• Korean Journal of Organic Agriculture
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• v.16 no.2
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• pp.205-218
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• 2008

This study was conducted to evaluate the effects of dietary pitamin, pine bark extracts, as a organic livestock feed additives on the egg production and egg quality of laying hens. One hundred-fifty laying hens (Hyline brown) were randomly allocated to one of the following 3 treatment groups for 6 weeks: control, pitamin 0.1% and pitamin 0.2%. The egg production of hens fed the diet containing 0.1% pitamin was similar to that of the control; however, the egg production of the pitamin 0.2% group was significantly lower than that of the other groups (p<0.05). Additionally, the Haugh unit was higher in groups fed diets that contained 0.1% or 0.2% pitamin than in the control group (p<0.05), but no significant difference in egg shell thickness and egg shell breaking was observed between the pitamin 0.1% group and the control group. Furthermore, the concentration of cholesterol in eggs produced by the pitamin 0.1% group was significantly lower than that of the other groups (p<0.05). Moreover, the saturated fatty acid content of eggs from hens in the pitamin 0.2% group was lower than that of eggs produced by hens in the other groups, whereas the unsaturated fatty acid content of eggs produced by hens in the pitamin 0.2% group was higher than that of eggs produced by hens in the other groups (p<0.05). Finally, the values corresponding to the storage days, Haugh unit, yolk index and albumin index of eggs produced by hens that were provided with a diet that contained 0.1% or 0.2% pitamin were significantly higher than those of the control group (p<0.05). Taken together, these results suggest that providing hens with a diet supplemented with 0.1% pitamin as a organic livestock feed additives may extend the shelf-life of eggs with maintaining the egg quality and egg production in laying hens.

• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.303-310
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• 2023

The current study was conducted to compare the effect of crossbred on the body weight and laying performance of Korean native chicken from hatch to week 40. A total of 873 one-day-old chicks were divided into twelve crossbreds (i.e., CFCK, CFYC, CFYD, CKCF, CKYC, CKYD, YCYD, YCCF, YCCK, YDCF, YDCK, and YDYC) and commercial layer (Hy-Line Brown) were obtained as a counterpart in the study. All the birds are raised in battery cages (76 × 61 × 46 cm³) and then raised until 14 weeks and subsequently moved to layer battery cages (60 × 25 × 45 cm³) and raised until 16 weeks. The body weight and viability were measured biweekly from hatching to week 16. The week of 16, body weight range was about 1,010.24 to 1,411.77 g. The body weight of specific crossbreeds (i.e., CKCF, YCYD, and YDYC) was found to be comparable to that of Hy-Line Brown). The viability hatch to week 14 range was about 55 to 100% and however week 14 to 16 range was 80 to 100%. The crossbred (i.e., CKCF) recorded superior (P<0.05) viability throughout the whole experiment period, even compared with Hy-Line Brown (100% vs 96%). Our results are indicating that crossbreds Korean native chicken including CKCF, and YDYC has the potential to enhance key features of laying hens during the growing phase like optimal body weight and higher viability.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.572-576
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• 2006

본 시험은 산란계에 생균제를 급여하였을 때 산란계의 산란능력과 계분내 유해가스 감소에 미치는 영향을 규명하기 위하여 실시하였다. 산란계용 사료에 생균제를 0.2%와 0.5%를 처리한 구와 무처리의 3개 처리구를 두고 처리당 6반복, 반복당 4수씩 총 72수의 갈색 산란계(36주령)를 공시하여 6주간(42일) 사양 시험을 실시하였다. 산란계 사료에 생균제의 참가량을 증가함에 따라 산란율은 증가하였으며, 사료 섭취량은 감소하였다. 한편 계란의 품질에서는 생균제의 첨가량을 증가함에 따라 난중, 농후난백고, HU 및 난항색도가 증가하였다. 산란계의 영양소 이용율에서는 가용무질소물을 제외하고 건물, 조단백질, 조지방 및 조섬유 이용율이 생균제를 첨가함에 따라 증가하였다. 계분내 유해가스 발생량에서는 암모니아, 황하수소 및 멜캅탄 가스의 감소에 효과가 있었으며, 특히 황화수소의 감소에 효과가 있었다. 이상의 시험결과를 종합해 볼 때 산란계에 첨가한 생균제는 산란율을 증가시킬 뿐만아니라 계란의 품질 향상에 효과가 있었다. 또한 영양소 이용율을 개선하고 계분내 유해가스를 감소시키는 효과가 있었다.

• Korean Journal of Poultry Science
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• v.16 no.4
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• pp.239-252
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• 1989

The present study was carried out to investigate the improvement of major production traits with the published data of twenty-two years'random sample tests held in Korea from 1966 to 1988. Eight traits-roaring viability, laying viability, age of sexual maturity, hen day egg production, hen-housed egg production, egg weight, feed requirement, 500 days body weight-were dealt with in this study. The results obtained in this study are summerized as follows； 1. Total mean value for rearing viability was 99.4% in 1980s. Mean value for rearing viability of colored hen was 99.5% and white hen was 99.06% in 1980s. Mean value for laying viability was increased by 0.98%, 0.86% and 0.86% per year in pool data, white hen and colored hen, respectively. 2, Age of sexual maturity was decreased from 171.1 day to 160.8 day in pool data during 1960s- 1910s but increased to 162.4 day in 1980s； and decreased from 160.5 day to 1595 nay in white hen but increased from 163.7 day to 166.1 day in colored hen during 1970s-1980s. 3. Mean values for hen-day egg production were increased by 0.96%, 1.09% and 0.63% per year in pool data, colored hen and white hen, respectively. 4. Mean values for hen housed egg production were increased by 45, 5.37 and 4.23 per year in pool data, colored hen and white hen, respectively. 5. Egg weight were improved by 0.22g and 0.25g per year in pool data and colored hen but decreased by 0.03g in white hen. 6. feed requirement were improved by 0.04, 0.05 and 0.1 per year in pool data, white hen and colored hen, respectively. 7. 500 days body weights were increased by 0.38g per year in pool data but decreased by 14.95g and 10.37g in colored hen and white hen, respectively. 8. Estimate of correlation coefficient between age of sexual maturity and other factors such as hen day egg production. hen housed egg production, egg weight and 500 days body weight were -0.4512, -0.2876, -0.4376 and 0.2045 in pool data； -0.358, -0.1530 0.3475 and 0.1208 in white hen； 0.0989, 0.1181, 0.2885 and 0.2248 in colored hen, respectively. Estimates of correlation coefficient between hen day egg production and egg weight were 0.6233, -0.2259 and 0.2973 in Pool data, white hen and colored hen； between hen day egg production and 500 days body weight, 0.2417, 0.0774, -0.4787 ： between hen-housed egg production and egg weight, 0.6171, -0.2706, 0.4579： between hen housed egg production and 500 days body weight, 0.3082, -0.0792, -0.3368： between egg weight and 500 days body weight, 0.2742, 0.2205, 0.1354, respectively.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.329-337
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• 2018

To increase the mating rate of Bombus ignitus used as insect pollinator, we investigated the sexual maturity time of B. ignitus. In investigating ovary development such as the number of eggs per ovariole and spermatheca size, the time of sexual maturity of queen was 10 days after eclosion. In case of male, the number of sperm was 246 thousand at immediately after eclosion, and was highest as 480 thousand at 9 days, and tended to show a dramatic decline at 35 days (87 thousand). The more mating time, the less the number of sperm. In consideration of number of sperms, the time of sexual maturity of male was 3-15 days after eclosion. In the sexual maturity time of queen in mating, the queen was not mated at immediately after eclosion, and showed a decrease in 20 days. In terms of the rate of mating and oviposition, the favorable time for mating of queen was 9-20 days. On the other hand, the male showed 3.3% of mating at immediately after ecolosion, showed the highest of 43.3% at 6 days after eclosion, and tended to decrease in 25 days. The sexual maturity time for mating of male was 6-20 days. In summary, our results indicate that sexual maturity time of B. ignitus in reproductive organs and mating is most favorable in 9-12 days after eclosion for queen and 6-9 days for male.

• Korean Journal of Ichthyology
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• v.35 no.1
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• pp.20-29
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• 2023

In order to identify the spawning characteristics of Barbatula nuda, seven surveys were conducted from March to May 2021 in the Sangcheoncheon Stream, a tributary of the Bukhangang River, Korea. During the survey period, 890 individuals were collected, and the sex ratio of female to male was 1 : 1.34. B. nuda spawned 15 March to 24 April, when temperature was 12~15.7℃. Total length of the individual with minimum maturity was 56.7 mm, and it was a 1-year-old. Spawning was observed from individuals with a total length of 80.5 mm more, and it was 2-year-old. The total length at 50% group maturity was 67.2 mm. As a result of injecting 10 IU/g of HCG hormone into B. nuda, about 15 hours later, spawning behavior in which the male wrapped around the body of the female in a circle was observed. After spawning, females and males rested, and fertilized eggs were feed by individuals not participating in spawning.

• Journal of Sericultural and Entomological Science
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• v.15 no.2
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• pp.67.2-67
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• 1973

춘채 휴면잠종을 산란후 약 50일째에 전기충격 (electric Shock)을 줌으로서 부화의 가능성 여부를 예비실험한 결과 다음과 같은 결론을 얻었다. 1. 휴면란에 대한 전기충격은 배자의 발육을 촉진 시켰다. 2. 전기처리시간은 5초에서 비교적 부화성적이 좋았다. 3. 침산처리일로 부터 약 15∼22일 사이에 산발적으로 부화가 시작 되었다.

• KOREAN POULTRY JOURNAL
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• v.5 no.3 s.41
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• pp.59-63
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• 1973

그간 많은 양계인들이 육성율이 낮아 걱정 하는 것을 많이본다. 재래의 방법으로는 대규모로 좋은 성적을 기대할 수 없는 것이다. 본인은 한흥목장에서 육추경험 결과 20주령까지 96$\%$의 좋은 육성율을 얻었다. 양계를 처음 시작하려고 하는 분이나 대규모 양계를 하고 있는 분에게 육추실을 특별히 만들지 않고도 산란계사(평사)라면 어느 곳에든지 간단히 육추할 수 있음을 독자들에게 알리고자 저의 육추시설과 육추일기를 소개하고자 합니다.

• KOREAN POULTRY JOURNAL
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• v.5 no.4 s.42
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• pp.98-102
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• 1973

근간 많은 양계인들이 육성율이 낮아 걱정 하는 것을 많이본다. 재래의 방법으로는 대규모로 좋은 성적을 기대할 수 없는 것이다. 본인은 한흥목장에서 육추경험 결과 20주령까지 96$\%$의 좋은 육성율을 얻었다. 양계를 처음 시작하려고 하는 분이나 대규모 양계를 하고 있는 분에게 육추실을 특별히 만들지 않고도 산란계사(평사)라면 어느 곳에든지 간단히 육추할 수 있음을 독자들에게 알리고자 저의 육추시설과 육추일기를 소개하고자 한다.

• Korean Journal of Poultry Science
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• v.13 no.2
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• pp.173-178
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• 1986

Data on egg production, egg weight and egg mass were obtained from a sample of the Synthetic White Leghorn population which was raised at Poultry Breeding Farm, Seoul National University. Egg mass was not measured directly, but was calculated from the egg numbers and the average egg weight for same period. Phenotypic means, components of variance and covariance, heritabilities and genetic correlations were computed. Egg mass was estimated to be a lowly heritable trait (0.204-0.270). High heritability estimates were found for age at sexual maturity and egg weight. Genetic correlation estimates were high and positive between egg mass and egg number(combined estimates 0.711). Egg mass and egg weight were moderately correlated genetically (0.431). Genetic correlation estimates was -0.280 between egg number and age at sexual maturity, but was 0.524 between egg weight and age at sexual maturity. Results show that selection for total egg mass based on record from a single period will not be satisfactory unless the single period chosen is one in the latter part of the laying year.