• 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.

• 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 Agricultural Science
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• v.29 no.1
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• pp.44-54
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• 2002

The fresh eggs of African ostrich in Korea were used in this study to investigate their interior and exterior quality characteristics. In ostrich egg shape characteristics, long and short length were measured as 15.1~16.1 cm and 12.1~13.6 cm, respectively. The egg shape index was calculated as 81.0 and the egg shell showed a more g loss white in color than that of hen egg. Calculated breaking strength of egg shell and egg shell surface based on the equation were $41.155kg/cm^3$ and $804.7cm^2$, respectively. Average egg shell thickness including egg shell membrane was 1.89 mm and there are no differences among parts of the shell. The egg shell membrane thickness was 0.10 mm showing relatively thick in equator compared with that of blunt end. The ave rage number of egg shell pores was counted as $19.7/cm^2$ showing relatively high number of egg shell pores at point end and the total number of egg shell pores in an egg was estimated as 15,241. The relative port ion of each parts based on egg weight was estimated as 25.1% for egg yolk, 58.2% for egg white, 16.7% for egg shell and the ratio of egg yolk to egg white (Y/W) was 0.43. The average diameter and the ave rage height of ostrich egg white were 19.7 cm and 13.2 mm, respectively. Calculated the H.U (Haugh Unit) was -69.7 and the pH was 8.3. In ostrich egg yolk, the diameter, the height, the egg yolk index, and it's pH were calculated as 14.4 cm, 29.4 mm, 0.20, and 6.6, respectively. And the egg yolk color showed a more thin in yellow chroma compared with that of hen egg as due to it's thicker membrane.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.839-844
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• 2012

This experiment was conducted to evaluate the effects of single or multi-particle size limestone on the egg shell quality, egg production, egg quality and feed intake in laying hens. A total of 280 laying hens (ISA brown) were used in this 10-wk trial. Laying hens were randomly assigned to 4 treatments with 14 replications per treatment and 5 adjacent cages as a replication (hens were caged individually). The experimental treatments were: i) L, basal diet+10% large particle limestone; ii) LS1, basal diet+8% large particle limestone+2% small particle limestone; iii) LS2, basal diet+6% large particle limestone+4% small particle limestone; iv) S, basal diet+10% small particle limestone. The egg production was unaffected by dietary treatments. The egg weight in S treatment was lighter than other treatments (p<0.05). The egg specific gravity in S treatment was lower than other treatments (p<0.05). The eggshell strength and eggshell thickness in S treatment were decreased when compared with other dietary treatments (p<0.05). The laying hens in LS1 and LS2 treatment had a higher average feed intake than the other two treatments (p<0.05). Collectively，the dietary multi-particle size limestone supplementation could be as efficient as large particle size limestone.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.6
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• pp.723-726
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• 1996

A water loaded pressure device using water as the breaking force was developed to evaluate eggshell strength and compared with a dropping ball techniques. Further, relationships of shell thickness and weight of eggs to shell strength were also studied. Values for both of the shell strength measuring methods showed a highly significant correlation (p < 0.001) with shell thickness. The water loaded pressure method had a much higher simple correlation coefficient for shell thickness (r = + 0.786) than the dropping ball method (r = + 0.577). The shell strength measured by the water loaded pressure method appeared not to be correlated to egg weight. On the other hand, the negative sign of the standard partial regression coefficient and the partial regression coefficient of egg weight in the estimated multiple regression equation implied that for a given shell thickness a larger egg tended to have less shell strength than a smaller egg.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.6
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• pp.850-854
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• 2001

Feed intake, egg weight, rate of lay and shell quality characteristics were measured in an Australian tinted egg laying strain from 31-42 weeks of age, housed at $30^{\circ}C$ and provided drinking water at 5, 10, 17 and $30^{\circ}C$. In a second experiment a European brown egg laying strain (59-66 weeks of age) housed at $30^{\circ}C$ were provided drinking water at 5, 10, 15 and $30^{\circ}C$. Brown egg layers given cool drinking water (5, 10 and $15^{\circ}C$) consumed more (p<0.05) feed and produced significantly (p<0.05) thicker and heavier shells than hens given drinking water at ambient temperature ($30^{\circ}C$). However the tinted egg layers given chilled drinking water only consumed more (p<0.05) feed and produced thicker (p<0.05) and heavier (p<0.05) shells when consuming drinking water at $5^{\circ}C$. As the tinted egg layers acclimatised to the environmental temperature there was a decline in the influence of cool drinking water on feed intake and shell quality. For brown egg layers, however, cool drinking water resulted in an improvement (p<0.05) in feed intake and shell quality over the entire period birds were provided cool water. These studies suggest that there is potential for using cool drinking water to improve feed intake and shell quality of hens housed under hot conditions. The combination of high ambient temperature and high drinking water temperature, a common occurrence in Australian layer sheds, should be avoided.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.4
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• pp.545-551
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• 2005

A feeding trial was conducted to determine whether dietary vitamin C (200 mg/kg) and vitamin E (250 mg/kg) prevent any drops in egg shell quality under heat stress in broiler breeder hens. One hundred and sixty molted Ross broiler breeders were housed randomly in an individual cage at 83 weeks of age. Four dietary treatments with forty hens and four replications per treatment were control (no additional vitamins), vitamin C-, or vitamin E-supplemented and combined supplementation of the two vitamins. After a tenday-adaptation period at 25$^{\circ}C$, the ambient temperature was kept at 32$^{\circ}C$ for a three-week-testing period. Egg production dropped dramatically over week but it did not show a significant change among treatments (p<0.05). However, egg quality parameters such as egg weight, specific gravity, shell thickness, SWUSA, puncture force and shell breaking strength from the birds fed the diet with the combined vitamins C and E were significantly improved over those of the control group during the heat stress period (p<0.05). The hens fed the vitamin C diet improved tibia breaking strength (37.16 kg), statistically higher than the birds fed the control and the vitamin E diets (p<0.05). The hens fed the control diet showed higher serum corticosterone levels, a mean of 5.97 ng/ml, than those of the other treatments (p<0.05). The heat stress resulted in elevated heterophils and decreased lymphocytes in serum, increasing the H/L ratios for all the treatments. However, the increases in H/L ratios were alleviated by feeding the diets containing vitamin C alone or together with vitamin E, although there were no significant differences in the ratio between the two groups (p<0.05). In conclusion, vitamins C (200 mg/kg) and/or E (250 mg/kg) supplemented to the diets for broiler breeder hens could prevent drops in egg shell quality and tibia bone strength under highly stressful environmental temperatures.

• Korean Journal of Poultry Science
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• v.23 no.1
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• pp.39-46
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• 1996

An experiment was conducted to investigate the effect of feeding split diets for a.m. and p.m. in laying hens on egg shell qualities, and to study the relationship among the methods of measuring shell quality with 480 ISA Brown layers during 32∼36, 52∼56 and 72∼76 wk of age, respectively. A total of 1,080 eggs were collected from 6 treatment groups in every laying period and weighed individually. Egg specific gravity, egg breaking strength, shell thickness and shell percentage of eggs were measured, and then correlation coefficients (r) and regression equations were calculated. By feeding the split diets for a.m. and p.m. differing in ME, CP, and Ca levels, and as the Ca level of the p. m. diet increased, eggshell qualities were improved(P<0.05). The correlation coefficient values indicate that shell percentage, shell thickness and egg specific gravity are highly correlated with the egg breaking strength(P<0.01).

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.11
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• pp.1611-1616
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• 2012

The aim of the study was to evaluate the effect of sodium nitrate consumption on egg quality and quantity, and some blood parameters of native breeder hens of West Azerbaijan province. One hundred native hens were used from wk 25 to 32 of age. These birds were divided into two groups. One group was fed the control diet (CD) but the other fed the same diet supplemented with 4.2 g/kg sodium nitrate (ND). After 2 wks of adaptation, eggs were collected daily and egg mass and egg production were measured weekly for five weeks. To assess the egg quality parameters, two eggs from each replicate pen were collected for three consecutive days each week. At the end of experimental period (wk 32 of age), blood samples of 5 birds per replicate were collected from the wing vein into anticoagulant tubes. Dietary sodium nitrate didn't affect the egg production, shell stiffness, shell thickness and Haugh unit (p>0.05) but it decreased the both egg production and egg mass during the last three weeks (wks 30, 31 and 32) (p<0.05). Furthermore, a treatment effect was observed for yolk colour (p<0.05). Both the egg production and egg mass were increased over time (p<0.05). No significant treatment${\times}$time interaction was observed for egg weight, egg production and egg mass (p>0.05). No effect of time or treatment${\times}$time were observed for shell stiffness (p>0.05). Over time, shell thickness was decreased while Haugh unit increased (p<0.05). None of the blood TP and TG or the activity of ALT, AST and LDH enzymes were affected by dietary consumption of sodium nitrate at wk 32 of age (p>0.05). Sodium nitrite decreased both the TAC and TC at wk 32 of age (p<0.001). It was concluded that the lower body antioxidant capacity of nitrate fed birds resulted in the lower performance (egg weight, egg production and egg mass).

• Food Science of Animal Resources
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• v.37 no.4
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• pp.571-578
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• 2017

This study aimed to determine the optimal ratio of natural calcium powders (oyster shell and egg shell calcium) as synthetic phosphate replacers in pork products. Ground pork samples were subjected to six treatments, as follows: control (-) (no phosphate added), control (+) (0.3% phosphate blend added), treatment 1 (0.5% oyster shell calcium powder added), treatment 2 (0.3% oyster shell calcium powder and 0.2% egg shell calcium powder added), treatment 3 (0.2% oyster shell calcium powder and 0.3% egg shell calcium powder added), and treatment 4 (0.5% egg shell calcium powder added). The addition of natural calcium powders resulted in an increase in the pH values of meat products, regardless of whether they were used individually or mixed. The highest cooking loss was observed (p<0.05) in the negative control samples, whereas the cooking loss in samples with natural calcium powder added was similar (p>0.05) to that in the positive control samples. CIE $L^*$ values decreased as the amount of added egg shell calcium powder increased. CIE $a^*$ values were higher (p<0.05) in samples containing natural calcium powder (treatments 1, 2, 3, and 4) than in the positive control. The combination of oyster shell calcium powder and egg shell powder (treatment 2 or 3) was effective for the improvement of textural properties of the pork products. The findings show that the combined use of 0.2% oyster shell calcium and 0.3% egg shell calcium should enable the replacement of synthetic phosphate in the production of cooked pork products with desirable qualities.