• Journal of Animal Science and Technology
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• v.54 no.1
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• pp.43-49
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• 2012

This study was carried out to investigate the effects of age of laying hens and grade of shell abnormality on internal egg quality. At each week, 1,000 eggs were randomly selected from 21,000 eggs laid by Hy-Line hens (100,000 birds) aged from 56 to 62 wk. The samples were divided into normal and externally abnormal eggs by an official egg grader. Then, egg quality including egg weight, egg white height, Haugh unit and yolk color was evaluated from each normal and abnormal eggs. The production rate of externally normal and abnormal eggs was 81.22 and 18.78%, respectively. No difference found in the production rate by the increase of hen's age, but Haugh unit of eggs from hens of 60-wk-old was higher (p<0.05) than that of 56-wk-old. When the same age groups were compared, egg white height and Haugh unit were lower in eggs which were externally abnormal. When the grade of abnormality increased, egg white height and Haugh unit were decreased further (p<0.05). Among the externally abnormal eggs, malformation showed the lowest Haugh unit. In conclusion, the shell abnormality of eggs laid by hens aged 56 to 62 wk was closely related with internal egg quality. Therefore, the grading external egg quality in the present egg grading system is directly related with the internal egg freshness.

• Korean Journal of Poultry Science
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• v.50 no.1
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• pp.23-30
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• 2023

This study was conducted to analyze the correlation between egg breakage rate and cumulative external forces on eggs during the egg transfer system in 12 commercial layers farms. The commercially available electronic egg device was used to detect the external forces on eggs during egg collection systems. In addition, egg breakage rate per farm was collected. It was found that the external force on eggs were greater in the order of washer and dryer connection part, conveyor connection part, transfer, sorter, collecting elevator, packer, egg transfer connection part, and egg tray. A positive relationship between the external forces on eggs during egg transit system and the incidence of cracked eggs per farm was noted. The external forces on eggs varied from 5G to 38G depending on the location and the egg breakage rate ranged from 3.2 to 14.5% per farm. Although efforts to produce eggs with high eggshell quality are considered important, extra care should be made to lower the external forces on eggs during the egg transfer system from laying house to egg packing center.

• Korean Journal of Veterinary Research
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• v.46 no.3
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• pp.207-214
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• 2006

Mycoplasma gallisepticum (MG) continues to persist in many commercial layer farms in Korea,resulting in losses in egg production. Bacterins and live attenuated vaccines have been used for the prevention of losses caused by MG. One of these attenuated vaccines, MG 6/85 vaccine has been reported to be safe and efficacious in layers. However, MG 6/85 vaccine has not been evaluated for its safety and its efficacy in any commercial layer in Korea. Six-week-old specific pathogen-free (SPF) chickens were vaccinated with MG 6/85 vaccine by aerosol and were challenged with virulent MG R strain at 4 weeks after vaccination. The vaccinated group was able to resist challenge into the air sacs because the vaccinated group showed much less air sac lesion compared with the unvaccinated group. Each of two commercial layer farms was divided into vaccinated and unvaccinated groups. For each vaccinated gorup, MG 6/85 vaccine were sprayed at 17 week old on farm A and at 15 weeks old on farm B. Hen-day egg production, Hen-housed eggs, egg weight, mortality were evaluated until 50 week after vaccination.Compared with the unvaccinated group in each farm, the vaccinated group showed higher average egg production and egg weight, and higher hen-housed number. Results of this study are in agreement with other previous reports which demonstrated that MG 6/85 vaccine favorable effect on performance in commercial layers.

• Korean Journal of Poultry Science
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• v.46 no.2
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• pp.87-94
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• 2019

Huge amount of persimmon peels, which are byproducts usually arising after making dried persimmons from fresh persimmons, are generated in fall, every year. As the dry matter of persimmon peel contains carbohydrates over 80%, it could be a good candidate for feed. In this study, we evaluated the persimmon peel as a feed resource for a hen laying eggs. Persimmon peel has lower ratio of crude protein and fat composition while higher ratio of crude fiber composition compared to a basal laying hen feed. Feeding the persimmon peel by adding to the feed at the level of 2% or 5% did not affect the egg-laying rate from beginning to the peak of laying. In addition, feeding the persimmon peel did not affect the egg quality either, as the pH, Haugh unit, yolk color and shell thickness of the egg were not different from each other. The composition of amino acids and fatty acids were also almost same for each other, except for the linolenic acid which was slightly higher in the persimmon peel feeding groups. In conclusion, addition of persimmon peel to the feed up to 5% might be helpful to increase the income and reduce the waste produced from the agricultural byproduct.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.11
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• pp.1503-1509
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• 2010

Forty-eight 40-wk-old Hi-sex laying hens were individually caged in an environmentally controlled house to evaluate the effect of garlic (Allium Sativum) juice administration on egg production, egg quality, and yolk cholesterol. Garlic juice was prepared by blending pealed garlic cloves with distilled water (1:1, w/w). Hens were randomly divided into four equal groups; one served as a control and the other three groups were individually gavaged, 3.75 ml, 7.5 ml, or 15 ml garlic juice, three times a week, which respectively represented 0.25, 0.50 and 1% of body weight. Egg production was recorded on a daily basis; egg weight, albumen height, albumen and yolk pH, Haugh unit, and bacterial count of E. coli-challenged eggs were recorded at day of oviposition (day-1) and after 5 and 10 days of storage at room temperature. Yolk cholesterol content was analyzed for five successive weeks. Garlic juice increased (p<0.05) egg weight and mass with no change in egg production intensity. Garlic juice administration recorded higher (p<0.05) albumen height and improvement in Haugh unit. Also, eggs from garlic-treated hens recorded lower (p<0.05) albumen and yolk pH when compared to eggs collected from control hens. Garlic reduced (p<0.05) the $log_{10}$ of bacterial count in egg contents linearly when challenged with E. coli. Egg-yolk cholesterol content was not influenced by garlic juice administration. It is concluded that garlic juice improved performance characteristics and may increase egg shelf life as indicated by egg quality improvement and lower bacterial count of E. coli-challenged eggs. The levels of garlic juice used in this study were insufficient to influence egg yolk cholesterol.

• Korean Journal of Poultry Science
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• v.35 no.1
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• pp.1-7
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• 2008

Three dietary herbs, Coptis japonica Makino (48.5%), Lonicera japonica Thunb (48.5%), and Morus alba L. (3%) were mixed and used as additives in hen's feed. One hundred-eight, 28-wk-old Lohmann Brown hens were assigned randomly with three diet treatments (0, 0.3, and 1% of herb mix). Hens were fed for 6 wks to investigate the effect of herb mix on the physicochemical quality of eggs during storage at $4^{\circ}C$ for 0, 3, 7, and 14 days. Proximate composition including the content of water, protein, fat, and ash had no difference among 3 diet treatments. Objective color of cooked whole egg from hens fed herb mix did not show any effect compared with control except for the color $a^*$- and $b^*$-values at day 3. However, color $a^*$- and $b^*$-values increased during storage regardless of treatment. From the texture analysis, eggs from hens fed with the herb mix were not different compared with control remove for springness at day 14. However, it was observed that springness and gumminess were decreased as storage period increased. Therefore, a dietary supplementation of herb mix to hen may not affect on proximate composition, color and texture of eggs.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1307-1316
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• 2016

This study was to execute the random arrangement of total 120 heads (10 heads per treatment plot ${\times}$ 3 repeats ${\times}$ 4 treatment plots) for four breeds [Blue arakana commercial Fowl (BC), Yeonsan silky fowl (YS), Korean native fowl (KN), White leghorn fowl (WL)] with the initiation of laying hens at 32 weeks old in order to comparatively analyze egg quality and composition by sorts of laying hens. In case of evaluation of the quality of eggs, this study has shown that BC had higher degree of Haugh unit coefficient (82.82) and in case cholesterol content of eggs, BC had significantly low content as 317.55mg/100g, but YS had rather higher content as 381.30mg/100g. Furthermore, this study has found out that BC had significantly low Oleic acid (C18:1n9) and WL had higher Amino acid content by breeds than those of other breeds (p<0.05).

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.272-285
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• 1987

In order to obtain the data for the effective separation and purification of lysozyme from egg white, optimal conditions for the homogenization of egg white and lysozyme activities of some fresh hen eggs were examined. The recovery and purity of lysozyme isolated by the direct crystallization method, the adsorption with Bentonite and the batch method with Duolite were also investigated. The results obtained were summarized as follows; 1. On the homogenization of egg white, optimal stirring time and stirring rate for the measurement of the lysozyme activities were found to be 10 min. and 2,000 rpm respectively. 2. On the activities of lysozyme in the fresh hen eggs, the activities of W. Leghorn was greater than that of R. Island or Ogol fowl, and the activities of the thick white was a little greater than that of the thin white. 3. The residual lysozyme activities of the hen eggs stored at $4^{\circ}C$ was greater than that of the ones stored at $25^{\circ}C$ or $-20^{\circ}C$ over the storage periods. 4. Hen egg lysozyme recrystallized three times by the method of direct crystallization showed the recovery of 64.3% and the increase of 29 fold in specific activities. 5. By the adsorption method with bentonite, lysozyme in the egg white was adsorbed to 95.7%, and the elution rate of the ones adsorbed was 89.1%, and the increase in specific activities was 13 fold. 6. In the experiment exploying duolite as an adsorbent, Jysozyme in the egg white was obtained with the bound rate of 97%, the recovery rate of 84.8%, and was purified by 30fold.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1191-1201
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• 2020

Objective: The aim of this study was to evaluate the chemical-nutritional parameters, oxidative stability and volatile profile of eggs and cakes made with eggs from laying hens fed with a dietary supplementation of extruded linseed. Methods: Two thousand ISA Warren laying hens were randomly divided into two groups: a control group was fed with a standard diet while the experimental group received the same diet supplemented with 7% of extruded linseed. The trial lasted 84 days, in which three samplings of laid eggs were performed. Samples of eggs and food systems arising from eggs were then analyzed in order to obtain information about β-carotene and total flavonoid content, antioxidant activity, fatty acid profile, lipid oxidation, and volatile profile. Results: Linseed induced the increase of α-linolenic acid with consequent reduction of the ω-6/ω-3 ratio (4.3:1 in egg yolk); in addition to this, was evidenced the cholesterol reduction and the significant increase in total flavonoids and β-carotene, although no variations were detected in antioxidant capacity. Even in cooked products there was not only a direct effect of linseed in increasing α-linolenic acid, but also in inducing the reduction of cholesterol and its major oxidation product, 7-ketocholesterol. The dietary linseed integration was also shown to affect the volatile profile of baked products. Conclusion: Data confirmed that dietary supplementation with extruded linseed resulted in food products with interesting implications for human health. With regard to the volatile profile of baked products it would be necessary undertake further sensorial analysis in order to evaluate any variations on flavor and consumer acceptability.

• Korean Journal of Poultry Science
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• v.46 no.2
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• pp.55-63
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• 2019

This study was conducted to evaluate animal welfare approved farms in three housing systems (open, windowless, and free-range). The survey was conducted in 25 animal welfare approved farms, and 10 farms were surveyed for distribution status. The main breed in all animal welfare approved farms of laying hens was Hy-Line Brown variety. In the case of open house, laying hens were bred in traditional and panel houses simultaneously; however, the ratio of panel house was 58.3%, which was higher than that of the traditional house. All the windowless houses were made of panels and more than 15,000 laying hens were housed in a single windowless house. In the case of free-range house, it was maintained on a small scale of less than 12,000 birds. Fifty-six percent of the surveyed farms were breeding at $7{\sim}8birds/m^2$. In terms of male and female ratios, most farms maintained 1 male:15 females, but there was a farmhouse that switched 17 or 20 females to 1 male. The daily dietary allowance was 110~170 g, and 32% of the surveyed farms provided feed of more than 150 g/day, which showed that forage feed was important. The age of at the first egg was 123 days, 122 days, and 120 days, and the peak percent was 91.8%, 94.9%, and 86.5% in open, windowless and free-range houses, respectively. The average egg production rate was 74.0%, 84.6%, and 72.7% in open, windowless, and free-range houses respectively, thus, there was no correlation between feed intake and hen-housed eggs. Distribution of welfare certified eggs was mainly a direct deal with the consumer or through contract production. The ratio of direct transactions between large-scale marts and eco-friendly specialty stores of welfare approved eggs was higher than that of conventional eggs. The rate of contract sales of eggs in both the barn and free-range systems was high, and the percentage of courier sales farms was also high. Excluding courier services, price of eggs in the barn system rose to more than 30 won/egg in the second half of 2017 (after AI). Price of eggs in the free-range system rose to more than 50 won/egg in the second half of 2017 (after AI). In the case of courier sales, the same price of 500 won was maintained before and after AI. In conclusion, the results of this study can be used as basic data for improving the animal welfare certification system for laying hens in Korea.