• 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.

• Korean Journal of Poultry Science
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• v.29 no.4
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• pp.237-241
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• 2002

To observe the effect of Induced molting on the recovery patterns of abdominal fat, visceral organs, and muscle tissues in spent laying hens after induced molting, three hundred sixty 77-wk-old, Babcock White hens were divided into 36 experimental units of 10 hens each and subjected to molt induction for seven wk. The post-molt production phase was spread over 84 to 126 wks of age. Thirty-six birds were randomly slaughtered and dressed at the pre-molt, 5% egg production, Peak, and end Phases of e99 Production. The body weight, abdominal fat, relative weight and length of visceral organs were measured. Proximate compositions of breast and thigh muscles were analyzed at each stage. The body weight was found to be minimal at the 5% egg Production stage, but increased as the egg Production increased for the rest of production. The pattern of abdominal fat change was very similar to that of body weight. The relative weight of the liver decreased to the lowest at the start of Post molting stage, but Peaked at the end Phase of egg Production (P<0.05). However, he heart and gizzard were observed to reach their maximum weight at the 5% egg Production (P<0.05), whereas they were, similar to those of the pre-molt phase for the rest of the production stages. Both intestine and reproductive tracts were found o be significantly smaller at 5% egg Production than at the other stages; however, their sizes increased gradually, reaching leak at the end Phase of e99 Production (P<0.05). Fat contents in breast and thigh muscles decreased significantly to the lowest at the start of the Post-molt stage, but increased to the highest at the end Phase of e99 Production (P<0.05). Thus, he Present study indicated that the molting process reduced body weight by decreasing the weights of abdominal fat and other visceral organs. Molting also influenced the breast and thigh muscle composition by decreasing fat content.

• Korean Journal of Poultry Science
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• v.45 no.1
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• pp.63-71
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• 2018

This study was conducted to evaluate the effect of age of laying hens on egg internal and external qualities. A total of 8,300 eggs were randomly collected from 15 grading & packaging (GP) centers, and 50 eggs per farm during April to May in 2015. Age of laying hens ranged from 18 to 65 weeks of age and they were classified into 5 age groups (18~25, 26~35, 36~45, 46~55, and 56~65 weeks). Egg weight increased, but the Haugh unit decreased as the age of laying hens increased. Yolk color was higher in eggs laid from 25~35 weeks of laying hens compared with that of 18~25-weeks-old chickens. The incidence of dirty eggs was highest (P<0.05) in 18~25 week group and remained constant after 26 weeks. Among eggshell defects, speckled and pimpled eggs increased as the age of laying hens increased. The incidence of calcium deposits and misshapen eggs was highest during 18~25 weeks of age and remained constant after 26 weeks. The percentage of total eggshell cracks increased as the age of laying hens increased. Among eggshell cracks, star- and hair-like cracks were frequently noted. The percentage of meat spot was higher than that of blood spot and their incidence was highest among the 56~65 week group. Age of laying hens significantly increased egg weight, incidence of pimpled or speckled eggs, star- or hair-like cracks, and meat spot. On the other hand, a significant negative interaction between age of laying hens and the Haugh unit was noted. In conclusion, our study revealed that the age of laying hens affected internal and external egg qualities.

• Korean Journal of Poultry Science
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• v.42 no.1
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• pp.9-13
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• 2015

This study was conducted to investigate the effect of heating temperature and time on the quality of baked egg. Eggs were baked at various temperatures (80, 90, 100, 105 and $110^{\circ}C$) for different times (5, 6, 7 and 8 h) using a commercial heater. Our results revealed that heating loss in the $110^{\circ}C$ treatment was significantly (p<0.05) higher than those of other remaining treatments. The pH value of egg white in the 5 h treatment was significantly (p<0.05) higher compared to those of other treatments. While, no significant differences in pH values of egg yolks occurred among the treatments. Regarding the texture, hardness and cohesiveness values were not significantly different among the treatments. Regarding color, the $110^{\circ}C$ treatment samples had lower lightness value whereas had higher redness and yellowness values compared to the $105^{\circ}C$ treatments (p<0.05). Moisture content of baked eggs showed an decreased tendency as increasing the heating temperature and time. These results suggested that the proper conditions were 8 hours for total baking time including more than 5 h at $105^{\circ}C$ or 2 h at $110^{\circ}C$.

• Korean Journal of Poultry Science
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• v.45 no.3
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• pp.201-207
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• 2018

An experiment was conducted to investigate the effect of fermented garlic solution (FGS) on the performance, egg quality and blood profiles of laying hens in the finishing period. In total, 432 Lohmann Brown hens aged 79 weeks were equally distributed into four dietary treatments with six replicate. Hens were fed the basal diet containing 2,750 kcal/kg of ME and 16% of CP, which was supplemented with either 0% (control), 0.05%, 0.10% and 0.20% FGS from 79 to 83 weeks old. Laying performance, egg quality, yolk fatty acids and serum characteristics were analyzed at the end of experiment. Egg production and feed conversion was numerically improved in FGS supplementation treatments compared to those in the control, but were not statistically different. The albumen height and Haugh unit showed significant increase (P<0.05) in the FGS supplementation groups. The concentration of saturated fatty acid decreased in the yolks of birds fed FGS (P<0.01), whereas the unsaturated fatty acid (UFA) and mono-UFA contents were significantly higher (P<0.01) in those treatments than in the control. Significantly lower natural fat and cholesterol in serum were observed in birds fed the 0.20% FGS supplementation diet (P<0.01). However, the high-density lipoprotein (HDL) cholesterol increased in both the 0.10% and 0.20% FGS supplementation groups. In addition, interleukin-2 mRNA and CD4+/CD8+ level in serum which were cellular immunity indicators showed statistical differences (P<0.01) among treatments and a higher concentration in the 0.10% and 0.20% FGS groups than in the control. Thus, it can be concluded that dietary supplementation of FGS improved egg quality and stimulated immune response in mature laying hens.

• Korean Journal of Poultry Science
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• v.36 no.1
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• pp.47-55
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• 2009

This study was carried out to investigate the effects of spider-derived protease [Arazyme (AZ)] supplementation on egg production, egg quality, cecal microflora and viscosity of intestinal contents in laying hens at the late production. A total of two hundred, 59-wks-old, Hy-Line Brown layers were divided into four groups, placed into 5 replicates per group (50 birds per group) and fed one of four diets containing 0.05, 0.075 or 0.1% AZ or control for 5 wks. The results showed that egg weight in group fed the diet containing 0.05% AZ was significantly higher than those of other groups (P<0.05). There were no significant differences in egg interior and eggshell qualities among the groups. The serum parameters such as total cholesterol, the levels of GOT and GPT were not influenced by AZ feeding. There were no significant differences in the cecal number of total microbes, Coliforms and lactic acid bacteria among the groups. The viscosity and ammonia concentration of intestinal contents in the groups fed AZ were significantly reduced compared to those of the control (P<0.05). In conclusion, laying hens fed AZ supplemented diet improved egg weight as compared with that of control. In addition, the AZ supplemented diet reduced the viscosity and ammonia concentration of intestinal contents, reflecting a significant feed enzyme effect.

• Korean Journal of Poultry Science
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• v.36 no.1
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• pp.15-21
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• 2009

A 10-wk layer feeding trial was conducted to investigate the effects of high quality corn distiller's dried grains with solubles (DDGS) on performance, egg qualities, and yolk fatty acid composition. The economics of using DDGS in the Korean situation was also analyzed. A total of 216 Hy-line Brown layers, 23-wk of age, were employed in this trial consisting of three dietary treatments (0%, 10%, and 20% DDGS), and six replicates per treatment. All experimental diets were prepared as iso-protein (17%) and iso-calorie (2,780 kcal/kg). The use of DDGS up to 20% in layer diets did not affect the feed intake, laying rate, egg weight, and feed conversion ratio (P>0.05). At 5th and 10th wk of the trial, the eggshell color, albumen height, and Haugh unit were not influenced by the DDGS supplementation. At 5th wk of the trial, the eggshell qualities, like eggshell weight, eggshell thickness, and eggshell strength, were not affected by the DDGS feeding; however, these eggshell qualities were decreased at 10th wk due to the 20% DDGS feeding (P<0.05). Yolk color of DDGS 20% increased compared to DDGS 0% at 5th and 10th wk of the trial (P<0.05). At 10th wk, yolk/egg ratio of DDGS 20% decreased compared to DDGS 0% (P<0.05). The yolk fat content was not changed due to DDGS feeding. The monounsaturated fatty acid content of yolk decreased linearly by feeding DDGS (P<0.05). The yolk polyunsaturated fatty acid content of DDGS 20% increased significantly compared to DDGS 0%. The DDGS feeding was not found to affect the degree of yolk fat unsaturation. The cost of feed (￦/kg feed) decreased as the level of DDGS increased. The production costs of egg (￦/kg egg) were cheap in the order of DDGS 10%, DDGS 20%, and DDGS 0%, indicating that DDGS is a viable alternative feed ingredient to corn and soybean meal. In conclusion, high quality DDGS ($L^*$ 61.72) could be used economically up to 20% level without any harmful effect on laying performance: however, the use of DDGS up to 10% is more economical than DDGS 20%.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.213-223
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• 2002

This study was conducted to investigate the influence of feeding various Lactobacillus on production performance, nutrients digestibility, intestinal microflora, and fecal $NH_{3}$ gas emission in laying hens. Three hundred and sixty ISA Brown layers, 21 weeks of age, were randomly allotted to nine treatments, with low replicates per treatment. Nine treatments consisted of Control(no Lactobacillus), Lactobacillus crispatus avibrol(LCB: KFCC-11195), Lactobaciilus reuteri avibro2(LRB: KFCC-11196), Lactobacillus crispatus avihenl(LCH: KFCC-11197), Lactobacillus vaginalis avihen2(LVH: KFCC-11198). Each Lactobacillus was added at two levels ($10^{4}$and $10^{7}$ cfu/g diets). Egg production, and egg weight were measured daily. A metabolism trial was conducted following the 12-week feeding trial, during which egg qualities, intestinal microflora and fecal $NH_{3}$ gas emission were examined. Egg production and daily egg mass improved significantly by the addition of various Lactobacillus(P<0.05), of which effect was more notable during the latter part of the feeding trial. But, no significant differences were found among Lactobacillus strains and between two levels of supplementation. Egg weight and feed intake showed no difference among all treatments. Feed conversion ratio of birds fed lactobacillus was significantly improved compared to that of the Control(P<0.05), but not different among lactobacillus treatments. Digestibility of crude protein, ether extract and crude ash improved significantly in lactobacillus treatments(P<0.05). However, there were not statistically different by adding levels and strains. Total counts of Lactobacillus spp. in ileum of layers fed Lactobacillus were significantly higher than that of the control, but no consistent trend was found in cecum. There were no significant differences in intestinal yeast and anaerobes counts among all treatments. The Lactobaciilus supplementation did not exert my effect on the eggshell quality and Haugh unit. Fecal $NH_{3}$ gas emission decreased significantly in Lactobacillus treatments, and showed no difference between the two supplementation levels. From the result of this study, it could be concluded that dietary supplementation of Lactobacillus, regardless of their species, Improves the laying performance and decreases the fecal ammonia gas emission. The proper level of supplementation appears to be $10^{4}$ cfu/g of diet.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.205-211
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• 2002

A feeding trial was conducted to study the effects of a live yeast, Pichia farinosa culture(PF), on the production performance and intestinal microflora in laying hens. One hundred and sixty ISA Brown layers, 21 weeks of age, were randomly allotted to four dietary treatments, with four replicates per treatment. Dietary treatments consisted of four levels (0, 0.1, 0.3, and 0.5%) of PF added to a com-soybean meal based diet. Egg production, egg weight, feed intake and fred conversion ratio(FCR) were measured. Egg qualifies were examined at 25th and 29th weeks of age. A metabolism trial was conducted following the feeding trial, during which intestinal microflora, nutrient digestibility and fecal NH3 gas emission were measured. Egg production of birds fed 0.1 and 0.3% PF were significantly higher than those from birds fed 0 and 0.5% PF(P<0.05). Daily egg mass of 0.3% PF increased significantly compared to that of 0% PF. There was no difference in egg weight among all treatments. Feed conversion ratio was significantly improved as the PF level increased. No significant difference was found in eggshell quality and Haugh unit at both 25 and 29 weeks of age. Viable count of ileal Lactobacillus spp. increased significantly as the rf level increased. However, the total number of yeast and anaerobes in ileum were similar among all treatments. Cecal Lactobacillus spp. and yeast counts showed no difference among all treatments. Fecal NH$_{3}$ gas emission of layers fed PF decreased significantly by the PF supplementation. From the result of this experiment, it could be concluded that dietary supplementation of the live yeast Pichia farinosa improves the laying performance and decreases the fecal ammonia gas emission.

• Korean Journal of Poultry Science
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• v.35 no.4
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• pp.391-398
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• 2009

The objective of the present study was to compare of the effects of four molting methods on performance of laying hens. In total, 120 White Leghorn layers (62 weeks of age) were used. The four molting methods consisted of 10 days of feeding and the first 3 days of water withdrawal (FW1, 2) followed by ad libitum access to a layer diet 1 and 2 from day 11; 28 days of restricted feeding (NFW1); 28 days without withdrawing their feed (NFW2). Egg production of postmolt decreased until $3{\sim}4$ days at FW1 and FW2 treatments and until $16{\sim}18$ days at NFW1 and NFW2. 50% recovery of egg production were 7, 6, 7 and 5 week at FW1, FW2, NFW1, and NFW2 treatments, respectively. At day 14 of postmolt, the weight of livers, hearts, and oviducts decreased at molting treatments (P<0.05). Egg quality was improved on egg weight, eggshell thickness, eggshell break strength, and Haugh unit except egg yolk color (P<0.05).