• Korean Journal of Poultry Science
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• v.35 no.2
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• pp.153-162
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• 2008

This experiment was conducted to evaluate the dietary effects of mixture of probiotics and colistin on laying performance, intestinal microflora and egg yolk cholesterol in laying hens. One hundred sixty 50-wk-old Hy-Line Brown layers were divided into four treatments and fed a commercial diet (Control) or experimental diets containing 0.2% mixture of probiotics or probiotics and colistin mixture (T1, Bacillus subtilis + Aspergillus oryzae + Lactobacillus plantarum; T2, Bacillus subtilis + Aspergillus oryzae; T3, Bacillus subtilis + Aspergillus oryzae+colistin) for 8 wk. No significant differences were found in laying performance and liver weight among the groups. The Haugh unit of treated groups were significantly improved (P<0.05) compared to that of control, but eggshell qualities were not changed by the treatments. The cecal ammonia concentration was significantly decreased in both T1 and T3 groups. The number of coli forms in cecal content and feces were significantly reduced in all treated groups compared to that of Control (P<0.05). The egg yolk cholesterol contents in the groups fed the diet containing mixture of probiotics and colistin were reduced in comparison with that of Control. In conclusion, dietary supplementation of mixture of probiotics and colistin improved quality of egg albumen, and reduced the egg cholesterol contents. They also reduced intestinal coli forms without harmful effects on overall productive and physiological responses in laying hens.

• Korean Journal of Poultry Science
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• v.36 no.1
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• pp.47-55
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• 2009

This study was carried out to investigate the effects of spider-derived protease [Arazyme (AZ)] supplementation on egg production, egg quality, cecal microflora and viscosity of intestinal contents in laying hens at the late production. A total of two hundred, 59-wks-old, Hy-Line Brown layers were divided into four groups, placed into 5 replicates per group (50 birds per group) and fed one of four diets containing 0.05, 0.075 or 0.1% AZ or control for 5 wks. The results showed that egg weight in group fed the diet containing 0.05% AZ was significantly higher than those of other groups (P<0.05). There were no significant differences in egg interior and eggshell qualities among the groups. The serum parameters such as total cholesterol, the levels of GOT and GPT were not influenced by AZ feeding. There were no significant differences in the cecal number of total microbes, Coliforms and lactic acid bacteria among the groups. The viscosity and ammonia concentration of intestinal contents in the groups fed AZ were significantly reduced compared to those of the control (P<0.05). In conclusion, laying hens fed AZ supplemented diet improved egg weight as compared with that of control. In addition, the AZ supplemented diet reduced the viscosity and ammonia concentration of intestinal contents, reflecting a significant feed enzyme effect.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.213-223
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• 2002

This study was conducted to investigate the influence of feeding various Lactobacillus on production performance, nutrients digestibility, intestinal microflora, and fecal $NH_{3}$ gas emission in laying hens. Three hundred and sixty ISA Brown layers, 21 weeks of age, were randomly allotted to nine treatments, with low replicates per treatment. Nine treatments consisted of Control(no Lactobacillus), Lactobacillus crispatus avibrol(LCB: KFCC-11195), Lactobaciilus reuteri avibro2(LRB: KFCC-11196), Lactobacillus crispatus avihenl(LCH: KFCC-11197), Lactobacillus vaginalis avihen2(LVH: KFCC-11198). Each Lactobacillus was added at two levels ($10^{4}$and $10^{7}$ cfu/g diets). Egg production, and egg weight were measured daily. A metabolism trial was conducted following the 12-week feeding trial, during which egg qualities, intestinal microflora and fecal $NH_{3}$ gas emission were examined. Egg production and daily egg mass improved significantly by the addition of various Lactobacillus(P<0.05), of which effect was more notable during the latter part of the feeding trial. But, no significant differences were found among Lactobacillus strains and between two levels of supplementation. Egg weight and feed intake showed no difference among all treatments. Feed conversion ratio of birds fed lactobacillus was significantly improved compared to that of the Control(P<0.05), but not different among lactobacillus treatments. Digestibility of crude protein, ether extract and crude ash improved significantly in lactobacillus treatments(P<0.05). However, there were not statistically different by adding levels and strains. Total counts of Lactobacillus spp. in ileum of layers fed Lactobacillus were significantly higher than that of the control, but no consistent trend was found in cecum. There were no significant differences in intestinal yeast and anaerobes counts among all treatments. The Lactobaciilus supplementation did not exert my effect on the eggshell quality and Haugh unit. Fecal $NH_{3}$ gas emission decreased significantly in Lactobacillus treatments, and showed no difference between the two supplementation levels. From the result of this study, it could be concluded that dietary supplementation of Lactobacillus, regardless of their species, Improves the laying performance and decreases the fecal ammonia gas emission. The proper level of supplementation appears to be $10^{4}$ cfu/g of diet.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.205-211
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• 2002

A feeding trial was conducted to study the effects of a live yeast, Pichia farinosa culture(PF), on the production performance and intestinal microflora in laying hens. One hundred and sixty ISA Brown layers, 21 weeks of age, were randomly allotted to four dietary treatments, with four replicates per treatment. Dietary treatments consisted of four levels (0, 0.1, 0.3, and 0.5%) of PF added to a com-soybean meal based diet. Egg production, egg weight, feed intake and fred conversion ratio(FCR) were measured. Egg qualifies were examined at 25th and 29th weeks of age. A metabolism trial was conducted following the feeding trial, during which intestinal microflora, nutrient digestibility and fecal NH3 gas emission were measured. Egg production of birds fed 0.1 and 0.3% PF were significantly higher than those from birds fed 0 and 0.5% PF(P<0.05). Daily egg mass of 0.3% PF increased significantly compared to that of 0% PF. There was no difference in egg weight among all treatments. Feed conversion ratio was significantly improved as the PF level increased. No significant difference was found in eggshell quality and Haugh unit at both 25 and 29 weeks of age. Viable count of ileal Lactobacillus spp. increased significantly as the rf level increased. However, the total number of yeast and anaerobes in ileum were similar among all treatments. Cecal Lactobacillus spp. and yeast counts showed no difference among all treatments. Fecal NH$_{3}$ gas emission of layers fed PF decreased significantly by the PF supplementation. From the result of this experiment, it could be concluded that dietary supplementation of the live yeast Pichia farinosa improves the laying performance and decreases the fecal ammonia gas emission.

• Korean Journal of Agricultural Science
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• v.34 no.1
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• pp.53-60
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• 2007

A layer feeding trial was conducted for 10 weeks to investigate the effects of the addition of corn distillers dried grains with solubles (DDGS) to layer diets on the laying performance, egg qualities, and yolk fatty acid composition. Nine hundred Hyline Brown layers, 24 weeks of age,were randomly allotted to 20 replicate laying cages, 45 birds per replicate. There were four diet treatments (0, 10, 15, and 20% DDGS), and five replicates per treatment. All experimental diets were prepared to contain iso-protein (17%) and iso-calorie (TMEn 2,780 kcal/kg). The use of DDGS up to 20% level in layer diets did not exert any influence on feed intake, laying rate, total egg mass, mean egg weight, and feed conversion ratio. DDGS did not exert any influence in weight of egg, breaking strength, and color of eggshell. The albumen height and Haugh unit was not influenced by DDGS addition. The yolk color was significantly increased by DDGS supplementation. As the DDGS level increased, the oleic acid content decreased, and the linoleic acid increased (P<0.05). The degree of saturation of yolk fatty acids was not affected by dietary DDGS. The inclusion of DDGS up to 20% in layer diets resulted in the decrease of feed cost per kg without any effect in the laying performance. In conclusion, the use of DDGS up to 20% level in layer diets could replace corn and soybean meal without any harmful effect on the laying performances.

• Korean Journal of Poultry Science
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• v.46 no.4
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• pp.279-286
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• 2019

Currently, feather-sexing, which is based on differences in feather development at hatching, is a widely used chick sexing method in the poultry industry. For effective chicken feather-sexing, paternal early-feathering (EF) chickens and maternal late-feathering (LF) chickens must be bred. Therefore, it is critical to identify the effect of EF and LF patterns on production traits in chickens. Thus, the purpose of this study is to analyze and compare the production performances between 522 EF and 232 LF chickens in order to establish the Korean native chicken feather-sexing lines. The results showed that the survival rate of the LF group was significantly higher than that of the EF group from hatching to 52 weeks of age (P<0.05). Body weight, however, was not significantly different between the two groups at all ages. LF and EF groups did not significantly differ in age at first egg laying. However, the hen-day and hen-housed egg production of the LF group were significantly higher than those of EF group (P<0.01). No significant differences were found between the EF and LF groups in all egg quality indicators such as egg weight, eggshell color, albumin height and Haugh unit. Because the breeding target of Korean native commercial chicken is meat-type chicken, feather-sexing strains of Korean native chicken should be established using weighing-based paternal EF lines and laying-based maternal LF lines. Therefore, these results are critical for establishing desirable and effective feather-sexing strains.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.225-231
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• 2002

Total 240 of ISA Brown layers were employed in this experiment to study the effects of single or mixed feeding of Lactobacillus and yeast on the performance and intestinal microflora of laying hens. They were randomly allocated to six dietary treatments; None(Control), Pichia farinosa(PF), Lactobacillus crispatus avihen1 (LCH), Lactobacillus vaginalis avihen1(LVH), LCH＋PF, and LVH＋PF. Viable microflora were added to meet 3${\times}$10$\^$6/ cfu PF and 10$\^$7/ cfu Lacrobacillus per g of feed. There were four replicates per treatment, and 10 birds per replicates. Laying performance was recorded for 10 weeks, followed by a metabolism trial during which nutrient utilization, pattern of intestinal microflora and fecal NH$\sub$3/ emission were examined. Egg production and daily egg mass of birds fed either single or mixed microorganisms were significantly higher than those of the control(P<0.05). Egg weight and feed intake were not statistically different among all treatments. However, feed conversion ratio tended to improve by the supplementation of microbes. Digestibility of crude protein, ether extract and crude ash tended to improve in Lactobacillus treatments, however, there were not statistically different. With regards to the number of intestinal microbes, number of anaerobes were increased in microbes feeding group. Eggshell quality of PF layers was significantly poorer than those of the other treatments. No consistent trend was found in Haugh Unit among all treatments. Fecal NH$\sub$3/ gas emission was significantly lower in LVH, LVH＋PF and LCH＋PF than the other treatments(P<0.05). From the result of this experiment, it could be concluded that single or mixed feeding of Lactobacillus and yeast improves the laying performance and decreases the fecal ammonia gas emission. No synergic effect was found when both microbes were mixed and fed to the layers.