• Korean Journal of Poultry Science
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• v.33 no.4
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• pp.283-293
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• 2006

Two experiments were conducted to investigate the effects of dietary activated charcoal mixed with wood vinegar (AC) on broiler performance and antibiotics residue in eggs. In experiment 1, a total of low hundred fifty, 1-day-old male broile. chicks (Ross) were divided into 6 groups, consisting 3 replicates of 25 birds each, and 134 one of the six experimental diets: devoid of AC and antibiotics (negative control), devoid of AC with 0.1% antibiotics (positive control), devoid of antibiotics with 1% AC, with 0.1% antibiotics and 1% AC, devoid of antibiotics with 2% AC, with 0.1% antibiotics and 2% AC, for 5 wks. Feed consumption and body weights were measured weekly. At the end of the experiment, eight birds from each group were selected and sacrificed. The relative weight of organs and characteristics of breast muscle were investigated. There were no significant differences in feed intake, body weight gain and feed conversion rate among the treatments. There were also no significant differences in the relative weight of breast meat, leg and liver. The abdominal fat tended to be decreased by the dietary AC. Significant differences were shown (P<0.05) in meat redness (a) and yellowness (b) among the treatments. However, the sensual characteristics of breast muscle was not affected by the dietary treatments. There were significant differences in total microbes, Coli forms and lactic acid bacteria (P<0.05) among the treatments. In experiment 2, a total of ninety, 40-wk-old Hy-line Brown laying hens were divided into 3 groups, consisting 3 replicates of 10 birds each and fed medicated control diet devoid of AC or diets containing 1% AC and 2% AC for 2 wks. The residue of antibiotics in Plasma and egg Yolk were significantly decreased (P<0.05) in 2% AC group compared to that of control. This study suggest that dietary AC may improve the external quality of edible meat and reduced antibiotics residue in chicken eggs without affecting laying performance.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.143-149
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• 2007

The experiment was conducted to examine the effects of dietary organic selenium and vitamin E on weight gain, feed intake, feed conversion, and selenium retention in meat of broiler chickens. For each growth phase, the basal diet was supplemented with 0 (control), vitamin E 150 IU/kg and the combination of 1.2 ppm Se from selenium yeast (SY) and vitamin E 100, 150, 200 and 300 IU/kg. Weight gain was significantly higher in supplemental control and vitamin E 150 compared to the combination of 1.2 ppm SY and vitamin E 150 IU during day 1 to 21. Feed intake significantly(P<0.05) increased in supplemental vitamin E 150 compared to the combination of 1.2 ppm SY and vitamin E 150 and 200 IU during day 1 to 21. Feed intake was significantly(P<0.05) higher in control compared to that of combination of 1.2 ppm SY and vitamin E 200 IU during day 21 to 35. However feed conversion was not affected in supplemental vitamin E and SY during day 1 to 35. Selenium concentrations of breast muscle and liver tissue significantly increased (P<0.05) in supplemental combination of 1.2 ppm SY and vitamin E compared to the control and vitamin E 150 IU. TBARS of control and vitamin E 150 IU were significantly (P<0.05) higher in day 3 than day 1, but the combination of Se 1.2 ppm and vitamin E of TBARS had no difference during day 1 to 3. TBARS in day 3 was significantly (P<0.05) lower in supplemental combination of Se 1.2 ppm and vitamin E than control and vitamin E 150 IU.

• Korean Journal of Poultry Science
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• v.17 no.3
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• pp.141-156
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• 1990

The experiments were conducted to investigate the possibility of improving the effectiveness of the existing method to estimate the edible meat weight in the live broiler chicken. A total of 360 birds, five male and female chicks from each line were sacrificed at Trial 1 (body weight 900-1, 000g), Trial 2 (body weight 1.200-1, 400g), Trial 3(body weight 1, 600-1, 700), and Trial 4(body weight 2, 000g) in order to measure the body weight, edible meat weight of breast, thigh and drumsticks, and various components of body weight. Each line was reared at the Poultry Breeding Farm, Seoul National University from the second of july, 1987 to the thirteenth of September, 1987. The results obtained from this study were summarized as follows ： 1. The average body weights of each line( H. T, M, A) were $2150.5\pm$34.9, $2133.0\pm$26.2, $1960.0\pm$23.1, and $2319.3\pm$27.9, respectively. at 7 weeks of age. The feed to body weight eain ratio for each line chicks was 2.55, 2.13, 2.08, and 2.03, respectively, for 0 to 7 weeks of age. The viability of each line was 99.7. 99.7, 100.0, and 100.0%, respectively, for 0 to 7 weeks of age.01 was noticed that A Line chicks grow significantly heavier than did T, H, M line chic ks from 0 to 7 weeks of age. The regression coefficients of growth curves from each line chicks were bA＝1.015, bH＝0.265, bM＝0.950 and bT＝0.242, respectively. 2. Among the body weight components, the feather. abdominal fat, breast, and thigh and drumsticks increased in their weight percentage as the birds grew older, while neck. head, giblets and inedible viscera decreased. No difference wat apparent in shank, wings and hack. 3. The weight percentages of breast in edible part for each line thicks were 19.2, 19.0, 19.9 and 19.0% at Trial 4, respectively. The weight percentages of thigh and drumsticks in edible part for each line chicks were 23.1, 23.3, 22.8, and 23.0% at Trial 4. respective1y. 4. The values for the percentage meat yield from breast were 77.2. 78.9 73.5 and 74.8% at Trial 4 in H, T, M and A Line chicks. respectively. For thigh and drumstick, the values of 80.3, 78.4. 79.7 and 80.2% were obtained. These data indicate that the percentage meat yield increase as the birds grow older. 5. The correlation coefficients between body weight and blood. head, shanks. breast. thigh-drumstick were high. The degree if correlation between abdominal fat(%) and percentage of edible meat were extremely low at all times, but those between abdominal fat (%) and inedible viscera were significantly high.

• Korean Journal of Poultry Science
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• v.31 no.2
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• pp.93-100
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• 2004

This study was conducted to evaluate the effect of organic iron supplemented to feed for broilers. One hundred forty four Ross broiler chicks were assigned to 6 treatments: control containing 80mg Fe from iron sulfate per kg diet(FE-80), FE-160 (control multiplied two times), YM-80 containing 80mg Fe from yeast mutant, YM-160 (YM-80 multiplied two times), YF-80 containing 80mg Fe from ferritin containing yeast, YF-160 (YF-80 multiplied two times) in the experiment. Each treatment had four replications of 6 birds each. The weight gain of the YM-160 was significantly higher (P＜0.05) than that of the control (FE-80). The YM and YF in the serum cholesterol level were significantly higher (P＜0.05) than the control. In the cholesterol level of carcass, although the control (FE-80) was highest and the YM and YF were very low; however, there were no significant differences among treatments. In the iron level of carcass, the control (FE-80) showed the lowest level among treatments; the YM and YF were significantly higher (P＜0.05) than the control. In conclusion, the supplementation with organic iron to broiler chicks improve productivity. We also expect the possibility on chicken meat with reinforcing iron.

• Korean Journal of Poultry Science
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• v.40 no.1
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• pp.1-9
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• 2013

This study was investigated the effects of dietary supplementation of Yacon by-product powder on performance, pH, total phenol contents, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, TBARS, WHC, shear force, meat color, and sensory evaluation of chicken thigh meat. Broiler chicks were fed diets for five weeks containing 0% Yacon by-products powder (Control), 0.5% Yacon by-products powder (T1), 1.0% Yacon by-products powder (T2), and 2.0% Yacon by-products powder (T3). There was no significant difference in performance among treatments, but mortality was decreased in diets by the supplementation of Yacon by-product powder than that of control. The total cholesterol, LDL-cholesterol and triglyceride of control were higher than treatment groups and HDL-cholesterol and glucose of control was lower than treatment. The pH and TBARS were significantly decreased by the supplementation of Yacon by-product powder compared to the control (P<0.05). The total phenol contents and DPPH radical scavenging activity were significantly increased by the supplementation of Yacon by-product powder compared to those of the control group (P<0.05), and especially, T3 was significantly (P<0.05) more effective in improving freshness compared to other treatment groups. The WHC (water holding capacity) and shear force were not significantly different. CIE $L^*$ and $a^*$ value of treatment groups showed significantly higher value compare to the control, however, no difference in the CIE $b^*$ values was observed among treatment groups. In conclusion, a supplementation of Yacon by-product powder was effective in decreasing pH and TBARS (thiobarbituric acid reactive substance), and increasing total phenol contents and DPPH radical scavenging activity.

• 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 Agricultural Science
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• v.10 no.2
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• pp.221-234
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• 1983

A study was conducted to devise a method to estimate the edible meat weight in live broilers. White Cornish broiler chicks CC, Single Comb White Leghorn egg strain chicks LL, and two reciprocal cross breeds of these two parent stocks (CL and LC) were employed A total of 240 birds, 60 birds from each breed, were reared and sacrificed at 0, 2, 4, 6, 8 and 10 weeks of ages in order to measure various body parameters. Results obtained from this study were summarized as follows. 1) The average body weight of CC and LL were 1,820g and 668g, respectively, at 8 weeks of age. The feed to gain ratios for CC and LL were 2.24 and 3.28, respectively. 2) The weight percentages of edible meat to body weight were 34.7, 36.8 and 37.5% at 6, 8 and 10 weeks of ages, respectively, for CC. The values for LL were 30.7, 30.5 and 32.3%, respectively, The CL and LC were intermediate in this respect. No significant differences were found among four breeds employed. 3) The CC showed significantly smaller weight percentages than did the other breeds in neck, feather, and inedible viscera. In comparison, the LL showed the smaller weight percentages of leg and abdominal fat to body weight than did the others. No significant difference was found among breeds in terms of the weight percentages of blood to body weight. With regard to edible meat, the CC showed significantly heavier breast and drumstick, and the edible viscera was significantly heavier in LL. There was no consistent trend in neck, wing and back weights. 4) The CC showed significantly larger measurements body shape components than did the other breeds at all time. Moreover, significant difference was found in body shape measurements between CL and LC at 10 weeks of age. 5) All of the measurements of body shape components except breast angle were highly correlated with edible meat weight. Therefore, it appeared to be possible to estimate the edible meat wight of live chickens by the use of these values. 6) The optimum regression equations for the estimation of edible meat weight by body shape measurements at 10 weeks of age were as follows. $$Y_{cc}=-1,475.581 +5.054X_{26}+3.080X_{24}+3.772X_{25}+14.321X_{35}+1.922X_{27}(R^2=0.88)$$ $$Y_{LL}=-347.407+4.549X_{33}+3.003X_{31}(R^2=0.89)$$ $$Y_{CL}=-1,616.793+4.430X_{24}+8.566X_{32}(R^2=0.73)$$ $$Y_{LC}=-603.938+2.142X_{24}+3.039X_{27}+3.289X_{33}(R^2=0.96)$$ Where $X_{24}$=chest girth, $X_{25}$=breast width, $X_{26}$=breast length, $X_{27}$=keel length, $X_{31}$=drumstick girth, $X_{32}$=tibotarsus length, $X_{33}$=shank length, and $X_{35}$=shank diameter. 7) The breed and age factors caused considerable variations in assessing the edible meat weight in live chicken. It seems however that the edible meat weight in live chicken can be estimated fairly accurately with optimum regression equations derived from various body shape measurements.

• Food Science of Animal Resources
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• v.24 no.2
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• pp.128-134
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• 2004

This experiment was conducted to investigate the effects of dietary pigment sources on the performance, color and antioxidant properties in broiler chick. Experimental diet was formulated to have isocalories and isonitrogen during the experiment period. Total xanthophylls content in the experimental diet was formulated to have 30ppm. Experimental trials were done for five weeks with six treatment groups; T1 (Control), T2 (Olo Glo, natural yellow pigment), T3 (Kern Glo, natural red pigment), T4 (canthaxanthin, synthetic red pigment), T5 (asthaxanthine, natural red pigment), and T6 (seaweed by-products). Body weight gain and feed intake were significantly lower (p＜0.05) in T6 group than in other treatments. Mortality was lower in T2, T3 and T4 than in control, but higher (p＜0.05) in T5 and T6. The sources of pigments did not have any effects on the dressed carcass and abdominal fat pad (p＞0.05). The gizzard weight was significantly lower in T6 (p＜0.05) than in others. Pigmentation of leg skin was significantly lower (p＜0.05) in control and T6. Effects of dietary pigments was greater with red pigments than with yellow pigments, and those were also greater with natural pigments than with synthetic ones. The peroxide value (POV), thiobarbituric acid reactive substances (TBARS) and pH values of chicken meat were increased (p＜0.05) in all treatments at 12 day storage, and was higher (p＜0.05) in pigments supplementation group. No differences of CIE L$\^$*/(lightness) and b$\^$*/(yellowness) were not found by storage days and xanthophylls sources. The a$\^$*/(redness) after 12 day storage was significantly (p＜0.05) decreased in all treatments, but those of T4 and T5 were higher than those of others. These results showed that feeding of xanthophylls sources to chick could improve color intensity and inhibit lipid oxidation of leg meat.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.287-295
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• 2021

In this study, we aimed to evaluate the impact of different feed withdrawal periods (2, 3, 4, 5, and 6 h) on Salmonella contamination in the crop, intestinal weight, and blood parameters of broilers before harvesting. A total of 100 broilers (initial live weight 1.906±0.06 kg) were randomly assigned to the same five treatment groups and broilers had access to water but no feed before catching. Feed withdrawal times were 2, 3, 4, 5, and 6 h prior to slaughter. Measurements included live weight, pre-slaughter weight, carcass weight, weight of gastrointestinal tract. In addition, Salmonella and Campylobacter contamination in the crop, serum biochemical profiles, counts of leukocytes, erythrocytes, and platelets, and meat quality were assessed. The results demonstrate that carcass weight, blood corticosterone, meat pH, meat color, and water holding capacity did not differ based on the feed withdrawal time. Carcass yield increased as the withdrawal time increased, but the weights of the crop, proventriculus, jejunum, ileum, and rectum were significantly reduced by 6 h (P<0.05). Salmonella counts were the lowest in the crops subjected to 6 h of feed withdrawal (P<0.05). Shear force was highest in chicken breast meat after 6 h of feed withdrawal (P<0.05). However, when the feed was withdrawn after 6 h, the shear force increased, but it did not affect the sensory characteristics in consumers, and the Salmonella count also decreased and had a reduction effect on contamination during slaughter. These findings can serve as reference data for setting the feed withdrawal time.

• Korean Journal of Poultry Science
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• v.39 no.3
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• pp.195-205
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• 2012

The objective of this study was to evaluate the effects of different levels of dietary ME on growth performance and carcass characteristics in two different strains of broiler chicken. A total of one thousand, 1-day-old A strain and R strain male chicks were randomly assigned into 8 treatments in a $2{\times}4$ factorial arrangement. They were fed iso-nitrogenic (CP 21%) crumbled diets formulated to contain metabolizable energy (ME) 2,950 to 3,250 kcal/kg in increment of 100 kcal/kg in the starter phase (1 to 21d) and iso-nitrogenic (CP 19%) pelleted diets containing same ME levels as in the finishing phase (22 to 38d). The body weight (BW) gain of chicks fed the lower ME diets (2,950 or 3,050 kcal/kg) were higher than those of the higher ME groups. The dietary energy level showed significant effects on feed intake and feed conversion rate (FCR) from 1 to 38 days of age (p<0.05). With the increment of dietary energy, feed intake tended to be reduced, whereas FCR was improved in the two strains of broiler chickens. The lowest FCR was observed at 3,250 kcal/kg diet groups in both of the two strains from 1 to 38 days of age. Feed intake and BW gain during 38 days were significantly affected by the strain factor. Increasing dietary energy up to 3,250 kcal/kg had no effect on the relative weights of breast meat and abdominal fat. The dietary energy and strains showed significant effects on the dressing percentage. There were no significant differences in various blood profiles except for GPT activity.