• Korean Journal of Animal Reproduction
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• v.20 no.3
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• pp.353-360
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• 1996

The study was conducted to determine the optimal cumulus cells, glucose and superoxide dimutase(SOD) levels during the in vitro culture of bovine oocytes matured and fertilized in vitro for morulae and blastocyst development. Oocytes were cultured for 0~8 days in TCM-199 medium supplemented with 20% FCS, cumulus cells and with different glucose and SOD levels. The results are summarized as follows; 1. The in vitro developmental rates of bovine oocytes cultured in TCM-199 medium containing cumulus cells and 0.1, 0.5, 1.0, 5.0mM glucose levels 0~3 and 0~8 days after insemination were 21.1, 25.0, 23.3, 17.9 and 26.3, 25.7, 23.1, 19.4% respectively and there was significant differences on the development to the molurae and blastocysts stage among the cumulus cells and glucose levels. 2. The in vitro developmental rates of bovine oocytes cultured in TCM-199 medium containing 0.1, 0.5, 1.0, 5.0mM glucose levels 0~3 and 0~8 days after insemination were 11.3~24.5% and 17.3~25.0%, respectively. 3. The in vitro developmental rates bovine oocytes cultured in TCM-199 medium containing 100, 200, 300, 500 $\mu\textrm{g}$/ml SOD levels 0~3 and 0~8 days after insemination were 12.5~22.9% and 12.9~22.2%, respectively. Hight levels of SOD(500$\mu\textrm{g}$/ml) significantly reduced the rates ofmolurae and blastocysts stage(P<0.05).

• The Korean Journal of Malacology
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• v.31 no.3
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• pp.171-178
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• 2015

The reproductive ecology of freshwater bivalve, Unio douglasiae in Lake Uiam were examined from March 2014 to February 2015. The gonads distributed in reticular connective tissue, the dioecious clams take an internal fertilization and fertilized eggs are stored in the foster-sack in the gills, then the hatched juveniles are released outside after an ovoviviparous process. The gonad index (GI) began to increase in April, reached the maximum value in July and to decrease in August. The reproductive cycle of U. douglasiae can be divided into five successive stages: multiplicative stage (November to January), growing stage (February to March), mature stage (February to May), spawning stage (April to September), recovery stage (August to December). The spawning periods were from April to September, and the main spawning occurred between April and July. The shell length at 50% group maturity was estimated to be 29.4 mm.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.614-620
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• 2002

The sea bass, Lateoiabrax japonicus is a highly valued fish in aquaculture in South Korea. For establishment of seedling production of sea bass,1 japonicus, we examined change of gonadal development and plasma steroid levels of sea bass reared in indoor tank. Male matured unsimultaneously faster than females and spawning of females took place between the end of January and March. After the spawning period, and until the following January, all the females were in preyitello genesis and in some males, spermatogenetic activity restarted gradually. In October, under reducing photoperiod, cortical alveoli appeared in growing oocyte and the development of spermatogenesis greatly increased. Between October and february, vitellogenesis and spermatogenesis occurred respectively in female and male and gonadosomatic index increased from 4.31 to $24.07\%$ in female and upper 6o/o in male. Also, two sex hormones were analyzed during the course of a reproductive cycle in the sea bass: plasma levels of the gonadal steroid testosterone (T) and estradiol-l7$\beta$ (E_{2}). Variation of the plasma concentrations of T and E, appeared to depend on gonad stages. Plasma T and E, levels were high from November to January, suggesting that an sufficient gonadal stimulation by both hormones may undergoing a processes for the formation of sperm and oocyte.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.224-230
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• 2019

The purpose of the study is to investigate the change in the blood progesterone (P4) and estrogen (E2) levels when applying different estrus induction protocols to Korean black goats, and this was done to gain understanding about their reproduction physiology. For the experiment, we performed three estrus induction protocols that are commonly used in bovine: controlled internal drug release (CIDR) + prostaglandin $F2{\alpha}$ ($PGF2{\alpha}$), $PGF2{\alpha}$ + gonadotropin-releasing hormone (GnRH) + $PGF2{\alpha}$, and CIDR + $PGF2{\alpha}$ + PMSG. The P4 and E2 concentrations showed different patterns until the last treatment of the three protocols. However, similar concentration patterns were shown after the last treatment in all the protocols. In conclusion, we monitored the blood P4 and E2 levels in Korean black goats following three different estrus induction protocols. Our findings may be used in other breeding programs of Korean black goats, such as artificial insemination and embryo transfer.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.615-626
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• 2022

This study investigated the habitat characteristics and spawning ecology of Hippocampus haema (Syngnathidae) in Soando Island, Korea, from May 2015 to December 2016. The survey site where seahorses inhabit was mainly formed by seagrass of Zostera marina populations. Total density and biomass (Mean±SE) of Z. marina were the highest at 136±14.4 shoots/m² and 489.8g DW/m², respectively, in spring (May), while the total density was lowest at 93±7.0shoots/m²in autumn (October), and biomass was the lowest and at 122.3g DW/m² in winter (February). During the study period, 293 individuals were identified through a diving and kick net survey, and the total length of H. haema ranged from 10.1 to 87.0mm. Male individuals nurturing fertilized eggs or larvae appeared beginning in May and were collected until October in both 2015 and 2016. Juvenile individuals were captured beginning in July 2015 and June 2016. As a result of a comprehensive analysis of the spawning season characteristics, it was estimated that the spawning season of H. haema was from April to October. The number of fertilized egg or larvae inside the male brood pouch were 38.3±14.8 (20-76), and the number of fecundity identified from female were 47.2±8.6 (31-59). The male-to-female ratio of H. haema was 1:1.7, indicating the dominance of males.

• Journal of Embryo Transfer
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• v.20 no.1
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• pp.25-33
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• 2005

This study is a part of research that development of effective genetic resources preservation system using the in vitro spermatogenesis, in vitro insemination and culture system. We aimed for establishment of in vitro culture system with in vitro activated porcine oocytes. The porcine oocytes were matured for 48 hours in $TCM199+10\%$ FCS and activated with $7\%$ ethanol. The activated oocytes were cultured for 7 days in $TCM199+10\%$ FCS or $NCSU23+0.4\%$ BSA medium. The activated oocytes were not developed to the blastocyst stage in $TCM199+10\%$ FCS medium. However in $NCSU23+0.4\%$ medium, those were developed to blastocyst with $3\%$ of treated oocytes. We extended maturation duration of porcine follicular oocytes fur 48, 52, 56, 60, 64, 68, and 72 hours and activated with $7\%$ ethanol and cultured using $NCSU23+0.4\%$ BSA medium. The six percents of activated oocytes were developed to blastocyst in 48 hours and $10\%$ in 52 hours with comparatively low rates suggested to be not fully activated by regenerated MPF. Maturation durations from 56 hours to 68 hours supported to develop upto $11.9\~18.3\%$ of blastocysts. However the developmental rate was declined to $7.2\%$ at 72 hours of maturation duration because of cytoplasmic deterioration. The assumed time window for activation will be $56\~68$ hours of maturation duration. When the matured oocytes were activated with electric pulse of 1, 1.2, 1.4, 1.6, 1.8 and 2.0kV/cm for $80{\mu}s$, although appling the electric current once was not enough for activation, appling twice with 1.6kV/cm for $80{\mu}s$ was shown the highest developmental rate with $11.3\%$. When those were compared with activating methods, $15.7%$ of blastocyst rate was obtained in the $7\%$ ethanol. That was higher than those in electric pulse with $9.5\%$ and calcium ionophore method with $5.8\%$. In this experimental condition, the $7\%$ ethanol treatment was the most effective method for activating porcine oocytes.

• Korean Journal of Poultry Science
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• v.31 no.1
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• pp.9-15
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• 2004

This study was conducted to evaluate the effects of dietary herbal plant mixture on the performance in laying hens under heat stress. One hundred ninety two 54-weeks-old ISA Brown commercial layers, were used in 56 d experimental assay. Dietary treatments included CON (control; basal diet), HPM0.05 (basal diet ＋ 0.05% herbal plant mixture), HPM0.1 (basal diet ＋ 0.1% herbal plant mixture), and HPM0.2 (basal diet ＋ 0.2% herbal plant mixture). For overall period, the hens fed with HPM0.1 and HPM0.2 diets showed lower in the hen day egg production than the hens fed with CON diet(P＜0.05). At the end of the experimental period, egg weight was heavier in HPM 0.1 treatment than in CON (P＜0.05). There were no significant differences among the treatments in egg shell breaking strength, egg shell thickness, Haugh unit, and yolk color unit. Total cholesterol concentration of yolk tended to decrease as the level of herbal plant mixture in the diet increased. Total protein of blood was higher in the hens fed with herbal plant mixture than in the hens fed with CON diet (P＜0.05). Albumin concentration of blood was increased in HPM0.05 and HPM0.1 treatments compared with CON(P＜0.05). Red blood cell (RBC) and white blood cell (WBC) concentrations in serum were increased in HPM0.1 and HPM0.2 treatments compared with CON treatment (P＜0.05). In conclusion, dietary herbal plant mixture in laying hens under heat stress adversely affected egg production but increased total protein, albumin, RBC and WBC in blood.

• Journal of Embryo Transfer
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• v.21 no.1
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• pp.59-67
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• 2006

To evaluate the functional status of ovarian cyst in Korean native cows, progesterone ($P_4$) and estrogen ($E_2$) level of cystic follicular fluid, ultrasonography for measuring the cystic diameter and thickness of cystic wall, and histological findings were investigated in cystic ovaries from slaughtered Korean native cows. Ovarian cysts were classified as single follicular cyst 51 cows (59.3%), multiple follicular cysts 19 cows (22.1%), single luteal cyst 13 cows (15.1%) and multiple luteal cysts 3 cows (3.5 %) by anatomical and ultrasonography. Ovarian cysts were classified as follicular cysts (54 cows), luteal cyst (16 cows) and non-functional ovarian cyst (16 cows) by hormone analysis, anatomical finding and ultasonography The luteal cyst was accurately diagnosed by cystic wall thickness, but follicular cysts was misdiagnosed 16 cows of 70 cystic cows The cystic fluid $P_4$ concentration was 3.3 ng/ml in follicular cysts and 30.1 ng/ml luteal cysts. There was significantly positive correlations between cystic wall thickness and serum $P_4$ concentration in follicular ($r^2=0.59$, p<0.001) and luteal cysts ($r^2=0.65$, p<0.001). These results indicated that ovarian cysts had various stages of degeneration and luteal cyst was accurately diagnosed measurement of cystic wall thickness by ultrasonography, but follicular cysts were not diagnosed only cystic diameter and cystic wall thickness.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.217-223
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• 2006

This study was carried out principally to obtain the basic data for the improvement of the reproductive performance and production using plasma progesterone assay and ultrasonography in dairy cow. The results obtained from this studies were as follows. The results of reproductive examination in 85,983 cows were ovarian diseases 40,399 (47.0%), uterine diseases 11,912 (13.9%), pregnancy or pregnant failures 26,587 (30.9%), adhesion of reproductive tracts 172 (0.2%), freemartin 8 (0.01%), and others 6,905 (8.3%), respectively. The treatment status of reproductive dysfunction in 30,241 cows were silent heat or error of estrus detection 14,909 (49.3%), follicular cysts 3,750 (12.4%), luteal cysts 907 (3.0%), inactive ovaries 665 (2.2%), granulosa cell tumor of ovary 3 (0.01%) and endometritis 6,986 (23.1%), respectively. The indices of reproductive efficiency after the periodical examination of reproductive status were as follows; the mean intercalving inteual was reduced from 475 days at the first examination to 381 days at the last examination of reproductive status, the mean interval calving to conception was reduced from 186 to 98 days, the mean interval calving to first service was reduced from 106 to 66 days, the cows showing heat by 60 days postpartum were increased from 32 to 90%, the mean conception rate to first service was increased from 42 to 64%, and the mean service per conception was reduced from 2.6 to 1.8 times, respectively.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.311-319
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• 2014

Early sexual maturation through temperature stimulation was induced in female and male of yezo scallop. Gonadosomatic index (GSI) in female showed $9.12{\pm}2.9$ in January, $14.89{\pm}2.9$ in February and $21.3{\pm}1.4$ in March in experiment I. GSI in experiment I showed a significant increase (P < 0.05) and in experiments II and III were not show significant variations (P > 0.05). It also showed significant between the control and the experiments I, II, and III in February (P < 0.05) measurements. Experiment I has showed good results in sexual maturation and spawning when compared with other experiments II and III and the control. Histological observation showed that ovary condition was in a growing stage in all the experiments I, II, and III. In February, ovary condition through histological observation was a late mature stage in all the experiments I, II, and III except the control of a growing stage. GSI and gonad weight were $4.4{\pm}0.88$ and 2.8 g, respectively in November whereas it was $15.1{\pm}2.8$, and 11.7 g, respectively in January and $21.7{\pm}5.4$, and 19.4 g, respectively in February after rearing at a water bath of $12^{\circ}C$ depending on the condition of experiment I. It was possible early releasing of eggs and sperms of yezo scallop in February instead of the middle of April to the end of May being spawning period. Fertilized eggs have become a gastrula stage through a spiral cleavage and then become a trochophore larvae after 36 hours. After 10 days, D-shaped larvae have changed into an umbo stage larvae and attached to juveniles in the post larvae after 20-23 days.