• 한국수정란이식학회지
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• 제27권1호
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• pp.21-28
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• 2012

A study was conducted on four crossbred bulls, used as artificial insemination (AI) sires, to correlate their semen quality with their non return rate (NRR). Semen was collected once a week via an artificial vagina, diluted in egg yolk-citrate and maintained at $+7^{\circ}C$ for three days. It was evaluated for sperm motility, viability, morphology immediately after collection and was examined daily for sperm motility, viability and morphology of acrosome, mid piece and tail for a total of three days. A total of 2016 cows were inseminated by two AI technicians. The proportions of sperm with normal heads were 83.4% (63.7~91.7%), the proportion of spermatozoa exhibiting normal morphology (acrosome, mid piece and tail), motility and viability were 89.2% (82.3~92.0%), 71.3% (61.7~75.0%) and 76.7% (65.7~85.0%), respectively in fresh ejaculates. Sperm motility and sperm viability was significantly ($p$ <0.05) lower in Holstein-Friesian ${\times}$ Local bull than in other bulls during all three days of storage. The overall NRR for four bulls was 82.7% (72.9-87.5%). Bulls with higher sperm motility, viability and normal morphology of spermatozoa of individual bull had significantly (each $p$ <0.05) higher NRR. The highest ($p$ <0.01) NRR (87.5%) was observed in a Red Chittagong bull whose semen qualities were significantly ($p$ <0.05) higher than Holstein-Friesian ${\times}$ Local bull (NNR 72.9%). The results of the present study concluded that NRR at 56 days post AI is related to parameters of semen quality. Therefore, semen evaluation may allow the discarding of bulls with poor fertility in an AI program.

• 한국동물위생학회지
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• 제27권3호
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• pp.273-280
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• 2004

The studies were performed for the PRRS antigen and antibody detection from breeding farms, artificial insemination(AI) center and growing farms in Jeonbuk province. 1. Specific PRRS primers were successfully amplified ORF6 617bp and ORF7 448 bp on agarose gel. 2. RT-PCR method has been establish by commercial kit and the thermal cycler program consisted of 30 cycles: $95^{\circ}C$ for 30 sec, $45^{\circ}C$ for 30 sec, and $72^{\circ}C$ for 45 sec. 3. The results of PRRS antibody test by ELISA method in AI centers were $6.6\%,\;53.3\%$ and breeding farms $65\%,\;65\%\;and\;38.7\%$, respectively. The serological positive of the antibody in gilt higher than sow. 4. The sero-positive of the PRRS antibody showed average $21\%$ in domestic farms, $56.2\%$ in breeding farms, and $29.9\%$ in AI center.

• 대한수의학회지
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• 제34권1호
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• pp.189-193
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• 1994

This study was undertaken to clarify the relationship between the cause of repeat-breeder and the luteal dysfunction in repeat-breeder dairy cows that failed to conceive to three or more artificial insemination(AI) at a regular interval. Progesterone concentrations were measured in milk fat for 20 to 22 days after AI. From the 15 repeat-breeder dairy cows, six cows had a normal progesterone profiles. Five cows showed a delayed rise of the progesterone concentrations until 7 to 10 days after AI, two cows had a comparatively low concentration of milk progesterone below 150 ng/ml through most of the luteal phase, and two cows had a combined pattern of a delayed rise and a low concentration of milk progesterone during luteal phase. It is suggest that luteal dysfunction as indicated by progesterone profiles is one of the causes of repeat-breeder in dairy cows.

• Reproductive and Developmental Biology
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• 제36권3호
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• pp.213-217
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• 2012

The decreased fertility is frequently thought to be problem of cattle production. However, studies figure out that number of these problems is related to bull factors especially in artificial insemination setting. Therefore, this study was designed to investigate the fertility status of bull by their estimated relative conception rate of cows that were inseminated by frozen semen from Korean proven bulls. Here we use the non-return rate (NRR) to access the bull fertility whereas, the NRR was define as the proportion of bulls that semen were used to inseminate cows and the number of cows that did not return for another service within 60 days. The data from 54,388 artificial inseminations (AI) were analyzed from 88 KPN semen. The NRRs of highest and lowest fertile bull were 83.81 and 51.33%, respectively. And mean NRR was 68.27%. In comparison to previously reported study, our data shows 17.38% higher NRR and the absolute value of difference in 50%>NRR and 50%

• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제9권3호
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• pp.299-302
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• 1996

Milk samples(n = 78) were taken 19d, 20d, 21d, 22d after artificial insemination(AI) for early pregnancy diagnosis by using the Enzyme immunoassay(EIA) kit. The progesterone ($P_4$) concentration in the whole milk was measured on the same day of pregnancy diagnosis. Rectal palpation(RP) was accomplished between 60d and 70d after AI to estimate the ovary condition and pregnancy status. Milk progesterone concentrations measured by Radio-immunoassay(RIA) method, in the pregnant cows at 17d, 19d, 21d after insemination were $17.10{\pm}0.91$, $17.60{\pm}0.46$, and $18.43{\pm}0.79nmol/l$, whereas those in the not-pregnant cows were $6.57{\pm}1.03$, $2.63{\pm}0.29$, and $0.67{\pm}0.08nmol/l$, respectively. When the progesterone concentration was less than 7 nmol/l, the color of the EIA kit was lighter and when the progesterone concentration was ${\geq}16nmol/l$, the color of the EIA kit was darker compared to the standard color. The detection rates of error by judging the color differences were 5.1% and 20.7%, respectively. In the early pregnancy diagnosis by the EIA kit and RIA method, the accuracy rates in the pregnancy of cows were 82% and 87%, and those in not-pregnant cows were 86% and 91%, respectively. For ovarian status estimated by the RIA method and certified by RP, the accuracy rates of the ovarian atrophy, follicular cyst and luteal cyst were 80, 91 and 83% and the progesterone concentrations were 2.51, 2.03, and 26.7 nmol/l, respectively.

• 한국수정란이식학회지
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• 제26권2호
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• pp.105-109
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• 2011

Ovulation synchronization (ovsynch) has proved to increase the number of insemination in cattle by overcoming the problems of heat detection. The aim of this study was to do ovsynch in water buffaloes where heat detection is a major reproductive problem and to determine the conception rates after timed artificial insemination (TAI). Twenty cyclic buffaloes at ${\geq}$ 60 days postpartum were selected by examining 24 unobserved estrus buffaloes based on milk progesterone assay (progesterone concentration ${\geq}$ 1.0 ng/ml) from the Mymensingh district of Bangladesh. Ovsynch treatment regimen was started irrespective of the stage of estrous cycle. Gonadorelin (500 ${\mu}g$) was injected intramuscularly at Day 0 followed by Alfaprostol (8 mg) at Day 7. A second injection of Gonadorelin was given at Day 9 and TAI was done with frozen semen from Mediterranean buffalo bulls at 16~20 hours of the second Gonadorelin injection. Milk progesterone ELISA at Day 10~12 post AI confirmed ovulation in 16 out of 20 (80%) buffaloes (progesterone concentration ${\geq}$ 1.0 ng/ml). High progesterone concentration (${\geq}$ 1.0 ng/ml) at Day 10~12 and Day 22~24 of AI showed pregnancy in six out of 20 (30%) buffaloes. Pregnancy was further confirmed by ultrasonography at Day 40 in these six buffaloes. In conclusion, ovsynch followed by TAI could be applied in cyclic buffaloes for overcoming the estrus detection problems; however, more studies are needed to increase the conception rate.

• Asian-Australasian Journal of Animal Sciences
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• 제19권6호
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• pp.789-792
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• 2006

Two separate trials were conducted to determine the effects of uterine priming prior to first breeding and quantify any changes in the reproductive efficiency of gilts. In trial I twelve (12) gilts were randomly assigned to 3 treatments:T1:infusion of distilled water (control), T2: single infusion of killed semen (KS1), and T3: double infusion of killed semen (KS2). Each treatment had 4 breeding gilts which were bred by natural insemination (NI). In trial II, another set of 12 breeding gilts were randomly allotted to the same treatments and were subsequently bred by artificial insemination (AI). Infusions, through the use of AI catheters, were done during the $2^{nd}$ estrous cycle for T1 and T2, whereas infusions for T3 were made during the $1^{st}$ and $2^{nd}$ cycles. Regular breeding was subsequently made during the $3^{rd}$ estrous cycle. All gilts that returned to cycle were rebred within the 30-day period. In trial I (natural breeding), total piglets born was higher (p<0.05) in T2 (12.75 piglets) and T3 (11.75 piglets) than in the control (10.5 piglets). T3 obtained the highest (p<0.05) litter size (10.25 piglets) and heaviest litter weight (74.12 kg) at 28 days weaning, followed by T2 (9.80 piglets and 65.0 kg, respectively). The control yielded the lowest (p<0.05) litter size (7.50) and the lightest litter weight (47.00 kg) at weaning. For Trial II gilts (artificially inseminated), T3 gave higher (p<0.05) litter size born alive (10.88 piglets), total piglets born (11.72 piglets) and live litter weight at birth (15.30 kg) than those of T2 and the control. These results indicate that prebreeding intrauterine infusion of killed boar semen, either single or double, improved the reproductive performance of gilts.

• 한국수정란이식학회지
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• 제22권4호
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• pp.257-263
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• 2007

This study was performed to investigate the relationship between PSS-HSP70 gene polymorphism and artificial insemination (AI) reproductivity in the pigs. The RFLP polymorphism of PSS and the SSCP polymorphisms of HSP70 K1, K3 and K4 PCR product were detected different patterns. In the experiment for AI of fresh semen, spring and fall season showed higher litter size born of 10.89 head than 10.47 head of summer season. Landrace was showed higher litter size of 9.96 head than that of Duroc and Yorkshire (p<0.05). Stress relating PSS and HSP70 polymorphism of PSS-Normal, HSP70 K1-BB, K3-AB, K4-AA showd a highest litter size born of 10.97 head and litter size born alive of 10.69 head than that of the other polymorphisms(p<0.05). In the experiment for AI of frozen semen, effects of season and pig breeds were not showed for litter size born. The stress relating polymorphism of PSS-Carrier, HSP70 K1-BB, K3-BB, K4-AB showed highest litter size born of 11.29 head and litter size born alive of 10.82 head and PSS-Normal, HSP70 K1-BB, K3-AB, K4-AA showed the lowest litter size born of 8.48 head and litter size born alive of 7.33 head than that of the other polymorphisms(p<0.05). These results suggest that AI litter size born for the stress of forzen thawed semen may be affected by PSS and HSP70 polymorphism in pigs.

• 한국동물생명공학회지
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• 제36권4호
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• pp.230-238
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• 2021

This study attempted to determine the characteristic features of postpartum dairy cows during their return to estrus. Moreover, it investigated the effects of abnormal ovarian cycles (AOC) on subsequent reproductive performance and the relationship between normal ovarian cycles (NOC) and the blood urea nitrogen (BUN) level postpartum. Incidentally, 56.3% of the Holstein cows and 66.7% of the Jersey cows had NOC, whereas the 43.7% and 33.3% of the Holstein and Jersey, respectively, had AOC. Within 100 days of calving, the cows with AOC had significantly lower rates of artificial insemination (AI) submission as well as pregnancy and a significantly longer interval to first AI, as compared to that in the cows with NOC. Additionally, the cows with NOC had a significantly higher first AI conception rate than that in the cows with AOC. In this study, of the 32 Holstein cows, 8 resumed their ovarian cycle within 20 days of calving, 10 resumed the cycle with 21-40 days of calving, 8 within 41-60 days of calving, while the remaining 6 did not resume their ovarian cycles until 60 days postpartum. Furthermore, the likelihood ratios of incidence of NOC are 0.93, 1.94, and 0.38, respectively, in the groups with BUN levels < 15, 15-19.9, and ≥ 20 mg/dl. In conclusion, AOC postpartum adversely affects reproductive performance such as AI submission rate, pregnancy rate, interval to first AI and first AI conception rate; moreover, an increase or decrease in the BUN levels beyond 15-19.9 mg/dL leads to the AOC postpartum.