• Journal of Animal Reproduction and Biotechnology
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• v.35 no.1
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• pp.50-57
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• 2020

The objective of this research work was to know ovarian dynamics and pregnancy rate of cyclic Murrah buffalo cows with induced estrus by administration of prostaglandin F2α (PGF2α) and timed artificial insemination (TAI) with frozen thawed semen. A total of 31 female buffaloes were selected for the study. The buffalos having matured CL observed by ultrasonography were given one intra muscular injection of cloprostenol 500 ㎍ and TAI was performed using frozen thawed semen of Indian Murrah buffalo bull. Results showed that 90.32% (significantly, at p < 0.05) cows explore the sign of heat after injection of PG and 67.85% (significantly, at p < 0.05) cows were become pregnant out of 28 inseminated (TAI) cows. In the 28 inseminated (TAI) cows, average number of smaller and larger size of follicles were non-significantly (p > 0.05) higher at day 3 post PG injection, but the medium size of follicles was nonsignificantly (p > 0.05) higher at PG injection. At day 3 post PG injection the diameter of follicles was significantly (p < 0.05) higher, but the diameter of CL was significantly (p < 0.01) lower compared at PG injection. At PG injection the diameter of largest follicle was non-significantly differences (p > 0.05) in between pregnant and non-pregnant cows. But at day 3 post PG injection it was significantly (p < 0.01) higher in pregnant cows compared to non-pregnant cows. The number of small, medium, and large follicles at PG injection and at day 3 post PG injection were non-significantly (p > 0.05) difference in between pregnant and non-pregnant buffalo cows. Finally, it is concluded that the CL was effectively regresses and induced the sign of heat in buffalo cows and after AI the cows were become pregnant with significant rate. The study will help to the veterinarian and researcher to know the efficacy of PG injection and AI for reproductive efficiency in buffalo cows.

• Atmosphere
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• v.25 no.4
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• pp.659-667
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• 2015

In this study, sensitivity of inflow wind speed and turbulent Schmidt number to pollutant dispersion in an urban street canyon is investigated, by comparing CFD-simulated results to wind-tunnel results. For this, we changed systematically inflow wind speed at the street-canyon height ($1.5{\sim}10.0m\;s^{-1}$ with the increment of $0.5m\;s^{-1}$) and turbulent Schmidt number (0.2~1.3 with interval of 0.1). Also, we performed numerical experiments under the conditions that turbulent Schmidt numbers selected with the magnitude of mean kinetic energy at each grid point were assigned in the street canyon. With the increase of the inflow wind speed, the model underestimated (overestimated) pollutant concentration in the upwind (downwind) side of the street canyon because of the increase of pollutant advection. This implies that, for more realistic reproduction of pollutant dispersion in urban street canyons, large (small) turbulent Schmidt number should be assigned for week (strong) inflow condition. In the cases of selectively assigned turbulent Schmidt number, mean bias remarkably decreased (maximum 60%) compared to the cases of constant turbulent Schmidt number assigned. At week (strong) inflow wind speed, root mean square error decreases as the area where turbulent Schmidt number is selectively assigned becomes large (small).

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.11
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• pp.1529-1534
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• 2005

Individual-breed assignments were implemented in six swine populations using twenty six microsatellites recommended by the Food and Agriculture Organization and the International Society for Animal Genetics (FAO-ISAG). Most microsatellites exhibited high polymorphisms as shown by the number of alleles and the polymorphism information content. The assignment accuracy per locus obtained by using the Bayesian method ranged from 33.33% (CGA) to 68.47% (S0068), and the accumulated assignment accuracy of the top ten loci combination added up to 96.40%. The assignment power of microsatellites based on the Bayesian method had positive correlations with the number of alleles and the gene differential coefficient ($G_{st}$) per locus, while it has no relationship to genetic heterozygosity, polymorphism information content per locus and the exclusion probabilities under case II and case III. The percentage of corrected assignment was highest for the Bayesian method, followed by the gene frequency and distancebased methods. The assignment efficiency of microsatellites rose with increase in the number of loci used, and it can reach 98% when using a ten-locus combination. This indicated that such a set of ten microsatellites is sufficient for breed verification purposes.

• Korean Journal of Animal Reproduction
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• v.16 no.4
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• pp.301-310
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• 1993

This experiment was performed to develop simple practical methods for short term preservation of rabbit embryos. A total of 55 cross bred does were superovulated by intramuscular injection of PMSG and HCG. Embryos were recovered at 25~30 hrs, 60~65 hrs and 80~85 hrs after mating and selected by morphological examination. Four cell stage, morulae and blastocyst embryos were stored in PBS enrich with 1, 10, 20 and 40% heat-treated FCS at 4, 20, 30 and 37$^{\circ}C$, respectively. Embryos were examined morphologically at 24, 48 and 72 hrs following storage. The result obtained in this experiment were summarized as follows: The superovulation was induced by PMSG 200 IU and HCG 100 IU. The average number of ovulation points and embryos recovered by collection time were 19.0, 15.6(25~30 hr), 17.3, 13.5(60~65 hr) and 19.2, 14.4(80~85 hr), respectively. And recovery rates of embryos recovered at 25~30 hr, 60~65 hr and 80~85 hr after mating were 62.8%(4 cell), 84.7%(morulae) and 79.6%(blastocyst), respectively. On the other hand, the average number of ovulation points collected by the no, of operations for the repeated collection was 17.3(60~65 hr), 19.2(80~85 hr) in 1st and 9.4(60~65 hr), 10.6(80~85 hr) in 2nd surgery, respectively. There was a significant decrease(P<0.05) in the number of ovulation points the 2nd surgery as compared to the 1st surgery. All of the 4-cell stage embryos stored at 4$^{\circ}C$ for 48 hrs showed the same morphology throught the storage period, on the contrary, 4-cell stage embryos stored at 2$0^{\circ}C$ and 3$0^{\circ}C$ for 48 hrs showed degeneration embryos and stored at 37$^{\circ}C$ for 24 hrs showed degeneration embryos. Morulae and blastodcyst stored at 4, 20, 30 and 37$^{\circ}C$ for 24 hrs showed degeneration embryos. All of the blastocyst stored at 37$^{\circ}C$ for 72 hrs showed degeneration embryos.

• Korean Journal of Animal Reproduction
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• v.27 no.1
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• pp.53-59
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• 2003

For somatic cell nuclear transfer in Hanwoo, fetal fibroblast cell lines were established from 35, 50, 70 and 90-day fetuses of Korean native cattle. The sex of these fetal fibroblast cells were analyzed by PCR using Y-specific primers and confirmed that two cell lines were female and the other two cell lines were male. Karyotyping of these cell lines indicates that the chromosome numbers of fetal fibroblast cells were not affected by passage number and more than 80% of fetal fibroblast cells have normal chromosome number. To evaluate Go stage in cell cycle of fetal fibroblast cells, Western blotting was performed to detect the expression level of PCNA which is known to be expressed in all cell cycle stages except G$_{0}$ stage. Following serum starvation or confluent culture for 7 days, fetal fibroblast cells were effectively reached to G$_{0}$ stage. The cell cycle was resumed after culture of these Go stage-fetal fibroblast cells with normal medium. These results indicates that fetal fibroblast cells originated from Hanwoo were successfully isolated and culture system and induction of cell cycle of these cells were established for somatic cell nuclear transfer in Hanwoo.woo.

• Korean Journal of Animal Reproduction
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• v.21 no.2
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• pp.111-116
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• 1997

We determined the effects of follicular fluid fractions in the maturation medium on bovine oocyte maturation, fertilization and subsequent development, as well as on number of cells in blastocysts following culture. Follicular fluid and oocytes from bovine follicles less than 5 mm in diameter were collected from the ovaries of slaughtered cows. Follicular fluid was separated into different molecular weight fractions by untrafiltration through a membrane using a centrifuge at 500$\times$g, for 2h. For the maturation medium, follicular fluid fractions (30%, v/v), whole fluid (30%) or PVP(3mg/ml) were added to TCM 199(0.1$\mu\textrm{g}$/ml estradiol-17$\beta$, 100IU hCG). After maturation for 24h, oocytes were fertilized in vitro with bull frozen-thawed spermatozoa and cultured on a monolayer of granulosa cells for 9 days after fertilization. There were no differences in maturation rates or fertilization rates among any maturation conditions. The rates of development to >2-cell stage of the oocytes were significantly decreased when fraction of follicular fluid below 10,000 MW were added into maturation medium, compared with control and fraction above 10,000 MW(26.0% vs 40.8% to 64.0%, respectveily. p<0.01). Likewise, the rates of development to blastocysts of fertilized oocytes were significantly decreased in maturation medium containing fraction of follicular fluid (<10,000 MW). The average cell number of blastocysts derived from oocytes that matured in the fraction(>10,000 MW) of follicular fluid was 154.7$\pm$13.7. These embryos contained more cells than those matured in whole follicular fluid, or the fraction(<10, 000 MW) of follicular fluid or control(107.0$\pm$8.4, 91.8$\pm$11.8 and 95.8$\pm$6.2, respectively). In conclusion, we found that fractions of follicular fluid contained factors stimulating or inhibiting oocyte cytoplasmic matruation. These suggest that a factor(s) inducing cytoplasmic maturation of oocytes may exist in >10,000 MW fraction of follicular fluid.

• Korean Journal of Animal Reproduction
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• v.9 no.1
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• pp.56-61
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• 1985

This study was conducted in order to obtain the number and size of Leydig cell in the testis in accordance with the growth of Korean native goat. Twenty-one Korean native male goats were examied, and was divided into seven groups by 4 weeks interval from 8 to 32 weeks of age. The results were as follows: 1. The number of Leydig cells in the interstitial tissue were increased in accordance with age. The number of cells were increased twice from 1.3 cells at 8 weeks to 2.6 cells at 12 weeks of age, from 2.6 cells at 12 weeks to 5.5 cells at 24 weeks, respectively. And the cells were slightly increased from 5.5 cells at 16 weeks to 6.7 cells at 32 weeks. 2. The smallest cells were found in goats at 8 weeks of age, being 8.2${\mu}$m, and it showed noncontinual growth among groups of 12, 16 and 20 weeks of age, recording 9.18, 8.82 and 9.05${\mu}$m respectively. Leyding cells in 24, 28 and 32 weeks of age showed matured size being 10.42, 10.81 and 10.67${\mu}$m respectively. 3. Rows or clusters of Leydig cells were scattered in the loose connective tissue around lymphatic simusoids and blood vessels. Nuclei of Leydig cells were found to have 2 types, one type was stained pale and the other were stained dark. As a result of this study, Leydig cells found in the interstitial tissue were considered to grow until 20 weeks of age after birth, and reached to almost full maturated form by 24 weeks of ages.

• International Journal of Industrial Entomology and Biomaterials
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• v.20 no.2
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• pp.69-74
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• 2010

Feeding is an important aspect of insect nutrition which in turn supports growth, development, reproduction and survival. The impact of quantitative feeding on nutritional parameters of fifth instar Antheraea mylitta larvae was studied by providing fresh leaves of Terminalia tomentosa for 1 to 4 times a day. All the parameters improved upon providing fresh diets more times over the single diet (1FD). The absolute body weight increased with increase in number of feeds/day significantly (P<0.001). While the maximum weight recorded was 29.61 g in 1FD, the respective weights for two feeds/day (2FD), three feeds/day (3FD) and four feeds/day (4FD) were 39.41 g, 40.63 g and 42.66 g respectively. Feeding period and instar duration were declined (P<0.001) and survival increased significantly (P<0.001) upon increase in the number of diets. Nutritional indices like ingestion, digestion, relative consumption rate (RCR), relative growth rate (RGR) and gain in body weight increased significantly with the increase in number of feeds/day, but approximate digestibility (AD) and efficiency of conversion of ingested food (ECI) declined, while efficiency of conversion of digested food (ECD) did not change.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.27 no.4
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• pp.281-295
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• 2023

This study aims to establish and analyze a mathematical model for the transmission dynamics of male adolescent smoking and to determine an optimal control strategy to reduce male adolescent smoking. We consider three groups in the population: smokers, non-smokers, and temporary nonsmokers. In our model to which optimal control theory was applied, the number of smokers decreased sharply and the number of non-smokers increased significantly. Our simulation results under various control scenarios reveal that integrated control measures(such as prevention, education, and treatment) may be necessary to reduce the growth rate of adolescent smoking. Moreover, we concluded that efforts to encourage current smokers and temporary quitters to quit should be sustained longer than efforts to reduce the rate at which nonsmokers become smokers through smoking prevention education.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.517-522
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• 2003

Scrotal measurements and semen production records of 19,742 during 7 years from 63 Hanwoo breeding bulls(6${\sim}$7 years of age) were used to determined the relationship between scrotal circumference(SC) and semen production including concentration and total number of sperm. The average of SC is 41.2$\pm$4.54cm; extreme ranges between a low of 34cm to a high of 48cm. Quantity of semen, concentration and total number of sperm are 5.47$\pm$0.89ml/ejaculation, 16.16${\pm}2.78{\times}10^8$/ml and 88.47${\pm}15.24{\times}10^8$/ejaculation, respectively. SC is positively correlated with semen production(0.14 with quantity of semen and 0.15 with total number of sperm). Reproduction data from 16 breeding bulls produced 1,289 offspring from spring 1993 to spring 2000 to examined relationship between SC and reproduction. Rate of fertility and delivery are 0.80$\pm$0.13 and 0.78$\pm$0.15, respectively. Also, SC is positively correlated with delivery rate(r=0.26) and favorably related to fertility rate(r=0.39). These results, that is, - SC correlates positively with semen production and with reproduction -, suggested that SC should be considered when selecting breeding bull.