• Asian-Australasian Journal of Animal Sciences
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• 제17권6호
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• pp.755-759
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• 2004

The present investigation was carried out to assess the effect of Sephadex (G-15) filtration on the post thaw bull semen quality and conception rate. Post thaw unfiltered (control) and Sephadex filtered semen from four healthy bulls (three cross bred and one pure bred Holstein Friesian) were subjected to microscopic examination viz. sperm concentration, individual motility, live sperm count and sperm morphology. Sixty-two healthy, normal cycling crossbred cows were inseminated with post thaw unfiltered (n=32) and filtered semen (n=30). Sephadex filtration of post thaw semen significantly (p<0.05) decreased total sperm concentration and sperm with abnormal head, mid piece and tail. The overall average total sperm concentration, head and tail defects in filtered semen decreased significantly (53.4, 1.2 and 6.4 million) than in the unfiltered semen (80.4, 2.4 and 15.7 million, respectively). However, after filtration significant (p<0.05) increase in overall average motile and live sperm concentration were observed (38.8 and 38.0) as compared to unfiltered semen (29.2 and 32.0 million, respectively). The overall conception rate recorded was 21.9% with post thaw unfiltered semen and 56.7% with filtered semen. It was concluded that Sephadex filtration of post thaw semen improved its quality and conception rate.

• 대한수의학회지
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• 제15권2호
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• pp.215-222
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• 1975

Infertility and breeding status of Korean cows which are reared in a extensive alpine ranches of Daegwanryeong area was investigated. The results obtained were summarized as follows, 1. Infertility frequency of the cows was 25.9% against a total examined number of 675 heads, and was 17.6% against a total rearing number. 2. The distributions of infertile cows 44.6% of Granular vaginitis-like syndrome, 36% of repeat breeder, 8.6% of symptom of ovary, 6.8% of symptom of uterus and 4% of other symptoms. 3. According to its age were found by 51.4% upon 2 years of age, 30.3% upon 3 years of age, 11.4% upon 4 years of age and 6.9% upon S years of age. 4. Breeding status of Korean cows showed 74.1% of conception rate in the cases of pre-treatment, while breeding status increased markedely in the cases of post-treatment by the 85.8%. 5. The conception rate by the artificial insemination mainly on the first mating was 36.1%. on the second mating 23.0% and on the third mating 18.0%. Total conception rate between first and third mating was 77.1%. 6. The therapeutic effect by treatment for granular vaginitis-like syndrome was 87.1%.

• Animal Bioscience
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• 제36권8호
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• pp.1151-1155
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• 2023

Objective: This study analyzes interactions of body condition score (BCS) with other factors and the effect of BCS on estimates of genetic paremeters of conception rate (CR) in Japanese Black cows. Methods: Factors affecting CR were analyzed through the linear mixed model, and genetic parameters of CR were estimated through the threshold animal model. Results: The interactions between BCS and each season and the number of artificial inseminations (AI) was significant (p<0.05), but that between BCS and parity showed no significance for CR. High CR was observed with BCS 3 in autumn (0.56±0.01) and BCS 4 in summer (0.56±0.02). The highest CR with BCS 3 (0.56±0.02) and BCS 4 (0.55±0.01) was observed at first AI. With BCS 5, however, the highest CR (0.55±0.08) was observed at second AI. Conclusion: The model with BCS was notably conducive to the estimation of genetic parameters because of a low deviance information criterion of heritability that, nevertheless, was slightly lower than the model without BCS.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제19권1호
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• pp.26-30
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• 2006

The study was undertaken to investigate the validity of milk urea concentration as an index of the reproductive performances in crossbred Karan-Fries (Holstein Friesian${\times}$Tharparkar) cows under farm condition. Milk urea was analysed in noon milk samples (1200 to 1300 h) to interrelate with the interval from parturition to first service, number of insemination per conception, first service conception rate and service period. Milk progesterone (P4) was analysed in noon milk samples on the day 1, 10, 20 and 30 post insemination to study the effect of milk urea concentration on early embryonic mortality. The interval from parturition to first service was found significantly (p<0.01) higher ($77.2{\pm}5.5$ days) when milk urea concentration was ${\geq}63.4mg/dl$. The average milk urea concentrations (mg/dl) were found $42.1{\pm}2.5$, $47.9{\pm}1.5$ and $50.3{\pm}3.1$, respectively in cows that conceived at $1^{st}$, $2^{nd}$ and $3^{rd}$ insemination. However, the variation was not statistically significant. The first insemination conception rate was found significantly (p<0.05) higher (68.8%) when milk urea level was ${\leq}32.4mg/dl$. The service period was found significantly (p<0.05) higher ($125.4{\pm}8.8$ days) when milk urea concentration was ${\geq}45.1mg/dl$. The milk P4 level indicated that the cows, those were detected as non-pregnant on day 60 post insemination were initially pregnant but the pregnancy was terminated sometime during the day 30 to 60 post insemination. The study indicates that the milk urea values may be used as an index of reproductive performances in dairy herd when individual animals are not being monitored for nutritional status. The altered milk urea values may be utilised by the farmers as ready reference to rectify the protein and energy nutrition in cows to achieve the better reproductive performances in herd.

• Asian-Australasian Journal of Animal Sciences
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• 제27권7호
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• pp.932-936
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• 2014

Breeding records of 57 Arabian and 66 Thoroughbred mares were analysed to assess their reproductive performance under the subtropical conditions of Pakistan. The Arabian mares showed significantly higher conception rates (p<0.05) in second mated oestrus and foal heat mated oestrus compared to Thoroughbred mares. However, conception rates for first lifetime mated oestrus were similar in both breeds of mares. Age at first mating ($1,301{\pm}40$ vs $1,500{\pm}32$ days) was significantly (p<0.05) less in Arabian compared to Thoroughbred mares. Both breeds of mares showed significantly (p<0.05) higher frequencies of oestrous cycles and conception rates during the winter (October to March) compared to summer (June to August) months. Age of mares affected the conception rates, as mares at ages 3 to 7 and 8 to 12 years of ages had significantly higher conception rates (p<0.05) than those ${\geq}18$ years old in both breeds. This study demonstrates that i) reproductive performance in Arabians is better than Thoroughbred mares under the subtropical conditions of Pakistan, ii) mares remain cyclic throughout the year and iii) conception rates were higher in mares bred during winter compared to summer months.

• 한국임상수의학회지
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• 제23권4권
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• pp.453-457
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• 2006

This study determined the effects of several reproductive factors at prostaglandin $F_{2{\alpha}}\;(PGF_{2{\alpha}})$ administration on the subsequent estrous exhibition and conception. Three hundreds and twenty six dairy cows in seven dairy herds received a 25 mg $PGF_{2{\alpha}}$ after confirming the presence of corpus luteum (CL) by ultrasonography, and the cows exhibited estrus within 7 days following $PGF_{2{\alpha}}$ administration were artificially inseminated (AI). Two hundreds cows among the 326 cows received additional ultrasonography at $PGF_{2{\alpha}}$ administration to measure the diameters of the largest follicle and CL on ovaries, and blood samples collected from the cows were analyzed for serum progesterone (P4) level. Cow parity, days open, body condition score (BCS), season and herd variables were recorded. Of the treated 326 cows, 171 cows (52.5%) showed estrus within 7 days after treatment, and the conception rate following AI was 37.4% (64/171). There were significant differences on the estrous exhibition ($31.3{\sim}65.8%$, p<0.01) and conception rates ($23.1{\sim}66.7%$, p<0.05) among the herds, while cow parity, days open, BCS and season did not affect the subsequent estrous exhibition and conception rates. The diameters of the largest follicle and CL on ovaries, and serum P4 level at the $PGF_{2{\alpha}}$ administration were not related to the subsequent estrous exhibition and conception. The results indicate that the improved outcomes of synchronization of estrus using a single $PGF_{2{\alpha}}$ administration may be related to the appropriate management of the herd.

• 한국초등과학교육학회지:초등과학교육
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• 제23권2호
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• pp.141-151
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• 2004

Pre-service teachers' understandings on magnet was investigated through the questionnaire method. The questionnaire was composed of 17 questions about the strength of magnet, the magnetized object and the direction of magnetic field around magnet. In this investigation study, 225 pre-service teachers were selected through random sampling method, who were sophomores in a National University of Education. The formation rate of the scientific conceptions on the strength of magnet was 30.3% and that on the direction of magnetic field around magnet was 53.9%. The average formation rate of scientific conception of all questions on magnet was 44.13%, which doesn't seem to be high as expected. It shows that many of subjects of the questionnaire don't understand fully the concept of moleclar magnet model and the superposition effects of magnetic field around magnet. The formation rate of the scientific conception on magnet of females who took courses in sciences in high school were higher than that of females who took courses in arts in high school, which had meaningful difference (p<.05).

• Journal of Animal Science and Technology
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• 제65권2호
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• pp.324-335
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• 2023

Korea, located in East Asia in the northern hemisphere, is experiencing severe climate changes. Specifically, the heat stress caused by global warming is negatively affecting the dairy sector, including milk production and reproductive performance, as the major dairy cattle Holstein-Friesian is particularly susceptible to heat stress. Here, we collected artificial insemination and pregnancy data of the Holstein and the Jersey cows from a dairy farm from 2014 to 2021 and analyzed the association between the conception rate and the temperature-humidity index, calculated using the data from the closest official weather station. As the temperature-humidity index threshold increased, the conception rate gradually decreased. However, this decrease was steeper in the Holstein breed than in the Jersey one at a temperature-humidity index threshold of 75. To evaluate the effects of heat stress on the oocyte quality, we examined the nuclear and cytoplasmic maturation of Holstein (n = 158, obtained from six animals) and Jersey oocytes (n = 123, obtained from six animals), obtained by ovum pick-up. There were no differences in the nuclear maturation between the different conditions (heat stress: 40.5℃, non- heat stress: 37.5℃) or breeds, although the Holstein oocytes seemed to have a lower metaphase II development (p = 0.0521) after in vitro maturation under heat stress conditions. However, we found that the Holstein metaphase II oocytes exposed to heat stress presented more reactive oxygen species and a peripheral distribution of the mitochondria, compared to those of the Jersey cattle. Here, we show that weather information from local meteorological stations can be used to calculate the temperature-humidity index threshold at which heat stress influences the conception rate, and that the Jersey cows are more tolerant to heat stress in terms of their conception rate at a temperature-humidity index over 75. The lower fertility of the Holstein cows is likely attributed to impaired cytoplasmic maturation induced by heat stress. Thus, the Jersey cows can be a good breed for the sustainability of dairy farms for addressing climate changes in South Korea, as they are more resistant to hyperthermia.