• Asian-Australasian Journal of Animal Sciences
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• v.20 no.11
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• pp.1684-1688
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• 2007

This study examined the caponization effects on the muscle characteristics (quality and quantity) of caponized male chickens fed before or after sexual maturity. Healthy and uniform Single Comb White Leghorn chickens were caponized at 3-week-old. Feeding was conducted until 16-week-old in trial 1 or from 12-week-old to 26-week-old in trial 2. Ten sham operated male chickens (Sham) were also assigned to each trial as the control group. Chickens used in both trials were housed in individual cages with each chicken representing one replicate. The results showed that early caponization (3-week-old) significantly increased (p<0.05) body weight and pectoral major muscle weight and percentage at 16-week-old compared to the Sham in trial 1. Caponization significantly increased (p<0.05) the protein content of the pectoral major muscle, but decreased (p<0.05) the ash content. Late caponization (12-week-old) significantly decreased (p<0.05) the ash content, myofibrillar ATPase activity and emulsification capacity of the pectoral major muscle in mature capons (26-week-old) compared to the Sham in trial 2. Early caponization (3-week-old) only increased the weight and protein content of the pectoral major muscle with decreased ash content in 16-week-old capons. Late caponization (12-week-old) showed no affects on pectoral major muscle quantity, while it decreased the ATPase activity and enhanced the emulsification capacity in mature (26-week-old) capons. Hence, the muscle quality improvement was shown as capons were fed to sexual maturity.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.396-400
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• 2010

This experiment investigated the effects of increasing dietary vitamin E (VE) on production performance and egg quality traits of Indian reared Kadaknath (KN) hens. One hundred and eighty (180), day old female KN chicks were randomly distributed to three dietary treatment groups for a period of 30 weeks. Each treatment comprised three replicates, each containing 20 chicks. The basal diet ($T_1$) contained 15 IU VE/kg and the two experimental diets were supplemented with 150 and 300 IU VE/kg (diets $T_2$ and $T_3$, respectively). DL-${\alpha}$-tocopherol acetate was used as the source of VE. All chicks were provided feed and water ad libitum. Production performance in terms of body weight, egg weight and hatchability did not differ significantly (p>0.05), whereas sexual maturity, egg production and fertility differed significantly (p<0.05) in $T_2$ compared to the other two groups. Egg quality traits in terms of albumin weight, yolk weight, shell thickness, albumin index and yolk index did not differ significantly (p>0.05), whereas the Haugh unit score was significantly higher (p<0.05) in $T_2$ than the control ($T_1$) and high dose treatment group ($T_3$). From this study, it can be concluded that lower levels of dietary VE may be beneficial for production performance and Haugh unit score but have no effect on egg quality traits in Indian reared KN hens.

• Journal of Preventive Medicine and Public Health
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• v.37 no.1
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• pp.72-79
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• 2004

Objectives : This cross-sectional study aimed to quantify the relationship between the bone mineral density at the os calcis and the body mass composition in healthy children. Methods : The areal bone mineral density was measured at the os calcis with peripheral dual energy X-ray absorptiometry. The fat free mass, fat mass and percentage fat mass were measured using bioelectric impedance, in 237 Korean children, aged 9 to 12 years. The sexual maturity was determined by self assessment, using standardized series of the 5 Tanner stage drawings, accompanied by explanatory text. Results : From multiple linear regression models, adjusted for age, sexual maturity and height, the fat free mass was found to be the best predictor of the calcaneal bone mineral density in both sexes. About 15 and 20% variabilities were found in the calcaneal bone mineral densities of the boys and girls, respectively, which can be explained by the fat free mass. After weight adjustment, the percentage fat mass was negatively associated with the calcaneal bone mineral density in both sexes. Conclusions : The findings of this study suggest that the fat free mass, among the body compositions, is the major determinant of bone mineral density at the os calcis in Korean children aged 9 to 12 years. Obesity, defined as the percentage fat mass, is assumed to have a negative effect on the calcaneal bone density in children of the same weight.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.991-997
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• 2019

This study was conducted to investigate the laying period performance of two crossbred Korean native chicken (KNC) grand parent stock (GPS) layer during 20 to 40 weeks. A total of 351 20-week-old KNC GPS were allocated in a completely randomized design to give 4 birds per each cage. The chickens were fed commercial diets [i.e., week 20 - 32, crude protein (CP) 18.0% and metabolizable energy (ME) 2,850 kcal/kg; week 32 - 40, CP 17.0% and ME 2,800 kcal/kg)] and fresh water during the whole experiment period ad libitum basis. Body weight, age of sexual maturity, egg weight, hen-day egg production (HDP) and feed conversion ratio (FCR) were measured during the experiment period (week 20 - 40). The results show no significant difference in the Body weight, age of sexual maturity, egg weight, and hen-day egg production (HDP) except for egg weight. 1B had a higher egg weight on week 36 only. We expect that the reason why most factors showed no significant difference is the lack of nutrients caused by limited feeding which follows the standard feeding system for the grand-parent stock. These results provide basic information for laying data in 2-way crossbred Korean native chickens.

• Korean Journal of Poultry Science
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• v.17 no.4
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• pp.281-283
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• 1990

Ten-week-old layer type pullets were used in this study, housed 10 birds per cage(61$\times$41cm) and were replicated 15 times After raising them on a 19% protein diet up to ten weeks of age they were fed a 12% protein corn-soy control diet or one with half or all of the soybean mea replaced with ground full-fat sunflower seeds. At 19 weeks of age, pulltes were transferred to a layer house and their respective diet was gradually changed to a 13.5% layer diet containing 635% oats. The 19% protein SFS diet in treatment 2 did not show my, adverse effect on body weight or subsequent egg productio. The higher level of SES(38%) appeared to delay sexual maturity somewhat as was indicated by body weight and egg production data. However, the higher replacement of soybean with SFS(38%) in the pullet ration may not be critical for sexual maturity, but beneficial in a full laying cycle. There were no adverse effects on later stages of production.

• Journal of Aquaculture
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• v.20 no.4
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• pp.212-218
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• 2007

Reproductive biology (sexual maturity and reproductive cycle) of starry flounder Platichthys stellatus were examined by histological methods. From March 2004 to February 2005, 144 females and males were sampled. Gonadosomatic index (GSI) of female and male were peaked in May and February, respectively. Monthly changes of hepatosomotic index (HSI) showed a negative correlationwith those of the GSI. Changes of condition factor (CF) in female were correlated with gonad maturation, while that of male were no difference all the year round. Based on monthly GSI and gonadal development the reproductive cycle of starry flounder could be divided into four stages: growing stage (September to November), maturation stage (September to February), ripe and spent stage (March to May), and recovery and resting stage (June to August). Biological minimum size of female was 1,074 g. The relationship between fecundity (F) and body weight (BW) of the fish was expressed as $F\;=\;455.86BW^{1.2006}$.

• Korean Journal of Poultry Science
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• v.9 no.1
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• pp.35-42
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• 1982

Data pertaining to the first generation of a Synthetic White Leghorn flock were used to estimate the heritabilities of and genetic correlation between partial egg production(egg number or percentage) or diversely segmented part records and other traits such as age at sexual maturity, residual and annual egg production, and to compare the expected genetic gain from selection on partial egg number or partial percent production with correlated response in other traits. The estimated heritabilites for six measures of egg Production were ranged from 29 to 35, while heritability for age at sexual maturity (SM) was intermediate (48). Genetic correlations between partial egg number (P) and annual egg number. (A), and partial percent production (P') and annual percent production (A') were 51 and 72, respectively. Genetic correlation between P and SM was estimated largely negative (-.64), while correlation bettween P' and SM was positively intermediate(34). In comparing direct response from selection on partial production (P or P') with another response in correlated trait, selection on P would be 25% more efficient than selection of P' for improving A, while selection of P' would be 94% more efficient than selection P for improving A' For shortening SM selection of P would be 98% more efficient than selection on P'.

• Fisheries and Aquatic Sciences
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• v.7 no.1
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• pp.16-22
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• 2004

Plasma steroid hormone levels in the viviparous rockfish (Sebastes schlegeli) were examined in relation to gonadal histology under controlled photoperiods and water temperatures. To investigate those effects in S. schlegeli the photoperiod was maintained at 15L:9D in June and then it was gradually decreased to 9L: 15D in October. It was then gradually increased to 12L:12D in January, followed by 14L:I0D in February. The water temperature was $19-20^{\circ}C$ in July. From August to October, it was from $18^{\circ}C\;to\;12^{\circ}C$. Then, it was dropped to a low of $19-11^{\circ}C$ in November to December and then gradually increased to $14-15^{\circ}C$ in February. In females, both plasma $estradiol-l7\beta\;$ (E2) and testosterone (T) levels from August to February showed a similar pattern in both the treatment and the control groups. In the treatment group, the peaks of plasma E2 and T were observed in November, and the peaks were closely correlated to histological observations. Oocytes contained many yolk globules (final vitellogenic oocytes), and oocytes at the migratory nucleus stage increased in size. Plasma levels of progesterone did not change much throughout the experimental period. However, in the control group, the peaks of E2, T, and progesterone were observed in February. These results indicate that the controlled photoperiod and water temperature accelerated sexual maturity, corresponding to the advancement of plasma E2 and T peaks by approximately 3 months. In males, plasma T levels showed a similar pattern from August to October in the treatment and control groups, though levels in the treatment group were higher than those in the control group. From histological observations, the treatment group copulated one month earlier.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.687-694
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• 2018

This study was conducted to investigate the laying performance of six strains of Korean domestic chickens (KDC 1A, 2A, 3A, 1B, 2B and 3B). A total of 288 20-week-old KDC hens were allocated in a completely randomized design to give 12 replicates per each strain (4 chickens per pen). The chickens were fed commercial diets (i.e., week 20 - 32, crude protein [CP] 18.0% and metabolizable energy [ME] 2,850 kcal/kg; week 32 - 40, CP 17.0% and ME 2,800 kcal/kg) ad libitum together with fresh water during the 20-week experiment. Body weight, age of sexual maturity, egg weight, hen-day egg production (HDP) and feed conversion ratio (FCR) were measured during the experiment period (week 20 - 40). Our results show that strain 3B had an improved (p < 0.05) HDP and FCR compared with the other strains on week 24 - 28. However, strain 3A had an improved (p < 0.05) HDP and FCR compared to the other strains on week 28 - 40. Similarly, strain 3A had a higher egg weight (p < 0.05) compared to the other strains on week 28, 32 and 40. In conclusion, the higher laying performance of strain 3A indicates its potential in the development of a KDC strain with improved commercial laying performance.

• Journal of Korea Entertainment Industry Association
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• v.15 no.8
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• pp.63-74
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• 2021

This study focuses on the increasing supply and consumption of affair dramas on TV with the theme of unconventional 'infidelity', therefore, is an empirical study that reveals factors related to the problem consciousness of married men and women about infidelity dramas that can affect the sexual socialization of married men and women. This study investigates the effect of married men and women's right to sexual self-determination between couples, personal psychological characteristics (emotional maturity, emotional alienation, self-perception), surrounding environmental characteristics (prevalence of extramarital relationships), and demographic background (gender, age, educational background, economic level) on 'the presence or absence of critical consciousness of infidelity dramas'. For the data of this study, an online survey is conducted on married men and women(614 people), and binary logistic analysis is conducted using SPSS. As a result of this analysis, first, 46% of married men and women have a relatively good level of critical awareness of affair dramas, and overall, the level of critical thinking of married men and women about the infidelity dramas is rather low. Second, there is no significant difference between genders in the perception of problems such as 'excessive beautification of infidelity', 'incitement of infidelity' and 'damage of family values', however, married women are more critical than married men regarding 'explicit sexual description', indicating differences according to gender characteristics. Third, for married men, the level of 'self-perception' and 'marital sexual self-determination right' have a significant effect on the critical mind with infidelity dramas. In the case of married women, it is found that 'the right to sexual self-determination' between married couples and 'emotional alienation' have a significant effect on 'the presence or absence of critical consciousness of infidelity dramas'.