• Journal of Embryo Transfer
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• v.13 no.1
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• pp.69-76
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• 1998

This study was carried out to establish an effective system for embryo transfer techniques by analyzing several factors affecting in-vivo embryo transfer in Korean cattle Embryos were transferred into a toral of 301 recipients. The results obtained in studies on the factors affecting pregnancy rate after embryo transfer by condition of transfer time were as follows ; 1. The pregnancy rate by the seasons of transferred fresh and frozen embryos were not different, but the pregnancy rate was slightly higher in summer(80.8%). 2. The pregnancy rate by the days of embryo transfer after estrus were not different when fresh embryos were transferred, but the pregnancy rate was highest at 8 days when frozen embryos were transferred(P<0.01, 40.0%). 3. The pregnancy rate at estrus synchronization was remarkably higher with PGF$_2$$\alpha$ treated than natural (P<0.05, 70.4%, 43.4%). 4. The pragnancy rate by the degree of estrus synchronization was best when the estrus was synchronized in both fresh and frozen embryos (83.3% and 29.7%, respectively), but the pregnancy rate was not different among $\pm$2 days. But the pregnancy rate of frozen embryos were slightly higher when the recipients exhibited estrus earlier than donors.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.7
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• pp.943-950
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• 2015

Heat stress has adverse effects on fertility of dairy animals. Decline in fertility is linearly associated with an increase in combination of both temperature and humidity. The purpose of this study was to investigate the relationship between temperature humidity index (THI) and the pregnancy rate of Murrah buffaloes in a subtropical climate. The effects of genetic and non-genetic factors viz., sire, parity, period of calving and age group at first calving were found non-significant on pregnancy rate. The effect of THI was found significant (p<0.001) on pregnancy rate of Murrah buffaloes calved for first time and overall pregnancy rate. The threshold THI affecting the pregnancy rate was identified as THI 75. The months from October to March showed THI<75 and considered as non heat stress zone (NHSZ), while months from April to September were determined as heat stress zone (HSZ) with $THI{\geq}75$. The lowest overall pregnancy rate (0.25) was obtained in July with THI 80.9, while the highest overall pregnancy rate (0.59) was found in November with THI 66.1. May and June were identified as critical heat stress zone (CHSZ) within the HSZ with maximum decline (-7%) in pregnancy rate with per unit increase in THI. The highest overall pregnancy rate was estimated as 0.45 in NHSZ with THI value 56.7 to 73.2. The pregnancy rate was found to have declined to 0.28 in HSZ with THI 73.5 to 83.7. However, the lowest pregnancy rate was estimated as 0.27 in CHSZ with THI value 80.3 to 81.6.

• Journal of Embryo Transfer
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• v.13 no.1
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• pp.61-67
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• 1998

This study was carried out to establish an effective system for embryo transfer techniques by analyzing several factors affecting in-vivo embryo transfer in Korean cattle. Embryos produced in-vivo were transferred into a total of 301 recipients The results obtained in studies on the factors affacting pregnancy rate after embryo transfer by condition of recipients were as follows ; 1. The pregnancy rate by age and parity of recipients showed high in 5~8 and over 12 years old(72.7~73.9%), and 3rd~4th parity(82.1%) for fresh embryos(P<0.05). The pregnancy rate did not differ by age and parity of recipients in frozen embryos. The pregnancy rate of frozen embryos tended to be similar to that of fresh embryos(38.5% and 25.0~36.7%). 2. The number of observation for normal estrus cycles of recipients did not differ In pregnancy rate between one and 2 times in fresh embryos(64.9%, 69.8%). The pregnancy rate by transferred frozen embryos showed significantly higher after 2 times of observation(P<0.05, 16.3%, 37.5%). The pregnancy rate by days open did not differ between fresh and frozen embryos. But the pregnancy rate was slightly higher in 12 months and 6 months of days open for fresh and frozen embryos, respectively(70.1~71.1% and 24.5%, respectively). 3. The pregnancy rate of transferred fresh and frozen embryos into right and left side of uterine horn did not differ(62.1% : 65.9% 25.0% : 24.3%, respectively). The pregnancy rate by the grade of CL was not different in fresh embryos, but the pregnancy rate was significantly higher in the grade A than B for frozen embryos(P<0.01, 43.2%, 16.2%).

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.361-371
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• 1989

This study was performed to investigate the effects of stage and quality of embryo, synchrony between donor and recipient and difficulty of transfer on pregnancy rate following non-surgical transfer of frozen-thawed bovine embryos. The results were as follows; 1. The overall pregnancy rate of this experiment was 63.4% and that of heifers(73.1%) was higher than that of cows(46.7%). 2. The pregnancy rates of recipients transferred with morulae, early blastocysts and blastocysts were 50.0%, 64.7% and 71. 4%, respectively. 3. The pregnancy rate of recipients transferred with good embryos(67.9%) was higher than that of recipients transferred with fair embryos(53.8%). 4. The pregnancy rates of embryos transferred to left and right uterine horn were 63.2% and 63.6%, respectively. 5. The pregnancy rate of recipients in estrous synchrony 0(76.2%) was higher than those of recipients in synchrony -1(55.6%) and +1(44.4%). 6. The pregnancy rate of recipients transferred with 2 embryos (71. 4%) was higher than that of recipients transferred with 1 embryo(61.8%). 7. The pregnancy rate of embryos transferred to uterine tip (72.0%) was higher than that of embryos transferred to uterine base(50.0%). 8. Ease of transfer was ranked to a scale of one to three on the basis of increasing difficulty. Transfers ranked as ease score 1 accounted for 77.8% of pregnancies and had higher pregnancy rate than ease score 2(66.7%) or 3(45.5%). 9. The pregnancy rate of recipients with excellent corpus luteum(CL) (70.0%) was higher than those of recipients with good CL(61.1%) or fair CL(61.5) %. In reviewing above results, it was considered that the factors such as embryo stage, embryo quality, estrous synchrony, corpus luteum quality, transfer site within uterus, recipient's parity and ease score affected the pregnancy rate after non-surgical transfer of frozen-thawed bovine embryos.

• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.187-195
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• 2000

The ejaculates from 67 HanWoo prove bull, bred in Livestock Improvement Main center of NLCF, were used to determine the correlation between the sperm motional characteristics and the pregnancy rate of artificial insemination(AI). The motional characteristics of sperm were analysed by Computer-assisted sperm analyser(CASA), thereafter inseminated equally 1,256 heads of cow regarding to parity, age, and live weight. There were no significant difference(p>0.05) in the pregnancy rate according to year from 1996 to 1998, but the LIN, ALH, STR, BCF, MAD and WOB of sperm in the year 1997, were highest pregnancy rate, were higher than those of sperm in the year 1998, were lowest pregnancy rate(p<0.05). The semen had no significant effect on pregnancy rate according to season(p>0.05). However spring, had a little higher pregnancy rate than that of autumn, were higher than autumn in VSL, VAP, LIN, ALH, BCF, MAD and WOB, but in DNM. The pregnancy rates of spring in the year 1996 and 1997 were higher than that of autumn in the year 1998(p<0.05). The spring in the year 1997, highest in pregnancy rate, were higher than the autumn in the year 1998 in VSL, VAP, LIN, STR, BCF, MAD and WOB, but in DNM(p<0.05). There were no the motion characteristic of sperm that was significant correlate with pregnancy rate of AI as the semen were analysed before artificial insemination and those, had some degree characteristics in motility, viability and abnormality, were used to AI. However there were a tendency that the higher the VSL, VAP, ALH, LIN, STR, BCF, MAD and WOB and the lower the DNM were, the higher the pregnancy rate of AI were.

• Korean Journal of Veterinary Research
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• v.20 no.2
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• pp.135-141
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• 1980

This experiment was carried out to investigate of the early pregnancy diagnosis by finger pressure method, mucus smear method and rectal palpation method in 169 heads of pregnant dairy cow. 1. Pregnancy diagnostic rate of previous, middle and late period of pregnancy by finger pressure methods were 87.3%, 82.0% and 70% respectively. 2. Pregnancy diagnostic rate of previous, middle and late period of pregnancy by mucus smear methods were 83.1%. 94.9% and 95.0% respectively. 3. Pregnancy diagnostic rate of previous, middle and later period of pregnancy by rectal palpation methods were 83.1%, 96.1% and 100% respectively. 4. Pregnancy diagnostic rate of early pregnancy by finger pressure method, mucus smear method and rectal palpation method were 86.7%, 86.8% and 66% respectively. 5. Accordingly, finger pressure method in pregnancy diagnosis is thought to be recommendable because this early diagnostic means are simple with accurate results.

• Korean Journal of Veterinary Research
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• v.9 no.2
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• pp.49-53
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• 1969

The distribution of radiophosphorus ($^{32}P$) was observed in three groups of female Albino tat consisted of early pregnancy group (10 days of pregnancy), late pregnancy group (18 days of pregnancy) and nonpregnanted control group. The results obtained were as follows: 1. The various sites arranged in the descending of absorption rate of $^{32}P$ were femur, mandible, liver, spleen, ovary, fetus (only from early pregnancy group) and kidney in both groups of non-pregnanted and early pregnancy and femur, mandible, fetus, liver, ovary, spleen and kidney in the late pregnancy group. 2. The significant difference (P<0.05) in the absorption rate was found between femur and mandible in the early pregnancy group. 3. The absorption rate of fetus from late pregnancy group was significantly (P<0.01) higher than that of fetus from the early pregnancy group. 4. The high absorption rate was observed with femur and mandible in both groups of non-pregnanted and early pregnancy. 5. The significantly (P<0.01) high absorption rate was observed with ovary and fetus from the late pregnancy group.

• Journal of Veterinary Clinics
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• v.20 no.1
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• pp.121-130
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• 2003

The purpose of this study was to investigate the effect of breeding conditions on reproductive efficiency of thoroughbred broodmares by ultrasonography. The mean age and breeding career of 120 mares used in this study were 11 years old and 6 years, respectively. The average pregnancy rate and embryonic loss rate were 87.5%, 11.8%. The groups that were 8-10 years old, 4-6 years, maiden and mated on May showed the highest pregnancy rate. While mares mated on 1st estrus post partus had the highest ovulation rate but showed the highest embryonic loss rate and he lowest pregnancy rate. And broodmares that had more intrauterine foreign bodies such as cyst and fluid with age and breeding career had represented lower pregnancy rate and higher embryonic loss rate than those having normal uterine condition. These results suggest that the breeding condition and uterine environment of mares had a significant influence on reproductive efficiency.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.53-53
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• 2001

Two trials were conducted in a commercial dairy farm on heifer synchronization with PGF$_2$ $\alpha$. Animals showing estrus following the first injection were bred and animals not showing estrus were given the second injection 10 days later. In the first trial, the injection sites were rump and rump. In the second trial, the injection sites were rump and shoulder. Estrous detection was peformed 24 h after injection. Animals were bred by the same technician. In the first trial, the response rate for the first injection was 51.4% and the subsequent pregnancy rate of these animals was 60.0%. The response rate in the second injection was 57.1% and the pregnancy rate was 50.0%. In the second trial, the response rate in the first injection on the rump was 48.7% and the subsequent pregnancy rate was 70.6%. The second injection was given on the shoulder and the response rate was 60.0% and the subsequent pregnancy rate was 25.0%. The data suggests that the site of PGF2 $\alpha$ administration was critical to achieve success in estrous synchronization and pregnancy rates.

• Journal of Embryo Transfer
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• v.13 no.1
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• pp.53-60
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• 1998

This study was carried out to establish an effective system for embryo transfer techniques by analyzing several factors affecting in-vivo embryo transfer in Korean cattle. Embryos produced in-vivo were transferred into a total of 301 recipients. The results obtained in studies on the factors affecting pregnancy rate after embryo transfer by condition of embryos were as follow ; 1. The pregnancy rate of 301 recipients was 45.2% and higher with fresh embryos than with frozen embryos(63.5% : 21.4%, P<0.01). Embryos superovurated by FSH-P had slightly greater than by SUPER-OV in pragnancy rate, athough these were no difference between two treatments. 2. The pregnancy rates of transferred morulae and blastocysts showed no difference between fresh and frozen embryos(63.5% : 63~6% ; 20.0% : 25.8%). However, the pregnancy rates by quality of flesh and frozen embryos were significantly different(P<0~05). The pregnancy rates were outstandingly high in the grade A, B of fresh embryos(59.0~66.4%), and in the grade A of frozen embryos(43.6%). 3. The number of transferred embryos showed no difference in pregnancy rate, but when frozen embryos transferred, the pregnancy rate was slightly higher with two embryos than that with one embryo.