• Asian-Australasian Journal of Animal Sciences
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• v.25 no.7
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• pp.1015-1020
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• 2012

An experiment was conducted to evaluate the effects of bacteriophage supplementation on egg performance, egg quality, excreta microflora, and moisture content in laying hens. A total of 288 Hy-line brown commercial laying hens (36-wk-old) were randomly allotted to 4 treatments in this 6-wk trial and dietary treatments included: i) CON, basal diet; ii) T1, CON+0.020% bacteriophage; iii) T2, CON+0.035% bacteriophage; iv) T3, CON+0.050% bacteriophage. There were 6 replicates for each treatment with 6 adjacent cages (2 hens/cage). Laying hens in T2 and T3 treatments had higher (p<0.05) egg production than those in CON and T1 treatments during wk 0 to 3. In addition, egg production in T1, T2, and T3 treatments was increased (p<0.05) compared with that in CON treatment during wk 4 to 6. At wk 4 and 5, birds in T2 group had higher (p<0.05) HU than those in CON. In addition, at wk 5 and 6, HU in birds fed T1 and T3 diets was greater (p<0.05) than those fed CON diet. E. coli and Salmonella spp. concentrations in excreta were decreased (p<0.05) by T1, T2, and T3 treatments. However, egg weight, egg shell color, yolk height, yolk color unit, egg shell strength, egg shell thickness, egg gravity, and excreta moisture content were not influenced by dietary treatments during the entire experimental period. In conclusion, bacteriophage supplementation has beneficial effects on egg production, egg albumen, and excreta microflora concentration in laying hens.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1478-1483
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• 2006

This experiment was carried out to determine the effects of supplementation of L-carnitine and humic substances alone or in combination in laying hen diets on performance, egg traits and blood parameters. A total of 180 IGH type brown laying hens aged 22 weeks were employed in a completely randomized block design with one control group and three treatment groups. Each group was divided into five replicates as subgroups, each comprising 9 hens. The diets of the first, second and third treatment groups were supplemented with 0.1 g/kg L-carnitine, 1.5 g/kg humic substances (Farmagulator$^{(R)}$ Dry Plus) and 0.1 g/kg L-carnitine+1.5 g/kg humic substances, respectively. The experimental period lasted 18 weeks. Feeding supplemental carnitine, humic substances or carnitine+humic substances resulted in increases in body weight gain (p<0.05). Dietary treatments did not significantly affect daily feed intake, daily metabolizable energy intake, egg production, egg weight, feed efficiency, mortality, egg shape index, egg breaking strength, egg shell thickness, egg albumen index, egg yolk index, egg Haugh unit and the percentages of egg shell, albumen and yolk. Supplementation of humic substances reduced egg yolk cholesterol as mg per g yolk and mg per yolk (p<0.05). Blood serum parameters were not affected by the supplementation of carnitine, humic substances or carnitine+humic substances. The results in this study demonstrated that humic substances supplementation reduced egg cholesterol without adverse effects on performance, egg traits and blood parameters of laying hens. It was concluded that the usage of L-carnitine alone or in combination with humic substances in diets had no beneficial effects in laying hens.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1182-1185
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• 2002

The objective of this study was to investigate the effect of long light regime (20 h light and 4 h dark, 20L:4D) and short light regime (4 h light and 20 h dark, 4L:20D) on egg production and egg characteristics of laying geese. Thirty-six laying birds, 4 replicates of 3 birds per treatment were allotted to three light regimes, i.e., 20L:4D, 4L:20D, and natural light (NAT) from March 7 to June 20. Results showed that the geese in 20L:4D consumed 54 g less feed per goose daily and laid 17.5 less eggs per goose (p<0.05) comparing to those in 4L:20D. The number of days from initiation of light treatment till cease of laying was 22 days shorter (p<0.05) in 20L:4D comparing to that in NAT. Five geese (41.7%) in 4L:20D kept laying by the end of applying light regime. Weight and surface area of the eggs in 4L:20D were greater (p<0.05) comparing to those in the other two light regimes. It is concluded that the period of egg production in goose could be manipulated by light regime in the ways such as using short light regime of 4 h light daily to prolong egg production through summer and using long light regime of 20 h light daily to induce cease of egg production.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.10
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• pp.1450-1455
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• 2017

Objective: The objective of this experiment was to investigate the effect of dietary ${\beta}-mannanase$ on productive performance, egg quality, and utilization of dietary energy and nutrients in aged laying hens raised under hot climatic conditions. Methods: A total of 320 84-wk-old Hy-line Brown aged laying hens were allotted to one of four treatments with eight replicates in a completely randomized design. Two dietary treatments with high energy (HE; 2,800 kcal/kg nitrogen-corrected apparent metabolizable energy [$AME_n$]) and low energy (LE; 2,700 kcal/kg $AME_n$) were formulated. Two additional diets were prepared by adding 0.04% (MN4) or 0.08% ${\beta}-mannanase$ (MN8) to LE treatment diets. The feeding trial was conducted for 28 d, covering a period from July to August in South Korea. The average daily room temperature and relative humidity were $29.2^{\circ}C$ and 83%, respectively. Results: Productive performance, egg quality, and cloacal temperature were not influenced by dietary treatments. The measured $AME_n$ values for MN8 diets were similar to those for HE diets, which were greater (p<0.05) than those for LE and MN4 diets. However, the $AME_n$ values for MN8 diets did not differ from those for LE and MN4 diets. Conclusion: The addition of ${\beta}-mannanase$ to low energy diets increases energy values for diets fed to aged laying hens. However, this increase has little positive impacts on performance and egg quality. These results indicate that dietary ${\beta}-mannanase$ does not mitigate the heat stress of aged laying hens raised under hot climatic conditions.

• Korean Journal of Acupuncture
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• v.20 no.3
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• pp.1-8
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• 2003

Objectives : To investigate the increasing effect of veterinary acupuncture (VA) on the eggs-laying rate, we carried out the experiment in old hens. Methods : Twenty four old hens (ISA Brown; 1,200 - 1,400 g) over 75 weeks old whose eggs-laying rates were under the 50% for recent 15 days were used. In experimental group, VA treatments were performed seven times during 10 days. Unang point at the end of bilateral wing and Migun point at the tail bone were stimulated about 30 seconds by the stainless steel needle (0.3 mm o.d.). In control group, similar manual stress were performed at same frequency. The numbers of laid eggs were observed for 26 days after the beginning of treatment. Bloods were sampled two times from wing veins during and after the treatment period and serum concentrations of luteinizing hormone (LH) and Estradiol were detected. Results : Eggs-laying rates of experimental group $(34.29{\pm}2.79%)$ were significantly increased than that of control group $(27.56{\pm}2.00%,\;p<0.05)$ with the significant increasing of LH serum concentration in experimental group $(from\;0.77{\pm}0.13\;IU/I\;to\; 1.42{\pm}0.22\;IU/I,\;p<0.05)$. Conclusions : Increasing effect of VA treatment on the eggs-laying rate in old hens were proved in this study, and it may be the first prompt on the experimental investigation and development of VA.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.3
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• pp.239-244
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• 1998

Dried carrot meal (DCM) prepared from fresh carrot was found to be a good source of xanthophyll (54 mg/kg) and morderate source of protein (188.3 g/kg) and energy (2,510 kcal/kg) with low level of fibre (80 g/kg). DM, EE and NFE content of DCM were 895, 35 and 661.7 g/kg respectively. The ingredient was used in laying hen diet to evaluate its pigmenting value for egg yolk. Thirty-two laying hens from Starcross strain were divided into four groups and fed four different diets: a control diet containing 62% ground wheat, a corn-based diet (50% ground yellow corn), control + 4% DCM and control + 8% DCM. Use of DCM at 8% level in layer mash significantly improved yolk colour at 3rd, 6th and 9th week of supplementation in comparison with wheat-based control diet. This improvement was statististically similar to that obtained from yellow corn-based diet. DCM at 4% level also improved yolk colour score. Wheat-based diet significantly increased feed consumption compared to yellow corn and diet supplied with 8% DCM. Body weight gain, egg production, feed conversion were not significantly affected due to dietary addition of DCM and no mortality was observed during 63-day experimental period. Further works on DCM are suggested.

• Journal of Environmental Science International
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• v.24 no.9
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• pp.1233-1237
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• 2015

This study was conducted to evaluate the effects of red ginseng marc powder on egg freshness in laying hens during 4 weeks. A total of 60 Hy-line Brown laying hens, 50 week of age, were randomly assigned to 2 groups with diets containing 0% and 2% red ginseng marc powder. There were 3 replications per group with 10 laying hens per pen. Throughout the period of the trial, there were no effects of red ginseng marc powder on egg weight (but not 4 weeks). Haugh Unit (HU) values were observed by showing significant differences between red ginseng marc powder and controls at 0 and 4 weeks, except for HU at 1 through 3 weeks. For egg yolk color, red ginseng marc powder has no difference in comparison with controls at 0, 3 and 4 weeks (but not 1 and 2 weeks). In conclusion, the dietary supplementation with 2% red ginseng marc powder improved HU values throughout the experiment.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1605-1609
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• 2001

A total of 252, 50 week-old Isa-brown laying hens were randomly allotted to 7 groups of 3 replicates. Mustard meal (MM) which is a by-product from mustard processing plant, was dried under the sun or in a gas heated pan. It contained on DM basis 30-32% CP, 19-22% EE and 12-13% CF. The meal from either drying method was incorporated into the diets at 0, 10, 20 and 30% which was equivalent to the substitution levels for soybean meal at 0, 31, 63 and 94%, respectively. All birds were individually kept in battery cages where feed and water were freely accessed throughout 84 days experimental period. It was found that egg production, feed intake, body weight gain and egg weight significantly decreased with the increased MM level. The inclusion of 20% MM did not show a significant difference in egg production and quality from the control, but produced 6-8% lower egg production. Feed intake was linearly decreased with the MM levels, except the 10% sun dried MM group. Fat deposition of the birds fed MM diets significantly decreased, while kidney weight increased when compared with the control group. However, the weight of thyroid glands and spleen trended to be heavier in the MM groups, but this was not significantly different among dietary treatments. It was concluded, MM from both drying methods could be incorporated in laying hen diets at the level of 10% without any adverse effect.

• Korean Journal of Veterinary Service
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• v.28 no.3
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• pp.245-251
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• 2005

The purposes of this study were to evaluate the distribution of quinolone and to investigate the effects of quinolones (enrofloxacin, ciprofloxacin) in blood(plasma) and eggs of laying hens. Animals were fed quinolones which supplemented with 20, 50, 80 mg/kg of body weight. Blood and egg samples were collected after oral administration and analyzed for quinolones (enrofloxacin, ciprofloxacin) by HPLC. In laying hens, the residue period of enrofloxacin were longer than that of ciprofloxacin and the levels of residues were elavated by drug dosage.

• Korean Journal of Veterinary Research
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• v.58 no.4
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• pp.193-199
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• 2018

As animal welfare issue becomes important, the European Union bans conventional cages for laying hens from 2012. So the alternative housing systems like floor pens, aviaries or free range systems have been suggested. From 2011 to 2014, we monitored 20 welfare-oriented laying hen farms in South Korea to figure out serological status of major viral diseases. During this period, total 3,219 blood samples were collected from the randomly selected chickens to test and evaluate the hemagglutination inhibition titers for low pathogenic avian influenza, Newcastle disease and egg drop syndrome '76. A total of 2,926 blood samples were tested through enzyme linked immunosorbent assay (ELISA) to assess the serological status of infectious bronchitis (IB). The distribution of ELISA titers for IB was various from almost 0 to 20,000 through the all weeks of age. Also, the antibody coefficient of variation for most of the diseases in this study was higher than those of typical cage layers. As this study was the first surveillance for major avian viral diseases of the animal welfare-oriented farms in South Korea, the results obtained from this study will help to determine what information and resources are needed to maintain better biosecurity and to improve the health and welfare of laying hen flocks.