• Korean Journal of Poultry Science
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• v.47 no.1
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• pp.1-7
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• 2020

The effect of stocking density on the growth and meat quality of native Korean chickens was investigated. A total of 364 one-day-old native Korean chickens were randomly assigned to one of 5 treatments, each of which was replicated 4 times. Five distinct stocking densities-14, 15, 16, 18, and 22 birds/㎡-were compared. The diet was fed ad libitum for 10 weeks. Results indicated that the final body weight, body weight gain, and feed intake were lower (P<0.05) for the 22 birds/㎡ stock density as compared to the other stock densities. There was no significant difference in the feed conversion ratio, proximate analysis (DM, crude protein, crude fat, and crude ash), water-holding capacity, and cooking loss among the different stock densities. These results indicate that increasing the stock density to 22 birds/㎡ elicits some negative effects on the growth performance and meat quality of Korean-native chickens.

• Korean Journal of Poultry Science
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• v.29 no.4
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• pp.279-286
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• 2002

This study was conducted to examine quality stability during storage periods, herb high pressure boiled extract(HPBE)(T$_1$), Korean Ogol chicken HPBE(T$_2$), cross-bred Ogol chicken HPBE(T$_3$), cross-bred Ogol chicken meat hydrolyzed with flavourzyme(T$_4$) were pouch packaged and stored at 37$\^{C}$. After each period, TBARS, VBN, pH, total microbial counts and sensory properties were determined and the results were as follows. There was no noticeable difference in TBARS value until 42 days at the ambient environment among the treatments, but T$_4$ showed a significantly higher TBARS value at 56 days. There was a tendency for a higher protein decomposition as storage time increased, and in particular at 56 days, T$_1$ group showed a significantly higher values than other groups. Given to the sensory properties in which overall sensory preference decreased after 42 day, it was considered that the maximum storage time for the extract was less than 42 days at 37$\^{C}$.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.261-268
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• 2010

This study was conducted to investigate the effects of environmental temperature (ET; $21^{\circ}C$ and $32^{\circ}C$) and antibiotic substitute conditions on meat quality of chicken breast during cold storage. Seven treatments were as follows; T1, ET $21^{\circ}C$ + antibiotics (+); T2, ET $21^{\circ}C$ + antibiotics (-); T3, ET $32^{\circ}C$ + antibiotics (+); T4, ET $32^{\circ}C$ + antibiotics (-); T5, ET $32^{\circ}C$ + 0.1% Lactobacillus; T6, ET $32^{\circ}C$ + 0.1% medicinal plant extract; T7, ET $32^{\circ}C$ + 0.1% essential oil. T7 had a higher (p<0.05) pH at 72 h post-slaughter value when compared to the other treatments. The CIE $b^*$ value of treatments at ET $32^{\circ}C$ showed significantly (p<0.05) higher when compared to the treatments at $21^{\circ}C$. T7 also had significantly (p<0.05) lower TBARS values than the other treatments as the storage time increased. T6 contained significantly (p<0.05) higher extractability of salt-soluble protein contents than the other treatments. The results from SDS-PAGE showed that the actin protein decreased for ET treatments at $32^{\circ}C$. The concentration of actin protein was not significantly different among T1, T2 and T7. Therefore, these result suggested that the antibiotic alternative with essential oil was effective under the high environmental temperature ($32^{\circ}C$) for chicken meat production.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.799-805
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• 2010

Since the consumption of spent laying hens as roasted skewered meat increases, the effects of various carotenoids on pigmentation and antioxidant activity were tested with 62-wk-old 250 ISA brown laying hens to improve the quality of chicken meat. In a 6-wk feeding trial, 4 carotenoids with different polarity (${\beta}$-8-apo-carotenoic acid ethyl ester (ACAEE)>astaxanthin>canthaxanthin>${\beta}$-carotene) at 100 mg carotenoid/kg feed were used. The more polar the carotenoids, the higher were the levels in blood. After 5-wk adaptation, the concentrations of astaxanthin, canthaxanthin, and ACAEE in blood were -4 ${\mu}g/ml$. Canthaxanthin decreased significantly (p<0.05) the level of total blood cholesterol. Decreases in blood triglyceride by all carotenoids used were significant. ACAEE and astaxanthin tended to increase skin yellowness of thigh, breast, and wing proportionally to feeding period. In the case of polar carotenoids (ACAEE and astaxanthin), the longer the period of feeding, the higher the accumulation in skin was observed. Only astaxanthin was effective against the production of lipid peroxides in skin. Conclusively, out of the commercially available carotenoids we tested, astaxanthin is recommended for pigmentation of skin and inhibition of lipid oxidation.

• Food Science of Animal Resources
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• v.27 no.2
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• pp.203-208
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• 2007

Organic duck's carcass weight was lower than general duck's because of the differences in breed and feeding method, but there was no difference in carcass percent among them. The rate of organic duck's fresh breast meat(17.62%) was significantly higher than that of general duck's(11.95%)(p<0.05). The rate of fresh leg meat rate was lower in organic duck, but there was no significant difference among them(p>0.05). The pH of breast and leg measured immediately after butchering were 6.48 and 6.73 in organic duck, respectively and there was significant difference among them(p<0.05). According to the sensory test, the texture, odor, tenderness, and taste showed better preference in organic duck than those of broiler chicken. According to above physicochemical analysis and sensory test, organic duck showed higher pH, higher shear force, and lower cooking loss. Therefore, it is considered to be very valuable to develop the exploitation of meat product in organic duck which had good quality and tastiness.

• Korean Journal of Poultry Science
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• v.40 no.1
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• pp.57-65
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• 2013

This study was conducted to evaluate the effect of dietary Weissella koreensis (Wk), a prominent kimchi lactic acid bacteria supplementation on growth performance, nutrients utilization, gut microbiota and meat characteristics in broiler chicken. Both live and killed Wk was compared to know which could be more efficacious as a feed probiotics. Three Wk supplemented groups and no Wk supplemented group were designated according to supplementation levels and cell status. Those were; Control (no Wk), 0.1 % live Wk (LWk 0.1), 0.5% live Wk (LWk 0.5) and 0.5% killed Wk (KWk 0.5). Body weight gain and feed conversion efficiency were improved (P<0.05) by dietary LWk supplementation. KWk did not exert any benefit on growth performance. Crude protein utilizability of KWk supplemented diet was lower (P<0.05) than that of other diets. However, there were no differences among treatments in other nutrients utilization. Serum IgG concentration and relative weight of bursa of Fabricius was highest (P<0.05) in broiler chicken fed KWk 0.5 diet. Cecal anaerobic lactic acid bacteria count of LWk groups were higher (P<0.05) than those of control and KWk 0.5 groups. Dietary Wk supplementation failed to lower the count of cecal and fecal E. coli. There was no effect of dietary Wk on TBARS values and fatty acids profile of broiler leg meat. However, the dietary supplementation of Wk exerted characteristic difference on electronic nose flavor of broiler meat. This study showed that dietary supplementation of LWk was able to improve body weight gain, feed conversion efficiency and cecal lactic acid bacterial count in broiler chicken. Further, the result of this study implemented that a live kimchi lactic acid bacteria, LWk, but not killed Wk, could be used as a probiotic feed supplement for broiler.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.187-195
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• 2013

This study was investigated the effects of dietary supplementation of Yacon by-products and pine needle powder on growth performance, carcass characteristics, pH, TBARS (thiobarbituric acid reactive substance), WHC (water holding capacity), shear force, and meat color of chicken thigh meat. Broiler chicks were fed diets for five weeks containing 0% Yacon by-products and pine needle powder (Control), 0.5% Yacon by-products powder (T1), 1.0% Yacon by-products powder (T2), 0.5% pine needle powder (T3), and 1.0% pine needle powder (T4). There was no significant difference in growth performance among treatments, but mortality was decreased in diets by the supplementation of Yacon by-products and pine needle powder than that of control. The chicken fed control diet had higher cholesterol. LDL-cholesterol. triglyceride compared to those chicken fed Yacon by-products and pine needle powder regardless of concentrations, and HDL-cholesterol of control was lower than treatment. The pH and TBARS were significantly decreased by the supplementation of Yacon by-products and pine needle powder compared to the control (P<0.05), especially, pine needle powder group was significantly more effective in improving freshness compared to other test groups (P<0.05). The WHC and shear force were not significantly different. CIE $L^*$ and $a^*$ value of test groups showed significantly higher value compare to the control, however, no difference in the CIE $b^*$ values was observed among test groups. In conclusion, a supplementation of Yacon by-products and pine needle powder were effective in decreasing pH, TBARS, total cholesterol and LDL-cholesterol and increasing HDL-cholesterol concentration. Pine needle powder supplementation was most effective (T3 and T4).

• Food Science of Animal Resources
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• v.31 no.1
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• pp.86-91
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• 2011

This experiment was conducted to investigate the effects of dietary supplementation with lutein-containing materials on meat quality and lutein accumulation in broiler tissue. Broilers were subjected to one of the following treatments: C, basal diet (BD); T1, BD + 2.223% lutein from spinach extracted by ethanol fermentation; T2, BD + 2% radish green powder; T3, BD + 0.61% spinach powder; and T4, BD + 1.83% spinach powder. The weight gain, feed intake, and feed conversion did not differ among treatments. An evaluation of the color of the chicken breast meat revealed that the CIE $L^*$ value of the control was significantly (p<0.05) lower than that of the other treatments, whereas T4 had a significantly (p<0.05) lower CIE $a^*$ value and a higher (p<0.05) CIE $b^*$ value than the other treatments. The lipid oxidation (thiobarbituric acid reaction substances, TBARS) value was not significant among treatments. The results of a high performance liquid chromatography analysis revealed that the lutein peak was present only in the T4 liver tissue. These results showed that spinach powder (T4) affected meat color (CIE $a^*$ and $b^*$) however, TBARS and lutein accumulation were not affected.

• Journal of Nutrition and Health
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• v.17 no.4
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• pp.262-272
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• 1984

A study on the balance of essential amino acids in Korean diet and further investigation on quality of protein through optimum combination of foods using the least square method based on FAO/WHO (1973) provisional score patterns were carried out The results of the optimum gross combination are summarized as follows: 1) The first limiting amino acids of the Korean diet was found to be methionine and cysteine based on both whole egg and FAO/WHO (1973) provisional score patterns. 2) Weight ratios between rice and beef, chicken, pork, rabbit meat are 7 : 3, 4 : 1, 4 : 1, and 3 : 1. The amino acid score and the least amino acid are 100(phe+tyr), 99(thr), 111(trp), and 109(leu) for each combination. This result indicates that pork and rabbit meat can be high quality protein sources for the rice eating people. 3) Weight ratios between rice and anchovy, saury, ark shell, pollack, cuttle fish, tuna and herring are 2 : 1, 5 : 1, 3 : 2, 3 : 1, 3 : 1, 4 : 1, and 3 : 1. 4) Weight ratios between potato and rice, wheat flour are 8 : 1 and 24 : 1. Lysine, the limiting amino acid of rice and wheat flour can be complemented by combining these with potato. 5) It is possible to apply this idea on typical Korean dishes. For example, in case of soybean-sprout rice the optimum combinations of rice : soybean-sprout : pork and rice : soybean-sprout : beef are 4 : 1 : 1 and 11 : 1 : 5. It is of utmost importance to pursue further more desirable combinations with more complex food items and transform the result obtained by the computer analysis into more practical terms for practical use.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.448-458
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• 2009

It has been well documented from animal and human studies that conjugated linoleic acid (CLA) has numerous beneficial effects on health. In chickens, CLA exerts many effects on performance ranging from egg quality and yolk lipids to meat quality. Although there are several CLA isomers available, not all CLA isomers have the same incorporation rates into egg yolk: cis-9,trans-11 and trans-10,cis-12 CLA isomers are more favorably deposited into egg yolk than other isomers investigated, but of the two isomers, the former has a higher incorporation rate than the latter. CLA alters the amounts and profiles of lipids in plasma, muscles and liver. Furthermore, increased liver weight was reported in chickens fed dietary CLA. As observed in egg yolk, marked reduction in intramuscular lipids as well as increased protein content was observed in different studies, leading to elevation in protein-to-fat ratio. Inconsistency exists for parameters such as body weight gain, feed intake, feed conversion ratio, egg production rate and mortality, depending upon experimental conditions. One setback is that hard-cooked yolks from CLA-consuming hens have higher firmness as refrigeration time and CLA are increased, perhaps owing to alterations in physico-chemistry of yolk. Another is that CLA can be detrimental to hatchability when provided to breeders: eggs from these breeders have impaired development in embryonic and neonatal stages, and have increased and decreased amounts of saturated fatty acids and monounsaturated fatty acids (MUFAs), respectively. Thus, both problems can be fully resolved if dietary sources rich in MUFAs are provided together with CLA. Emerging evidence suggests that CLA exerts a critical impact on stress and immune functions as it can completely nullify some of the adverse effects produced by immune challenges and reduce mortality in a dose-dependent manner. Finally, CLA is a key regulator of genes that may be responsible for lipid metabolism in chickens. CLA down-regulates both expression of the gene encoding stearoyl-CoA desaturase-1 and its protein activity in the chicken liver while up-regulating mRNA of sterol regulatory element-binding protein-l.