• Korean Journal of Poultry Science
• /
• v.28 no.3
• /
• pp.187-192
• /
• 2001

The repeatabilities on Yolk percentage and yolk to albumen (Y:A) ratio of the eggs produced consecutively were investigated. The differences between two yolk lines in major egg characteristics were also evaluated. The investigations using one hundred ISA-Brown layers were conducted at 29 wk, 33 wk, 38 wk, and 43 wk of age. At the initiated age (29 wk of age) of the experiments, the birds producing eggs with lower or higher Y:A ratio than the overall mean Y:A ratio were classified as Low Yolk Line (LYL) or High Yolk Line (HYL), respectively. Overall, the eggs of LYL were significantly (P<0.05) lighter in yolk weight and lower in yolk percentage for the whole egg weight and Y:A ratio, but heavier in egg weight, albumen weight, and shell weight than those of HYL. The overall mean correlations among the three consecutive laying days in Y:A ratio showed highly significant (P<0.001) in both lines. At four different ages, the mean phenotypic correlation coefficients (r$_{p}$) among the three consecutive laying days in Y:A ratio also had very high significant(P<0.01 ~ 0.001) positive values. The egg weight was more closely associated with albumen weight than with yolk weight in both yolk lines.s.

• Korean Journal of Environmental Biology
• /
• v.33 no.4
• /
• pp.419-424
• /
• 2015

In order to determine the ovarian cycle of Asian Toad, Bufo gargarizans, the developmental stage based on the gonadosomatic index (GSI), size of follicle oocytes in ovary and vitellogenesis for adult females were investigated all around the year. The weight of ovary and GSI were the lowest from April, and all follicle oocytes exist in the pre-vitellogenic form, indicating that the vitellogenesis was suspended. The follicle oocytes in early-vitellogenic stage appeared in ovary during may when the weight of ovary and GSI start to increased, and the follicle oocytes in mid-vitellogenic and pre-vitellogenic stages existed during June and the weight of ovary and GSI also increased. This indicates that vitellogenesis has been carried out actively during this period. The follicle oocytes in mid-vitellogenic stage and late-vitellogenic stage when the vitellogenesis was also completed existed on September. Post-vitellogenic follicle oocytes after vitellogenesis started to appear from October and rapidly increased from December in hibernation. The full grown follicle oocytes existed during February, indicating the ovarian cycle that all follicle oocytes in ovary are developed separately, not synchronized, during the growing period of follicle oocytes and the post-vitellogenic follicle oocytes are maintained the ovulation period.

• Korean Journal of Environment and Ecology
• /
• v.28 no.3
• /
• pp.287-292
• /
• 2014

In order to determine the ovarian cycle of Korean brown frog, Rana coreana, the developmental stage based on the gonadosomatic index (GSI), size of follicle oocytes in ovary and vitellogenesis for adult females were investigated all around the year. The weight of ovary and GSI were the lowest from March to May, and all follicle oocytes existed in the pre-vitellogenic form, indicating that the vitellogenesis was suspended. The follicle oocytes in early-vitellogenic stage appeared in ovary during June when the weight of ovary and GSI started to increase, and the follicle oocytes in mid-vitellogenic and pre-vitellogenic stages existed during August and the weight of ovary and GSI also increased. This indicates that vitellogenesis has been carried out actively during this period. The follicle oocytes in mid-vitellogenic stage and late-vitellogenic stage when the vitellogenesis was also completed existed between September and November. Post-vitellogenic follicle oocytes after vitellogenesis started to appear from December in hibernation, and the full grown follicle oocytes existed during February, indicating the ovarian cycle that all follicle oocytes in ovary are developed separately, not synchronized, during the growing period of follicle oocytes and the post-vitellogenic follicle oocytes are maintained the ovulation period.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.25 no.1
• /
• pp.118-122
• /
• 1996

난황을 이용한 유화식품인 마요네즈 제조시 천연고분자 물질인 chitosan의 사용가능성을 조사하기 위하여 난황의 유화력과 유화 안전성에 미치는 chitosan의 효과와 마요네즈 제조시 chitosan 첨가특성을 조사하였다. Chitosan을 난황 무게에 대해 0.1% 첨가한 결과난항의 유화력은 약 10%증진되었으며 유화 안정성은 뚜렷이 증진되었다. 마요네즈 제시 0.1% chitosan 첨가에 의해 마요네즈의 유화 안정성을 증가되었으며 대조구의 첨가 대두유에 비해 40% 증량 처리구에 있어 유화 안정성 및 점도는 대조구에 비해 우수하였으며 색택은 비슷한 경향을 나타내었다. 마요네즈의 퍼짐서, 점성, 맛, 종합적 기호도에 관한 기호성은 0.1% chitosan 첨가구가 대조구에 비해 양호하였으며, 40% 증량한 경우 더욱 우수하였으며 60% 증량한 겨웅 대조구와 유사하였다.

• Korean Journal of Poultry Science
• /
• v.24 no.4
• /
• pp.169-177
• /
• 1997

Four experiments were conducted to investigate the association of yolk cholesterol level with egg trails, serum cholesterol level, body weight (BW) and breed differences and other variations. Athens Canadian Randombred (ACRB), a commercial layer breed (CL) and two commercial broiler breeds (BR1 and BR2) were used for this studies. Egg weight of CL was heavier by 8.7g per egg than that of ACRB, but the yolk percentage and yolk cholesterol were lower by 7.8％ per egg and 5.5mg per g yolk than those of ACRB, respectively. Yolk cholesterol content had no significant relation with the average egg weight or yolk weight in ACRB, but was significantly related with yolk fat level. However, yolk cholesterol level in CL showed inverse relationship with other egg traits compared to that of ACRB. In the CL female group, the association of yolk cholesterol level with BW was significant(P$\leq$0.05) at 25 weeks of age, but was not significant different at 26 wks of age. The relationship of yolk cholesterol with serum was not significantly different at 25 weeks of age, whereas it showed significant negative(-) correlation coefficient(P$\leq$0.01) at 26 wks of age. The association of yolk cholesterol level with egg age in CL population was not high comared to that of other treatments. The serum cholesterol content of CL was not significantly different with BR1 and BR2 populations at 25 weeks of age, but was significantly(P$\leq$0.05) higher than that of BR1 or BR2 at 26 weeks old.

• Korean Journal of Poultry Science
• /
• v.47 no.3
• /
• pp.181-188
• /
• 2020

In this study, sixteen egg quality traits, including egg weight, albumen weight, yolk weight, eggshell weight, albumen weight ratio, yolk weight ratio, eggshell weight ratio, yolk color, eggshell color, egg height, egg width, shape index, albumen height, Haugh unit, eggshell thickness, and eggshell strength were investigated in 12 strains of Korean native chicken using 600 eggs from birds at 38 weeks of age. Results showed that the Korean White Leghorn F strain had the highest egg weight of 62.7 g and the lowest (47.5 g) was observed in the Korean native chicken W strain. The Haugh unit was significantly different between strains. The mean Haugh unit for Korean native chicken ranged between 84.2 (L strain) and 76.0 (F strain), with an overall average of 79.9. Eggshells were the thinnest in Korean Rhode Island Red C and D strains (0.342 mm), whereas the highest eggshell thickness (0.393 mm) was observed in the Korean White Leghorn K strain. Korean Rhode Island Red C and D strains had low egg strength compared to that of other strains. Korean Cornish and Korean native chicken showed significant differences in egg quality traits between strains within breeds. Positive correlation coefficients were observed between egg weight and egg quality traits. The traits for color showed zero or low correlations with most egg quality traits. Egg shape index showed no correlation with most egg quality traits. Albumen height and the Haugh unit showed a positive correlation with albumen traits. Eggshell strength showed a positive correlation with eggshell traits.

• Korean Journal of Poultry Science
• /
• v.16 no.1
• /
• pp.9-15
• /
• 1989

This study was conducted to estimate genetic parameters for egg yolk cholesterol. Content of egg yok cholesterol was measured for a total of 473 hens of White Leghorn line. Cholesterol values were obtained from tee consecutively laid eggs when hens were 53 weeks of age. The yolk of each egg was weighted and freeze dried. Dried egg yolks were stored at -2$0^{\circ}C$ until analyzed. The results obtained from this study were as follows; 1. Yolk cholesterol content was measured in average $56.00\pm$0.194 mg/g dry yolk. 2. Heritability from the sire component of variance was $0.522\pm$0.215 and from the sire＋dam component of variance $0.33\pm$0.209. 3. Estimates of phenotypic correlation between your cholesterol and other factors such as body weight at 20 weeks of age, age at first egg, 40-week total egg number, egg Production rate: 53-week egg weight and 53-week yolk weight were -0.0208, -0.0321, -0.0378, -0.0834, 0.0790 and 0.1624, respectively. And genetic correlation coefficients for each item in the order were -0.5293, 0.7105, -0.4062, -0.0254, 0.2164 and 0.5027, respectively. 4. These results suggest the possibility that egg Yolk cholesterol should be reduced through selecting of sire families. To breed for low egg yolk cholesterol, it makes age at first egg earlier and enhances total egg number so that we can obtain the high rate of egg Production.

• Food Science of Animal Resources
• /
• v.24 no.3
• /
• pp.277-282
• /
• 2004

This study was conducted to investigate changes of egg characteristics according to feeding of far infrared irradiated rice. The feeding of rice irradiated by far infrared rays did not affect the body weight of laying hens, but egg weight (3.6∼7.6%), yolk weight (3.9∼30.2%) and thickness of egg shell (5.4∼13.5%) together with the rate of laying eggs (5.4%) were positively increased than normal rice.

• Korean Journal of Food Science and Technology
• /
• v.34 no.3
• /
• pp.459-465
• /
• 2002

To obtain the basic data for commercial 10% salted egg yolk for mayonnaise preparation, 3 types of egg yolks [pasteurized egg yolk (Yolk A)-not salted, pasteurized before salting (Yolk B)-salted, and pasteurized after salting (Yolk C)-salted] were prepared, and the changes in quality characteristics of these egg yolks with frozen storage were tested. The results obtained were as follows; Yolk A gelatinized during frozen storage, thus could not used for mayonnaise preparation. The viscosity of the egg yolk increased $3{\sim}5$ times after salting. Viscosity of the salted egg yolk increased with frozen storage time. Viscosity of Yolk B was higher at $-20^{\circ}C$ than $-15^{\circ}C$. Viscosity of Yolk C, however, was higher at $-15^{\circ}C$ than $-20^{\circ}C$. Frozen storage of pasteurized salted egg yolk showed some effects on the emulsification capacity. The effect, however, was smaller than that of unpasteurized salted egg yolk. Microbes of salted egg yolk were decreased with frozen storage, but there was no difference between Yolk B and Yolk C. It was suggested that commercially pasteurized 10% salted egg yolk for mayonnaise preparation can be successfully stored for 12 months at the temperature of $-15{\sim}-20^{\circ}C$.

• Food Science of Animal Resources
• /
• v.22 no.3
• /
• pp.252-258
• /
• 2002

The objective of the study was to investigate the effects of dietary conjugated linoleic acid (CLA) on the egg quality. The ISA Brown (200 days and 500 days) hens were assigned randomly to six diets containing 0, 0.6, 1.2, 1.8, 2.4 and 4.8% CLA, respectively. The CLA contents was not detected in control eggs, whereas the CLA contents of eggs that fed with CLA diets was significantly increased (p.0.05) as increasing of dietary CLA levels and feeding periods. Eggs weight, Haugh unit (HU), shell color, shell weight, shell density, and shell thickness were not significantly different among treatments. However, the albumen height from hens fed CLA was significantly (P<0.05) lower than those of control at 7 weeks. As increasing of the CLA levels in diet, the rate of saturated fatty acid in egg yolk was increased and yolk color showed more yellow color. Especially, T4 showed significantly (P<0.05) more yellow color than those of control in yolk color. When e99s were boiled, egg yolks from CLA dietary groups showed significantly (p<0.05) higher hardness value than control.