• Korean Journal of Poultry Science
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• v.43 no.2
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• pp.97-103
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• 2016

This study aimed of effects of replacing maize with rice or brown rice on laying performance, egg quality, and apparent fecal digestibility of nutrient in Hy-Line Brown laying hens. A total of 200, 25-week old Hy-Line Brown laying hens were randomly assigned to one of 5 treatments, each of which was replicated 4 times. Four experimental diets that were formulated two different grains (brown rice or rice) with two inclusion levels of (15 and 30%) as a replacement of maize. The experimental period was 8 weeks. During the experiment, hens were provided with feed and water ad libitum and were exposed to a 16:8=L:D lighting schedule. There were no differences in feed intake, egg weight, and egg mass during the 8 weeks of the feeding trial among groups. However, hen-day egg production was greater (P<0.05) for Brown rice treatment groups than that for basal and rice treatment groups. In addition, the supplementation of brown rice or rice did not have an effect on eggshell strength, eggshell thickness, and HU during of the feeding trial (Table 4). However, egg yolk color was less (P<0.05) for basal treatment groups than that for among treatment group. ATTD of dry matter (DM) and crude fat were greater (P<0.05) for brown rice 15 treatment than for rice 30 treatment. Crude protein (CP) was greater (P<0.05) for brown rice 15 treatment than for basal treatment. In conclusion, brown rice or rice grains is a good alternative energy feedstuff and can be used in laying hens, totally replacing maize, without any negative effect on the laying performance, egg quality, and nutrient digestibility.

• Korean Journal of Poultry Science
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• v.43 no.2
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• pp.89-96
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• 2016

This study aimed to determine the effect of different dietary level of rice bran extract (RBO) on the laying performance, egg quality, blood parameter, cholesterol, and fatty acids in yolk of Hy-Line Laying hens. In all, 144 Hy-Line Brown laying hens (29 weeks old) were randomly allocated to one of 4 dietary treatments, with 4 replicates per treatment. A commercial basal diet was used and three additional diets were prepared by supplementing 2.5, 5.0 or 10.0 g/kg of RBO to the basal diet. The experimental diets were fed on an ad libitum basis to the bird during 8 weeks. Hen-day egg production increased (quadratic, p<0.05) with inclusion level of RBO, but feed intake, egg weight, and egg mass were not influenced by inclusion of level of RBO in diet. However, the supplementation of RBO did not have an effect on eggshell strength, eggshell thickness, egg yolk color, and HU during the feeding trial. There were no significant differences in the level of leukocyte. However, heterophil and lymphocytes decreased (quadratic, p<0.01) with inclusion level of RBO. H:L ratio tended to decrease (linear p=0.08) with inclusion level of RBO. As expected, increasing inclusion level of RBO in diets decreased (linear, p<0.01) the concentrations of total cholesterol in plasma. AST, ALT, glucose, and albumin were not affected by inclusion of RBO in diets. Egg yolk cholesterol increased (linear and quadratic, p<0.05) with inclusion level of RBO in diet. The results of this study indicate that dietary supplementation of RBO improves laying performance and decreased total cholesterol and egg yolk cholesterol levels in laying hens. Therefore, dietary RBO is considered a valuable functional ingredient to improve the performance of birds.

• Animal Bioscience
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• v.34 no.5
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• pp.811-823
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• 2021

Objective: Eggshell color is an important indicator of egg quality for consumers, especially for brown eggs. Various factors related to laying hens and their environment affect brown eggshell coloration. However, there have been no studies investigating hepatic functions of laying hens with variable intensity of brown eggshell color. Therefore, this study was aimed to identify potential factors affecting brown eggshell coloration in aged laying hens at the hepatic transcriptomic level. Methods: Five hundred 92-wk-old Hy-line Brown laying hens were screened to select laying hens with different intensity of brown eggshell color based on eggshell color fans. Based on eggshell color scores, hens with dark brown eggshells (DBE; eggshell color fan score = 14.8) and hens with light brown eggshells (LBE; eggshell color fan score = 9.7) were finally selected for the liver sampling. We performed RNA-seq analysis using the liver samples through the paired-end sequencing libraries. Differentially expressed genes (DEGs) profiling was carried out to identify their biological meaning by bioinformatics. Results: A total of 290 DEGs were identified with 196 being up-regulated and 94 being down-regulated in DBE groups as compared to LBE groups. The Kyoto encyclopedia of genes and genomes (KEGG) analysis revealed that these DEGs belong to several biological pathways including herpes simplex infection (toll-like receptor 3 [TLR3], cyclin-dependent kinase 1, etc.) and influenza A (TLR3, radical S-adenosyl methionine domain containing 2, myxovirus [influenza virus] resistance 1, etc.). Genes related to stress response (ceremide kinase like) and nutrient metabolism (phosphoenolpyruvate carboxy-kinase 1, methylmalonic aciduria [cobalamin deficiency] cblB type, glycine receptor alpha 2, solute carrier family 7 member 11, etc.) were also identified to be differentially expressed. Conclusion: The current results provide new insights regarding hepatic molecular functions related to different intensity of brown eggshell color in aged laying hens. These insights will contribute to future studies aiming to optimize brown eggshell coloration in aged laying hens.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.569-577
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• 2019

The current experiment was conducted to compare nutrient utilization in the aged laying hens with different eggshell strengths or different intensities of brown eggshell color. Two metabolic trials with 96-week-old Hy-Line Brown laying hens were conducted. Twelve hens with a strong eggshell strength (SES) and 12 hens with a weak eggshell strength (WES) were selected and used in the first experiment, whereas 12 hens with dark brown eggshells (DBE) and 12 hens with light brown eggshells (LBE) were selected and used in the second experiment. All hens were fed a common commercial layer diet. Diets included chromic oxide as an indigestible marker to determine the apparent total tract retention (ATTR) of the gross energy (GE), dry matter, acid-hydrolyzed ether extract, nitrogen, neutral detergent fiber, acid detergent fiber, ash, and minerals. The results indicate that the ATTR of Ca in the aged laying hens with SES (59.7%) was greater (p < 0.05) than in the aged laying hens with WES (48.6%). However, the ATTR of the GE and other nutrients was not different between the hens with SES or WES. There were no differences in the ATTR of GE and nutrients between the hens with DBE or LBE. In conclusion, aged laying hens with SES have a greater ability to utilize dietary Ca than those with WES, indicating that the extent of dietary Ca utilization determines the eggshell strength of aged laying hens. However, nutrient utilization in diets may have little impact on eggshell brown coloration in aged laying hens.

• Animal Bioscience
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• v.35 no.8
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• pp.1205-1214
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• 2022

Objective: Spent ginger is a byproduct of juice extraction from the rhizome of ginger (Zingiber officinale). Despite its nutritional value, it is difficult to preserve or further process and thus is often wasted. This study uses spent ginger as a substrate for fermentation and cultivates spent ginger yeast cultures (SGYCs) that are then added to the feed of laying hens. The effects of SGYCs on production performance, egg quality, serum composition, and intestinal microbiota of laying hens were investigated. Methods: Eighty 60-week-old Hy-Line Brown hens were separated into 5 experimental groups with 4 replicates per group (4 hens per cage, 4 cages per replicate). The control group was fed a basal diet while experimental groups were also given SGYCs at the levels of 5, 10, 20, and 40 g/kg for 6 weeks. Results: The addition of SGYCs significantly increased the laying rate and nutrient digestibility, decreased feed conversion ratio, and enhanced the color of egg yolks (p<0.05). No changes were observed in activity levels of alanine aminotransferase and aspartate aminotransferase in the serum (p>0.05), but the activities of superoxide dismutase, glutathione peroxidase, and peroxidase all significantly increased, and contents of malondialdehyde were significantly reduced (p<0.05). In addition, changes in the relative abundance of Firmicutes and Bacteroidetes might be the main factor contributing to the significant increase in the apparent digestibility of crude protein and crude fat in laying hens (p<0.05). Conclusion: The current evidence shows that dietary supplementation of SGYCs to the feed of laying hens can improve laying rates, enhance antioxidative defenses, and influence dominant intestinal bacteria.

• Journal of Animal Environmental Science
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• v.6 no.2
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• pp.91-96
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• 2000

This study was carried out to determine the effect of sound stimulation on growth performance, feeding behaviour and egg production of laying hens. A total of 180 laying hens(4 weeks old) were alloted to 18 cages with 10hens per cage and 6 cages per treatment. Laying hens were exposed to three sounds: control, Leq 50dB and Leq 75dB. The growth performance was measured fro m4 weeks to 17 weeks of age, feeding behaviour was observed at 5weeks, 7weeks, 10weeks and 50 weeks of age using data from real-time videotapes, while eg production was recorded from 20 weeks to 50 weeks of age. Growth performance was improved in the sound stimulated laying hens from 12 weeks to 17 weeks of age. In the 50dB simulated laying hens spent more longer time for feeding than others during the experimental period. Egg production of 50dB stimulated laying hens from 20 weeks to 50 weeks was higher than others, however 75dB stimulated laying hens were significantly lower than 50dB stimulated hens(P<0.05). The results indicated that the growth and egg production of egg type chicken can be influenced by sound stimulation through physiological rhythm.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.6
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• pp.502-508
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• 2001

In this paper, slack is computed from a comparison of the cable pay out rate and the ship ground speed in accordance with laying conditions, and the speed controller of the cable engine based on an H(sub)$\infty$ servo control id designed for adjusting the cable engine in order to lay a desired amount of slack. The controller is designed for robust tracking of the cable engine under disturbances. The performance of the designed controller is evaluated by computer simulation, and, consequently, a feasibility study for laying the submarine cable stably is done through analyzing simulation results.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.1
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• pp.1-4
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• 2013

Mines are classified as the attack, defense and protect mine depending on laying position. In case of the defense and protect mine for protecting the major ports, it is important to predict that mines are laid position for a safe maneveuring of friendly ships. Furthermore, the marine environment affects mines laying position. Therfore, this paper is studied on a prediction of mines laying position through the prediction of the marine environment.

• Korean Journal of Poultry Science
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• v.47 no.4
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• pp.237-245
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• 2020

This study investigated the effects of breed, laying age, and egg storage period on hatching performance. Eggs were collected from early laying period (27 to 29 weeks old) and late laying period (50 to 52 weeks old) in Hwanggalsaek Jaeraejong, Korean Rhode Island Red, and Korean White Leghorn chicken breeds. Eggs laid for each period were stored for 3, 7 and 14 days and then hatched. Fertility, hatchability, and embryonic mortality were observed to determine the hatching performance. The results showed that hatching performance was affected by breed, laying age, and egg storage period with independently or interactively. The Korean Rhode Island Red breed had the lowest hatching performance. Hatchability and early embryonic mortality rate increased in early laying period eggs compared to the late laying period, but the late embryonic mortality rate increased in late laying period eggs. Additionally, hatching performance decreased as the egg storage period increased. Using breed-specific hatching management techniques, avoiding late laying period eggs, and shortening the egg storage period to seven days after laying may improve the hatching performance.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.694-699
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• 2009

The present study was conducted to evaluate the effect of chilled drinking water on the productivity of laying hens under constant high ambient temperature. A total of seventy-two, 123-day-old Hy-line brown layers was divided into two equal groups. The first group (UDWG) was given unchilled water ($23.0{\pm}2.5^{\circ}C$) as a control, and the second group (CDWG) was given chilled water ($16.0{\pm}0.5^{\circ}C$). The laying hens were kept at $30^{\circ}C$ constant temperature with 50% relative humidity and were exposed to 17 h of light per day. Feed intake, egg production, egg quality (egg weight, shell weight, shell thickness, egg color, yolk color, and Haugh unit), and blood samples were collected and analyzed. The results showed that the feed intake of CDWG laying hens was significantly higher (11.64%) than the UDWG counterparts (p<0.01). Egg production of CDWG was also significantly higher (11.27%) than the UDWG counterparts (p<0.001). Furthermore, we observed that the CDWG laying hens had significantly higher (11.72%) levels (p<0.10) of blood calcium, with a corresponding value of 21.92 mg/dl compared to the UDWG hens (19.62 mg/dl). The higher calcium concentration in the CDWG animals may contribute to increased egg production. The CDWG laying hens also contained higher (12.53%) phosphorus concentrations in blood compared to the UDWG (4.22 mg/dl vs. 3.75 mg/dl), although not statistically different (p>0.10). Egg weight and egg quality were not affected by chilled drinking water. In conclusion, providing chilled drinking for laying hens under high ambient temperature improved feed intake and egg production.