• Korean Journal of Poultry Science
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• v.23 no.2
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• pp.77-84
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• 1996

The purpose of this paper is to introduce the present situation of broiler breeder industry, and to investigate some problems related to it in Korea. The number of broiler breeding farms were 231 in 1990. It peaked to 264 in 1992, but decreased afterward to 232 in 1995. The number of broiler parent stock were over 4 millions since 1992 except in 1993. The number of commercial chicks produced per breeding hen was around 100, which is far below to the suggested values of breeding companies. The number of hatching eggs produced per breeding hen were 168 eggs in US, 156~170 eggs in Thailand, and 160~170 eggs in China. Factors involved in the lowered performances of broiler parent stock in Korea appear to be 1) the poor isolation of breeding farms from commercial broiler farms, causing easy contamination with various diseases, 2) the failure to provide proper environment to the breeder, and 3) the failure to control body weight during laying periods.

• Korean Journal of Poultry Science
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• v.14 no.2
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• pp.113-123
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• 1987

This study was carried out to investigate the effects of age of hen and oviposition time on egg weight, egg shell quality and e88 shape index in White Leghorn laying hens. The data were collected from 150 laying hens for about 4 months from September 1, 1986 to January 6, 1987. The results obtained from this study were summarized as follows; The percentage of the eggs produced before noon was decreased and that of the eggs produced after noon was increased as the hen gets older. Egg weight was increased rapidly to 270 days of age but after 270 days of age the rate of egg weight increase was slowly downed. The egg shell thickness became thinner and egg shell breaking strength was reduced and egg shape index was increased as the hen gets older. The egg weight was decreased as the oviposition time was proceeded and the regression coefficients of egg weight on oviposition time were -0.6788--0.4170, which means that the egg weight was decreased 0.4170-0.6788g per one hour delay of oviposition time. Egg shell thickness was increased 0. 0.00377-0.00643mm and egg shell breaking strength improved 0.0287-0.034kg/$\textrm{cm}^2$ per one hour delay of oviposition time. But it seems that there was no relationship between the oviposition time and the egg shape index.

• Korean Journal of Poultry Science
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• v.24 no.3
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• pp.127-137
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• 1997

This study was conducted to estimate the laying performance and heterosis of Korean Native Chicken(KNC), Rhode Island Red(RIR), and KNC x RIR crossbreds A total of 1,274 female pullets were produced from KNC, RIR and RIR crossbreds in National Livestock Research Institute, Korea. The experiment was conducted for 2O~64 weeks from Jan 20. to Nov.25, 1996. The age at first egg of crossbreds were 144.1~148.7 days. The first egg weight of crossbreds was 39. 4~40.3 g, and body weights at first egg of KNC dark brown strain x RlR(DR), KNC light brown strain x RlR(LR) and KNC dark black strain x RlR(BR) were 1,943 g, 1,925 g and 2,044 g, respectively. During the laying period the average viability of crossbreds was 96.6~98.3%. The hen-day egg production of crossbreds were 111.1~113.O eggs at 40 weeks of age, and 223.5~227.5 eggs at 64 weeks of age, respectively. The hen-day egg production peaks were 78.2~80.1% in KNC, and 85.8~87.5% in crossbreds. The heterosis were estimated to be 3.61%, 9.21%, 4.78%, 2.97% and -1.63% for the first egg days, body weights at first egg, layer viability, hen-day egg production, and feed conversion ratio, respectively.

• Korean Journal of Veterinary Service
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• v.29 no.1
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• pp.65-70
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• 2006

In order to detection of the intestinal parasites, fecal samples were taken from broiler (n=290), parent stock (n=168) and laying hen (n=114) in Jeonbuk province. The prevalence and identification of intestinal parasites were determined by the fecal examination using the floatation method and microscopical examination, respectively. The detection rate of parasite-eggs from 3 flocks (total=572) was 44.9%. In the breed and type of breeding, infection rate of parasite-eggs was detected 65.5% as broiler (floor breeding, 290 chickens), 20.2% as parent stock (floor breeding, 168 chickens) and 28.9% as laying hen (cage breeding, 114 chickens), in order. In the concern of mixed infection such as single and double, the rate were 40.7% and 4.2%, respectively. Six kinds of infective eggs were isolated 257 fecal sample from 3 flock. They were classified 74.7% as Eimeria spp, 18.1% as Ascaridia galli and 6.0% as Capillaria spp and 0.4% as Heteratkis gallinarum, Railleina spp or Trichostrongylus spp, single or in combination.

• Korean Journal of Veterinary Service
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• v.16 no.1
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• pp.82-89
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• 1993

In order to detection of the intestinal parasites, fecal samples were taken from broiler (n=262), laying hen(n=244), parent stock(n=207) and native stock(n=287) in Chonbuk province. The prevalence and identification of intestinal parasites were determined by the fecal examination using the floatation and /or sedimentation methods and microscopical examination, respectively. The results were obtained as follows : 1. The detection rate of parasite-eggs from 4 flocks(total=1,000) was 65.7%. 2. In the breed and type of breeding, infection rate of parasite-eggs was detected 84.0％ as native stock (floor breeding, 241 chicken), 79.7％ as parent stock (floor breeding, 165 chickens), 73.3% as broiler(floor breeding, 192 chicken) and 24.2% as laying hen(cage breeding, 59 chicken), in order. 3. In the concern of mixed infection such as single, double and triple, the rate was 55.1%, 8.7% and 1.9%, respectively. 4. Ten kinds of infective eggs were isolated from 657 fecal sample of 4 flock. They were classified 51.l% as Eimeria spp., 12.7% as Ascaridia galli, 5.1% as Capillaria spp., 4.1% as Strongyloides avium, 2.3% as Heterakis gallinarum, 0.5% as Hymenolepis spp., 0.3% as Railleina spp. and 0.2% as Syngamus spp., Trichostrongilus spp., or Choanoteania spp., single or in combination.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.772-776
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• 2010

This study was conducted to investigate the effect of dietary domestic Skullcap (Scutellaria baicalensis) extracts (SCE) on laying performance and egg quality in laying hens. There were no significant differences in feed intake, egg production, or relative liver and spleen weights. The egg weights in groups fed diets containing SCE were significantly increased as compared with the control. The number of cecal total microbes in the group fed a diet containing 0.5% SCE was significantly reduced as compared with other groups. The malondialdehyde contents in stored eggs were significantly lowered by feeding SCE. The Haugh unit in the groups fed diets containing SCE tended to be increased after 2 weeks storage, but not significantly. This result indicated that dietary domestic SCE may delay lipid oxidation in eggs when added to laying hen diets.

• Korean Journal of Poultry Science
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• v.50 no.2
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• pp.73-80
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• 2023

Vitamin D3 is an essential nutrient which plays an important role in calcium metabolism for eggshell formation, in calcium and phosphorus metabolism for bone mineralization, and in maintaining host immunity. Although there have been a great deal of studies investigating the role of vitamin D3 in eggshell quality and vitamin D3 contents in eggs, no attempts have been made to monitor the eggshell quality and vitamin D3 contents in eggs at farm level. Thus, this survey was conducted to measure eggshell quality and vitamin D3 contents in eggs laid from laying hens fed diets containing different levels of vitamin D3. Eggs from four commercial laying hen farms were sampled before and 1, 2, 3 and 5 weeks after provision of the vitamin D3-enriched diets added with the level of 16,500 IU and 29,000 IU. Dietary vitamin D3 did not affect the eggshell color and breaking strength, but increase the eggshell thickness. In addition, vitamin D3 contents in eggs were elevated as vitamin D3 in diets was increased. It is concluded that addition of dietary vitamin D3 into the diets of laying hens at the commercial laying hen farms could improve eggshell quality and vitamin D3 contents in eggs. It is expected that the prediction equation for egg vitamin D3 contents might be produced if more data on vitamin D3 contents in diets and eggs at the farms are to be analyzed.

• Korean Journal of Poultry Science
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• v.19 no.4
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• pp.177-185
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• 1992

This study was carried out to investigate the relationship between frequency of soft and broken eggs and the economic traits for colored laying hens using the data sampled 7 times in Korea from 1985 to 1991. In addition, the correlation coefficients of frequency of soft and broken eggs on the economic traits for colored laying hens in order to decrease the frequency of soft and broken eggs were studied. The results obtained were summarized as follows ： 1. For colored laying hens, mean of the sexual maturity(SM) was 163.6 days, hen-day egg Production(HDEP) was 79.49％, hen-housed egg Production(HHEP) was 272.9 eggs, egg weight (EW) was 62.69g and the frequency of soft and broken eggs was 1.363％ during 18∼72wks. For white laying hens, SM was 157.2 days, HDEP was 77.87％, HHEP was 265.1 eggs, EW was 60. 26g and the frequency of soft and broken eggs (FSBE) was 1.174％ during 18∼72wks. 2. Statistical significances were observed in laying viability, SM, HDEP, FR, BW and FSBE during 18 ∼72wks and 18 ∼78wks by year for colored laying hens. 3. Sexual maturity was shortened from 168.5 days to 155.9 days. FSBE decreased from 1.4∼l.69％ to 0.94∼o.89％ during 18∼72wks, and HDEP was increased from 74.5∼75.1％ to 77.8∼80.6％, HHEP was increased to 302.0∼304.6 eggs and FSBE was increased from 1.54∼2.02％ to 0.98％ during 18∼78wks in colored laying hens. 4. Estimate of correlation coefficients between FSBE and trait of SM, EW, 72 wks BW were 0.3985, 0.1072, 0.4225, and those of HDEP, HHEP, FR were -0.5662, -2896, -0.245 during 18∼72wks In colored laying hens, respectively. 5. Estimate of correlation coefficients between FSBE and traits of SM, EW, 78wks BW were 0.3791, 0.1171, 0.4609, and those of HDEP, HHEP, FR were -0.5041, -0.2372, -0.2421 during 18∼78wks in colored laying hens, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.2
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• pp.91-100
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• 2006

Effects of the supplement of earthworm cast produced from the feeding of organic wastes and earthworm on the productivity and nutritional constituents of functional eggs were investigated. Compared with control experiments, the case supplemented with earthworm cast showed high ratios in egg production, selection and the reserved feed. According to the experiment with earthworm, both the number of jumbo eggs and the quantity of reserved feed were increased. Therefore, the nutritional effect of earthworm in the feed was positive. The optimum percentage of earthworm cast in the feed was 10%: the average laying increased to 96.8, which was a 5% increase; the ratio of the large eggs increased by 5% although the ratio of jumbo eggs and of extra large eggs decreased by 5% and 1.1%, respectively; the average reserved feed was 662.5g. Also, Beauveria bassiana was inoculated into the feed as valuable microorganisms to prevent the growth of pathogen and to obtain essential amino acid. With the inoculatio of B. bassiana KACC 40039, the average laying was 0.82/hen and with B. bassiana HYB, it was 0.77/hen. Those numbers were three to eight percentage over the control. As for the effect of inoculation of B. bassiana in the feed on the production of broken eggs, B. bassiana KACC 40039 produced no broken eggs. Analysis of nutritional contents of eggs showed the increase in protein content and decrease in lipid content when compared with the control. According to these results, increase in the income of farmers can be expected.

• Korean Journal of Poultry Science
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• v.40 no.1
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• pp.67-73
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• 2013

With an increasing concern on laying hen welfare, barn system has appeared as one of the alternatives to replace the conventional cage. This study was conducted to compare the early laying performance and egg quality at the barn system with those at the conventional cage. A total of 288 shaver-579 brown layers were used for 9 weeks ($21^{st}$ to $30^{th}$ weeks of age) feeding study. Feed consumption and egg weight were significantly (P<0.01) higher at barn than at cage. However, there were no significant differences between two housing systems on hen day egg production (HDEP), egg mass, body weight, feed efficiency and livability. In case of egg quality parameters, shell thickness, albumen height and Haugh unit were significantly (P<0.05) different between two systems. Haugh unit and albumen height were significantly higher in eggs produced at cage (88.97 and 8.16 mm) compared than those produced at barn (83.11 and 6.87 mm), whereas shell thickness was thicker in eggs produced at barn than those produced at cage. Shape index, breaking strength, blood spots and yolk index data were not influenced significantly by the types of housing system. To implement welfare bestowing production, this study showed that the barn system can replace the conventional cage without serious sacrifices on starting phase egg production. In addition, this study suggested that the barn system need to be optimized in view of daily feed consumption.