• Korean Journal of Poultry Science
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• v.50 no.1
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• pp.1-13
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• 2023

The study was carried out to investigate the effects of dietary combined supplementation of antioxidants as catechin and vitamin C on growth performance, meat quality, blood profiles and stress responses of broilers exposed to high temperature. For this experiment, a total of 360 21-day-old male Ross 308 broilers were used. Treatments were assigned with 6 replicates per treatment and 10 birds per replicate in a 2 × 3 factorial design with vitamin C (0, 250 mg/kg) and catechin (0, 600, 1,200 mg/kg). The heat stress environment was maintained at temperature 32±1℃ and relative humidity 60±5% for 24 hours until the end of the experiment. The supplemented antioxidants had no significant difference in weight gain, feed intake and feed conversion ratio (P>0.05). The content of total cholesterol in blood had no interaction, but decrease (P<0.01) in the supplemented catechin group. Also, the supplementation with catechin showed increase in the SOD activity of blood, and lower corticosterone and IgM levels of broilers. The contents of HSP70 and MDA in liver decrease (P<0.05) with the supplementation of antioxidants, and HSP70 showed an interaction between groups. DPPH radical scavenging ability in breast meat increased (P<0.01) in catechin, but meat quality did not show difference according to treatments. Respiratory rate decreased (P<0.05) in catechin, but no interaction with vitamin C. In conclusion, the combination of vitamin C and catechin can alleviate stress under high temperature, such as HSP70 and MDA, but further study on the optimal supplemental level is needed.

• Korean Journal of Poultry Science
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• v.47 no.2
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• pp.95-105
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• 2020

This study presents the production characteristics and physiological characteristics of five Korean native chicken (KNC) breeds consisting of Hwanggalsaek Jaeraejong (HJ), Korean Rhode Island Red (KR), Korean White Leghorn (KL), Korean Brown Cornish (KC), and Korean Ogye (KO). We investigated their production performances, vitalities, and stress responses. We measured the survival rate, body weight, age at first egg-laying, hen-day egg production, egg weight, amount of telomeric DNA, heterophil-lymphocyte ratio (H/L ratio), and heat shock protein (HSP)-70, HSP-90α and HSP-90β gene expression levels for 493 KNCs. The survival rate was highest in KR, and lowest in KO. Body weights were steadily high in the order of KC, KR, HJ, KO and KL. Average hen-day egg production was highest in KL, and lowest in KC. While the amount of telomeric DNA was highest in KR, and lowest in KC. Furthermore, both the H/L ratio and the HSP-90β gene expression level were highest in KC, and lowest in KR. These results indicated that the KR breed was highly resistant to stress, whereas KC was more susceptible to stress. Taken together, it is considered that with improvements the KC breed would be more suited to be used as a Korean broiler breed while KL would be more appropriately used as a Korean layer breed. In addition, it is considered that the KR breed is appropriate to be used as a maternal chicken breeder based on good production capacity and excellent robustness, while the HJ breed is desirable to be improved as a high-quality Korean meat breed based on its excellent meat quality.

• Korean Journal of Poultry Science
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• v.46 no.4
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• pp.255-262
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• 2019

The micronutrients and flavor compounds of three new native chicken strains (A, C, and D) being developed in a breeding program (Golden Seed Project) were compared with a commercial native chicken strain (H) and the Baeksemi (W, white semi broiler). After 100 male chicks in each strains were reared for 5 weeks, the breast muscles from randomly selected 40 birds were analyzed at 8 replications. Native chicken strain A had greater amounts of α-tocopherol and α-tocotrienol compared with strain W. Native chicken strains showed higher contents of vitamin B₁₂ than Stain W. Stain H strain had the highest values of cholesterol content and strain D did the lowest. There was no different content of most minerals between native chickens (A, C, D, and H) and W, but Cu were more contained in native chicken strains compared with W. In terms of nucleotide-related flavor compounds, Stain A had the lowest content of hypoxanthine and strain D had highest inosine monophosphate. Native chicken strains had higher contents of umami-related free amino acids (glutamate and aspartate) than W. Among native chickens, strain A had more amounts in the contents of taurine, tasty flavor compounds, and certain vitamins, despite of the relatively low growth productivity. This result will provide information to select a strain with characteristic meat quality in a chicken breeding program.

• Korean Journal of Poultry Science
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• v.46 no.4
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• pp.215-221
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• 2019

This study investigated the effects of various stocking densities on the growth performance of Korean native ducks. Twelve hundred day-old ducklings were reared for 50 days in a duck house (windowless, plastic wire-floor pen). Two weeks later, 852 of these ducks (350±30 g) were selected for at least 80% uniformity per stocking treatment (six treatments, four replications/treatment, depending on a stocking density of 4~9 birds m^-2). Experimental diets were corn-soybean-based and broiler ducks were grouped based on age [0~21 days of age (CP 21%, ME 2,900 kcal/kg) and 21~50 days of age (CP 17%, ME 3,100 kcal/kg)]. Body weight (BW) did not significantly differ among different aged treatment groups (P>0.05); however, uniformity decreased with higher stocking densities (P<0.05). Feed intake and feed conversion ratio of ducks aged 42~50 days significantly decreased in the T4-6 treatments compared with the T1-3 treatments (P<0.05). In all experimental periods, BW gain was not significantly different among treatments, but feed intake decreased significantly as the stocking density increased (P<0.05), and feed conversion ratio was significantly different among six treatments with stocking density (P<0.05). In conclusion, we found that the stocking density of Korean native ducks in a plastic wire-floor pen was approximately 7 birds m^-2 in consideration of productivity and uniformity.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.2
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• pp.65-71
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• 1999

This study was conducted to evaluate the feasibility of food waste as a feed resources by fermentation and fermented food waste as a substitute of rat feed on the performance with measuring the liveweight gain, feed consumption, feed conversion and digestibility Sixty-two grams Sprague-Dawley line 36 rats were allocated three treatments 12 rats of each(3replication ${\times}$ 4 rats). The substitution level of fermented food waste to commercial broiler feed were control, 0: 100: treatment I, 10: 90: treatment II, 20:80. The chemical composition of fermented food waste was appeared to follows : dry matter, 88.47% : crude ash. 12.95: crude protein, 20.82%; crude fiber, 13.62; ether extract, 9.15%. The body weight of treatment I and II at 1 weeks was significantly lower than those of control(p<.05) and weekly weight gain of control at 0-1 weeks was significantly higher than those of treatment I and II(p<.05). Those were higher in treatment I than those of rest groups at 1-2 weeks(p<.05). Total weight gain of treatment II was significantly lower than those of control and treatment I(p<.05) Total feed consumption of treatment II was significantly higher than those of control (p<.05) and weekly feed consumption of control and treatment II at 3-4 weeks was significantly higher than those of treatment II(p<.05). but those were higher in treatment I and II than those of control at 2-3 weeks(p<.05). Commutative feed conversion of treatment II was significantly higher than those of control(p<.05) and weekly feed conversion of treatment II and III at 0-1 weeks was significantly higher than those of control(p<.05) Dry matter digestibility of control and treatment I was significantly higher than those of treatment II(p<.05) and organic matter digestibility was higher in control than those of treatment II(p<.05).

• Journal of Animal Science and Technology
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• v.53 no.5
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• pp.409-418
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• 2011

This study was conducted to investigate the effects of dietary probiotics and immunomodulator on growth performance, carcass characteristics, fecal $NH_3$ content and pathogenic bacteria counts in ileum and cecum and ileum of broiler chicken (Korean native chicken, HanHyup No. 3). A total of 120 (day-old) chicks were randomly divided into 5 treatments with 3 replicates and there were 8 birds per replicate. Dietary treatments consisted of five diets; the corn-soybean based control diet (C), the diet containing antibiotics (Avilamycin) 10 ppm (T1), the diet containing probiotics 1 [(Lactobacillus ($4.45{\times}10^6$) + yeast ($1.51{\times}10^6$) + Bacillus subtilis ($3.50{\times}10^5$)] at 0.5% level (T2), probiotics 2 [(Lactobacillus ($6.70{\times}10^7$) + yeast ($3.10{\times}10^6$)] at 0.5% level in diet (T3), and the diet containing probiotics 3 [T2 + ${\beta}$-glucan + organic acid] (T4) and raised for 9 weeks. There were no significant differences among treatments in weight gain, feed intake and feed conversion. Carcass ratios of broilers were higher in T3 and T4 than other treatments, however, the differences were non-significant. Internal organs and liver, heart weight were significantly increased in T4 (p<0.05) compared to other treatments. The fecal $NH_3$ gas content was decreased (p<0.05) in antibiotics fed group than others. However, probiotic fed groups were not different when compared with control. The number of Salmonella and E. coli in cecum were reduced in the group supplemented with probiotics and immunomodulator compared to the antibiotics (p<0.05). In this experiment, we showed that diets containing pro-biotics and immunomodulator were capable of an alternative to antibiotics.

• 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.