• Korean Journal of Poultry Science
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• v.31 no.3
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• pp.177-185
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• 2004

This experiment was conducted to examine the dietary effects of local granular ark shell(GAS) replacing limestone on egg shell quality in aged hens. A total of 200 Hy-Line Brown layers of 54-weeks-old were allotted into four treatments with five replications each. They were fed control(limestone only) 1% GAS, 2% GAS and 3% GAS diets for 6 weeks. GAS was substituted for coarse-type limestone at 0, 1, 2 or 3% of diet on weight basis. Particle sizes of limestone and GAS were within the ranges of 2~4 mm in diameters. In vitro HCl solubility of GAS was significantly lower(6.27 vs. 7.90%) compared to that of limestone(p < 0.05). The dietary treatment did not affect feed intake and egg production rate of the birds. Egg shell strength and thickness tended to be improved for birds fed the diets containing higher levels of GAS. The average egg shell strength and thickness of 2 or 3% GAS groups were significantly greater than those of the control (P < 0.05). The Tibial ash content of birds from 3% GAS group increased significantly as compared to that of the control. Tibial breaking strength, however, was not affected by the dietary treatment. Serum Ca and P contents of the birds were also not different among the dietary treatments. In conclusion, locally prepared GAS can be used as a calcium source in aged layer diet.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.255-263
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• 2004

Two experiments were conducted to evaluate the feeding values of sesame oil meal (SOM) and to investigate the effects of its dietary supplementation on egg production in laying hens. In experiment I, the values of true metabolizable energy (TME), nitrogen corrected true metabolizable energy (TMEn) and true amino acid availability (TAAA) were determined by force-feeding 16 ISA-Brown roosters and collecting the total excreta from the birds, The TME and TMEn of SOM were 2.30 and 1.99 kcal/g, respectively, and the average TAAA of 15 amino acids was $76.93\%$. In experiment 2, a total of ninety, 48 weeks old ISA-Brown layer were randomly divided into 9 groups of 10 birds each and assigned to three experimental diets containing 0, 5 and $10\%$ SOM for 4 weeks (30 birds per treatment). The inclusion of SOM into laying hen diets at the 5 and $10\%$ level did not affect production and quality of egg. The C18:3 $\omega$3 content of egg yolks in the $10\%$ SOM group was higher than the other groups, but not significantly. There were no adverse effects on blood parameters in layers fed treated diets containing $5\%$ or $10\%$ SOM, The results indicate that SOM can be used for layers diet up to $10\%$ without any significant negative effects on egg production and quality.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.8
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• pp.1171-1175
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• 2005

An experiment was conducted (28 to 44 weeks) to study the laying performance, shell quality, and nutrient retention of White Leghorn layers fed different levels of non-phytate phosphorus (NPP). Six levels of NPP (0.15, 0.18, 0.21, 0.24, 0.27 and 0.30%) at a constant calcium (Ca) level (3.5%) in maize-soya-deoiled rice bran based diets were formulated, and each experimental diet was offered ad libitum for 16 weeks to five replicates with five birds in each replicate. The body weight of WL layers fed diet containing 0.15% NPP was significantly (p<0.05) lower than those fed diet with 0.30% NPP, at 44 weeks of age. However, the hen day egg production, egg weight, daily feed intake and feed consumed per dozen eggs were not influenced by the variation in the NPP levels in the diet. The bone ash content was significantly (p<0.05) higher in the birds fed 0.30% NPP as compared with those fed diets up to 0.24% NPP. Bone ash content was intermediate in the birds fed diet containing 0.27% NPP. The tibia strength followed the same trend as that of bone ash. Dietary NPP content had no influence on serum Ca and protein concentration and activity of alkaline phosphatase. However, serum inorganic P concentration increased linearly with NPP content in the diet. The concentration of P was significantly (p<0.05) higher in the birds fed 0.27% NPP or higher as compared with those fed 0.15% NPP. Levels of dietary NPP had no influence on egg quality parameters like shell wt, shell thickness, shell strength and specific gravity. The retention of nutrients such as DM, N and Ca were comparable among the WL layers fed different levels of NPP. However, the retention of P decreased linearly with increase in the level of NPP in the diet. The retention of P in the birds fed diets up to 0.24% NPP in the diet was comparable, however further increasing the content of NPP (either 0.27% or 0.30%) reduced the retention of P. Based on the results of the present study, 0.15% NPP (180 mg/b/d) in the diets of WL layers is adequate for optimum production performance during 28 to 44 weeks of age, however, WL layers require 0.27% NPP (324 mg /b/d) in the diet for optimum production with better bone mineralization.

• Journal of Food Hygiene and Safety
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• v.18 no.2
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• pp.61-66
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• 2003

This study was conducted to produce the egg yolk Imunoglobulin (IgY) on Vibrio parahaemolyticus from immunized hen with lipopolysaccharide (LPS). Vibrio parahaemolyticus is considered as a potentially pathogenic bacteria, the causative agents of the gastroenteritis. According as the LPS antigens were injected into laying hens in order to produce antibodies against Vibrio parahaemolyticus in egg yolk. After chickens were immunized four times in 2 weeks interval and three times booster in 2 weeks interval, the profile of antibody Production was examined by ELISA. The Production of antibody in egg yolk was started in 1 week after the first immunization, reached peak in 7 weeks and maintained until 13 weeks later. The antibody titre in serum showed similar tendency as IgY. No significant difference in antibody titre when the titre compared to water diluted IgY and commercial IgY kit. Purified IgY reacted with only Vibrio parahaemolyticus, but other Vibrio species and food-borne pathogenic bacteria. In conclusion, we showed that it is possible to obtain a high antibody titre in chicken with quite low amounts of LPS antigen. These results suggested that egg yolk antibodies could be a good source for production of specific antibodies to pathogenic bacteria inducing epidemic gastroenteritis.

• Korean Journal of Poultry Science
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• v.48 no.2
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• pp.69-80
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• 2021

We conducted a 4 × 4 diallel cross-mating test using 934 chickens from four grandparent stock lines to develop a new synthetic breed of Korean native chicken. The mean values, combining ability, and reciprocal effects on survival rate, body weight, and hen-day egg production were analyzed. In phenotypes, most chickens have yellowish-brown, reddish-brown and mixed color feathers. The average survival rate was 86.8±12.3%, with the highest in YH combination. Specific combining ability (SCA) had a greater effect on survival rate than general combining ability (GCA), and the SCA of HY combination was the highest. The 16 cross-combinations were distinctly divided into three weight groups according to their genetic characteristics. At 12 weeks of age, GCA showed a greater effect on weight than SCA, and the SCA of FH combination was the highest. The age at first egg laying was 157 days, and the crosses reached sexual maturity faster than the pure lines. The egg production rate was highest in SY at 79.5±2.1%. The GCA and SCA for hen-day egg production were similar, and the SCA was highest in the HS and FY combinations. The reciprocal effect showed that the offspring's egg production rate was high when S and Y were maternal parents in almost all combinations. In conclusion, FH and HF combinations, which have excellent growth performance, are the most desirable paternal parent stock strains, and FY, FS, HY, and SY combinations, which have excellent laying performance with moderate weight, are the preferred maternal strains.

• Korean Journal of Poultry Science
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• v.32 no.1
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• pp.35-41
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• 2005

The objectives of the present study were to investigate the effects of varying levels of dietary oil containing conjugated linoleic acid (CLA) on the egg production and fatty acid composition of egg yolk. Seventy-two 59-wk-old ISA Brown laying hens were randomly allotted to four dietary treatments, each consisting of three replicates with six birds per replicate. There were four treatments that consist of diets containing 0, 1, 2, or $3\%$ commercial CLA-containing oil. Egg production was not significantly different among the dietary treatments at 0, 2, 4, and 6 week. The proportion of saturated fatty acids such as C16:0 and C18:0 in egg yolk were increased, but that of monounsaturated fatty acid C18:1 was decreased by feeding CLA-containing oil supplementation. However, the proportion of polyunsaturated fatty acids such as C18:2 and C18:3 in egg yolk were not different among dietary treatments at 2 and 4 wk of the experiment. At 6 week, the proportion of C18:2 in egg yolk was decreased by feeding CLA-containing oil compared with the control. Polyunsaturated fatty acid:saturated fatty acid (P:S) ratio and n-6:n-3 polyunsaturated fatty acid ratio were similar across the treatments between 2 and 4 week. The P:S ratio was decreased by dietary CLA-containing oil supplementation at 6 week. The proportion of CLA in egg yolk was linearly increased with increasing levels of CLA-containing oil supplementation. In conclusion, dietary supplementation of CLA-containing oil to laying hens increased beneficially increased CLA content in their egg yolk.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.449-457
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• 2010

This study investigated the effects of three kinds of water extract mixtures each with different ratios of A. capillaris, C. sinensis, S. chinensis, and V. coloratum on laying performance, egg quality, blood characteristics, and egg storage stability in laying hens. One hundred and sixty 35-wk-old laying hens (Hy-line brown) were divided into four groups of 10 birds each replicated times four. The treatments involved a basal diet (C, control) or diets containing three kinds of water extract mixtures at 200 ppm (T1, water extract mixture A; T2, water extract mixture B; T3, water extract mixture C). The egg production rate, egg mass, and feed conversion ratio were significantly improved in all treatments compared to those of control (p<0.05). Haugh unit and egg yolk color in all treated groups were significantly improved in comparison with control (p<0.05), but no significant differences were observed for egg shell quality. The content of total cholesterol in blood serum was significantly decreased in all treatments compared to that of control (p<0.05). The blood biochemical parameters of liver and kidney damage were significantly decreased in all treatments compared to those of control (p<0.05). Total antioxidant activity in the blood serum of all treated groups was increased as well. The Haugh unit and malondialdehyde content in the egg yolk during storage were significantly decreased in all treated groups compared to control (p<0.05). Consequently, the dietary supplementation of water extract mixtures of A. capillaris, C. sinensis, S. chinensis, and V. coloratum improved laying performance and egg quality but decreased egg quality deterioration with increased storage. These results suggest that medicinal plant extracts could be used as a feed additive in feed for laying hens.

• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.225-231
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• 2006

To investigate the effect of feeding rare earth (RE) on the performance of breeder hens a feeding trial with sixteen thousands of 158 day old Ross broiler breeder hens was conducted for thirty weeks. A mixture of RE- chlorides containing mainly La, Ce, and Pr was mixed into corn-soy based diet at two levels, 300 and 600 mg/kg, All the hens were housed in flat layer houses and the ratio of male to female was maintained at one to ten. Dietary supplementation of the of RE at a level of 300 mg/kg made the hens reach egg production peak higher by about 6% and earlier by about two weeks. As a result, it made higher hatchable egg production by 3.5%. It also reduced dramatically the mortality of both male and female breeders(P<0.05). Egg weight was slightly increased but egg qualify was not much influenced by dietary supplementation of RE. Egg albumin hight and Haugh unit were significantly improved while egg shell thickness, egg breaking strength and yolk color were similar to those of the control. Experimental results appeared to show a good possibility that egg fertility and hatchability were improved by feeding RE. Dietary supplementation of RE at a level of 300 mg/kg should be acceptable but not the 600 mg/kg level for breeder hens. Further studies on the effect of RE on egg fertility and hatchability appears to be necessary.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.07b
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• pp.37-54
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• 2003

It has been recognized that the hen. like its mammalian counterparts. provides young chicks with antibodies as protection against hostile invaders. This system facilitates the transfer of specific antibodies from serum to egg yolk. and provides a supply of antibodies called immunoglobulin Y(IgY) to the developing embryo and the hatched chick. The protection against pathogens that the relatively immuno-incompetent newly hatched chick has. is through transmission of antibodies from the mother via the egg. Egg yolk. therefore. can be loaded with a large amount of IgY against pathogens which can immobilize the existing or invading pathogens during the embryo development or in day-old chicks. Thus. the immunization of laying hens to various pathogens results in production of different antigen-specific IgY in eggs. Egg yolk contains 8~20 mg of immunoglobulins (IgY) per $m\ell$ or 136~340 mg per yolk suggesting that more than 30 g of IgY can be obtained from one immunized hen in a year. By immunizing laying hens with antigens and collecting IgY from egg yolk. low cost antibodies at less than ＄10 per g compared to more than ＄20.000 per g of mammalian IgG can be obtained. This IgY technology opens new potential market applications in medicine. public health veterinary medicine and food safety. A broader use of IgY technology could be applied as biological or diagnostic tool. nut-raceutical or functional food development. oral-supplementation for prophylaxis. and as pathogen-specific antimicrobial agents for infectious disease control. This paper has emphasized that when IgY-loaded chicken eggs are produced and consumed. the specific antibody binds. immobilizes and consequently reduces or inhibits the growth or colony forming abilities of microbial pathogens. This concept could serve as an alternative agent to replace the use of antibiotics. since today. more and more antibiotics are less effective in the treatment of infections. due to the emergence of drug-resistant bacteria.

• Korean Journal of Poultry Science
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• v.35 no.2
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• pp.183-190
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• 2008

This study was conducted to investigate the effect of feeding diets supplemented with ${\beta}-glucan$ products on the performance, small intestinal microflora and immune response in laying hens. The ${\beta}-glucan$ products used in the experiment were $BetaPolo^{(R)}$ ; soluble ${\beta}-glucan$ of microbial cell wall origin, $HiGlu^{(R)}$ ; microbial cell wall origin, $OGlu^{(R)}$ ; oat origin, $BGlu^{(R)}$ ; barley origin. A total of 720 Hy-Line Brown laying hens of 40wks old were divided into 5 dietary treatments : T1 ; Control( C), T2 ; $BetaPolo^{(R)}$, T3 ; $HiGlu^{(R)}$, T4 ; $OGlu^{(R)}$, T5 ; $BGlu^{(R)}$. Each treatment was replicated 4 times with 36 birds/replicate housed in 2 bird cages, and arranged according to completely randomized block design. Feeding trial lasted 40ds under 16 h lighting regimens. There were significant differences among treatments in hen-house egg production feed intake and feed conversion. HiGlu treatment was significantly higher than OGlu treatments in hen-house egg production. ${\beta}-glucan$ supplemented treatments were lower than the control in feed intake and feed conversion ratio. All ${\beta}-glucan$ supplemented treatments were significantly higher than the control in eggshell strength. Eggshell color and Haugh unit tended to be lower in the supplemented group than the control. IgY concentration was not significantly affected by treatments. At $5^{th}$ week of experiment, however, IgY concentration tended to increase in the supplemented groups. Among the leucocytes parameters, WBC, heterophil, lymphocytes, monocyte and eosinophil concentration were lower in the supplemented groups than those of the control. Among erythrocytes, HCT(hematocrit) and MCV(mean corpuscular volume) were significantly affected by treatment. MCV of supplemented groups were higher than that of the control. Immunoglobulin concentrations in the birds were not significantly different among treatments. However, IgA concentration tended to be low in the supplemented groups than the control. The cfu of small intestinal microflora were not significantly different among treatments, but that of Cl. perfringens tended to be lower than the control. The result of this experiment indicateted that feeding ${\beta}-glucan$ to laying hens improve feed conversion ratio and eggshell strength. Also intestinal microflora and immune responses are modified.