• Korean Journal of Poultry Science
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• v.35 no.4
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• pp.367-373
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• 2009

This experiment was conducted to determine optimum dietary levels of dietary energy and protein for laying performance and egg quality in organic laying hens. In a $2{\times}3$ factorial arrangement, 360 Hy-Line pullets (21 wk of age) were randomly assigned to experimental diets with 2,800, 3,080, and 3,360 kcal of ME/kg of diet, each containing 16 and 18% CP, respectively. Each dietary treatment was replicated 4 times, and feed and water were provided ad libitum. Experimental birds were raised in floor and received 14h of light throughout 52 weeks of experimental period. The birds were observed for feed consumption, egg production, egg weight, egg mass, feed conversion ratio, Haugh unit, shell thickness, and shell color at 30, 50, and 70 wk of age. Egg production, egg weight, and egg mass were higher (P<0.05) in hens receiving diets with 2,800 kcal/kg of ME/kg of feed than those fed diets containing 3,080 and 3,360 kcal of ME/kg of diets. Eggshell breaking strengths were not significantly different among the dietary ME and CP concentrations. Eggshell thickness was higher (P<0.05) in hens receiving diets with 3,360 kcal of ME/kg of feed than those fed diets containing 2,800 and 3,080 kcal of ME/kg of diets at 50 and 70 week. With increasing in dietary energy levels, the concentrations of blood total cholesterol were also significantly increased. Overall, the laying hens fed organic diet of 2,800 kcal ME/kg and 16% CP showed superior egg production than those of other dietary regimens.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.265-271
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• 2004

A feeding trial was conducted to investigate the influence of feeding Lactobacillus reuteri culture (LR) on productive performance, intestinal microflora and availability in laying hens. Four hundred and eighty, Isa-Brown layers, 49 weeks of age, were fed diets supplemented with LR at the level of 0 (control), 0.1, 0.2, and $0.4\%$ of the diets for eight weeks. Egg production and egg weight were measured daily. Feed intake was weighed every two weeks. Egg quality was measured three times at the start, mid-term, and end of the experiment. Intestinal microflora were examined for Lactobacillus spp., E. coli and Salmonella at the end of the experiment. Overall egg production was the highest in $0.2\%$ LR (P<0.05), but that of $0.1\%$ or $0.4\%$ LR treatments did not significantly differ from that of control. Egg weight was significantly higher in LR feeding group than the control (P<0.05). Daily egg mass was significantly higher in $0.2\%$ and $0.4\%$ LR treatments compared to the control and $0.1\%$ LR (P<0.05). The number of jumbo and extra large eggs were increased in LR supplemented groups, especially in $0.1\%$ LR. Feed intake of layers fed LR supplemented diets tended to be lower than the control. However, feed conversion ratio significantly improved in LR supplemented groups (P<0.05). Availability of dry matter and crude protein improved significantly in $0.4\%$ LR treatment (P<0.05). But, those of ether extract and crude ash were not significantly different among treatments. Eggshell breaking strength and eggshell thickness were not significantly influenced by LR supplementation, and Haugh unit and yolk index were also similar to the control. Total number of Lactobacillus spp. in ileum and cecum fed LR supplemented diets were significantly higher than those of the control (P<0.05). There were no significant differences in intestinal E. coli and Salmonella in all treatments. Therefore, it is concluded that dietary supplementation of Lactobacillus reuteri culture can improve the laying performance, feed efficiency and intestinal Lactobacillus.

• Korean Journal of Poultry Science
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• v.45 no.2
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• pp.119-124
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• 2018

This study was conducted to assess the effect of dietary addition of Germanium (Ge) on performance, egg quality, serum biochemical properties and yolk fatty acid composition in laying hens. At 74 weeks of age, a total of 360 Hy-line brown commercial layers were divided into four treatments with five replicates per treatment. Four dietary levels of Ge (0, 1, 2 and 4%) were added to the basal diets (ME: 2,750 kcal/kg, CP: 16%) and fed corresponding diet for a period of 12 weeks. The effects of these treatments on production performance and egg quality were measured three times at four week intervals, and at the end of the experiment, blood and egg yolk fatty acid were analyzed. The results showed that production performance parameters including egg production rate, feed intake, egg weight, egg mass and feed conversion ratio were non-significant, but dietary addition of 2% Ge tended to increase egg production rate. Eggshell strength was found to be significantly higher in Ge supplemented groups than in the control group (P<0.05), and eggshell thickness was also trended to be improved in Ge treated groups. In serum, triglyceride content was significantly greater (P<0.05), and the highest total cholesterol was found in hens of the control group as compared with that of the Ge supplemented groups. The yolk fatty acid composition including polyunsaturated fatty acid, unsaturated fatty acid and saturated fatty acid were not affected among the treatments but addition of 2 or 4% Ge in basal diet had significantly (P<0.05) increased monounsaturated fatty acid. Therefore, supplementation of Ge in laying hens diet has positive effects on egg quality and triglyceride in serum.

• Korean Journal of Poultry Science
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• v.35 no.3
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• pp.303-311
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• 2008

This study was conducted to investigate the effect of dietary supplementation of Cu-methionine chelate(Cu-Met) and Cu-soy proteinate(Cu-SP) on the performance, small intestinal microflora and immune response in laying hens. A total of 960 Hy-line $Brown^{(R)}$ laying hens of 39 wks old were assigned to one of the following 6 dietary treatment: control(C), antibiotic(Avilamycine 6 ppm), Cu-Met 50 and Cu-Met 100(50 and 100 ppm Cu as Cu-methionine chelate), Cu-SP 50 and Cu-SP 100(50 and 100ppm Cu as Cu-soy proteinate). Each treatment was replicated 4 times with forty birds per replication, housed in 2 birds per cages. Forty birds units were arranged according to randomized block design. Feeding trial lasted 6 wks under 16 hours lighting regimen. Hen-day and hen-house egg production of groups treated with Antibiotic and Cu supplements tended to be higher than the control with significant difference (P<0.05) shown between Cu-Me 100 and control. Egg weight was significantly (P<0.05) heavier in antibiotic and Cu-SP treatments than Cu-Met treatments but they were not significantly different from the control. Eggshell strength, egg shell thickness, egg yolk color and Haugh unit were not significantly different among treatments. There were no significant differences in leukocytes and erythrocytes in the chicken blood. But mean corpuscular hemoglobin value(MCH) was significantly (P<0.05) higher in Cu-SP 100 than antibiotic treatment. The concentrations of serum IgG and IgA were not significantly different among treatments. Copper concentration in the liver tended to increase as the level of copper supplementation increased, that of Cu-SP 100 being significantly (P<0.05) higher than those of the control and antibiotic treatment. Concentrations of iron and zinc of the liver were not significantly influenced by treatments. Populations of Cl. perfringens and Lactobacilli in the small intestinal content were significantly (P<0.05) influenced by treatments. Population of Cl. perfringens decreased and that of Lactobacilli increased in the copper supplemented groups. The result of this experiment showed that Cu-Met and Cu-SP are comparable to antibiotic in improving egg production in laying hens. Birds fed diets supplemented with Cu-SP produced heavier eggs than those fed diets with Cu-Met. There were no significant differences in the performances between 50 ppm and 100 ppm copper supplementation as organic forms.

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.109-116
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• 2002

The objective of this study was to investigate the effect of feeding organic acid mixture and yeast culture on the Performance and e99 quality of laying hens fur sixteen weeks. Four hundred and fifty 19-wk-old ISA Brown layers were alloted to five treatments with five replications of each. The supplemental levels of organic acid mixture(OAM) and yeast culture(YC) in the experimental diets were 0(control), OAM 0.1, 0.2%, and YC 0.1, 0.2%, respectively. Corn -Soy basal diet containing 16.0% CP and ME 2,770 kca1/kg ME. Eggs were collected and weighed every day. Eg3 Production, fred intake and fled conversion were recorded in every four weeks. Fatty acid composition of e99 Yolk, e99she11 breaking strength, thickness and Haugh unit were measured a(her every eight weeks. Egg Production and daily egg mass of birds fed 0.2% OAM and 0.1% YC tended to be higher than those of the other treatment groups. Egg weight was the highest in hens fed with 0.2% OAM treatment, but was not significantly different. Feed conversion of hens in all OAM and YC treatments was lower than those of control, but was not statistically different. Eggshell breaking strength of hens on OAM treatments tended to be higher than those of YC treatment and control. Haugh units of the birds fed OAM was significantly higher than controls (P<0.05). 599 yolk color score of OAM treatment was higher than those of YC treatments and control, but the difference was not significant. At 27-wk-old, arachidonnic acid content in eggs from the birds fed 0.1% OAM diet was significantly higher(P<0.05) than controls. The results of this experiment indicated that dietary organic acid mixture and yeast culture tended to improve the egg Production and internal egg quality.

• Journal of Life Science
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• v.22 no.7
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• pp.880-888
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• 2012

This study was carried out to investigate the effects of inuloprebiotics (INPs), an alternative antibacterial growth promotor, from Jerusalem artichoke extract (Helianthus tuberosus L.) on egg production and quality in Hyline brown laying hens. The hens were divided randomly into four treatment groups and housed in individual cages for 10 weeks: a control group (0 ppm INP) (T1), 450 ppm (T2), 600 ppm (T3), and 750 ppm (T4). Egg production, egg weight, Haugh unit, eggshell thickness, and breaking strength were significantly higher in all of the INP-treated groups compared with the control (p<0.05). Egg cholesterol was highest in the T1 group and decreased with INP addition from 15.04 to 17.98% (p<0.05). Compared with the T1 group, triglycerides in the blood and in total cholesterol decreased significantly in groups T2, T3, and T4 by 21.71-24.07% and 27.17-30.36%, respectively (p<0.05). The growth of cecum Bifidobacterium and Lactobacillus was stimulated in groups T2, T3, and T4 compared with T1, whereas the growth of Escherichia and Salmonella was clearly inhibited (p<0.05). The results suggest that the addition of 450 ppm INP to the diet of laying hens can improve egg production and egg quality.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1769-1774
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• 2005

This experiment was carried out to evaluate the effects of feeding green tea powder on laying performance and egg quality in hens. A total 180 'Tetran Brown' laying hens aged 40 weeks were assigned to 6 treatments in a completely randomized design. Each treatment consisted of five replicates accommodating six layers per replication. The experimental diets were a negative control containing no green tea, a positive control diet containing antibiotics (0.05% chlortetracycline) and diets containing 0.5%, 1.0%, 1.5% and 2.0% green tea powder. Egg production rate of layers fed the diets containing green tea powder did not differ significantly from that of the negative and positive controls (p>0.05). Egg weight was decreased significantly in the group fed the diet containing 0.5% green tea powder (p<0.05). Feed intake of layers was significantly higher for the diet containing 1.5% green tea powder compared to that of negative and positive control diets (p<0.05). The eggshell thickness reduced significantly in the layer group fed the diets containing green tea powder regardless of dietary levels (p<0.05). Green tea powder tended to reduce egg yolk cholesterol in this experiment. Particularly, dietary 2% level of green tea powder significantly suppressed the cholesterol contents of the egg yolk (p<0.05). Thiobarbituric acid value (TBA) of egg yolk was significantly reduced by green tea diets (p<0.05). The yellowness of egg yolk was increased in the layers fed the 2.0% green tea diet compared with that of control diet (p<0.005). The Linoleic and $\alpha$-linolenic acids tended to increase in the group fed diets containing 1.5% green tea powder even though there were no significant differences among treatments (p>0.05). The oleic and docosahexaenoic acid contents of the egg yolk were similar among treatments (p>0.05). Based on the results of the experiment, it is concluded that green tea powder inclusion in the diet for layers at 2.0% level can reduce the cholesterol content and TBA value of the egg yolk, implying its potential effect on egg quality parameters.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.2
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• pp.206-210
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• 2017

Objective: A study was conducted to test six threonine (Thr) levels (0.39%, 0.44%, 0.49%, 0.54%, 0.59%, and 0.64%) to estimate the optimal dietary Thr requirements for Longyan laying ducks from 17 to 45 wk of age. Methods: Nine hundred Longyan ducks aged 17 wk were assigned randomly to the six dietary treatments, where each treatment comprised six replicate pens with 25 ducks per pen. Results: Increasing the Thr level enhanced egg production, egg weight, egg mass, and the feed conversion ratio (FCR) (linearly or quadratically; p<0.05). The Haugh unit score, yolk color, albumen height, and the weight, percentage, thickness, and breaking strength of the eggshell did not response to increases in the Thr levels, but the albumen weight and its proportion increased significantly (p<0.05), whereas the yolk weight and its proportion decreased significantly as the Thr levels increased. Conclusion: According to a regression model, the optimal Thr requirement for egg production, egg mass, and FCR in Longyan ducks is 0.57%, while 0.58% is the optimal level for egg weight from 17 to 45 wk of age.

• 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.