• Asian-Australasian Journal of Animal Sciences
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• v.4 no.3
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• pp.227-230
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• 1991

A comparative study was conducted in total thirty six large while weaner pigs of about 15 kg body weight namely boars, barrows and gilts to evaluate best sex and economic slaughter weight with one standard ration. In 159 days study period feed consumption, growth, feed conversion ratio and carcass quality were judged in all sexes of pigs at 50, 70 and 90 kg body weight. It was noted that upto 70 kg body weight the growth in boars and gills 46.0 and 49.0 kg and feed conversion ratio 4.83 and 4.81 were superior and economical over the barrows, which were 45.5 kg and 4.95. Later on there were too many fluctuations in growth and feed conversion ratio in all sexes of pigs, which would be uneconomical. Carcass quality was also better in boars and gilts than barrows, No boar taint was noted in most of the boar carcasses. Hence it is concluded that boars and gilts can be raised upto the 70 kg body weight for economic pork production.

• Animal cells and systems
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• v.13 no.3
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• pp.339-344
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• 2009

This study aims to find out the effect of heavy metals, as is the case of EDCs (endocrine disrupting chemicals), on reproductive endocrine disruption of aquatic animals. In the present experiment zinc, which is a heavy metal well known for its androgenous activity, was used. The experimental period was 24 weeks, starting in November during the inactive stage of the clam's reproductive cycle. The experimental groups were composed of one control condition and three zinc exposure conditions (0.64, 1.07, and 1.79 mg/L). The sex ratio (F:M) was 1:1.06 in the control group and 1:1.70 in all the exposed group, illustrating the tendency for higher proportion of males with increases in zinc concentration. Gonad maturity was higher in 1.07, and 1.79 mg/L groups compared to the control group, with higher maturity observed in males than females. Intersex individuals made up 24.7% of the exposed group, while females exhibited a higher ratio than the males with increasing zinc concentration. The results of this study indicate that zinc functions as an androgenic effector on the reproduction of Gomphina veneriformis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.2
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• pp.173-179
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• 2019

We investigated the ecological characteristics and proximate composition of Muraenesox cinereus off the southern coast of Korea. Anal length distribution, sex ratio, condition factor of M. cinereus individuals caught by costal complex (longline) fisheries were investigated from June to October 2018. The mean anal length was 23.5 cm, which was less than $L_{50}$, indicating that the individuals were mostly immature. Sex ratio is 9:1, we captured 382 females and 29 males, which produced a significantly different ratio (P<0.05). Condition factor remained constant over the study period. The proximate composition of M. cinereus individuals was analyzed from July to October 2018. No significant differences in moisture, crude lipid, crude protein, and ash content were observed between individuals caught in summer and those caught in fall.

• Development and Reproduction
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• v.10 no.3
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• pp.197-202
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• 2006

Sex steroids are generally considered as natural sex inducers in fish, and aromatase (cytochrome P450 aromatase) that catalyzes androgens into estrogens in the steroidogenic pathway is also known to be involved in sex differentiation. The timing of aromatase action is, thus, of central importance in the study of fish sex differentiation. We treated sexually undifferentiated tilapia (Oreochromis niloticus) larvae with $Fadrozole^{TM}$, a non-steroidal aromatase inhibitor (AI), by immersing the fish in a solution containing AI during the sex differentiation period to narrow down the critical period of aromatase action. Fish were treated once at 11 or 13 days post fertilization (dpf), or twice at 11 and 13 dpf. The concentrations of AI at each time of the treatment were 0 mg/L (control), 50 mg/L or 100 mg/L. Survival rate was not statistically associated with AI immersion treatment (p>0.25). However, sex ratio was significantly altered by the treatment, with higher concentration and double immersion being more effective in masculinizing genetic females (p<0.05). These results suggest that aromatase action for sex differentiation in this fish species would begin at least from 11 dpf which is much earlier than previously expected, and that only 3 hours of brief immersion in AI solution is powerful enough to alter genetically programed sex.

• The Korean Journal of Malacology
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• v.19 no.1
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• pp.9-17
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• 2003

The gonad index (GI), reproductive cycle with gonad developmental phases, first sexual maturity and the sex ratio of the jedo venus, Protothaca jedensis, on the coastal waters of Boryeong, Korea were investigated by histological study. Samples were collected from the subtidal zone of Boryeong, Korea from January to December, 1999. Monthly changes in the gonad index in femal and male clams gradually increased from February and reached the maximum in May, and then the values rapidly decreased from June and reached the minimum in November as seen in variations of the reproductive cycle. The spawning period of this species was once a year between May and July, there was a spawning peak between June and July when seawater temperature was over 20$^{\circ}C$. The reproductive cycle of this species in female and male clams can be classified into five successive stages: early active stage (December to March), late active stage (February to June), ripe stage (April to July), partially spawned stage (May to July) and spent/inactive stage (July to January). Percentages of first sexual maturity of female and male clams of 30.1-35.0 mm in shell length were 52.6% and 60.0%, respectively, and 100% for the clams over 45.1 mm in shell length. The sex ratio of individuals > 30.1 mm in shell length was 1:1 (X$^2$ = 0.40, p > 0.05).

• Journal of fish pathology
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• v.23 no.2
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• pp.211-219
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• 2010

Specimens were collected from the coastal region near industrial complex of Ulsan-Onsan, Sihwa-Ansan and Yeosu-Gwangyang in 2008 and 2009. The total number of individuals used in analysis was 1,289 of Acanthogobius flavimanus, Chelon haematocheilus, Hemibarbus labeo, Leiognathus nuchalis, Mugil cephalus and Synechogobius hasta. The sex ratio in the total individual was 1:0.73 (female:male). Specific sex ratio of fishes in the areas, namely the Ulsan-Onsan, Sihwa-Ansan and Yeosu-Gwangyang were 1:0.79, 1:0.81, and 1:0.25, respectively. Especially, female in Yeosu-Gwangyang was higher than male. The intersexuality in the total individual was 11.7%. Intersexuality of fishes in the areas were 4.98, 14.39 and 25.0% in the Ulsan-Onsan, Sihwa-Ansan and Yeosu-Gwangyang, respectively. It was indicated female higher than male in Ulsan-Onsan and male higher than female in Sihwa-Ansan and Yeosu-Gwangyang.

• Journal of Animal Science and Technology
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• v.65 no.4
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• pp.779-791
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• 2023

This study aimed to assess the effects of embryonic developmental stage, quality grade, and fresh or frozen/thawed conditions on the pregnancy rate and sex ratio of live offspring in Hanwoo (Bos taurus coreanae) cows. The quality and developmental stage of in vivo-derived (IVD) transferred embryos were evaluated using the standard criteria of the International Embryo Technology Society. The recipient cows were synchronized using conventional (estradiol benzoate and progesterone) protocols before embryo transfer. Embryos were transferred to 297 cows, and pregnancy was monitored for 60-70 days after embryo transfer. The pregnancy rates of fresh and frozen/thawed embryos were 56.90% and 52.49%, respectively. Pregnancy rates varied according to embryo quality (56.18% for grade 1 vs. 36.67% for grade 2). Pregnancy rates also varied by developmental stage and cryopreservation (67.86% vs. 63.49% for stage 4-1, 64.00% vs. 54.72% for 5-1, and 50.00% vs. 47.83% for 6-1, in fresh embryos vs. frozen/thawed embryos, respectively). For stage 7-1, the pregnancy rates were 72.73% for fresh embryos and 20.00% for frozen/thawed embryos. In 66 fresh embryos, the sex ratio of live offspring was 5:5, whereas it was 4(female):6(male) for frozen/thawed embryos among the 95 frozen/thawed embryos. The miscarriage rate was approximately 3% higher for frozen/thawed embryos than for fresh embryos (18.1% for fresh vs. 21.1% for frozen). Seasonal fertility rates were 33.3% in spring, 55.67% in summer, 52.8% in autumn, 60.0% in winter. The following male-to-female ratios were observed in different seasons: 6.7:3.3 in spring, 4.0:6.0 in summer, 5.5:4.5 in autumn, and 3.3:6.7 in winter. The current data revealed no significant differences in pregnancy rates between fresh and frozen/thawed IVD embryos. However, there was a lower pregnancy rate with advanced-stage frozen/thawed embryos (stage 7-1). The current study provides comprehensive results for the better optimization of embryo transfer in Hanwoo cattle to obtain the desired fertility rate, pregnancy rate, and sex ratio of calves. These results provide important insights into the factors that influence the viability and success of IVD embryo transfer in Hanwoo cows and may have practical applications for improving breeding programs and reducing production costs.

• Journal of the Korea Fashion and Costume Design Association
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• v.6 no.2
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• pp.123-133
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• 2004

This research analyzed the role of sex and clothing in the seventh version of elementary school textbook-Korean. Analyzed materials were described contents and illustrations or pictures in textbooks - Korean of the wholeclasses with content analysis. The followings are the summary of the results. First, the proportion of males to females is 55.6%. Second, the proportion of female's skirts to trousers is 80.6%. Third, the proportion of female's long hair style to short hair style is 61. 9%. Fourth, mother and female-teacher clothes mainly show skirts. Fifth the results compare father's working with mather's in home: fathers mainly spend the time with family and mothers mainly cook and play roles of housewife. As it was shown above, the ratio of sex in textbooks of elementary school has a tendency to be unfair. Clothing and apperearances of female don't also reflect the present actual tendency. Contents of textbooks are apt to emphasize on the traditional feminine attitudes.

• Ocean and Polar Research
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• v.30 no.4
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• pp.401-406
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• 2008

Early gonadal development and sexual differentiation of dark-banded rockfish (Sebastes inermis Cuvier) were followed from parturition to 400 days post parturition (dpp). During this period, average total length (TL) increased from 0.57 to 13.18 cm. Primordial germ cells (PGCs) were first detected at 0.68 cm TL (10 dpp). When fish reached 1.52 cm TL (50 dpp), initial stages of ovarian differentiation were identified by the presence of PGCs containing condensed chromatin and their transformation into meiotic oocytes. At 10.23 cm TL (300 dpp), the ovaries gradually developed into oocytes in the primary yolk stages. Ovary growth was rapid after sex differentiation, but testis tissue continued to multiply without growing until fish reached 6.97 cm TL (200 dpp), after which the production of spermatocytes, spermatogonia, and cyst cells was apparent. Histological analysis of gonadal structure suggested a gonochoristic sexual development pathway. Our analysis of the sex ratio at 400 dpp showed a significantly higher proportion of males.

• Korean Journal of Veterinary Research
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• v.28 no.2
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• pp.307-310
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• 1988

This experiment was carried out to provide the data of blood chemistry in use of application to clinical diagnosis in racehorses. Blood was collected from 30 racehorses(♀ 17, ♂ 13). Calcium, inorganic phosphorus, blood glucose, blood urea nitrogen, cholesterol, bilirubin, fibrinogen and ketone body in serum were analyzed as follows. 1. The values of calcium and inorganic phosphorus were maintained a certain level without much variation regardless of sex and species, Ca/P ratio was in the range of 3.13~3.35. 2. The value of blood glucose was 60 mg/100ml, Age and sex of racehorses make no difference in the value. 3. The value of blood urea nitrogen and total cholesterol showed a tendency to increase according to the age. Total cholesterol value was somewhat higher in male than in female. 4. The value of total bilirubin showed a tendency to increase according to the age. There was no difference between sexes in the value. 5. The value of fibrinogen showed no apparent difference with age and sex. 6. Ketone body was negative in all of the cases. 7. There was no variation in the species of the racehorses.