• Korean Journal of Poultry Science
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• v.31 no.1
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• pp.55-59
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• 2004

1975년의 통계를 100으로 하여 각 연차별 증감비율을 나타내었다. 1975년도 사양농가수는 507,300호, 총 사양수수는 154,504천 수, 성계 암탉수수는 116,420천 수 및 계란 생산량은 1,787,845톤이었다. 다만 1995년도와 1998년도의 통계에는 사양수수가 300수 미만인 농가는 제외하였다.(중략)

• Korean Journal of Poultry Science
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• v.35 no.3
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• pp.275-281
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• 2008

This experiment deals with lycopene-enriched egg production in chicken and their effects on egg quality, especially antioxidant status of eggs upon their long term storage. Forty two laying hens(Hyline, 36 weeks of age) were assigned randomly to 1 of 2 diets containing 0 mg and 2 mg lycopene per kilogram feed for 4 weeks. There was a comparable concentration of lycopene in egg yolk($1.57{\mu}g$/1 g yolk) of chickens supplemented with dietary lycopene. No measurable concentration of lycopene was detected in egg yolk of chickens fed the control diet. Dietary lycopene supplementation increased egg yolk color(P<0.01), egg yolk height(P<0.08), egg yolk diameter(P<0.19), egg shell intensity(P<0.19), egg white height(P<0.33), and Haugh unit (P<0.34). After 4 week of storage of eggs in room temperature, lycopene treated eggs were tested for freshness. The ESI, EYH, EWH, HU, and EYC of lycopene treated eggs were comparably higher than those of control groups, even though there was not statistically significant difference between two groups whereas EYD of the control group was smaller than that of lycopene treated group. In conclusion, dietary lycopene supplementation to chickens might be improved egg quality.

• Korean Journal of Poultry Science
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• v.40 no.4
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• pp.361-368
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• 2013

This experiment was conducted to determine optimum levels of dietary crude protein for productivity and egg quality in laying hens during early stage. A total of seven hundred and twenty 24-wk-old Hy-Line Variety Brown layers were randomly assigned to 4 experimental diets varying with 16%, 17%, 18%, and 19% CP and fed the diets for 12 wks. There were no significant differences in egg production, daily egg mass and feed intake among experimental diets. Although no difference was found on egg weight among experimental diets, decreasing levels of dietary crude protein tended to reduce the egg weight. Haugh unit and egg shell quality were not affected by different levels of dietary crude protein. Although there was no difference on yolk color among experimental diets, increasing levels of dietary crude protein slightly reduced the yolk color. It is concluded that laying hens did not need more than 16% CP to maximize egg production.

• Korean Journal of Poultry Science
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• v.33 no.1
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• pp.41-47
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• 2006

A study was conducted to investigate the effect of supplementing earthworm meal(EWM) on the egg quality and performance of laying hens. A total of 360 laying hens at 55 weeks of age were fed the experimental diets containing 0(Control), 0.3 and 0.6% of EWM for 5 weeks. Eggs were collected and weighed in every day and egg production and feed conversion were weekly recorded. However egg quality were measured fer last week of experimental period. When fed both 0.3 and 0.6% of EWM, egg production and daily egg mass tended to increase but were not different between those treatments. Feed intake and feed conversion ratio of laying hens were not different among three groups. Egg shell thickness, breaking strength, color and egg yolk color were tend to improve in both 0.3 and 0.6% of EWM compared to those of control. The haugh units(HUs) showed no difference among each treatments at 14 after laying egg, but increased in EWM treatments compared to control for storage period. As, Cd, Cr, Hg and Pb detected 4.41, 1.23, 1.18, 0.00 and 3.39ppm in EWM, respectively, but which were not detected in control. It assumed that supplementing 0.3% of earthworm meal in the 55 weeks old laying hens diet, improved the laying performance and egg quality.

• Korean Journal of Poultry Science
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• v.32 no.3
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• pp.203-209
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• 2005

This study was conducted to evaluate the ffeding value of dried fly larva (DFL), and the effects of dietary DFL on the performance of laying hens. Ninety laying hens of 43 weeks of age(ISA brown) were randomly allotted to 5dietary treatments (0, 2, 5, 10 and $15\%$ DFL), and fed one of the experimental diets for 8 weeks. The formulae of 5 experimental diets were modified to contain $18.8\%$ CP and 2,900 ME kcal/kg. There were 3 replicates per treatment, and 6 brids Per replicate. No significant difference was found in egg Production among dietary treatments. The egg weight was increased (p<0.05) in DFL treatments compared to the control. Also, the egg shell breaking strength was increased(p<0.05) in DFL treatments by $14\%$ compared to the control. The saturated fatty acid content in egg yolk was decreased by $16\%$, and that of unsaturated fatty acid increased by $7\%$ in DFL treatments. Therefore, it could be suggested that DFL supplementation could improve the egg Qualify by increasing the egg weight, egg shell strength, and unsaturated fatty acid content in egg yolk.

• Korean Journal of Poultry Science
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• v.20 no.3
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• pp.125-131
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• 1993

This study was performed to find the desirable conditions for processing salted hard-boiled egg without cracking egg shell in NaCl solution under pressure. Among the many factors affecting saltiness of the shell egg, concentration of NaCl solution(0~40%), different salting time(0~45h) and salting pressure (0~4.5kg/$\textrm{cm}^2$) were employed to identify the permeability of NaCl into shell egg at ambient temperature. The saltiness of the shell egg was proportionally risen as concentration of NaCl solution, salting time and pressure increased. The most desirable saltiness was observed at the 0.70~1.00% of NaCl in albumen and 0.40~0.45% in yolk, Besides the saltiness, sensory evaluation of the shell egg were carried out to evaluate the quality of the salted shell egg. The effect of various concentration of NaCl solution, salting time and pressure on sensory scores of hard-boiled salted eggs showed that 20~40% of NaCl solution, 12~20 h of salting time, 3~4.5 kg/$\textrm{cm}^2$ of salting pressure were proper conditions for processing the product. These results indicate that the desirable condition to get salted hard-boiled shell egg were ; 30% of NaCl solution, 16h of salting time and 4.0kg/$\textrm{cm}^2$ of salting pressure.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.610-615
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• 2008

This experiment was conducted to investigate the effects of drinking of Rhus tree-extract on laying performance and egg quality in hens. Four hundred eighty, 55-wk-old ISA brown, laying hens were divided into six groups, control, Rhus tree-extract 500 ppm, 1,000 ppm, 2,000 ppm, 3,000 ppm and 5,000 ppm. The hens were fed a supplemented drink containing Rhus tree-extract for 12 weeks. Egg production and egg mass increased by drinking Rhus tree-extract (p<0.05) and the feed conversion ratio also improved in Rhus tree-extract groups. Cecal numbers of Lactobacillus spp., E. coli and Salmonella were not different in treatments. Availability of protein and ash improved in the Rhus extract groups. The eggshell breaking strength and egg shell thickness were significantly increased in Rhus tree-extract 3,000 ppm and Rhus tree-extract 2,000 ppm groups compared to the other groups. Also, egg yolk color and Haugh unit were significantly improved by the dietary Rhus tree-extract (p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.948-953
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• 2007

The relative performance and immune response was evaluated in White Leghorn layers fed liquid DL-methionine hydroxyl analogue-free acid (MHA-FA) relative to dry DL-methionine (DLM) in maize-soybean-sunflower based diets. Three graded levels of methionine (Met) from DLM or MHA-FA were added to the basal diet containing 0.27% Met on an equimolar basis to achieve 0.30, 0.36 and 0.42% Met in the diet. Each diet was fed ad libitum to 25 replicates of one bird (individual feeding) each, from 24 to 40 weeks of age. A regime of 16 h light was provided and all the layers were kept under uniform management throughout the experimental period. None of the parameters studied were influenced by the interaction between source and level of Met in diets. Similarly, the majority of parameters, except for daily feed consumption and immune response (influenced by level) and egg specific gravity and shell thickness (influenced by source), were not affected by either source or level of Met in the diets. Feed consumption was significantly lower in the birds fed a diet containing 0.42% Met compared to those fed lower levels of Met. The cutaneous basophilic hypersensitivity response to PHA-P and antibody titre (32 and 40 wk) to inoculation of sheep red blood cells increased significantly by increasing the concentration of Met in the diet from 0.30 to 0.36%. Thus, the Met requirement for immune competence was higher than for optimum production. The source of Met significantly influenced the egg specific gravity and shell thickness. The specific gravity and shell thickness of eggs increased significantly when MHA-FA was used as the source of Met in the diet compared to DLM. From the study it is concluded that Met requirement for immune competence (360 mg/b/d) is higher than for optimum production (300 mg/b/d). MHA-FA was comparable with DLM as a source of Met for production performance and immunity, when the bioavailability of MHA-FA was considered as 88% of DLM. Further, MHA-FA improved egg shell quality compared to DLM.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.6
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• pp.657-664
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• 1997

432 Babcock ISA white leghorn pullets reared for 8 weeks on a standard managemental conditions were exposed to feed/nutrient and light restrictions from 9 to 20 weeks of age. Four feeding regimes i. e. 100, 85 or 70 percent of the recommended allowance and low energy (2,500 Kcal/kg) low protein (13% CP) ration were fed each in the three light regimes i. e. (A) Natural day light starting from 13.24 hr/day at 8 weeks of age and ending 10.41 hr/day at the end of 20 weeks; (B) Constant 11 hr/day light and (C) starting with 13 hr/day at 8 weeks and decreasing @ 20 min/week till 20 weeks of age. At the age of 20 weeks all the birds were shifted to separate cages under uniform lighting feeding and management. During the 21st week light was increased to 12 hr a day and thereafter with an increase of 30 min per week, increased to 16 hr a day at the age of 29 weeks. From 20 weeks onward till 72 week age, all the birds were offered commercial layer rations ad libitum, prepared according to climatic conditions. The results of the study revealed that birds reared under natural and constant light had higher weights than decreasing light, yet they could not out perform during production period. The effect of feed and nutrient restriction, on the other hand, was found significant during rearing as well as production period. The birds exposed to higher level of feed and those exposed to nutrient restriction were lighter in weight. The 100% fed birds laid their first egg at an early age. However, those reared on 85% of the recommendation excelled all other groups in terms of produced number of eggs, egg mass, hen housed and hen day production and net returns.

• Korean Journal of Poultry Science
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• v.51 no.2
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• pp.27-37
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• 2024

The poultry plays a crucial role in the animal industry, providing humans with efficient, high-quality animal protein. The rapid growth and short generational intervals of broilers offer significant benefits compared to other economic animals. This growth and increased muscle mass in modern commercial broilers result from advancements in breeding. However, the high productivity of contemporary broilers indicates they are approaching their physiological limits, with excessive fat accumulation becoming a significant industry issue. This not only reduces lean meat yield and feed efficiency but also negatively impacts consumers, especially due to problematic abdominal fat, which consumes more energy than lean meat production. Laying hens, reared for extended periods, maintain high productivity, producing a substantial number of eggs. This productivity in laying hens, akin to broilers, stems from genetic selection and breeding. For egg production, laying hens require physiological support for necessary nutrients. In this context, yolk fat accumulation is a critical physiological process. Lipoproteins, essential in avian lipid metabolism, are vital for yolk and body fat accumulation. Understanding these lipoproteins and their metabolism is key to developing healthier, more productive animals, offering economic benefits to farmers and improved nutritional quality to consumers. This review focuses on the physiological aspects of dietary fat transport, fatty acid biosynthesis in the liver, fat accumulation in the abdomen and muscles, and lipid deposition in egg yolks in chickens. It also highlights recent research trends in the regulation of fat metabolism in poultry.