 58두에 2가지 배란 동기화법을 사용하여 수태율을 확인해 본 결과, Ovsynsh 법은 55.2%의 수태율을, CIDR-based TAI 법은 65.5%의 수태율을 나타냈다. 농장의 번식률을 높이기 위해서는 정확한 번식 기록 작성, 발정 관찰, 수정 후 임신 감정, 번식 기관 검진, 번식률을 고려한 첫 수정 시기 수정 등이 필요하다.