• Korean Journal of Poultry Science
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• v.39 no.2
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• pp.157-161
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• 2012

The objective of this study was to evaluate the effects of feeding dried Thymus vulgaris powder (TVP) on the layer performance, egg quality and egg yolk fatty acid composition. Two hundred eighty eight, 35 weeks old Brown nicks were allocated in the cage for five TVP (0, 0.25, 0.5, 1.0 and 2.0%) diets with four replicates in each treatment. Each basal diet contained 16.0% CP and 2,800 kcal/kg ME and supplied to layers for 8 weeks. Egg production and egg weight were not statistically different but numerically increased in birds fed 2.0% TVP than other treatments. Egg mass was not consistent depending on the TVP addition levels in diets. Feed intake was significantly lower in TVP addition treatments than the control (p<0.05), however, feed conversion was not significantly differed among control and treatments (p<0.05). Dietary addition of 2.0% TVP showed high values on albumin height, Haugh unit and egg yolk color and they are 7.93, 86.79 and 7.20, respectively (p<0.05). Palmitic and arachidonic acids were remarkably lowered when 2.0% TVP added to basal diets and then fed to birds for 8 weeks, in contrast, significantly higher linolenic acid composition was determined in birds fed 2.0% TVP (p<0.05). As the results, the highest unsaturated fatty composition and UFA/SFA ratio were observed in 2.0% TVP treatment as compared to those of control and other treatments. Therefore, the results indicate that the Thymus vulgaris powder addition to basal diet tended to have positive effects on egg quality and egg yolk fatty acids composition, and the optimum addition of Thymus vulgaris powder may be 2.0%.

• Korean Journal of Poultry Science
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• v.39 no.3
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• pp.167-175
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• 2012

This study was undertaken to assess dietary CP and ME concentrations for optimum growth performance and carcass characteristics of Korean Native male ducks. In a $3{\times}3$ factorial arrangement, 1-d-old Korean Native male ducks were completely randomized design to experimental diets with 3,000, 2,900, and 2,800 kcal of ME/kg of diet; each contained 23, 22, and 21% CP, respectively, from 0 to 3 wk of age. From 4 to 8 wk of age, experimental diets had 3,100, 3,000, and 2,900 kcal of ME/kg of diet, and each contained 19, 18, and 17% CP, respectively. Each dietary treatment was replicated 4 times, and feed and water were provided ad libitum. Body weight, feed intake and uniformity were measured at 3 wk and 8 wk, and carcass characteristics were evaluated at 8 wk. As CP increased from 21 to 23 %, the body weight, BW gain and feed conversion ratios (FCR) linearly improved (P<0.01) during 0 to 3 wk of age. From 4 to 8 wk of age, the body weight, feed intake, BW gain, FCR and uniformity were not different (P>0.05). Carcass ratios of birds fed 3,000 kcal of ME/kg diets from 3 to 8 wk of age were quadratically increased significantly (P<0.01). As ME and CP increased, respectively, relative weight of liver weight per 100 g of BW was linearly decreased (P<0.01). Relative weights of left breast, thigh and drumstick weight per 100 of BW were not different (P>0.05). Also, breast meat color, pH, cooking loss and shear force were not different (P>0.05). Thus, diets with 2,800 kcal of ME/kg and 23% CP or with 2,900 kcal of ME/kg and 17% CP at 0 to 3 wk and 4 to 8 wk, respectively, were used more efficiently. However, diets with 3,000 kcal of ME/kg at 4 to 8 wk in carcass rate was quadratically increased.

• Korean Journal of Poultry Science
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• v.47 no.3
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• pp.159-167
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• 2020

This study investigated the effect of different light sources in the poultry house on performance, meat quality, and blood composition of finishing broilers. Two hundred and forty male broilers (1-day-old, 42.2±0.1 g) were divided into three groups and subjected to different light source treatments (incandescent, LED, and fluorescent lamps) from 3 weeks of age (four replications/treatment, 20 birds/replication). After breeding for 6 weeks, the carcass yield and meat quality of broilers with similar body weight (BW; 3.4±0.07 kg) were investigated, and blood components were analyzed. Corn-soybean meal-based feed was provided as starter (CP 22.5%, ME 3,020 kcal/kg), early (CP 18.5%, ME 3,050 kcal/kg), and finishing (CP 18%, ME 3,100 kcal/kg). Performance, carcass yield, meat quality, and blood components were evaluated. BW, BW gain, feed intake, and feed conversion ratio did not show any significant differences among treatments. There was no significant difference on live weight and carcass yield among treatments. There was no significant difference on meat color, shear force, and water holding capacity; however, cooking loss at 17.2% was the highest in the LED treatment (P<0.05). There was no significant difference on blood components except for glucose (blood biochemistry component) among treatments. Glucose was 234.5 mg/dL, 256.9 mg/dL, and 250.1 mg/dL in the three treatments, respectively, with a significant difference between incandescent and LED treatments (P<0.05). These results are used useful as basic data for investigating the effect of lighting in broilers production.

• Korean Journal of Poultry Science
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• v.25 no.4
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• pp.169-175
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• 1998

A feeding trial was carried out to evaluate optimum feeding system to Korean Native Chicken (KNC) with various feeding programs for 64 weeks. Eight hundreds and ten KNC＇one day birds were assigned to three feeding systems, NRC(T1), Japanese Feeding Standard(T2), Korean Feeding Standard(T3). Each treatment had three replicates of 90 birds a replicate. Data were obtained growing performance to 20 week of age and laying performance from twenty one to sixty four week. Viability to 20 week of age was similar to treatments. Growth characteristics by feeding systems were not significantly difference on body weight, feed intake and 50％ egg production days. However, body weight was less about 100g in T2. There were no different on egg production, egg weight, and egg mass during laying period. Feed intake of T1 was 104g daily and showed lower than other treatments, but was not different significantly. Feed conversion was significantly improved in T2(P <0.05) compared to other treatments(P<0.05). Egg production of all treatments was the highest between 27 to 30 week of age. ME intake of T1 was significantly maximized, whereas CP intake was the lowest of all treatments(P < 0.05). Nutrient requirements for egg mass tended to depend on nutrients intake. Interior egg and eggshell characteristics were not different among treatments except yolk color. Fertility and hatchability were similar to treatments, and the results at 39 week of age were higher than at 62 week in all treatments. In conclusion, treatments fed three or four phase feeding would be superior to other treatments during the growing period and suggest 2,800 ㎉/kg ME, 15％ CP for Korean native laying hen.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.504-511
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• 2010

This study was undertaken to investigate the effects of feeding complex probiotics (Lactobacillus casei, Bacillus subtilis, Saccharomyces cerevisiae, Aspergillus oryzae, Streptomyces griseus, $1.5{\times}10^{10}$ CFU/kg) and antibiotics (oxytetracycline (OTC), 110 ppm) on growth performance and meat quality characteristics of broiler chicks. In the experiment 1, 0.3% complex probiotics feeding level was chosen to be proper addition level due to better average daily gain (ADG), feed conversion (FC) and dressing percent (DP) results among 3 levels (0.1, 0.3 or 0.5%). In the experiment 2, 5 treatments (T1, no probiotics + no antibiotics; T2, probiotics 0.3% + no antibiotics; T3, probiotics 0.3% + antibiotics 50%; T4, probiotics 0.3% + antibiotics 100%; T5, no probiotics + antibiotics 100%) were investigated. In the growth performance of broilers, T5 (antibiotics 100% only) showed the highest (p<0.05) ADG and FC values while T1 (control) showed the worst growth performance. However, T3 (probiotics 0.3% + antibiotics 50%) showed higher ADG (p<0.05), FC (p<0.05) and DP (p>0.05) values compared to control. In the breast and leg meat quality, T3 showed similar pH, proximate composition, cooking loss and meat color values except shear force value compared to T5. Addition of 0.3% probiotics with 50% antibiotics (T3) tended to lower the blood cholesterol levels of broiler chicks and Escherichia coli or Salmonella counts in cecum microflora of broiler chicks compared to T5. In the residual antibiotics analysis, T3 contained 0.04 ppm of residual antibiotics in the breast meat while T4 or T5 contained 0.1 ppm of residual antibiotics and addition of 0.3% probiotics with 50% antibiotics in broiler diets could lower the residual antibiotics level to 40% in the meat. As a result, 0.3% probiotics addition with 50% antibiotics in the broiler diets could be recommended for the production of high quality broiler meat.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.449-457
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• 2010

This study investigated the effects of three kinds of water extract mixtures each with different ratios of A. capillaris, C. sinensis, S. chinensis, and V. coloratum on laying performance, egg quality, blood characteristics, and egg storage stability in laying hens. One hundred and sixty 35-wk-old laying hens (Hy-line brown) were divided into four groups of 10 birds each replicated times four. The treatments involved a basal diet (C, control) or diets containing three kinds of water extract mixtures at 200 ppm (T1, water extract mixture A; T2, water extract mixture B; T3, water extract mixture C). The egg production rate, egg mass, and feed conversion ratio were significantly improved in all treatments compared to those of control (p<0.05). Haugh unit and egg yolk color in all treated groups were significantly improved in comparison with control (p<0.05), but no significant differences were observed for egg shell quality. The content of total cholesterol in blood serum was significantly decreased in all treatments compared to that of control (p<0.05). The blood biochemical parameters of liver and kidney damage were significantly decreased in all treatments compared to those of control (p<0.05). Total antioxidant activity in the blood serum of all treated groups was increased as well. The Haugh unit and malondialdehyde content in the egg yolk during storage were significantly decreased in all treated groups compared to control (p<0.05). Consequently, the dietary supplementation of water extract mixtures of A. capillaris, C. sinensis, S. chinensis, and V. coloratum improved laying performance and egg quality but decreased egg quality deterioration with increased storage. These results suggest that medicinal plant extracts could be used as a feed additive in feed for laying hens.

• Korean Journal of Poultry Science
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• v.48 no.3
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• pp.101-110
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• 2021

In this study, we performed a cross-combination test using offspring from two paternal and five maternal parent stock lines to produce a new synthetic breed of Korean native commercial chickens. The survival rate, body weight, feed intake, and feed efficiency were measured for 10 crosses, with 837 Hanhyup-3 chickens used as a control. Most chickens had brown-based feathers, and there was little difference in color phenotypes among combinations. The average survival rate of the combinations was 94.9%, which was significantly different from that of Hanhyup-3 at 75.3% (P<0.01). There was significant differences in body weight among the combinations at all weeks of age (P<0.01). At 10 weeks of age, the FHHY combination was the heaviest with 2,300 g, while the weight of Hanhyup-3 was 1,922 g. In addition, the weight difference between the male and female chickens was 458 g. As a result of regression analysis, the duration needed to reach 1.9 kg was about 61 days for the FHFY, FHHY, and HFFY combinations, and 70 days for Hanhyup-3, exhibiting a 9-day difference. The average feed conversion ratio of the combinations until 10 weeks was 2.42, which was significantly different from that of Hanhyup-3 at 2.97 (P<0.01). In conclusion, FHHY, FHFY, and HFFY were determined to be the best new breed combinations based on production capacity. When these combinations are used as new commercial breeds, they are expected to increase the average weight by 18% and improve feed efficiency by 19%, as compared to the existing Hanhyup-3 breed.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.227-238
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• 2021

This study investigates the effect of perch type and height on the growth performance, footpad dermatitis (FPD), blood parameters, behavioral characteristics, and meat quality of broilers. A total of 912 one-day-old male Ross 308 broilers (48.23±0.264 g) were subjected to a three x two factorial design of three types of perch (wood, steel, plastic) and two levels of perch height (10→30 cm change, 10 cm fixed) over a five-week experiment. Growth performance, perch availability, litter quality, FPD incidence, serum biochemical parameters, and meat quality of the broilers were evaluated. There were no significant differences in the body weight, feed conversion ratio, and biochemical parameters (except for aspartate aminotransferase), pH, color, and water holding capacity. The incidence of FPD was significantly higher in the plastic perch group than in the wood and steel perch groups (P<0.05) at five weeks of age. Perch use was high in the order of wood, steel, and plastic groups in the daytime and nighttime at one, three, and five weeks of age (P<0.05). Perch use was higher in the 10 cm fixed group than the 10→30 cm group (P<0.05). The shear force of the breast significantly increased in the order of wood, steel, and plastic groups (P<0.05). In conclusion, the group with a fixed perch height of 10 cm had high perch usage. Additionally, the use of wooden perches was higher than that of other materials, and it lowered the incidence of FPD in broilers.

• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.189-197
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• 2022

This study was conducted to compare the egg productivity, egg quality, and blood characteristics of laying hens with different laying rates, and the frequency and cumulative duration of the sitting behavior observed before laying was investigated. Twelve 45-week-old Hy-Line Brown laying hens were randomly assigned to two treatment groups with three replicates. Treatment groups were classified as layers laying over 80%(high egg performance layers; HEP) and layers laying below 50%(poor egg performance layers; PEP). The experiment lasted 4 weeks. HEP showed higher hen-house egg production ratio and egg mass and lower feed conversion ratio(FCR) (P<0.05) compared with PEP, although egg weight was higher in PEP (P<0.05). In terms of egg quality, PEP showed differences in eggshell quality (eggshell color, eggshell thickness, and eggshell weight) (P<0.05). Additionally, HEP showed high triglycerides(TG), and PEP showed high alanine transaminase(ALT) level (P<0.05) in serum collected in the morning. In the afternoon, the HEP showed higher lactate dehydrogenase(LDH) levels (P<0.05). No differences in the Ca: P ratio were observed between layers with different laying rates. One hour before egg laying, HEP exhibited sitting behavior 4 times on average, each lasting 25 minutes. In conclusion, egg production and quality differ between HEP and PEP, and HEP showed frequent sitting behavior before egg laying. However, additional research is necessary to explore approaches other than specific behavioral observation to distinguish poor layers in the flock for application in farms.

• Korean Journal of Poultry Science
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• v.35 no.2
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• pp.143-151
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• 2008

This study was conducted to identify the correlation of bacterial phytase ($Transphos^{(R)}$) to the calcium level in feed. Of all 21-week-old 720 HyLine brown laying hens, 2 birds of similar weight were placed on each individual cage. The experiment was conducted by $3{\times}2{\times}3$ factorial design with including 3 different levels of phytase (0, 300, and 1,000 DPU/kg), 2 different levels of calcium (3.5% and 4.0%), and 3 different levels of no NPP addition 0% (0.095 NPP), 0.5% (0.185% NPP), and 1.0% (0.275% NPP). The feeding trial maintained the ME level of 2,800 kcal/kg and 16% for crude protein. The diet was fed ad libitum and 17 hours of lighting was provided throughout the experimental period. Egg production seemed to increase, in the 300 DPU of bacterial phytase added group and the cracked egg tended to reduce in Transphos added group. The egg productivity between treatment groups did not show significant difference by dietary calcium level, whereas non NPP added group (0.095% NPP) was found to be low compared to NPP added groups (P<0.05). The highest mean egg weight and the highest daily egg mass were detected in 300 DPU phytase added group. Although the mean egg weight was significantly higher in treatment groups fed with 3.5% calcium containing feeds (P<0.05), daily egg mass was no among treatment groups. The mean egg weight and daily egg mass were the lowest in non NPP added group (0.095% NPP) compared to other treatment groups (P<0.05). The feed intake showed similar pattern regardless of the bacterial phytase and calcium levels in the diet. However, the treatment groups fed diets containing NPP level of 0.275% and 0.165% showed significantly higher feed intake than the group fed with 0.095% NPP (P<0.05). Although the feed conversion was not affected by calcium and NPP levels in the diet, the most improved result was obtained from 300 DPU phytase added group (P<0.05). The eggshell breaking strength and thickness increased as dietary calcium level increase the level of calcium increases in diet. The treatment groups fed diet containing 0.275% and 0.165% NPP revealed to show improvement in eggshell breaking strength and yolk color index compared to the NPP non added (0.095% NPP) treatment group. The result of the present study suggests that the appropriate level of microbial phytase is 300 DPU and at this level, tricalciumphosphate supplementation in feed can be reduced to 40% of NRC recommendation. Higher calcium level in feed fail to show synergistic effect by adding microbial phytase.