• 한국가금학회지
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• 제22권2호
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• pp.77-84
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• 1995

In order to investigate the effect of feeding live yeast culture on the performance of laying hens, a feeding trial was conducted with 96 20-wk-old Hy4ine brown layers during their laying period of 60 wk. The live yeast culture used was a product from Saccharomyces cerevisiae that was cultured on the corn-based substrate followed by careful drying of whole material not to lose the viability of yeast. Three levels of yeast culture as 0.5, 1.0, and 2.0% for three treatments and 0% for the control were included in the experimental diets. The feeding trial was carried out for 60 wk from August 26, 1992 to October 26, 1993. To evaluate the performance of layers during cold or hot periods as affected by the yeast culture feeding, data from the 12-wk winter period and 12-wk summer period were separated and analyzed accordingly. During 60 wk of laying period hen-day egg production was slightly but significantly(P<.05) improved by feeding the yeast culture. The average egg weight and daily egg weight(g /day) were also increased by the yeast culture. Feeding the yeast culture did not increase feed intake but feed efficiency was improved significantly (P<.05). No significant difference was detected in egg or eggshell qualities between control and yeast culture-treated groups. Feed intake and egg weight were not affected by the yeast culture feeding under both cold and hot period, but egg production and feed efficiency during hot summer improved significantly by its feeding. This result indicates that the effectiveness of the yeast culture feeding is greater during summer than winter for laying hens.

• Molecules and Cells
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• 제39권7호
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• pp.573-579
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• 2016

During copulation, male Drosophila transfers Sex Peptide (SP) to females where it acts on internal sensory neurons expressing pickpocket (ppk). These neurons induce a post-mating response (PMR) that includes elevated egg-laying and refractoriness to re-mating. Exactly how ppk neurons regulate the different aspects of the PMR, however, remains unclear. Here, we identify a small subset of the ppk neurons which requires expression of a pre-mRNA splicing factor CG3542 for egg-laying, but not refractoriness to mating. We identify two CG3542-ppk expressing neurons that innervate the upper oviduct and appear to be responsible for normal egg-laying. Our results suggest specific subsets of the ppk neurons are responsible for each PMR component.

• Asian-Australasian Journal of Animal Sciences
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• 제21권8호
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• pp.1164-1170
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• 2008

In this study, the effects of propolis and vitamin C (L-ascorbic acid) supplementation in diets were investigated on feed intake (FI), body weight (BW), body weight gain (BWG), feed conversion rate (FCR) and digestibility and on egg production and qualities (weight, mortality, shell thickness) in laying hens exposed to heat stress. A total of 150 Hyline White Leghorn, aged 42 weeks, hens was divided into five groups of 30 hens. Chicks were randomly divided into 1 positive control, 1 control and 3 treatment groups. The chicks were kept in cages in temperature-controlled rooms at $22^{\circ}C$ for 24 h/d (positive control, Thermoneutral, TN group) or $34^{\circ}C$ for 9 h/d from 08.00-17.00 h followed by $22^{\circ}C$ for 15 h (control, heat stress, HS group) and fed a basal diet or basal diet supplemented with vitamin C (250 mg/kg of L- ascorbic acid/kg of diet) or two levels of propolis (2 and 5 g of ethanol extracted propolis/kg of diet). Increased FI (p<0.05) and improvement in FCR (p<0.05), hen day egg (p<0.05) and egg weight (p<0.05) were found in Vitamin C and propolis-supplemented laying hens reared under heat stress conditions. Mortality rate was higher in the control group than TN, vitamin C and propolis groups (p<0.05). Digestibility of dry matter, organic matter, crude protein and ether extract improved with increasing of both dietary vitamin C and propolis (p<0.05). Vitamin C or propolis supplementation did not affect either the percentage shape index, yolk index or haugh unit and albumen index (p>0.05). However, the egg shell thickness and egg shell weight appeared to be increased in Vitamin C and propolis groups in comparison to HS group birds (p<0.05). In conclusion, dietary supplementation of laying hens with anti-oxidants (vitamin C and propolis) can attenuate heat stress-induced oxidative damage. These positive effects were evidenced by increased growth performance and digestibility, improvement of egg shell thickness and egg weight in comparison to non-supplemented birds. Moreover, supplementation with propolis (5 g/kg diet) was the most efficient treatment.

• 한국가금학회지
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• 제22권3호
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• pp.161-166
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• 1995

To evaluate the nutritional values of Spirulina platensis as the protein supplement for laying heo diet, two experimental diets (Control, Spirulina platensis 2%) were prepared. Total 120, 40-wk old ISA Brown layer hens were randomly employed with 15 hens per replicate and 4 replicates per treatment. Hen-day egg production, egg weight, feed intake, intake /egg weight, egg shell thickness, yolk color score and yolk cholesterol content were examined during 6 weeks of experimental period. Hen-day egg production and feed conversion ratio (intake /egg weight) were significantly (P<0.01) improved by the 2% Spirulina plalensis supplementation. However, there were no differences in egg weight and feed intake between hens fed two experimental diets. Egg from hens fed Spirulina platensis 2% diet have more yellowish yolk color than the control egg although there was no difference in egg shell thickness. Yolk cholesterol content was significantly (P

• Asian-Australasian Journal of Animal Sciences
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• 제26권6호
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• pp.831-837
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• 2013

An experiment was conducted to investigate the effects of dietary supplementation of Rhodobacter capsulatus KCTC-2583 on egg-yolk and serum cholesterol, egg production and quality parameters during the late laying periods in hens. A total of 160 Hy-Line Brown layers (54 wk-old) were randomly allotted to 4 treatment groups on the basis of laying performance. Each treatment had 4 replicates with 10 birds each (40 birds per treatment). Two hens were confined individually with cage size $35{\times}35{\times}40$ cm and each 10 birds (5 cages) shared a common feed trough between them forming one experimental unit. Dietary treatments were; basal diet supplemented with 0 (control), 0.05, 0.10 and 0.15% R. capsulatus KCTC-2583. Experimental diets were fed in meal form for 56 d. Dietary supplementation of increasing levels of R. capsulatus KCTC-2583 reduced (linear, p<0.05) egg-yolk cholesterol and triglycerides (d 28, 42 and 56) concentrations. Also, serum cholesterol and triglycerides (d 21, 42 and 56) concentrations were linearly reduced (p<0.05) with increasing dietary R. capsulatus KCTC-2583. Laying hens fed a diet supplemented with increasing levels of R. capsulatus KCTC-2583 had increased (linear; p<0.05) overall egg production, egg weight, egg mass and feed efficiency. However, dietary treatments had no effect (linear or quadratic; p>0.05) on feed intake of laying hens. At d 28 and 56, breaking strength and yolk colour of eggs were linearly improved (p<0.05) in laying hens fed dietary increasing levels of R. capsulatus KCTC-2583. Dietary treatment had no effects (linear or quadratic; p>0.05) on albumin height, shell thickness and shell weight at any period of experiment. These results indicate that dietary supplementation of R. capsulatus KCTC-2583 has the potential to improve the laying hen performance and lead to the development of low cholesterol eggs during late laying period in Hy-Line Brown hens.

• 한국가금학회지
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• 제28권1호
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• pp.1-6
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• 2001

Two experiments were carried out to evaluate the effects of adding phytase on nutrient availability and serum Ca and P level and to determine the effects of phytase on laying performance and egg quality in laying hens. In Exp. 1, twenty four laying hens(1.9kg average body weight and 78.4% egg production) were allotted to four treatments. Treatments included 1) corn-soybean meal based-control diet and 2), 3) and 4) control diet with phytase 200, 400 and 600 unit/kg, respectively. There were no significant effects of treatments on dry matter and nitrogen digestibility(P〉0.05). Ash, Ca and P digestibility in layer fed diet with phytase were greater than those in layer fed control diet(P〈0.05). Laying hens fed diets with phytase 200 and 400 unit retained more Ca than those fed other treatments (P〈0.05). No statistical difference was found for Ca exsretion(P〉0.05). P retention was greater for laying hens fed diet phytase 600 unit than other treaments(P〈0.05). P level in serum was higher for laying hens fed diets with phytase 400 and 600 unit than for laying hens fed other treatments. In Exp. 2, three hundred, IAS Brown layer, 40-week-old, divided into two treatment groups(control vs phytase supplementation without inorganic phosphate in the diets) with five replications per treatment and 30 layers per replication were fed the diets for 6 weeks. Egg production, egg weight and eggshell breaking strength and thickness were not different significantly(P〉0.05). In conclusion, phytase supplementation can be used to increase P utilization and retention in laying hens. Also, phytase supplementation was effective to spare inorganic phosphate in laying hen diets without any adverse effects on production performances.

• 한국가금학회지
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• 제50권1호
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• pp.15-22
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• 2023

본 연구는 토종 종계의 육성기 체중과 산란 능력 간의 연관성을 규명하고자 성숙 이전 주령별 체중과 이들의 초산일령, 산란율 및 난중과의 상관 관계를 분석하였다. 공시계는 (주)한협원종이 보유한 신품종 토종 종계 1,384수로써 발생부터 20주령까지의 체중과 초산일령, 초산이후 50주령까지의 일계 산란율 및 산란지수, 32주령 및 50주령 난중을 분석 대상으로 하였다. 분석 결과, 육성 초기 체중과 초산일령 간에는 정(positive)의 상관이, 육성 후기 체중과 초산일령 간에는 부(negative)의 상관이 나타났다. 육성기 체중과 일계 산란율 및 산란지수 간에는 비슷한 상관계수를 보이고, 육성전기 체중과 산란율 간에는 부의 상관이, 육성 후기 체중과는 정의 상관을 보였다. 육성기 체중과 32주령 난중 간에는 거의 상관 관계가 없는 것으로 나타났고, 50주령 난중과는 낮은 정의 상관을 보였다. 결론적으로 토종 종계에 있어서 8주령 이전까지의 육성 초기 체중과 산란 능력 간에는 거의 연관성이 없는 것으로 보여지고, 12주령 이후 육성 후기 체중과 산란 능력 간에는 정의 상관이 있는 것으로 나타났다. 이는 육성 후기 때 병아리의 체중이 증가할수록 성 성숙이 빠르고, 산란율도 높고 난중도 증가함을 시사한다. 따라서 토종 종계 모계의 경우 육성 후기 병아리의 체중 관리가 매우 중요하고, 이때 종계들의 체중이 표준 체중 이상이 되도록 유지하여야 한다.

• 한국가금학회지
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• 제39권1호
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• pp.27-32
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• 2012

This experiment was conducted to investigate the dietary effects of turmeric powder (TP) on laying performances, egg qualities and its transfer into eggs. A total of two hundred, 60-wk-old, Lohmann Brown layers were divided into 4 groups, placed in to 5 replicates per group (10 layers each) and fed each one of four diets containing 0% TP (control), 0.10, 0.25 or 0.50% TP, respectively, for 7 wks. Egg production in the all groups fed diets containing TP were significantly higher than that in control (P<0.05). No differences in feed intakes, egg and eggshell qualities were observed among the treatments, but Roche color fan number (yolk color) in group fed diet with 0.5% TP was significantly higher than in control (P<0.05). In the groups fed diets containing TP, Haugh units after 2 wk of storage were significantly higher than that of control (P<0.05). The curcumin content of egg yolk in the groups fed diet containing 0.50% TP was significantly higher than those in the other groups (P<0.05). The cholesterol levels of egg yolk were not influenced by dietary TP. It was concluded that dietary TP was effective in improving laying performance and internal egg qualities. TP can be also used as a feed additive for the production of value-enhanced eggs with increased yolk color and curcumin content.

• 한국환경과학회지
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• 제24권9호
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• pp.1233-1237
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• 2015

This study was conducted to evaluate the effects of red ginseng marc powder on egg freshness in laying hens during 4 weeks. A total of 60 Hy-line Brown laying hens, 50 week of age, were randomly assigned to 2 groups with diets containing 0% and 2% red ginseng marc powder. There were 3 replications per group with 10 laying hens per pen. Throughout the period of the trial, there were no effects of red ginseng marc powder on egg weight (but not 4 weeks). Haugh Unit (HU) values were observed by showing significant differences between red ginseng marc powder and controls at 0 and 4 weeks, except for HU at 1 through 3 weeks. For egg yolk color, red ginseng marc powder has no difference in comparison with controls at 0, 3 and 4 weeks (but not 1 and 2 weeks). In conclusion, the dietary supplementation with 2% red ginseng marc powder improved HU values throughout the experiment.

• Asian-Australasian Journal of Animal Sciences
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• 제6권2호
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• pp.243-248
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• 1993

The effect of dietary lipid factors (plant and animal oil, cholesterol and ${\beta}$-sitosterol) on the liver, serum, and egg yolk cholesterol levels of the laying hen was studied. Single Comb White Leghorn laying hens, at 28 weeks of age, were fed two basal diets containing 8.0% soybean oil or 8.0% fish oil, with or without supplemental cholesterol (1.0%), ${\beta}$-sitosterol (2.0%) or combinations of both. Restricting caloric intake resulted in significantly (p<.05) decreased egg production and the total amount of cholesterol excreted via the egg was significantly (p<.05) different among treatment groups. Cholesterol supplementation to the two basal diets resulted in a significant elevation of liver, serum and egg yolk cholesterol levels. The addition of ${\beta}$-sitosterol lowered the cholesterol levels in liver and serum, while increased in the egg yolk (SO + ST, FO + ST). The anticholesterogenic effect of dietary ${\beta}$-sitosterol was not clearly exhibited in this study.