• Korean Journal of Ichthyology
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• v.8 no.1
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• pp.49-55
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• 1996

The growth of total length(TL), total weight(TW) and somatic weight(SW) of rainbow trout, Oncorhynchus mykiss alevin at yolk absorption period was expressed by the Gompertz growth model as $TLt=2.7e^{-1.24{\cdot}e^{-0.11t}}(r^{2}=0.66)$, $TWt=1.8e^{-2.03{\cdot}e^{-0.11t}}(r^{2}=0.66)$ and $SWt=1.8e^{-5.41{\cdot}e^{-0.13t}}(r^{2}=0.83)$ respectively. Yolk length, yolk height and yolk volume of rainbow trout decreased linearly. The relative growth of total weight-total length, somatic weight-total length, yolk length-total length, yolk height-total length, yolk volume-total length, yolk weight-total length, yolk weight-total weight, yolk weight-yolk height and yolk weight-yolk length at yolk absorption period revealed the pattern of yolk absorption in rainbow trout.

• Korean Journal of Organic Agriculture
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• v.24 no.1
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• pp.115-122
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• 2016

The main purpose of the current study was to compare quality of eggs 1) produced from hens housed in battery cages vs. free range, 2) from young vs. old hens, and 3) tagged with the lowest vs. the highest price in a local franchised mart. The ages of hens, at which their eggs were used for the analysis of quality, were 70 weeks old in the experiment 1, 22 and 47 weeks old in the experiment 2, and were unknown in the experiment 3. Eggs were analyzed for weight, albumen height, Haugh unit, shell color, shell strength, shell thickness, shell weight, yolk color, yolk weight, and egg white weight. In the experiment 1, significant differences were detected between two housing systems in shell color, shell weight, yolk color, and yolk weight (P<0.05), but not in egg weight, albumen height, Haugh unit, shell strength, shell thickness, and egg white weight (P>0.05). Although egg weight was slightly but not significantly higher in battery cages by 2.2 g than in free range, yolk weight was significantly higher in battery cage (P<0.05). On the contrary, shell color was greatly increased in free range system by 68.5% compared with battery cage. In the experiment 2, there were significant differences between young and old hens in egg weight, albumen height, Haugh unit, shell strength, shell weight, yolk color and yolk weight (P<0.05). Egg weight, shell weight, yolk color and yolk weight were increased in old hens than young hens while albumen height, Haugh unit, and shell strength were decreased. In the experiment 3, egg weight, albumen height, Haugh unit, shell weight, and egg white weight were significantly higher in the highest priced eggs than the lowest ones (P<0.05), whereas shell strength and yolk color were lower (P<0.05) but shell color, shell thickness and yolk weight were not different (P>0.05). So, egg freshness was clearly higher in the highest priced ones than in the lowest (P<0.05). Due to the limited information on raising and husbandry of laying hens whose eggs were tested for egg quality in the current study, the present results should be cautiously interpreted while contributing to the future study as a basis in this field.

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

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.4
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• pp.538-543
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• 2015

This experiment was conducted to measure the effects of olive leaf powder on performance, egg yield, egg quality and yolk cholesterol level of laying hens. A total of 120 Lohmann Brown laying hens of 22 weeks old were used in this experiment. The birds were fed on standard layer diets containing 0, 1%, 2%, or 3% olive leaf powder for 8 weeks. Egg weight and yield were recorded daily; feed intake weekly; egg quality and cholesterol content at the end of the trial. Olive leaf powder had no effect on feed intake, egg weight, egg yield and feed conversion ratio (p>0.05) while olive leaf powder increased final body weight of hens (p<0.05). Dietary olive leaf powder increased yellowness in yolk color (p<0.01) without affecting other quality parameters. Yolk cholesterol content was tended to decrease about 10% (p>0.05). To conclude, olive leaf powder can be used for reducing egg yolk cholesterol content and egg yolk coloring agent in layer diets.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.10
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• pp.1447-1455
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• 2011

Sixty four, 30-week-old, Lohmann Brown-Lite laying hens were randomly allocated to one of four treatments with eight replicates per treatment and two hens per replicate for a 10 week study. The control diet was a high energy (11.81 MJ/kg) diet and the moderate energy (11.39 MJ/kg) diets were formulated dropping the level of animal fat. The three moderate energy diets were fed either unsupplemented (0.0%) or supplemented with 0.05 or 0.10% glycine. There were no significant differences (p>0.05) in hen-day egg production, egg weight, feed intake or feed conversion between birds fed the unsupplemented moderate energy and high energy diets. Significant differences were detected concerning egg components and quality measurements as assessed by albumen percentage (p = 0.02), yolk weight (p = 0.02), yolk percentage (p<0.01), yolk to albumen ratio (p<0.01) and yolk color (p = 0.01) between birds fed the unsupplemented moderate and high energy diets. Glycine supplementation of the moderate energy diet linearly increased (p<0.01) egg weight and feed intake with no significant (p>0.05) effects on egg production or feed conversion. Glycine supplementation significantly increased egg content (p<0.01), albumen weight (p<0.01) and percentage (p<0.01) as well as yolk weight (p<0.01) while yolk percentage (p = 0.04), yolk to albumen ratio (p = 0.01) and egg shell percentage (p<0.01) were linearly decreased. Supplementation with glycine produced a tendency (p = 0.09) towards an increase in the percentage of large eggs (63-72.9 g) produced with a concomitant decrease in the percentage of small (below 53 g) eggs (p = 0.09). The overall results of this study indicate that glycine supplementation of laying hen rations has the potential to increase egg production and weight. These increases appeared to be mediated through increases in feed intake and the ileal digestibility of fat and energy.

• Korean Journal of Poultry Science
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• v.25 no.1
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• pp.11-19
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• 1998

This study was conducted to estimate the heritabilities and genetic correlations on egg weight and egg compositional traits for breeding plan and selection in Korean native chicken. Data analyzed were the records of 46,908 eggs from 430 layers produced from 180 dam and 26 sire families, from April, 1994 to September, 1995. On egg weight and egg compositional traits at 1st egg, 300 and 500 days of age, the egg weights were 41.489, 49.544 and 52.770g ; the albumin weights were 25.953, 29.979 and 31.288g; the yolk weights were 11.091, 14.541 and 16.368g; shell weights were 4.472, 5.037 and 5.099g, respectively. The estimates of heritability of egg weights and egg compositional traits based on the variance of sires, dams and combined components at 300 days of age were 0.214, 0.226 and 0.720 for egg weight ; 0.307, 0.152 and 0.730 for albumin weight ; 0.124, 0.953 and 0.699 for yolk weight ; 0.047, 0.026 and 0.536 for shell weight. The genetic correlation coefficient between egg weight and albumen weight was 0.083~0.951 ; 0.310~0.507 between egg weight and yolk weight ; 0.242~0.523 between egg weight and shell weight ; 0. 237~0. 413 between albumen weight and yolk weight ; 0.232~0.449 between albumen weight and shell weight ; -0.264~0.239 between yolk weight and shell weight, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.539-548
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• 1995

The process of yolk absorption and the growth pattern of churn salmon, Oncorhynchus keta alevin were studied. Matured males and females of chum salmon were sampled from the Namdaechun River in the east coast of Korea, and then an artificial fertilization was carried out using their eggs and sperms. Fertilized eggs were incubated in controlled water temperature of $13^{\circ}C$ and samples of 40 alevins were randomly taken at just hatching and at every three days between 12 days alter hatching and yolk absorption. The means of total length and total weight of hatched alevins were respectively 1.97cm and 1.85g and the yolk absorption took about 33 days after hatching, based on the morphological measurement. Growth curves of total length, total weight and somatic weight were fitted well with the Gompertz growth model. However, the shrinking in yolk-sac length, yolk-sac weight, yolk-sac height and yolk-sac volume revealed a linear phenomenon until the absorption of yolk was completed. The relative growth of chum salmon alevin, such as the relationship between total length and total weight, or between total weight and yolk-sac weight, was also studied.

• Korean Journal of Poultry Science
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• v.22 no.3
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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

• Korean Journal of Human Ecology
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• v.5 no.1
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• pp.75-80
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• 1996

The immunogenecity of low molecular weight ($MW{\le}30,000$) immunogens in laying hens was investigated. Immunogens were insulin derivatives and ${\beta}$-lactoglobulin(${\beta}-Lg$). Insulin derivatives were reduced- carboxymethylated(RCM) insulin, and RCM-A and RCM-B chain of insulin. The yolk antibodies against RCM-A chain of insulin appeared after the first immunization. The yolk antibodies against RCM-B chain of insulin were elicited 5 weeks after the third booster injection. Although the anti-RCM-B chain yolk antibodies recognized native insulin, the anti-RCM-A chain yolk antibodies didn't native insulin. The anti-RCM insulin yolk antibodies were induced after the second booster injection and showed cross-reactivities with native insulin. On the other hand, ${\beta}-Lg$ showed stronger immunogenecity than insulin derivatives. The $anti-{\beta}-Lg$ yolk antibodies were produced after the second booster injection and the peak titer was reached 3 weeks after the third booster injection.

• Korean Journal of Poultry Science
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• v.43 no.1
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• pp.31-38
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• 2016

Consumers demand fresh and high-quality eggs. Egg quality may be represented by shell color, shell weight, egg weight, shell thickness, shell density, albumen height, yolk color, albumen pH and viscosity. Various factors such as strain, age of hen, storage temperature, humidity, the presence of $CO_2$ and storage time affect egg quality. Therefore, we investigated the effects of storage time and temperature on egg quality to define the freshness of Korean market eggs. A total of 1,800 eggs were used for this experiment and were separated into 45 treatments with 40 eggs in each. The treatments were consisted of 15 storage periods (2 d to 30 d) and 3 storage temperatures ($2^{\circ}C$, $12^{\circ}C$, $25^{\circ}C$). Each egg was weighed and broken, and the height of the thick albumen, Haugh units (HU), egg shell color and yolk color were measured by a QCM+system. We also observed the physiochemical properties of eggs such as yolk pH, albumen pH and albumen viscosity. The egg weight, shell weight, albumen height, HU and albumen viscosity significantly decreased with increasing storage time and temperature. However, the albumen and yolk pH significantly increased with increasing storage period and temperature. The interaction effects between the storage period and temperature were significant for shell weight, shell density, egg weight, albumen height, HU, yolk color, yolk pH, albumen pH and albumen viscosity. In the analysis of the correlation with egg quality, the storage temperature exhibited a higher correlation coefficient than the storage period. In conclusion, storage time and temperature are the major factors affecting egg quality, but the storage temperature is a more sensitive determinant of egg quality deterioration compared with the storage period.