• 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.

• Korean Journal of Poultry Science
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• v.31 no.2
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• pp.79-84
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• 2004

A total of 225 ISA Brown layers, 63-wk-old, were used in a 5-wk feeding trial to measure the effect of dietary canthaxanthin(0, 50, 100, 200, and 300mg/kg feed) on its accumulation in various body parts and the egg yolk. There were three replications per treatment and 15 birds per replication. The redness(a$\^$*/) and yellowness(b$\^$*/) of wing and thigh skin significantly(P＜0.05) increased when canthaxanthin was fed at 2200 and 250mg/kg feed, respectively. However, the color of breast skin was not significantly affected by the canthaxanthin supplementation. Skin lightness(L$\^$*/) was not influenced by the dietary canthaxanthin. The dietary canthaxanthin supplementation did not significantly affect the redness or the yellowness of breast and thigh muscles. However, feeding canthaxanthin at 300mg/kg, compared to the control(0mg/kg feed), significantly(P＜0.05) decreased the lightness of wing and breast muscles. Feeding of canthaxanthin for 1-3d also significantly increased the color of egg yolks. In conclusion, canthaxanthin can be used to improve the color of skin and egg yolks, but it should be used cautiously because too intense egg yolk redness could be rejected by consumers.

• Korean Journal of Poultry Science
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• v.31 no.2
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• pp.73-78
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• 2004

The effect of supplemental yellow ${\beta}$-8-Apo-carotenoic acid ethyl ester (ACA) (0~300mg/kg feed) on its accumulation in each body part of laying hens and the pigmentation in egg yolk was determined. The chickens used in this study were 78-wk-old ISA brown laying hens. ACA significantly affected the color of the bodies of laying hens. The yellowness ($b^*$) but not the redness ($a^*$) and, the lightness ($L^*$) of the skin, and muscle as measured by a colorimeter significantly (P < 0.05) increased when ACA was fed at 50~100 mg/kg feed. Egg yolk color was also significantly affected by feeding ACA longer than 2 days (P < 0.05) at the levels higher than 50 mg/kg feed. Conclusively, ACA is recommended for improving yellowness of skin.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.7
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• pp.946-951
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• 2010

The objective of this research was to evaluate the effects of dietary supplementation of blood meal (BM) as a source of histidine, and magnesium oxide (MgO) as a catalyst of carnosine synthetase, on carnosine (L-Car) content in the chicken breast muscle (CBM), laying performance, and egg quality of spent old hens. Four hundred eighty laying hens (Hy-Line$^{(R)}$ Brown), 95wk old, were allotted randomly into five replicates of six dietary treatments: T1; 100% basal diet, T2; 100% basal diet+MgO, T3; 97.5% basal diet+2.5% BM, T4; 97.5% basal diet+2.5% BM+MgO, T5; 95% basal diet+5% BM, T6; 95% basal diet+5% BM+MgO. Magnesium oxide was added at 0.3% of diets. The layers were fed experimental diets for 5wk. There were no significant differences in the weekly L-Car content in CBM among all treatments during the total experimental period, but some of the contrast comparisions showed higher L-Car in CBM of T6. The L-Car contents linearly decreased (p<0.01 or p<0.05) as the layers got older except in T4 (p>0.05). There were significant differences in egg weight (p<0.01) and soft and broken egg ratio (p<0.05). The control (T1) was highest in egg weight and T6 was lowest in soft and broken egg ratio. Among the parameters of egg quality, there were significant differences in eggshell strength (p<0.01) and egg yolk color (p<0.05). Magnesium oxide supplementation increased the eggshell strength and BM tended to decrease egg yolk color. Eggshell color, eggshell thickness, and Haugh unit were not influenced by BM and MgO. In conclusion, BM and MgO did not significantly influence the L-Car in CBM of spent layers. The L-Car content rapidly decreased as the layers became senescent. Eggshell strength was increased by MgO supplementation.

• Food Science and Preservation
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• v.17 no.3
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• pp.328-333
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• 2010

The effects of green tea on the physicochemical properties of eggs were investigated. One-hundred-and-fifty Isa Brown hens (27 weeks of age) were studied over 10 weeks. Green tea was added to the diet at levels of 4% and 8% w/w. The contents of Ca, K, P, Fe and Mg in eggs increased upon dietary supplementation with green tea powder, and were higher in the yolk than in the white, with the exception of Mg. The increase was greatest for Ca, from 41.0 mg% to 119.8 mg%, in egg white. For Fe, an increase from 3.7 mg% to 12.6 mg% was apparent in egg yolk. When hens consumed the green tea-supplemented diets, average egg weight decreased from 68.8 g to 64.4 g, but the total cholesterol content of egg yolk did not significantly change (control value: 1,899.1 mg% test value: 2,011.3 mg%). In sensory evaluation tests, egg white was similar in terms of astringency and grayness regardless of diet, and egg yolk was yellow-to-orange in color, and rated as fishy or slightly fishy, when green tea diets were administered. Such diets reduced pH values in all of the white, yolk, and white/yolk combination groups. The major fatty acids of egg yolk, constituting more than 90% of total fatty acids, were palmitic, stearic, oleic, and linoleic acid. Green tea diets reduced the saturated fatty acid level from 32.0% to 27.4% of total fatty acids, and unsaturated fatty acid levels increased from 68.0% to 72.6% in egg yolk.

• Korean Journal of Poultry Science
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• v.35 no.3
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• pp.275-281
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• 2008

This experiment deals with lycopene-enriched egg production in chicken and their effects on egg quality, especially antioxidant status of eggs upon their long term storage. Forty two laying hens(Hyline, 36 weeks of age) were assigned randomly to 1 of 2 diets containing 0 mg and 2 mg lycopene per kilogram feed for 4 weeks. There was a comparable concentration of lycopene in egg yolk($1.57{\mu}g$/1 g yolk) of chickens supplemented with dietary lycopene. No measurable concentration of lycopene was detected in egg yolk of chickens fed the control diet. Dietary lycopene supplementation increased egg yolk color(P<0.01), egg yolk height(P<0.08), egg yolk diameter(P<0.19), egg shell intensity(P<0.19), egg white height(P<0.33), and Haugh unit (P<0.34). After 4 week of storage of eggs in room temperature, lycopene treated eggs were tested for freshness. The ESI, EYH, EWH, HU, and EYC of lycopene treated eggs were comparably higher than those of control groups, even though there was not statistically significant difference between two groups whereas EYD of the control group was smaller than that of lycopene treated group. In conclusion, dietary lycopene supplementation to chickens might be improved egg quality.

• Korean Journal of Poultry Science
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• v.44 no.4
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• pp.235-243
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• 2017

This experiment was aimed at investigating the effects of dietary supplementation with fermented rice bran (FRB) or fermented broken rice (FBR) on egg-laying performance, egg quality, blood parameters, and cholesterol level in egg yolk of Hy-Line Brown egg-laying hens. Altogether, 144 Hy-Line Brown egg-laying hens (32-week-old) were randomly allocated to one of 4 dietary treatment groups, with 4 replicates per treatment. Of them, 3 treatments diets were prepared by supplementing the basal diet with 0.1% probiotics (PRO), 1% fermented rice bran (FRB), or 1% fermented broken rice (FBR) at the expense of corn. Hen-day egg production was higher (P<0.05) in PRO and FRB treatment groups than in the basal treatment groups. However, feed intake, egg weight, egg mass, and feed conversion ratio did not differ among the treatment groups. Additionally, supplementation with FRB or FBR did not affect eggshell strength, eggshell thickness, egg yolk color, and Haugh unit during the feeding trial. There was no significant difference in leukocyte count. Total cholesterol level was lower (P<0.05) in the FRB treatment group than in the basal treatment groups. Asparate aminotransferase, alanine transferase, glucose, and albumin levels were unaffected by dietary supplementation with FRB or FBR. Egg yolk cholesterol level was lower (P<0.05) in the FRB and FBR treatment groups than in the basal treatment groups. In conclusion, dietary supplementation with FRB or FBR improved egg-laying performance, and reduced the levels of total serum cholesterol and cholesterol in egg yolk of Hy-Line Brown egg-laying hens.

• Journal of Animal Science and Technology
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• v.44 no.2
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• pp.213-220
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• 2002

This study was conducted to investigate the effects of feeding probiotics on the egg quality and excretal noxious gas in laying hens. One hundred forty four, 36 weeks old ISA brown commercial layer, were employed in a 28 d feeding trial with a 7 d adjustment period. Dietary treatments are 1) control(basal diet), 2) PB0.3(basal diet+0.3% probiotics), 2) PB0.6(basal diet+0.6% probiotics). For overall period, hen-day egg production, egg weight and egg shell breaking strength tended to increase (P>0.05) by dietary probiotic supplementation. Egg shell thickness was improved by supplementation of probiotics(linear effect, P$<$0.01). Diets PB0.3 and PB0.6 improved the yolk color compared to control diet(linear effect, P$<$0.02). As supplementation level of probiotics increased in the diets, egg yolk index tended to increase(linear effect, P$<$0.04). $NH_3$-N concentration in excreta fed PB0.6 diet was significantly (P$<$0.04) lower than either control or PB0.3 diet. In conclusion, supplementing probiotics to a Corn-SBM diet for laying hens increased egg shell thickness, yolk color and decreased egg yolk index, and decreased excretal $NH_3$-N concentration.

• Korean Journal of Agricultural Science
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• v.50 no.2
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• pp.249-256
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• 2023

The purpose of this experiment was to determine the influence of providing laying hens with extra feed on egg production and egg quality parameters. A total of 480 laying hens (38-weeks old), were divided into five treatment groups (eight replicate cages/treatment and 12 layer/replicate) according to their starting body weight (1.98 ± 0.05 kg) in this four-week feeding trial. Five different feed allowances of the same diet (105, 110, 115, 120, and 125 g·day^-1·bird^-1) were assigned to layers. Daily inspections of remaining feed (around 0.1g) and layer mortality (0%) showed no harmful impact of supplying extra feed to layers. Providing 120 and 125 g of feed per day to layers resulted in the highest final body weight, large-egg ratio, and improved yolk color among all treatment groups. Layers receiving 125 g of feed daily had the highest egg weight, but the highest egg production ratio was observed in layers receiving 110 g of feed/day. The additional supply of feed did not have a negative impact on the productive performance or egg quality of the layers. The provision of 125 g feed per day led to an improvement of large-egg ratio, egg weight, and yolk color, but likely led to obesity of the layers, which manifested as an increase in body weight and a decline in the egg production ratio. We concluded that 110 grams of feed was the proper quantity after taking into consideration the significance of the health of the laying hen to the overall production performance.

• Korean Journal of Poultry Science
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• v.33 no.4
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• pp.317-321
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• 2006

The effects of dietary humic substances (HS) on egg Production and egg Quality were studied using 252(55-wk old) ISA brown laying hens. laying were divided into 21 groups of 12 hens each and seven groups (experimental units) were assigned to 1) CON (basal diet), 2) HS5 (basal diet 4- 5% humic substances) or 3) HS10 (basal diet +10% humic substances) in a completely randomized block design. Hens had free access to diets and water fur 6 wk. Egg Production and egg quality were monitored over the 6-wk Period. Results showed that 10% dietary HS decreased egg Production and yolk diameter (P<0.05) compared to CON. Egg weight and yolk cole. were improved (P<0.05) in HS10 compared to CON. Egg shell breaking strength was increased significantly (P<0.05) when hens were fed HS5 diet compared to the others. There were no effects of treatments on egg shell thickness, yolk index, albumen height and Haugh nit. The results suggest that the dietary supplementation of HS at 5% or 10% decreases egg Production, but HS at 5% can increase egg shell breaking strength. Hens fed 10% HS could increase egg weight and yolk color and decrease yolk diameter.