• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.524-530
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• 2012

Laying hens were fed commercial diets added with supplemented fat (SFAT) at 0.6, 1.2, and 1.8% in order to study the long term dietary effects - on - their productive performance from 22 to 75 wk of age. Five hundred and seventy six Single Comb White Leghorn hens were assigned to one of the four dietary treatments. The experimental phase consisted of three periods of 18 wk each. The final body weight and gain of hens fed on diets with SFAT at 1.2% and 1.8% were lower (p<0.05) than those hens given no SFAT. The SFAT at the 1.2% and 1.8% levels improved egg production rate, egg weight and mass, as well as FCR. Mortality and feed consumption were not affected by dietary SFAT. Administration of a diet with SFAT significantly decreased the cracked-broken egg ratio (p<0.01). The beneficial effects of SFAT on egg production performance were particularly more pronounced at intermediate and later ages. Hence, SFAT by period interactions were significant for all traits studied except feed intake. Hens fed SFAT deposited significantly higher abdominal fat than those on the no-SFAT diet. As a result, SFAT at 1.2% and 1.8% inclusion levels provided benefits in terms of efficient table egg production.

• Korean Journal of Poultry Science
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• v.25 no.1
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• pp.21-30
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• 1998

The effects of dietary levels and feeding period of Korean hot pepper (Capsicum annum) seed on the performance and egg quality were investigated. Rhode Island Red layers of 84 wk of age were fed the experimental diets containing O.O(Control), 0.5, 1.0, 2.0, and 3.0% of HPS, respectively, in individual cages during 10 wk of the feeding period. The dietary hot pepper seed significantly(P<0.05) improved hen-day egg production and daily egg rnass, but reduced egg weight(P<0.05). During the 10 wk of the feeding period, the egg production and daily egg mass improved after 6 or 7 wk of feeding 0.5, 1.0 or 2.0% hot pepper seed diets. When the layers were fed the 3.0% HPS diet, it only took 1 wk to improve the egg production and daily egg mass. In addition, the birds fed 3.0% hot pepper seed diet showed relatively constant egg weight while those of the Control increased gradually as the feeding period passed. The dietary hot pepper seed significantly improved the eggshell thickness, and redness and whole color of egg yolk. The results indicate that dietary hot pepper seed( $\geq$2.0%) may improve the egg production and egg shell thickness, and increase the redness of egg yolk in layers.

• Journal of Chest Surgery
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• v.7 no.1
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• pp.9-12
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• 1974

Bronchogenic cysts, though known as a relatively common malformation of the mediastinum, were rarely discussed in Korean literatures. Since the surgical removal of asymptomatic lesions was adopted as the reasonable therapeutic principle, the incidence of bronchogenic cysts were found to be higher than previously expected. Two cases of bronchogenic cysts operated on in The Dept. of Thoracic Surgery, Korea University Woo Sok Hospital were reported and related literatures were reviewed. Case 1. 5 year old boy with chief complaints of bulging cystic mass on left supraclavicular region during straining or coughing since his age of 2 was admitted, and cystogram with Lipiodol revealed hen-egg sized mass in the left antero-superior mediastinum without any communication with bronchus or esophagus. Cyst was successfully removed under general anesthesia thru left supraclavicular incision, and pathological examination of the cyst revealed thin cystic wall lined with stratified columnar epithelium and it`s content was milky white mucoid fluid devoid of any bacterial growth. Case 2. 15 year old school girl has been noted slowly growing walnut-sized mass on anterolateral side of the neck for 4 months without any subjective symptom except cosmetic problem... Mass was aspirated to find milky white mucoid fluid in some loculation and yellowish turbid fluid in other part due to chronic infection. Cystic tumor was removed under local anesthesia, which was loculated in between the trachea and esophagus without any communication, and pathological diagnosis of the cyst was bronchogenic cyst with columnar epithelial cell lining with moderate chronic inflammatory cell infiltrations. Postoperative conditions of the two cases were all excellent with normal life.

• Korean Journal of Poultry Science
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• v.21 no.4
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• pp.267-275
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• 1994

Three dietary ME levels of 3,200, 2,900 and 2,600 kcal /kg in the same 13% single-stage low protein diet were compared to evaluate the effect of ME levels of grower diets on egg-type pullet growth and subsequent laying performance. As the ME levels of grower diets decreased, cumulative feed and protein consumptions increased(P<0.05), however, the ME intake and body weight at 18 wk of age decreased(P<0.05). Grower feed cost decreased as the dietary ME level was decreased, but no significant difference was found among dietary ME levels of grower diets. During the laying period, sexual maturity, hen-day egg production and average egg weight were not significantly affected by the ME levels of grower diet, however, daily feed intake and feed required per egg decreased as the dietary ME level of grower diet was reduced(P<0.05). Results of this study indicate that pullets can be reared on the low ME diet of 2,600 kcal /kg and it would he economical to utilize the low energy diet during the growing period when they are reared on a 13% single-stage low protein diet.

• Animal Bioscience
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• v.35 no.3
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• pp.444-452
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• 2022

Objective: An experiment was conducted to evaluate the effect of different levels of crude protein (CP) and two rearing systems (cage and floor), on blood parameters and digestive and reproductive organ development of brown laying hens. Methods: A total of 400 Hisex Brown laying hens between 30 and 45 weeks of age were distributed in a completely randomized design and a 2×4 factorial arrangement, with main effects including two rearing systems (cage and floor) and levels of CP (140, 150, 160, and 180 g/kg), in a total of eight treatments and five replicates of 10 birds each with initial body weight of 1,877 g (laying hen in cage) and 1,866 g (laying hens in floor). The parameters evaluated were plasma total protein, albumin, uric acid, total cholesterol, relative weights of oviduct, abdominal fat, liver, gizzard, crest and dewlap, length of small intestine and oviduct. Results: The blood parameters were similar in birds reared in cage and floor systems. The birds reared on the floor showed greater small intestine and oviduct weight (%) and lower liver and pancreas weight (%). A significant interaction was observed between factors for the relative gizzard, crest and dewlap weight, serum protein, uric acid, and total cholesterol (p<0.05). The diets with 140 g/kg CP resulted in lower serum protein and lower cholesterol in birds reared in floor system, while birds reared in cage system showed no effect of CP on both parameters. Birds reared in cage and fed with 140 and 150 g/kg CP presented lower uric acid. The group of birds reared in floor system fed 180 g/kg had greater uric acid. Conclusion: The dietary protein level can be reduced up to 140 g/kg for Hisex Brown hens (30 to 45 weeks of age) without an important effect on metabolic profile and organ development in both rearing systems.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.195-204
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• 2002

Two experiments were conducted to study the effects of nutrient level and feeding method of split diets for a.m. and p.m. on laying hen performance, feed cost and eggshell quality. In experiment 1, 384 ISA Brown layers of 30∼38wk of age were assigned to four treatments which comprise of three replicates each containing 32 birds. The control(C) was fed a conventional single diet throughout the day and split diet groups(T1, T2 and T3) were offered high energy/protein-low Ca diets, and low energy/protein-high Ca diets in a.m.(04:00∼15:00) and p.m.(15:00∼21:00), respectively. In the split diet groups, daily ME and CP consumption, and feed cost were significantly reduced(P<0.05) compared to the C, while the hen-day egg production, average egg weight and daily feed intake were not different among treatments. Due to the reduced daily ME and CP intakes and feed cost, the conversions of feed, ME, CP and feed cost required per day and per kg egg mass were also significantly improved(P<0.05) in the split diet groups. Eggshell qualities (egg specific gravity, egg breaking strength and eggshell thickness) were improved(P<0.05) by split diet feeding. As the Ca level of the p.m. diet increased. In Experiment 2, 384 ISA Brown layers of 50∼58 wk of age were used in three treatments and each treatment was represented by four replicates each containing 32 birds. The control(C) was fed a conventional single diet throughout the day and split diet group(T1) was offered high energy/protein-low Ca diets, and low energy/protein-high Ca diets in a.m.(04:00∼l5:00) and p.m.(15:00∼21:00), respectively. T2 group was fed the diet mixed (50:50) with the a.m. diets in mash and p.m. diet in pellet used T1 group. In T1 and T2 groups, daily feed intake and average egg weight were significantly reduced(P<0.05) compared to the C, while the hen-day egg production was not influenced by the feeding system. Daily ME and CP consumption, and feed cost were reduced(p.0.05), and the conversions of ME, CP and feed cost required per egg were also significantly improved(P<0.05) in T1 and T2, while the conversions of feed, ME, CP and feed cost required per kg egg mass were not different to the C. Eggshell qualities of T1 and T2 were improved(P<0.05) compared to the others. It was concluded the feed and nutrients consumption, feed cost per day or per kg egg mass could be reduced by introducing split diets for a.m. and p.m. and the feeding method of mixed diet of split diets were also convenient and effective for sparing feed cost and improvement of eggshell quality.

• Korean Journal of Poultry Science
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• v.7 no.1
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• pp.1-11
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• 1980

About 6 to 8% of the eggs annually produced are broken or cracked between the hen and the consumer's carton. The majority of this breakage is due to interrelationships between egg shell quality and the many biological, environmental and managerial factors which have been individually identified as affecting breakage. Some of the factors associated with shell damage discussed in this review include age of hens, temperature ana humidity of the laying house, design of the cage systems and of the cage floors, type of material used to manufacture the cages frequency of daily egg collection in the laying house and, Probably most important, the frequency and quality of handling equipment maintenance. Age and genetic constitution of the hens, environmental temperature, and design and quality of equipment maintenance are the major factors that influence shell breakage. There is a curvilinear relationship between shell quality and shell breakage which explains why small changes in shell quality may be associated with large changes in the incidence of breakage. Published data indicate the incidence of breakage may range from as low as 1 to 2% to 35% or more for other egg producers.

• 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.39 no.3
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• pp.245-252
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• 2012

This study was carried out to investigate the performance of laying period of two-crossbred of Korean native chickens for producing laying hens. A total of four hundred eighty female 2-crossbred chicks that restored strains and were aboriginal at National Institute of Animal Science. There were four crossbreds (4 replications/crossbred, 30 birds/replication) as A) C strain ${\times}$ Y strain, B) C strain ${\times}$ L strain, C) C strain ${\times}$ G strain, and D) C strain ${\times}$ W strain, respectively. There were no significant difference on age at first egg among crossbreds (P>0.05). Egg weight and body weight of B crossbred at first egg was higher than other crossbreds (P<0.05). Body weight of B crossbred was the highest 20 to 72 weeks (P<0.05), and C and D crossbreds were lower compared to A and B crossbreds (P<0.05). Average feed intake of B crossbred was the highest among crossbreds (P<0.05), and that of A crossbred was higher compared to C and D crossbreds (P<0.05). Weekly feed intake of four crossbreds decreased from 50 weeks. Weekly egg weight of B crossbred was the highest and that of D crossbred was the lowest among crossbreds (P<0.05). Feed conversion ratio of A and B crossbreds was lower than that of C and D crossbreds. Hen-house egg production of C crossbred was the highest among crossbreds until 26 weeks old (P<0.05), but there was no significant difference among crossbreds from at the age of 26 weeks (P>0.05). Hen-day egg production decreased after at the age of 38 weeks. Weekly egg production of A and B crossbreds was higher compared to C and D crossbreds at the age of 68~72 weeks (P<0.05). These results suggested the basic data on the record of laying period of 2-crossbreed Korean Native Chickens for producing laying hens.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.299-306
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• 2004

The objective of this study was to investigate the influence of egg storage, broiler breeder age, and the change of egg weight during incubation on growth rate of chicks and 43-day-old dressing percentage. The trials involved hatching eggs obtained from 27-wk-old hens and stored for 6 d for the Young-EXP group, from 28-wk-old hens and stored for 0 d for the Young-CON group, from 51-wk-old hens and stored for 6 d for the Old-EXP group, and from 52-wk-old hens and stored for 0 d for the Old-CON group, The hens were two commercial broiler breeder flocks of the same strain (Cobb) but of different egg producing stages(early and middle stages of egg production). The chicks were grown on floor pens for 6 wks, The differences of setting egg weights between Old-CON and Old-EXP groups were 1 g, but those between Young-CON and Young-EXP groups were 2.9 g(P<0,05). The loss of egg weight during 18 d incubation did not greatly differ among four groups, but the loss of egg weight during 21 d incubation was significantly (P<0.05) more in the middle stage of egg production groups than in the early stage of egg production groups. The mean birth weights of the middle stage of egg production groups were significantly(P<0,05) heavier by 8,7 g than those of the early stage of egg production groups; however, the differences of 6-wk-old body weight were not significant between egg producing stages. The differences of body weights in both egg producing stages were not significantly influenced by egg storage period in overall wks of ages. Egg storage and hen age did not greatly influence to the 43 d dressing percentages, either, The correlations of the setting egg weight with 18 d egg weight during incubation, growth rate of chicks, or 43 d dressing percentage were not significant.