• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.101-102
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• 2003

This experiment was conducted to investigate the effect of restricted feeding to pullet on growth pattern and body composition. Conventional diets(C) was formulated by NRC recommendation, and one of restricted diet started from seven to seventeen week of age(T1), and another started from twelve to seventeen(T2) with adjusted eighty percentage amount of conventional diet. Body weight decreased with starting restriction of feeding comparing to the C(P＜0.05), but reached to similar weight in all treatments at twenty week regardless restriction. All of birds started to lay egg around 1,400 to 1,450gram of body weight though the age was in order of C, T2 and T1. Fat contents of restricted group in the body were less than that of C around one thousand gram of body weight. And the tendency of body fat was similar to the first egg. After twenty week, all content of body composition were similar in all treatments. The proportion of intestinal organ weight was higher in T1 than others during restriction.

• Korean Journal of Poultry Science
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• v.27 no.2
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• pp.109-114
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• 2000

The objective of these experiments was to develop an attenuated thermostable Newcastle disease virus(NDV), CBP-1 strain isolated from infected pheasants. Safety, pathogenicity and protective effects against velogenic NDV were also investigated to evaluate if the attenuated NDV, CBP-1 strain could be a candidate for a new NDV vaccine strain. CBP-1 strain was passaged up to the 173 times by nine days old embryonated eggs and chicken embryo fibroblast(CEF) cell cultures. Its sensitivitly to lipid solvents and low pH, thermostability, mean death time(MDT), intracerebral pathogenicity index(ICPI) of one day old chicks and intravenous pathogenicity index(IVPI) of four weeks old chicks were examined. Safety, boosting and protective effects were tested by chicks mortality. CBP-1 NDV strain had significant thermostability at 56$\^{C}$ for 30 minutes. by hemagglutinin activity and egg infectivity test, but was not resistant to lipid solvent. It showed possibility to use as a feed or water vaccine because of the resistance to low pH. MDT, ICPI and IVPI of CBP-1 were attenuated from 51.5, 1.96, 2.60 to 112.4, 1.12, 1.45. These results implied that the 173rd passages in embryonated egg and CEF cell cultures induced a substantial attenuation of the pathogenicity of the parent virus, changing the virulence from velogenic to intermediate between mesogenic and lentogenic. After vaccination with CBP-1 at one day old by drinking water mortality was 17.5%. However, spray vaccination with B1 at one day old, CBP-1 at two weeks ild and challenge with velogenic Kyojeongwon strain at four weeks old showed 93.5% survival rate. Mortality of chicks, vaccination with 173rd passaged CBP-1 strain at one day old, two weeks old and challenge with Kyokeongwon strain at four weeks old, was 20.0%. The results of these studies indicated that partial attenuated CBP-1 strain tended to be a low safety for ND of broiler chicks and would need to be more successive attenuation.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.383-388
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• 2010

The chicken eye can discriminate light color, and different light wavelengths may affect reproduction ability. This study was carried out to identify effect of monochromatic light using light emitting diode (LED) in laying hens. Chickens were exposed to white light (WL), blue light (BL), yellow light (YL), green light (GL) and red light (RL) made by using LED as well as incandescent light (IL) (control). All light sources were equalized to a light intensity of 20 lux. The results indicated that the age of first egg laying and 50 % egg laying in laying hens treated under RL is significantly younger than under other lights (P<0.05). And the ovary weight of laying hens reared under RL is significantly heavier than under other at from 16 to 20 wks (P<0.05). The largest number of eggs production was produced in a group with treated with RL by 59 wks of age compared with any other group. The egg weight of YL was greater than other treatment groups from 26 to 45 wks (P<0.05). The egg shell from hens treated with RL was the strongest and thickest at 20 wk (P<0.05). These results suggest that the egg quality of laying hens reared in different spectrum of LED can be different and RL may enhance the laying performance.

• Korean Journal of Poultry Science
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• v.38 no.3
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• pp.205-211
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• 2011

This work was carried out to investigate the effect of the induced molting diet based on wheat bran on the postmolt performance of layers. Two hundred White Leghorn layers (65-old-wk) with over 80% egg production were used for 8 weeks in this work. Treatments were non-molt control (CO), fasting treatment for 10 days (FW), molt treatment with used molting diet for 4 wk (UM), molt treatment with molting diet based on corn-wheat bran for 4 wk (CW), and molt treatment with molting diet based on wheat bran for 4 wk (WM) as 5 treatments (4 replications/treatment and 10 birds/replication). Feed intake decreased at molting treatments at first weeks and increased after the 3rd week compared to control (P<0.05). Body weight (BW) loss were 18.6% of initial BW at first week in FW treatment, and were 11.4, 14.2 and 17.4% in UM, CW and WM treatments at 4th weeks (P<0.05). Egg production decreased at 1 week in molt treatment and stopped at 2 week in FW, whereas, other molting treatments didn't stop laying eggs. The birds started to lay egg at 4 week in FW and recovered at 5 week in other molting treatments. Egg quality (eggshell thickness, eggshell breaking strength, haugh unit) was high in molting treatments compared with control at 8th weeks (P<0.05). Finally, molting diet based on wheat bran affected BW loss and egg quality such as eggshell thickness, eggshell breaking strength and haugh unit.

• Korean Journal of Poultry Science
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• v.15 no.3
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• pp.211-218
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• 1988

Data on egg number from time of first lay to 71 week of age were obtained from samples of single comb white leghorn breeder and brown layer breeder populations which were raised at manny breeding Co. These data were used to estimate the heritabilities of age at sexual maturity, early egg number, residual egg number and annual egg number. Also, the genetic correlation coefficients between these traits were estimated and selection efficiencies of each segment in early part record were estimated by use of the heritabilities and generic correlations. The estimated heritabilities and standard errors in two lines(W and B) were $0.30\pm0.07$ and $0.33\pm0.08$ at early records, $0.19\pm0.06$ and $0.18\pm$0.05 at residual records and $0.37\pm0.09$ and $0.49\pm0.10$ at time of first lay. Those at annual records were $0.24\pm0.06$ equally. The estimated correlation coefficients and standard errors between early record and annual record were $0.76\pm0.08$ and $0.77\pm0.07$. Those between early record and residual record were $0.46\pm0.15$ and $0.39\pm0.16$ respectively. At improving annual egg production per year, selection based on early part record(SM to 40 week of age) would be 69% more efficient than on annual record in line W and 80% more efficient than on annual record in line B. But, if it were considered that egg weight decreased due to sexual maturity and cost for data collection, use of selected segment from 35~40week of age in line W and from 31~40 week of age in line B would be desired in spite of a. small loss in relative selection efficiency. The generation interval would not be shortened.

• Korean Journal of Poultry Science
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• v.32 no.2
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• pp.89-96
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• 2005

This studies were conducted to investigated the feeding effects of extruded broiler manure(BMERF) mixture and swine manure(SFERF) mixture on laying performance and egg qualify of laying hens. As a experimental feed, broiler manure, corn and tapioca were mixed in 50, 30 and $20\%$ to use for treated extrusion feed(BMERF, Exp. 1) and food waste(FW), swine manure and com were also mixed in 40, 40 and $20\%$ to use it(SFERF, Exp. 2) and implemented during 12 weeks, four replication and 30 chick of each treatment. The nutritional ingredients(protein, energy and calcium contents) of food waste, broiler manure and swine manure had been significantly improved(p<0.05) when handling extrusion. In the Exp. 1, the feed intake was much higher BMERF $40\%$ and BMERF $20\%$ than control and BMERF $10\%(p<0.05)$, the egg production of control, BMERF $10\%$ and BMERF $20\%$ were not significantly difference(p>0.05), but BMERF $40\%$ was significantly lower(p<0.05). The feed efficiency of control and BMERF $10\%$ were not significantly difference(p>0.05), but BMERF $20\%$ and BMERF $40\%$ were significantly lower(p<0.05). York color, White height and Haugh unit did not affected by BMERF additive. In the Exp. 2, the feed intake of control, FW $20\%$, SFERF $10\%$ and SFERF $20\%$ were not significantly difference(p<0.05), but FW $40\%$ and SFERF $40\%$ were significantly higher(p<0.05). The egg production of SFERF $10\%$ and SFERF $20\%$ were not significantly difference(p>0.05) with control, but FW $20\%$, FW $40\%$ and SFERF $40\%$ were significantly lower(p<0.05). The feed efficiency was similar tendency to the egg production, however, the egg weight, york color, white height and haugh unit were not significantly difference among each treatments(p>0.05).

• Korean Journal of Poultry Science
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• v.35 no.1
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• pp.15-20
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• 2008

This study aimed at evaluating the effects of a molting diet method in molt induction and post-molt performance of laying hens. Eighty-one ISA Brown hens at 62 wk of age were randomly divided into three groups. After a 4-wk preliminary period, a control group was fed a corn-soybean-based layer diet, and for the other groups, molting was induced by starvation (MS) or feeding a molting diet (MD). For the MS group, feed was withdrawn for 2 wk; this was followed by feeding a layer diet every other day for 1 wk and then the control diet. The MD group was fed a molting diet containing low-protein and low-energy diet based for 4 wk; this was followed by feeding a layer diet. They had a free access to their diet and water. Egg production, egg quality, feed intake, and ovary and oviduct weights were measured throughout the experimental period. During molting, the feed intake in the MD group was lower than that of the control. Body weight of the molted groups was significantly reduced. The MS group feeding totally ceased egg production within 4d; after the initiation of feeding and decreased; in the MD group, egg production to 9.3% by d 10. On d 14, the ovaries and oviducts of the molted groups were distinctly lighter than those of the control. Throughout the post-molt period, egg production and egg shell thickness of the molted group improved; but there were no significant differences. Eggs from the MD-fed or control group were heavier than those of the MS-fed or control group. Finally, feeding of a low-protein and low-energy diet effectively induces molting and increase post-molt production, but further research will be conducted to determine the effects of the molt diet with other ingredients and to reduce the energy level of the molt diet for maximizing molt induction and post-molt egg quality.

• Korean Journal of Poultry Science
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• v.45 no.2
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• pp.97-107
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• 2018

This study aimed to evaluate the dietary effect of organic sulfur (OS) supplementation on performance, egg quality and serum constituents in laying hens. A total of 360 Lohmann brown laying hens at the age of 31 weeks were distributed into four treatments having five replicates of 18 hens each until 54 weeks. The hens were fed four levels (0.0, 0.1, 0.2 and 0.4%) of OS with basal diet. The number of eggs was investigated daily, and egg quality was confirmed every 8 weeks. Sulfur content in eggs, interleukin 2 (IL-2), T help cells (CD4+) and cytotoxicity cells (CD8+) were measured at the termination of the experiment. The result of the study showed that egg production tended to increase with 0.4% OS in diet after 39 weeks of age and, there was a significant effect (P<0.05) from 47 to 54 weeks of age. Egg quality traits of albumen height and haugh unit increased significantly (P<0.05) owing to the addition of OS to the diet. The polyunsaturated fatty acids in yolk were gradually increased while saturated fatty acids were decreased with increasing levels in OS (P<0.05). Total sulfur concentration in the eggs increased significantly (P<0.05) in treatments fed OS. Moreover, albumin, AST and HDL cholesterol levels in serum improved significantly (P<0.05) owing to the addition of OS. The IL-2 concentration and the ratio of CD4+ and CD8+ in blood were generally higher (P<0.05) at 0.4% OS. Therefore, it can be recommended that supplementary OS diet affected the performance, egg quality and stimulated immune response in laying hens.

• Korean Journal of Poultry Science
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• v.11 no.2
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• pp.86-92
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• 1984

Present study was carried out to estimate phenotypic and genetic parameters influencing body weight (BW) at 4 weeks of age egg breadth (EB), egg length(EL), egg shape index (SI) and egg weight (EW) at 32 weeks of age and egg numbers (EN) up to 38 weeks of age in broiler male and female lines. The data were collected from closed White Plymouth Rock (female line; G) and Cornish (male line; C) flocks involving 1193 pullets from 211 dams and 48 sires in 1982. The results obtained are summarized as follow: 1. General performance for various trails of lines C and G. The means and standard deviations of BW, EB, EL, SI, EW and EN were 668.34${\pm}$47.18, 4.23${\pm}$0,11, 5.49 ${\pm}$0.19, 77.06${\pm}$2.98, 55.73${\pm}$3.54 and 59.72${\pm}$13.39 in line C, respectively and 487.89${\pm}$ 41.43, 4.22${\pm}$0.11, 5.51${\pm}$0.19, 76.72${\pm}$3.20, 55.43${\pm}$3.26 and 76.93${\pm}$12.17 in line G, respectively. 2. Heritability Heritabilities were estimated from sire, dam and combined components. Estimates for BW, EB, EL, SI, EW and EN from combined components were 0.30, 0.29, 0,40, 0.22, 0.45 and 0.60 in line C, respectively and 0.33, 0.23, 0.28, 0.13, 0.49 and. 0.33 in line G, respectively. 3. Correlation Genetic and phenotypic correlations showed similar trend in line C and G. Genetic correlations, estimated EW with EB and EL, were high and positive (line C; 0.99, 0.75, respectively and line G; 0.94, 0.82, respectively), also correlation of EB with EL was 0.58 (both lines; 0.58). High and negative genetic correlations were shown between SI and EL in line C and G (-0.70, -0.65, respectively). Genetic correlations between SI and EW were relatively low and negative in line C and G (-0.11, -0.19, respectively) and between SI and EN were relatively low and positive in line C and G (0.25, 0.17, respectively). Between other traits, low genetic correlations were shown in both lines, High and positive correlation was estimated between hatchability and egg shape index and polynomial regression of egg shape index on hatchability was estimated; Y=-216.77＋7.6216X-0.0146939X$^2$.

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.109-116
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• 2002

The objective of this study was to investigate the effect of feeding organic acid mixture and yeast culture on the Performance and e99 quality of laying hens fur sixteen weeks. Four hundred and fifty 19-wk-old ISA Brown layers were alloted to five treatments with five replications of each. The supplemental levels of organic acid mixture(OAM) and yeast culture(YC) in the experimental diets were 0(control), OAM 0.1, 0.2%, and YC 0.1, 0.2%, respectively. Corn -Soy basal diet containing 16.0% CP and ME 2,770 kca1/kg ME. Eggs were collected and weighed every day. Eg3 Production, fred intake and fled conversion were recorded in every four weeks. Fatty acid composition of e99 Yolk, e99she11 breaking strength, thickness and Haugh unit were measured a(her every eight weeks. Egg Production and daily egg mass of birds fed 0.2% OAM and 0.1% YC tended to be higher than those of the other treatment groups. Egg weight was the highest in hens fed with 0.2% OAM treatment, but was not significantly different. Feed conversion of hens in all OAM and YC treatments was lower than those of control, but was not statistically different. Eggshell breaking strength of hens on OAM treatments tended to be higher than those of YC treatment and control. Haugh units of the birds fed OAM was significantly higher than controls (P<0.05). 599 yolk color score of OAM treatment was higher than those of YC treatments and control, but the difference was not significant. At 27-wk-old, arachidonnic acid content in eggs from the birds fed 0.1% OAM diet was significantly higher(P<0.05) than controls. The results of this experiment indicated that dietary organic acid mixture and yeast culture tended to improve the egg Production and internal egg quality.