• Korean Journal of Poultry Science
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• v.30 no.1
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• pp.35-40
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• 2003

This experiment was conducted to investigate the effects of natural and synthetic commercial pigments on the growth performances, skin pigmentation and color difference of broiler chicks. Experimental diet was formulated to have isocalories and isonitrogen for experimental period, and xanthophyll concentration in the diet was 8.45g/1on. The experiment was conducted for six weeks with 450 broiler chicks. The birds were assigned to 10 treatment groups and each group had 15 chicks with three replications. Results showed that the types of pigments did not have any effect on body weight, feed intake and feed efficiency. The mortality was lower with higher pigment supplementation and greater in the natural pigment groups than in the synthetic ones. Dressed carcass, abdominal fat pad and gizzard weight were not significantly different among treatments. The pigmentation of shank skin was increased with high pigment supplementations, and the pigmentation effect was greater with synthetic pigments than in natural pigments. In the shank meat or skin, the color difference(L*, a*, b*, c* and h*) was not consistently related to pigmentation.

• Journal of Animal Science and Technology
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• v.47 no.2
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• pp.195-204
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• 2005

The current study was conducted to investigate the effects of dietary conjugated linoleic acid(CLA) on growth performance and body fat metabolism in broiler chickens. A total of 48 male birds aged 3 days were randomly allotted into three dietary groups; CORN(com oil 1.5%), CLA I (com oil 0.75 %+ CLA 0.75 %) and CLA II(CLA 1.5%) groups. After feeding commercial diet ad libitum for 3 weeks, eight selected birds on the basis of body weight were housed, two birds in a cage, and continuously given ad libitum corresponding experimental diet for another 2 weeks. As a result, dietary addition of CLA did not influence on body weight, gain and feed conversion rote. The relative weights of the liver and deposited fats(abdominal and thigh fat' pads) were not also affected by the dietary treatments. Serum glucose, triglyceride and cholesterol levels markedly( P < 0.05) decreased in CLA II compared with those in CORN group. However, serum nonesterified fatty acid(NEFA) was not altered by dietary CLA. Serum leptin level was tended to be decreased by dietary CLA without statistical difference. The diet supplemented with CLA caused a significant(P< 0.05) decrease in hepatic total lipid and NEFA without changing triglyceride level. Also, feeding dietary CLA at the level of 1.5% reduced leptin mRNA expression in the liver and abdominal fats compared with feeding com oil, In conclusion, our results suggest that dietary 1.5% CLA may affect, at least in part, lipid metabolism in the liver of broiler chickens.

• Animal Bioscience
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• v.37 no.5
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• pp.875-882
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• 2024

Objective: An experiment was conducted to study the effect of supplementing DL methionine (DL Met) at graded concentrations on performance, carcass variables, immune responses and antioxidant variables in broiler chicken fed folic acid (FA) fortified (4 mg/kg) low-methionine diet. Methods: A basal diet (BD) without supplemental DL Met, but with higher level (4 mg/kg) of FA and a control diet (CD) with the recommended concentration of methionine (Met) were prepared. The BD was supplemented with DL Met at graded concentrations (0%, 10%, 20%, 30%, 40%, and 50% supplemental DL Met of CD). Each diet was fed ad libitum to 10 replicates of 5 broiler male chicks in each from 1 to 42 d of age. Results: Body weight gain (BWG) reduced, and feed conversion ratio (FCR) increased in broilers fed low-Met BD. At 30% and 20% inclusion of DL met, the BWG and FCR, respectively were similar to those fed the CD. Similarly, supplementation of 10% DL Met to the BD significantly increased ready to cook meat yield and breast meat weight, which were similar to those of the CD fed broilers. Lipid peroxidation reduced, the activity of antioxidant enzymes (GSHPx and GSHRx) in serum increased and lymphocyte proliferation increased with increased supplemental DL Met level in the BD. The concentrations of total protein and albumin in serum increased with DL Met supplementation to the BD. Conclusion: Based on the data, it can be concluded that supplemental Met can be reduced to less than 50% in broiler chicken diets (4.40, 3.94, and 3.39 g/kg, respectively in pre-starter, starter and finisher phases) containing 4 mg/kg FA.

• Korean Journal of Poultry Science
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• v.12 no.2
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• pp.59-64
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• 1985

The study was carried out to determine if a difference in initial chick weight was still evident in market body weight(6 or 8 week body weight) of broilers. The data of a total of 800 broiler commercial chick raised at Poultry Breeding Farm, Seoul National University from Aug. 6, 1981 to Oct. 1, 1981 were analysed. The results were summarized as follows: 1. Although the initial chick weight was about the same, male chick grew more rapidly than female and sex difference was the most striking factor in growth rate of broiler in this analysis. 2. The relationship between initial chick weight and body weight after hatching was decreased to the increase of weeks of age in both sexes. Though the correlation coefficients of the 6 week and 8 week body weight to the initial chick weight were 0.15 & 0.15 in female and 0.18 & 0.17 in male, the relationship was highly significant in both sexes. 3. Regressions of 6 and 8 week body weight on the initial chick weight in both sexes indicate that, for each increase of one gram in weight of chick at hatching, the average increase in body weight was 8.33 gram ＆ 10.07 gram in female and 7.85 gram ＆ 11.28 gram in male. Results show that the initial chick weight (1 day of age) influence average body weight of commercial broiler at 6 and 8 weeks of age.

• Food Science and Preservation
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• v.19 no.3
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• pp.385-392
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• 2012

The characteristics of the components related to the meat taste of the commercial broiler (CB) and the Korean native chicken (KNC) were compared. The breast meat from CB showed higher amounts of $C_{16:1}$ and $C_{18:2}$ but lower amounts of $C_{16:0}$ and $C_{22:6}$. The thigh meat from CB showed a higher amount of $C_{18:1}$ but lower amounts of $C_{16:0}$, $C_{18:0}$, $C_{20:4}$, and $C_{22:6}$. The flavor- and taste-contributing amino acids, including aspartic acid, threonine, serine, glycine, alanine, tyrosine, lysine, histidine, and arginine, were significantly higher in the KNC breast meat, but the level of amino acids in the thigh meat were not different between the two breeds. The measurement of the volatile compounds revealed that CB contains much higher volatile compounds compared to KNC in their fresh breast and thigh meat. Both in the breast and thigh meat, however, the amount of flavor compounds increased significantly after cooking; as such, KNC turned out to have more flavor compounds than CB.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.6
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• pp.745-752
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• 2007

This study examined the effects of different levels of evening primrose oil (EPO) on the accumulation of ${\gamma}$-fatty acids in broiler meat. Six hundred one-day-old male chicks (Ross strain) from commercial broilers were divided randomly into 6 groups${\times}$4 repeat pens. The broilers were fed experimental diets containing 4.0% tallow (control), 0.5% EPO, 0.7% mixed oil (EPO 70:soy bean oil 30), 1.5% EPO, 3.0% EPO or 4.0% EPO for two weeks of broiler finisher. There was a significant difference in body weight gain between the control and treatment groups except for the 0.5% EPO group (p<0.05). There was a significant difference in the percentage of thigh and breast weight against the carcass weight between control and treatment groups except for the 0.5% EPO group in the thigh and 0.5% EPO and 4.0% EPO groups in the breast weight (p<0.05). The saturated fatty acid levels of the skin and breast muscle lipid of the broilers fed diets containing EPO were significantly lower than that of the control group (p<0.05), while the level of unsaturated fatty acid was significantly higher than that of the control group (p<0.05). The ${\gamma}$-fatty acid (GLA, gamma.linolenic acid, 18:3n-6) level was particularly higher in the chicken meat lipids from the broilers fed EPO than in the control group (p<0.05). This shows that feeding EPO to chicks can produce novel functional broiler meat that is enriched in gamma-linolenic acid.

• Korean Journal of Poultry Science
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• v.31 no.3
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• pp.151-155
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• 2004

This experiment was conducted to investigate the influence of dietary supplementation of granite porphyry (GP) on growth performances and meat sensory quality in commercial broiler chicks. A total of four hundred-fifty 5-day-old male broiler chicks were divided into 15 pens and fed one of five experimental diets for 5 weeks; 0% GP with antibiotics (Control), 1% GP with or without antibiotics, and 2% GP with or without antibiotics. Final body weight and daily weight gain of all GP supplemented groups were slightly higher than those of control. Feed conversion rate was improved in GP 1 % supplemented groups, although there was no significant difference. Feeding antibiotics in addition to GP did not influence the growth parameters. Relative weights of liver and abdominal fat tended to be reduced in broiler chickens fed GP supplemented diets. Feeding of 2% GP diet resulted in a significant improvement in meat sensory quality in terms of taste and tenderness(P < 0.05), but the effect of the 1% GP on meat sensory quality was not significant. The results of this study indicate that GP could be used as a favorable feed additive for production of sensory-enhanced broiler meats.

• Korean Journal of Poultry Science
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• v.31 no.1
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• pp.25-31
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• 2004

The effect of drinking rhus tree-extract on performance of broiler was performed to investigate development of natural antibiotic in process of broilers production. A total of 320 broiler chicks at 1 day of age were fed the commercial diet and water, drinking water containing 0 ppm(control), 500 ppm (T1), 1,000 ppm (T2) and 2,000 ppm (T3) of rhus tree-extract fur seven weeks. The body weight gain and fred conversion ratio were not different by drinking rhus tree-extract until 35 days of age, but body weight gain and feed conversion ratio were tend to improve by drinking rhus tree-extract over 35 days of age, the improvement was higher in both T$_1$, and T$_3$ than control group(p＜0.05) when 35 to 42 days of age. There was a decrease in the microflora population of both E. coli. end Salmonella in the cecum contents and feaces in broilers by drinking rhus tree-extract. The digestibility of dry matter, crude fat, and crude ash of feed were tend to increased in broiler drinking rhus tree-extract. Digestibility of crude protein of feed in broiler three treated groups was significantly improved (p＜0.15) as compared with those in control group. These results indicated that the drinking rhus tree-extract were effective in the body weight gain, feed conversion ratio, decreasing of microflora population of both E. coli and Salmonella in the cecum contents and feaces, and it had also effective the digestibility of nutrients in broilers.

• Korean Journal of Poultry Science
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• v.30 no.4
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• pp.253-257
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• 2003

The suitability of processed cardboard(PC) as litter of broiler house was evaluated by comparing the growth performances of broiler chicks reared on the PC with those of birds reared on conventional rice hull litter(RH) as the control group. A total of 180 male broiler chick (5d old, Ross) were randomly divided into 2 groups and placed into 2 types of litter, PC and RH, with 3 replicates of 30 birds per replicate. Commercial broiler feeds and water were provided ad libitum for 5 weeks. The body weight gains of the birds reared on PC were heavier than those on RH(P<0.05). The average feed conversion rate of chicks reared on PC was appeared to be improved as compared to that of the control. The Enterobacter aerogens counts in PC were significantly rduced than those in the control litter(P<0.05), but a total number of Salmonella and E. coli were not affected by the litter materials. No difference was observed between the average moisture contents of the litters. The average mortality of the chicks reared on PC was significantly lower than that of RH(P<0.05). The results indicate that processed cardboard can substitute other conventional litter materials when the others are in short supply or expensive.

• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.233-238
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• 2006

In order to study the effect of feeding rare earth(RE) on growth of broiler chicks, feed conversion ratio, and probable harmfulness of feeding high levels of RE, two feeding trials with broiler chicks were conducted; one using a commercial broiler compound feed and the other using a self mixed feed excluding any growth stimulating feed additives. The the first trial used three hundred sixty of one day old Cobb broiler chicks for six levels of dietary supplementation of RE : 0, 100, 200, 400, 800 and 1,600 mg/kg. There were significant effect of RE stimulating broiler chick growth and improving feed conversion ratio, The dietary supplementation of RE at a level of 100 mg/kg was the best of all and increased body weight gain by 8.9% (p<0.05). Chicks fed RE at a level of 1,600 mg/kg grew as good as chicks fed feeds without RE and did not show my abnormalities. The second feeding trial was conducted in the same manner as the first trial using Ross broiler chicks and self-mixed experimental diets supplemented with RE at levels of 0, 50, 100 and 150 mg/kg. Differently from Results of the first trial, body weight gain and feed conversion ratio of were the best at the level of 50 mg/kg RE supplementation(p<0.05). In this trial all the birds fed RE showed significantly lower ratio of abdominal fat against live weight than those of the control group birds. Overall, it can be said that dietary supplementation of RE will improve broiler growth and feed conversion ratio and the proper dietary level would be $50\sim100mg/kg$. These results suggested that the proper level of RE for broiler chicks would be 50 to 100 mg/kg and its effectiveness is varied depending upon RE mixture. There appears abdominal fat of broiler chicks is decreased by feeding RE but further investigation is in need.