• Journal of Animal Science and Technology
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• v.53 no.2
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• pp.133-138
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• 2011

Two experiments were conducted to determine the effects of supplementing different levels of kaolin (Exp. 1) and effects of age of layers and levels of kaolin (Exp. 2) on the performance, egg and shell quality parameters of laying hens. In Exp.1, 64 laying hens of 58 wks age were randomly allotted to 4 treatments of 16 hens in each. Dietary treatments were basal diet supplemented with 0.0, 0.2, 0.4 and 0.6% kaolin. In Exp. 2 96 laying hens were divided into 6 groups of 16 hens each in a 2 ${\times}$ 3 factorial arrangement (two different ages, 30 and 58 wk and three levels of kaolin, 0.0, 0.2 and 0.4%). In both the experiment there were linear decreases in feed intake (P<0.001), improvement in FCR (P<0.05), and egg production (P<0.05), with increasing dietary kolin level. Supplementation of kaolin had no effect on the egg and shell quality parameters in both experiments. Thus, it is concluded that kaolin may improve performance, and 0.2% level showed the best laying performance.

• Animal Bioscience
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• v.34 no.2
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• pp.276-284
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• 2021

Objective: The objective of this study was to determine whether a dietary vitamin E (VE) supplement could alleviate any detrimental effects of aged corn on lipid metabolism and antioxidant status in laying hens. Methods: The experiment consisted of a 2×3 factorial design with two corn types (normal corn and aged corn (stored for 4 yr) and three concentrations of VE (0, 20, and 100 IU/kg). A total of 216 Lohmann laying hens (50 wk of age) were randomly allocated into six treatment diets for 12 wk. Each treatment had 6 replicates of 6 hens per replicate. Results: The results show that aged corn significantly decreased the content of low-density lipoprotein cholesterol (p<0.05), and reduced chemokine-like receptor 1 (CMKLR1) mRNA expression (p<0.05) in the liver compared to controls. Diet with VE did not alter the content of crude fat and cholesterol (p>0.05), or acetyl-CoA carboxylase, lipoprotein lipase, fatty acid synthase or CMKLR1 mRNA expression (p>0.05) in the liver among treatment groups. Aged corn significantly increased the content of malondialdehyde (MDA) (p<0.05) and decreased superoxide dismutase (SOD) activity (p<0.05) in the liver. The VE increased the content of MDA (p<0.05) but decreased glutathione peroxidase (GSH-Px) activity in serum (p<0.01) and in the ovaries (p<0.05). Adding VE at 20 and 100 IU/kg significantly increased GSH-Px activity (p<0.05) in liver and in serum (p<0.01), 100 IU/kg VE significantly increased SOD activity (p<0.05) in serum. Aged corn had no significant effects on GSH-Px mRNA or SOD mRNA expression (p<0.01) in the liver and ovaries. Addition of 100 IU/kg VE could significantly increase SOD mRNA expression (p<0.01) in the liver and ovary. Conclusion: Aged corn affected lipid metabolism and decreased the antioxidant function of laying hens. Dietary VE supplementation was unable to counteract the negative effects of aged corn on lipid metabolism. However, addition of 100 IU/kg VE prevented aged corninduced lipid peroxidation in the organs of laying hens.

• 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.

• Korean Journal of Poultry Science
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• v.33 no.1
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• pp.41-47
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• 2006

A study was conducted to investigate the effect of supplementing earthworm meal(EWM) on the egg quality and performance of laying hens. A total of 360 laying hens at 55 weeks of age were fed the experimental diets containing 0(Control), 0.3 and 0.6% of EWM for 5 weeks. Eggs were collected and weighed in every day and egg production and feed conversion were weekly recorded. However egg quality were measured fer last week of experimental period. When fed both 0.3 and 0.6% of EWM, egg production and daily egg mass tended to increase but were not different between those treatments. Feed intake and feed conversion ratio of laying hens were not different among three groups. Egg shell thickness, breaking strength, color and egg yolk color were tend to improve in both 0.3 and 0.6% of EWM compared to those of control. The haugh units(HUs) showed no difference among each treatments at 14 after laying egg, but increased in EWM treatments compared to control for storage period. As, Cd, Cr, Hg and Pb detected 4.41, 1.23, 1.18, 0.00 and 3.39ppm in EWM, respectively, but which were not detected in control. It assumed that supplementing 0.3% of earthworm meal in the 55 weeks old laying hens diet, improved the laying performance and egg quality.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.553-558
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• 2001

The effect of poor feather cover on feed intake and production was examined in two commercial strains of layers (tinted and brown egg) over 91-98 weeks of age. Hens were housed at four per cage ($600cm^2/bird$) in a commercial layer shed which ranged in temperature from 13.2 to $16.8^{\circ}C$. At the start of the experiment 50% of the birds were classified as having poor feather cover. Feather score was highly correlated with feed intake. Poor feather cover on the neck and the back were the best indicators of hens with high feed intake. Feed intake of hens with poor feather cover was 16% higher (p<0.05) than hens with good feather cover. Hens with good feather cover produced more eggs (p<0.05) early in the trial and had a higher (p<0.05) liveweight, but there was no significant differences in egg weight. Feed per dozen eggs was superior (p<0.05) in hens with good feather cover. Feather cover on the back and vent were the best indicators of overall feather score, while the tail, base of tail and vent were the body parts most affected in birds with poor feather cover.

• Korean Journal of Veterinary Research
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• v.36 no.2
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• pp.463-470
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• 1996

The red yeast Phaffia rhodozyma, which contains astaxanthin(3, 3'-dihydroxy-$\beta$, $\beta$-carotene-4, 4'-dione) as its primary carotenoid, was tested as a dietary pigment source for egg yolks of laying hens. When the yeast was fed to laying hens at several concentrations, the intensity of redness in egg yolks was dependent on the yeast concentration in the feed and the deposition period. Addition of P rhodozyma in feed did not cause any visible adverse effect on laying hens.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1752-1760
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• 2005

In this experiment, the effects of cage density (CD) and probiotic supplementation (PS) on laying performance, metabolic profile, and egg quality in peak-producing hens were evaluated. After blocking according to the cage location, Lohman layers (n = 180, 46 wks of age) were allocated randomly to two levels of CD (540 vs. 360 $cm^2$/hen) and three levels of PS (0, 0.15, and 0.30%). Probiotic contained Enterococcus faecium culture (10${\times}$10$^9$ cfu/g). Egg production (EP) and feed consumption (FC) were measured daily; egg weight (EW) was measured bi-weekly; BW was measured before and after the experiment; and blood samples were obtained at the end of the experiment. The data were analyzed using two-way ANOVA. Increasing CD decreased FC (125.0 vs. 120.8 g/d, p<0.0001) and FCR (1.93 vs. 1.87, p<0.0001) and did not alter EP, EW, and BW. Increasing level of PS linearly decreased FC (p<0.02) and FCR (p<0.006). Averages were 123.9, 123.2, and 121.6 g/d for FC and 1.91, 1.92, and 1.86 for FCR in hens supplemented with 0, 0.15, and 0.30% probiotic, respectively. Hens placed in high-density cages had greater serum corticosterone concentration than hens placed in normal-density cages (12.8 vs. 11.3 $\mu$g/dL, p<0.04); CD did not affect concentrations of other metabolites. Increasing level of PS linearly increased serum glucose, albumin, and creatine concentrations and quadratically increased total protein, globulin, Ca, and P concentrations. Average concentrations (mg/dL) were 260, 297, and 305 for glucose; 6.28, 8.09, and 7.58 for total protein; 1.98, 2.48, and 2.38 for albumin; 4.30, 5.62, and 5.19 for globulin; 0.40, 0.52, and 0.54 for creatine; 16.0, 16.5, and 16.3 for Ca; and 6.27, 8.14, and 7.17 for P in hens supplemented with 0, 0.15, and 0.30% probiotic, respectively. There was no effect of CD on egg quality. Increasing level of PS linearly improved yolk color (YC) and quadratically increased albumen index (AI) and Haugh unit (HU). The mean values were 9.67, 9.75, and 10.58 for YC; 8.94, 6.93, and 8.72% for AI; and 85.6, 74.9, and 82.9 for HU for hens supplemented with 0, 0.15, and 0.30% probiotic, respectively. There was also CD by PS effect on FC, EP, and serum glucose, total protein, albumin, globulin, creatine, Ca and P concentrations. In conclusion, increased CD partially depressed laying performance and caused stress. Probiotic supplementation improved laying performance and metabolic profile. It also partially alleviated the adverse effects of stress resulting from increased caging density.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.7
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• pp.1006-1013
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• 2015

Heat-stress remains a costly issue for animal production, especially for poultry as they lack sweat glands, and alleviating heat-stress is necessary for ensuring animal production in hot environment. A high ${\gamma}$-aminobutyric acid (GABA)-producer Lactobacillus strain was used to investigate the effect of dietary GABA-producer on laying performance and egg quality in heat-stressed Hy-line brown hens. Hy-Line brown hens (n = 1,164) at 280 days of age were randomly divided into 4 groups based on the amount of freeze-dried GABA-producer added to the basal diet as follows: i) 0 mg/kg, ii) 25 mg/kg, iii) 50 mg/kg, and iv) 100 mg/kg. All hens were subjected to heat-stress treatment through maintaining the temperature and the relative humidity at $28.83{\pm}3.85^{\circ}C$ and 37% to 53.9%, respectively. During the experiment, laying rate, egg weight and feed intake of hens were recorded daily. At the 30th and 60th day after the start of the experiment, biochemical parameters, enzyme activity and immune activity in serum were measured. Egg production, average egg weight, average daily feed intake, feed conversion ratio and percentage of speckled egg, soft shell egg and misshaped egg were significantly improved (p<0.05) by the increasing supplementation of the dietary GABA-producer. Shape index, eggshell thickness, strength and weight were increased linearly with increasing GABA-producer supplementation. The level of calcium, phosphorus, glucose, total protein and albumin in serum of the hens fed GABA-producing strain supplemented diet was significantly higher (p<0.05) than that of the hens fed the basal diet, whereas cholesterol level was decreased. Compared with the basal diet, GABA-producer strain supplementation increased serum level of glutathione peroxidase (p = 0.009) and superoxide dismutase. In conclusion, GABA-producer played an important role in alleviating heat-stress, the isolated GABA-producer strain might be a potential natural and safe probiotic to use to improve laying performance and egg quality in heat-stressed hens.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.313-322
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• 2020

Objective: An experiment was conducted to investigate the response of laying hens fed corn distiller's dried grains with solubles (DDGS) that are naturally contaminated with deoxynivalenol (DON). Methods: One hundred and sixty 52-week-old Lohmann Brown Lite hens were randomly allotted to five dietary treatments with 8 replicates per treatment. The dietary treatments were formulated to provide a range of corn DDGS contaminated with DON from 0% to 20% (i.e., 5% scale of increment). All laying hens were subjected to the same management practices in a controlled environment. Body weight, feed intake and egg production were measured biweekly for the entire 8-week experiment. The egg quality was measured biweekly for 8 weeks. On weeks 4 and 8, visceral organ weights, blood metabolites, intestinal morphology, and blood cytokine concentrations were measured. Results: The inclusion of corn DDGS contaminated with DON in the diet did not alter (p>0.05) the body weight, feed intake, hen-day egg production, egg mass and feed efficiency of the laying hens. No difference was found (p>0.05) in the egg quality of hens that were fed the dietary treatments. Furthermore, hens that were fed a diet containing corn DDGS contaminated with DON showed no change (p>0.05) in the visceral organ weights, the blood metabolites, and the cytokine concentrations. The crypt depth increased (p<0.05) as the amount of corn DDGS contaminated with DON increased. Proportionately, the villus height to crypt depth ratio of the laying hens decreased (p<0.05) with the increasing level of corn DDGS contaminated with DON in the diet. Conclusion: The inclusion of corn DDGS contaminated with DON up to 20% in layer diets did not cause changes in egg production performance and egg quality, which indicates that DON is less toxic at the concentration of 1.00 mg DON/kg.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.412-417
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• 2007

An experiment was conducted to determine the distribution of nitrogen-15 in tissues of laying hens receiving different levels of $^{15}N$-CCC in diets. Twenty brown laying hens were divided into four groups and randomly assigned into one of four dietary treatment groups consisting of 0, 5, 50 and 100 ppm $^{15}N$-CCC inclusion. The hens were individually fed with the $^{15}N$-CCC diets in battery cages for 11 days and then all hens restored to feeding on the control diet for 7 days. After eleven days, eight hens were slaughtered, and the others were slaughtered seven days after $^{15}N$-CCC diets withdrawal. Samples of blood, liver, heart and meat were collected and their $^{15}N$ contents were determined. The ${\delta}^{15}N$ excess (${\delta}^{15}N$-ex) and atom percentage excess in $^{15}N$ were calculated. The ${\delta}^{15}N$-ex and atom percentage excess $^{15}N$ increased significantly (p<0.05) with increasing levels of $^{15}N$-CCC in diets in all tissues after feeding $^{15}N$-CCC diets for eleven days. The highest concentration of ${\delta}^{15}N$-ex and atom percentage excess $^{15}N$ were detected in blood, followed in order by liver, heart and thigh meat. The concentrations reduced significantly (p<0.05) after $^{15}N$-CCC diets were withdrawn. Comparison between treatment groups showed that ${\delta}^{15}N$-ex and atom percentage excess $^{15}N$ were still higher in hens that had been fed diets with higher levels of $^{15}N$-CCC. This study showed that nitrogen-15 was distributed in blood, liver, heart and meat of laying hens.