• Journal of Life Science
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• v.20 no.3
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• pp.381-387
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• 2010

To find offspring of Jeju Black cattle (JBC) produced by embryo transfer (ET) and artificial insemination (AI), a molecular genetic study was carried out in candidate cattle populations collected from cattle farms in Jeju Island, Korea. The genetic marker set was composed of 11 ISAG microsatellite (MS) markers, 11 SAES MS markers selected by our preliminary analysis for population diversity of JBC and two major coat color related genes: MC1R and ASIP. The results showed a combined non-exclusion probability for first parent (NE-P1) that was higher than that recommended by ISAG (above 0.9995), and a combined non-exclusion probability for sib identity of $5.3{\times}10^{-10}$. Parentage analysis showed that the cases identified the candidate's father only (77.0%), mother only (54.0%), and both parents (40.5%) in the candidate offspring population. The ET and AI calves were identified as 14.7% in the in vitro fertilized eggs provided and 32.4% in total population, respectively. However, the result from ISAG marker analysis showed 3 identical allele-combinations in 7 calves, and that from ISAG/SAES MS marker combination also showed 1 identical allele-combination in 2 calves. Data from MS and coat-color gene analyses provided information for complete identification of all animals tested. Because the present JBC population was mostly bred using small nuclear founders through bioengineering techniques such as AI and ET, the genetic diversity levels obtained from MS analysis in the JBC population were relatively lower than those of other cattle populations, including Hanwoo. The results suggested that the more efficient marker combinations, including coat color related genotypes, should be studied and used for constructing a system for identification and molecular breeding of JBC as well.

• Journal of Veterinary Clinics
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• v.28 no.4
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• pp.339-343
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• 2011

This study determined the effects of twin birth on subsequent postpartum disorders, culling and reproductive performance, and its risk factors in dairy cows. Detailed data related to reproduction, health, and calving events, including dates of artificial insemination (AI) and calving, hormonal treatment prior to conception, cow parity, twin birth, retained placenta, metabolic disorders, and endometritis were collected from 1,717 individual calvings on 9 dairy farms. The incidence rate of twin birth was 3.4%. Gestation length was shorter in cows with twin birth ($270.6{\pm}2.0$ days) than cows giving birth to singletons ($279.5{\pm}0.2$ days, P < 0.01). The incidence of retained placenta (47.5 vs. 16.0%), metabolic disorders (18.6 vs. 3.8%) endometritis (62.7 vs. 28.2%), and culling rate (32.2 vs. 16.5%) was greater in cows with twin birth than in cows giving birth to singletons, respectively (P < 0.01). The hazard of pregnancy (adjusted hazard ratio, AHR) by 210 days in milk analyzed using Cox proportional hazards model was affected by calving season, in that the rate of pregnancy for cows calved during spring was less than for cows calved during winter (AHR = 0.80; P = 0.01); this was also true for endometritis (AHR = 0.46, P < 0.01). AHR was not affected by twin birth. Logistic analysis demonstrated that increasing the cow parity (P < 0.01) and hormonal treatment prior to conception (adjusted odds ratio, AOR = 1.84, P < 0.05) increased the risk of twin birth. These results demonstrate that twin births are responsible for severe economic losses through the increased occurrence of postpartum disorders and culling; thus, appropriate management for the deleterious impact of twin birth, and/or reducing the risk factors by herd control regarding cow parity and the use of reproductive hormones prior to conception might be necessary.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.257-262
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• 1999

This study was carried out to evaluate the effect of pH and storage temperature on the viability of boar sperm diluted with extender KpA for swine artificial insemination. The results obtained in this experiment were summarized as follows : 1. The viability of boar sperm diluted with KpA was higher than that with BTS during storage and especially more than 60% of sperm viability in KpA was maintained through 6 days. The pH values of all extenders were kept during storage of semens following dilution. 2. The sperm diluted with acidic (pH 6.3~6.8) or alkalic (pH 7.8~8.0) KpA and stored at 4$^{\circ}C$ or 37$^{\circ}C$ were more sensitive in viability than that with neutral pH (6.8~7.3) and at 17$^{\circ}C$ storage. But pH values of all conditions were not increased rapidly. Especially acidic and alkalic diluents were more stable in pH after dilution. Conclusively, extender pH and storage temperature was the important factors for sperm viability. The KpA setting up around neutral pH was the optimal boar semen extender for maintaining liquid semen at 17$^{\circ}C$.

• Journal of Life Science
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• v.26 no.8
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• pp.943-947
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• 2016

The objective of this study was to see if fairly simple magnetic nano-particle treatment enhances boar semen qualities. Boar semen samples were prepared from the swine AI center and samples were divided by 4 different motility groups (1, >90%; 2. 80~90%; 3. 70~80%; 4. <70%) using computer assisted sperm analysis (CASA) evaluation. Boar semen was extended using BTS extender and same number of magnetic nano-particles as total number of spermatozoa in each sample was treated for 20 min and collected for 5 min at room temperature. Sperm qualities such as motility and viability were evaluated by the CASA before and after treatment. Sperm abnormality and degree of agglutination were also evaluated under the microscopic examination before and after treatment. There were significant changes (p<0.05) on sperm motility from all 4 different groups in the average of 7.11% after treatment. The enhancement of sperm motility changes was more clear in the groups of lower sperm motile groups (<70% and 70~80%; 19.12±1.08% and 5.67±0.71%, p<0.05). The sperm motility character in terms of curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP) and linearity (LIN, %) showed also similar pattern but motility enhancement wear more clear in below 70% motile group. Average sperm viability was increased to 4% by magnetic nano-particles (p<0.05). The percentage of sperm abnormality was also reduced significantly (p<0.05) to the range of 3.7~4.5% before after treatment. The degree of sperm agglutination was also reduced in lower motility groups by the magnetic nano-particle purification.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.177-182
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• 2006

This study was conducted to investigate the effects of melengesterol acetate (MGA) and $PGF_{2{\alpha}}$ administrations on serum progesterone level, synchrony of estrus and conception rates in Han-woo. Firstly, ten heifers and one freematin were fed 0.5 mg MGA/day for 14 days in a grain carrier, and after 19 days of MGA feeding, a single injection of 25 mg $PGF_{2{\alpha}}$ were treated. Blood samples were collected to evaluate serum progesterone concentrations from the start of feeding of MGA until the end of feeding and subsequent estrous detection and artificial insemination (AI) at 3 days intervals, and on days of $PGF_{2{\alpha}}$ injection, estrous detection, AI, and 15th and 60th days after AI. The level of progesterone in the blood began to increase from 7 days after MGA feeding, and 9 days after feeding it became 5.4 ng/ml and maintained that level thereafter. On the 33th day when the $PGF_{2{\alpha}}$ was injected, it reached the peak level of 7.6 ng/ml. However, 2-3 days after $PGF_{2{\alpha}}$ injection, it dropped to 1.4 ng/ml drastically (p<0.05). Secondly, one hundred and ninety four Hanwoo heifers or cows were divided into two groups to compare estrous induction and conception rates: the one treated with MGA and $PGF_{2{\alpha}}$, (n=104) and the other with $PGF_{2{\alpha}}$ treatment (two injections at 11 days interval, n=90). The heifers or cows treated with MGA and $PGF_{2{\alpha}}$ were identical to those used as above. The percentages of heifers or cows showed estrus were higher in the $MGA+PGF_{2{\alpha}}$ treatment (91.3%) than in the $PGF_{2{\alpha}}$ treatment (72.2%, p<0.05). Conception rates were also higher in the $MGA+PGF_{2{\alpha}}$ treatment (94.2%) than in the $PGF_{2{\alpha}}$ treatment (88.9%, p<0.05). The results of this experiment indicate that estrus synchronization using $MGA+PGF_{2{\alpha}}$ is more effective than that using $PGF_{2{\alpha}}$ (two injections) in Hanwoo.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.925-936
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• 2005

The present study evaluated whether pentoxifylline added to the freezing extender could improve the sperm characteristics and function in canine frozen semen. Also the conception rate following AI with frozen-thawed semen was investigated. The beneficial effects of pentoxifylline supplementation were visible in motility, viability, acrosome reaction, and tail swelling patterns. Especially, highest sperm viability and function were obtained in the forzen semen supplemented with 1mM pentoxifylline. The follicle size measured by ultrasonography was 6.48 mm, 11.52 mm and 8.9 mm on 11, 13 and 15 days after the onset of natural estrus, respectively and ovulation occurred on 13 and 15 days. The pregnancy rates in bitches inseminated with frozen semen on natural and induced estrus were 71.4% and 75.0%, respectively. There was no significant difference between the pregnancy rates in bitches inseminated with frozen semen following natural and induced estrus, but the litter size was slightly increased in natural cycle.

• Journal of Embryo Transfer
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• v.17 no.2
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• pp.153-162
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• 2002

In order to develop the breeding techniques to increase Hanwoo (Bos taurus coreanae) population, the present study was performed 1) to establish the treatment protocol on reproductive disorders with GnRH or PGF／sub 2$\alpha$／, 2) to improve intraovarian PG $F_{2}$$\alpha$／ administration for reducing open period. Among total of 43 diagnosed, high percentage of cows (41.9％, 18 cows) were diagnosed as silent heat, followed by inactive ovaries (32.6％, 14 cows), ovarian cysts (9.3％, 4 cows), persistent corpus luteum (7.0％, 3 cows), endometriosis (4.7％, 2 cows), pyometra (2.3％, 1 cow) and luteal cysts (2.3％, 1 cow). To treat silent heat, 18 cows were administrated with 25 mg PGF／sub 2$\alpha$／, heat-detected, artificially inseminated and monitored pregnancy. All treated cows were heat-detected and 16 cows (88％) were successfully pregnant. With 200 $\mu\textrm{g}$ GnRH treatment, 7 cows (70％) with inactive ovaries and 3 cows (75％) with ovarian cysts were successfully pregnant. Administration with 25mg PGF／sub 2$\alpha$／, successfully treated 3 cows (100％) with persistent corpus luteum and 1 cow (100％) with luteal cysts, followed by 100％ pregnancy rate. With the combined treatment of 25 mg PG $F_{2}$$\alpha$／and antibiotics, 2 cows (100％) with endometriosis were effectively treated and got pregnant after. artificial insemination (AI). In order to reduce open period, 5 mg PGF／sub 2$\alpha$／ was administrated intraovarian to 20 days cows after delivery, heat-detected, artificially inseminated and monitored pregnancy. In the first experiment, in order to recover uterus, 5mg PGF／sub 2$\alpha$／were administrated, followed by administration of 5mg PGF／sub 2$\alpha$／ at the interval of 14 days. As results, 74％ (17／23 cows) of pregnancy rate after AI. In order to further reduce the open period, 5 mg PGF／sub 2$\alpha$／was administrated at the interval of 11 days without the period of uterus recovery, resulted in 94％ (16／17 cows) pregnancy rate. In conclusion, these results showed that PGF／sub 2$\alpha$／ and GnRH treatment were effective hormonal treatment resume in Hanwoo with various reproductive disorders. In addition, modified protocol of intraovarian PGF／sub 2$\alpha$／ administration could be the effective method for reducing the open period.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.5
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• pp.605-611
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• 2015

A synthetic strain of ducks (Anas platyrhynchos) was developed by introducing genes for long duration of fertility to be used as mother of mule ducklings and a seven-generation selection experiment was conducted to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. Reciprocal crossbreeding between Brown Tsaiya LRI-2 (with long duration of fertility) and Pekin L-201 (with white plumage mule ducklings) ducks produced the G0. Then G1 were intercrossed to produce G2 and so on for the following generations. Each female duck was inseminated 3 times, at 26, 29, and 32 weeks of age. The eggs were collected for 14 days from day 2 after AI. Individual data regarding the number of incubated eggs (Ie), the number of fertile eggs at candling at day 7 of incubation (F), the total number of dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) with plumage colour were recorded. The selection criterion was the breeding values of the best linear unbiased prediction animal model for F. The results show high percentage of exhibited heterosis in G2 for traits to improve (19.1% for F and 12.9% for H); F with a value of 5.92 (vs 3.74 in the Pekin L-201) was improved in the G2. Heritabilities were found to be low for Ie ($h^2=0.07{\pm}0.03$) and M ($h^2=0.07{\pm}0.01$), moderately low for Dm ($h^2=0.13{\pm}0.02$), of medium values for H ($h^2=0.20{\pm}0.03$) and F ($h^2=0.23{\pm}0.03$). High and favourable genetic correlations existed between F and Dm ($r_g=0.93$), between F and H ($r_g=0.97$) and between Dm and H ($r_g=0.90$). The selection experiment showed a positive trend for phenotypic values of F (6.38 fertile eggs in G10 of synthetic strain vs 5.59 eggs in G4, and 3.74 eggs in Pekin L-201), with correlated response for increasing H (5.73 ducklings in G10 vs 4.86 in G4, and 3.09 ducklings in Pekin L-201) and maximum duration of the fertile period without increasing the embryo mortality rate. The average predicted genetic response for F was 40% of genetic standard deviation per generation of selection. The mule ducklings' feather colour also was improved. It was concluded that this study provided results for a better understanding of the genetics of the duration of fertility traits in the common female duck bred for mule and that the selection of a synthetic strain was effective method of improvement.

• Reproductive and Developmental Biology
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• v.32 no.1
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• pp.51-58
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• 2008

This study was performed to investigate the relation between birth weight and survivability on the production of cloned Hanwoo calves. The 580 cloned embryos were transferred into the 293 recipients. The pregnancy rate of the cloned embryos was 72.3% at 50 days after embryo transfer, and then the rate was dramatically decreased. The mean gestation lengths were 287 days in both clone (range of$279{\sim}295$ days) and artificial insemination (AI, range of $255{\sim}293$ days) calves, respectively. The mean birth weight of cloned calves (30.3kg) was significantly higher compared to that of AI calves (23.7kg) (p<0.05). Among the cloned calves, the birth weight was not different in both normal delivery (n=17, 29.9kg) and caesarean section (n=14, 32.3kg). The weight, however, was significantly higher in the clones (n=18, 32.8kg) dead within 175 days than that of the clones (n=11, 28.3kg) alive more than 175 days after birth (p<0.05). Interestingly, all cloned calves weighed <15kg (n=5) or >35kg (n=9) at birth have been dead within 175 days from the date of birth. The causes of death in the cloned calves were premature birth (n=2, 10.0%), abnormal function of lung and liver (n=2, 10.0%), abnormal function of lung (n=4, 20.0%), malformation (n=4, 20.0%), unknown (n=4, 20.0%), and sudden death syndrome (n=4, 20.0%), respectively. Our findings suggest that normal birth weight is one of the most important factors to survive more than 6 months in cloned calves.

• Development and Reproduction
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• v.5 no.1
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• pp.47-52
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• 2001

Predetermination of sex in livestock of offpring is in great demand and is of critical importance to providing for the most efficient production of the animal ariculture. Such a sexing techlology would also enhance the economy of conventional artificial insemination(AI) and aid the porcine industry. The purpose of this study was to evaluate the efficiency of enriching X-bearing porcine sperm using discontinuous percoll gradients and PCR mefhod. Semen was collected from mature boars of proven fertility center (AI center KimHae). Sperm was leaded on the isotonic discontinuous percoll gradient and then it was centrifuged at 120 ${\times}$ g for 20 minutes. After centrifugation, sperm included in each fraction were recovered (7${\times}$10$^6$ sperms/ml) and then sperm genomic DNA was extractedfor the PCR. SRY gene was used to evaluate the ratio between X and Y sperm in the separated fractions. Ju viro ffrtilization wascarried out by adding the unseparated sperm (control) or separated (experimental poop) to the matured oocytes in TCM-199. Embryos for sex determination were obtained at 2 cell stage and then was used for SRY gene amplification. After centrifugation of discontinuous percoll gradient, the most motile sperm was obtained at 95% fiaction (94.4% ${\pm}$ 5.1%, p < 0.01). The PCR analysis evaluated that 30%, 50% and 65% fractions were Y sperm rich, whereas 80% and 95% fractions were X sperm rich. PCR analysis with each porcineembryo showed that 33.3% of control and 66.7% of experimental group were determined as female embryos. In conclusion, in vitro matured oocytes inseminated with sperms (95% fraction) prepared by percoll gradient centrifugation showed high fertilization rates and female embryos than control sperms.