• Asian-Australasian Journal of Animal Sciences
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• 제32권11호
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• pp.1753-1762
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• 2019

Objective: The study was aimed to compare carcass traits, physicochemical and textural properties of meat in two different genotypes of Pekin ducks with regard to sex effect. Methods: The study involved 120 Pekin ducks: 30 males and 30 females of strain P33 (Polish native Pekin ducks) and 30 males and 30 females of Star 53 HY (commercial hybrid Pekin ducks). At 49 d of age, 48 birds (12 males and 12 females of each genotype) were selected for dissection. After the dissection, meat samples were collected to determine meat quality traits. Results: The studied Pekin ducks of different genotype showed significant differences in body weight, carcass weight, dressing percentage, as well as percentages of breast muscles, skin with subcutaneous fat, abdominal fat, neck, and remainders of eviscerated carcass with neck. Duck genotype influenced the content of crude protein, crude fat, Na, K, P, Zn, $pH_{24}$, electric conductivity ($EC_{24}$), cooking loss, $L^{\star}$, $a^{\star}$, most textural traits of breast muscle, and also Na, Mg and Fe content, $EC_{24}$, drip loss, cooking loss and $L^{\star}$, $a^{\star}$, and $b^{\star}$ colour coordinates of leg muscles. Regardless of genetic origin, males exhibited higher BW, carcass weight and carcass neck percentage, as well as lower redness, hardness, chewiness and gumminess of breast muscle compared to females. The genotype${\times}$sex interaction was significant for the crude fat content and cooking loss of breast muscle, and for the yellowness of leg muscle. Conclusion: Star 53 HY ducks are more suited for broiler production due to their higher body weight and dressing percentage. Their breast and leg meat are characterized by more beneficial chemical composition but has poorer sensory and textural properties compared to the meat of P33 ducks.

• 한국축산식품학회지
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• 제41권5호
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• pp.788-801
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• 2021

This study examined biochemical components, fatty acids, antioxidant dipeptides, and muscle fiber density of breast and thigh muscles from Korean new native chicken strains (A and B) at two slaughter ages, compared with white semi-broiler (W) or broilers. The pH values were different by chicken breed. The new native strains had the lowest fat content in the breast at 12 wk (p<0.05). Regardless of the muscles, A and B at 12 wk had higher levels of arachidonic acid (ARA; C20:4), docosahexaenoic acid (DHA; C22:6), and nervonic acid (C24:1) than broilers (p<0.05). A similar result was observed for the polyunsaturated fatty acids (PUFAs) and polyunsaturated and saturated fatty acids ratio (P/S) content in the breast. Irrespective of the muscles, A and B enriched with omega-3 fatty acids had a lower ω-6/ω-3 PUFA ratio than broilers (p<0.05) at 12 wk. Of the antioxidant di-peptides, the anserine contents were highest in A and B than in the W or broilers (p<0.05), regardless of the muscles and slaughter ages. Furthermore, the breast meat from A and B contained a higher muscle fiber density for both slaughter ages than the W and broilers (p<0.05). Based on these findings, even if the commercial birds (broilers or W) are raised under the similar environmental conditions as A and B, the new native chicken strains have distinct meat quality attributes, particularly higher ARA and DHA levels, lower ω-6/ω-3 PUFA ratio, and higher anserine contents.

• Animal Bioscience
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• 제37권5호
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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.

• 농업과학연구
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• 제46권2호
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• pp.351-359
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• 2019

The purpose of this study was to compare the growth performance, nutrient digestibility, fecal microflora, blood profiles and meat quality of broilers, Korean native chickens and white semi broilers under identical feeding conditions. Sixty 1-d chicks of each type were randomly placed into 12 pens per cage (5 chicks per cage) and fed commercial diets for 28, 49, and 28 days, respectively. The broilers showed a significantly higher (p < 0.05) growth performance from 0 to 4 weeks compared with the other types. Korean native chickens had a significantly higher (p < 0.05) digestibility of dry matter and nitrogen than that of the other species. The blood glucose was significantly higher in the Korean native chickens compared to the other species, and the blood cholesterol was significantly lower. The Lactobacillus content in Korean native chickens was significantly higher (p < 0.05) compared to the other species, and the E. coli content in the broilers was significantly higher (p < 0.05) than in the Korean native chickens and white semi broilers. In terms of meat quality, the breast meat of the broilers had a high water content and pH level. The breast meat of the white semi broilers had a significantly lower (p < 0.05) shear force than that of the other species. In conclusion, there was an interspecific physiological difference due to the age and body weight of the chickens. The broilers had a higher growth performance and meat quality compared to the Korean native chickens and white semi broilers.

• 한국가금학회지
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• 제29권2호
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• pp.125-134
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• 2002

육계사료에 CLA, 대두유, 시판용 우지의 수준별 급여가 육계의 생산성 및 계육의 성상에 미치는 영향을 비교하기 위하여 두 차례의 사양실험을 5주간 시행하였다. 사육 전기 3주간에 사료내 조단백질은 21.5%, ME 3,100kca1/kg으로 하였으며, 사육 후기 2주간에는 조단백질 19%, ME 3,100kcal/kg 수준으로 급여하였다. 처리구는 실험 1과 2에서 CLA 대두유(Soybean Oil; SBO), 시판용 우지(Commercial Tallow; CT)를 각각 1, 2, 3%와2, 3%씩 기초사료에 첨가 급여하였으며, 전체 540수와 360수를 공시하였다. 조사항목으로 CLA SBO, CT의 MEr, 육계의 증체량, 사료섭취량, 사료요구율, ND 항체가, 가슴육의 지방산 및 CLA 함량을 측정하였다. 본 연구에 이용된 CLA SBO, CT의 MEn는 각각 8,542, 9,179, 8,733 kcal/kg으로 분석되었다. 실험 1에서 첨가된 유지 종류에 따른 증체량의 차이는 보이지 않았으나, 사료요구율은 SBO 급여 구에서 CLA 급여구에 비하여 현저하게 개선되었다(P<0.05). CLA 2와 3% 처리구는 1% 처리구에 비하여 증체 량과 사료섭취 량이 증가하였으며, 사료요구율을 현저하게 개선하였다(P<0.05). 실험 2에서는 CLA급여로 SBO와 CT에 비하여 사육후기의 증체량이 현저하게 높았다(P<0.05). ND 항체가는 CLA와 다른 유지급여구간에 통계적인 차이가 없었다. 계육의 지방산 조성은 사료내 CLA급여수준에 따라서 차이를 보였는데 CLA 1, 2, 3% 급여구에서 CLA 함량은 각각 12.23, 18.74, 25.67mg/g으로 처리구간에 현저한 차이를 나타냈다(P<0.05).본 연구의 결과CLA의 급여는 SBO와 CT에 비하여 증체량을 개선하고 계육내 CLA 함량을 현저히 증가시켰다(P<0.05).

• 한국가금학회지
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• 제32권4호
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• pp.255-260
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• 2005

본 연구는 Spent Bleaching Clay(SBC)를 육계사료의 에너지 공급원으로 활용 가능성을 구명하기 위하여 실시하였다. 부화 직후의 120수의 병아리(한협 3호)를4처리 3반복, 반복당 10수(암수 각각 5수씩)를 Control(T1) 사료에 SBC를 $2.0\%(T2),\;4.0\%(T3)$ 및 $6.0\%(T4)$ 첨가한 4처리로 배치하였다. 시험사료 급여전 1주일은 시판사료를 급여하였다. 4주간의 시험 기간동안 증체중 및 사료 섭취량은 T3 및 T4 처리구에서 증가하는 경향이 인정되었다. 사료효율은 T3구에서 개선되는 경향이 인정되었다. 가슴살 및 다리살에서 치방산 조성을 사료의 처리에 따른 효과는 인정되지 않았다. 육계 초기 및 후기 사료 급여시 모두, 사료중의 건물, 조단백질 및 조지방 이용율은 T4 처리구가 다른 처리구에 비해서 유의하게 감소하였으며(p<0.05), 대사에너지가도 T4 처리구가 다른 3구에 비해서 유의하게 저하하였다(p<0.05). 사료중의 조회분의 이용율은 사료의 처리에 따른 차이는 인정되지 않았다. 결론적으로 본 시험의 결과 육계사료에 $2\~4\%$의 SBC첨가는 육계의 성장 및 사료효율 개선의 가능성이 있음이 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권7호
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• pp.1000-1006
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• 2004

Selenium and vitamin E are micronutrients essential for normal health and maintenance in poultry. They are necessary in preventing free radical damage to phospholipid membranes, enzymes and other important molecules. Two experiments were conducted in a semi-commercial environment to examine the effect of Se source and vitamin E level in diet on broiler performance and meat quality. Increasing vitamin E from 50 IU to 100 IU did not affect growth performance of broilers although the 24 h drip-loss was tended to be reduced (p=0.06). There was an interaction between vitamin E and the source of Se in glutathione peroxidase activity (GSH-Px) and Se concentration in excreta. Increasing vitamin E from 50 IU to 100 IU elevated GSH-Px and Se concentration in excreta by 42 IU/g Hb and 0.9 ppm for the organic Se group, respectively, but reduced GSH-Px and Se concentration in excreta by 16 IU/g Hb and 1.3 ppm for inorganic group, respectively. Vitamin E played no role in the feather coverage of the birds when scored on day 37. Organic Se is more effective in improving feather score and 24 h drip-loss, with a markedly higher deposition rate in breast muscle and a lower excretion rate in the excreta (p<0.05) compared to the inorganic Se source. Both vitamin E and the source of Se did not affect (p>0.05) the energy utilisation by birds.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.516-523
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• 2005

The experiment was conducted to study the effect of dietary combinations of vitamin A (VA), vitamin E (VE) and methionine (Met) on growth performance, meat quality and immunity in commercial broilers. Ross chicks (n=3,630) were allocated to five experimental treatments with three replicates per diet. The dietary treatments were: VA 8,000 IU, VE 10 IU (diet 1); VA 12,000 IU, VE 10 IU (diet 2); VA 8,000 IU, VE 100 IU (diet 3); VA 12,000 IU, VE 100 IU (diet 4) and; VA 12,000 IU, VE 100 IU/kg diet and 20% Met higher than other groups (diet 5). The Met content in diet 1 to diet 4 were as per the requirement suggested by NRC. Separate vitamin premixes were prepared for each treatment diet as per the requirement of study. The 35 d study revealed significantly (p<0.0001) higher weight gains in broilers fed diet 3 and diet 5, than in the rest of the groups during starter phase (0-3 weeks) only. The feed intake did not vary significantly at all phases of study, but feed efficiency was significantly (p<0.05) lower in diet 1 during starter and overall phase (4-5 weeks). The bone strength and bone composition, except bone calcium, remained unaffected due to experimental diets studied after 35 d of experimental feeding. The thio-barbituric acid reactive substances (TBARS) were significantly (p=0.0013) lower in the breast meat in group 5, followed by group 3, than in the rest of the groups. The immune studies conducted, antibody titers to sheep red blood cells, thickness index to phytohaemagglutinin-P, and heterophil: lymphocyte ratio, did not show any significant difference among treatments. It could be concluded that supplementation of VA, VE and Met at higher levels could be beneficial to broilers only during the starter phase.

• Asian-Australasian Journal of Animal Sciences
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• 제19권3호
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• pp.418-424
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• 2006

This experiment was conducted to explore the efficacy of lacquer (Rhus verniciflua) supplementation on growth performance, nutrient digestibility, carcass traits and serum biochemical values in commercial broilers. Eight hundred and forty Hubbard broiler chicks (1d old) were randomly distributed and allotted to four dietary treatments for five weeks. Each treatment had 5 replicates with 42 birds each. The dietary treatments were (1) control (2) 1% lacquer, (3) 2% lacquer and 4) 4% lacquer supplied as meal in the diet. Supplementation with lacquer improved weight gain (p = 0.0960) showing a linear trend during the starter phase (0-3 wk), but weight gain, feed intake and feed conversion ratio remained unaffected at the finisher phase (4-5 wk) and overall (0-5 wk). The nutrient digestibility studies conducted after 18 and 35 days of experimental feeding showed a linear (p<0.05) increase in digestibility of CP and ether extract at both measurement timess. The carcass studies were conducted on two birds per replicate (10 per treatment) at the end of both 3 and 5 wk. The dressing percentage, liver weight, heart weight, abdominal fat and the breast meat expressed as a percentage of live weight, did not differ significantly due to treatments at both phases. The serum cholesterol and high-density lipoprotein (HDL) showed a linear decrease (p = 0.0683 and p = 0.0322, respectively) as the level of supplementation increased at 3 wk; at 5 wk serum cholesterol, HDL and triglyceride levels decreased significantly showing a positive linear effect of lacquer on fat metabolism. The meat color values such as lightness, redness and yellowness did not reveal any significant trend. Overall, it could be concluded that lacquer supplementation at higher levels did not affect growth performance, but had a positive impact on fat metabolism by influencing fat digestibility and reducing serum cholesterol and triglyceride.

• Journal of Animal Science and Technology
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• 제47권6호
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• pp.1017-1024
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• 2005

육계의 도계과정 중에서 실신 전압을 50V, 255Hz로 고정하고 실신 시간을 변화시켜 닭고기의 육질에 미치는 영향과 저장 특성을 조사하여, 최적 실신 시간을 구하고자 실시하였다.실신시간에 따른 닭고기의 pH는 실신시간이 증가함에 따라 감소하는 경향을 나타내었으며, 육색에서 명도 및 적색도는 껍질, 가슴살, 다리살의 경우 실신시간이 증가할수록 높아지는 경향을 나타냈으나, 황색도는 껍질, 가슴살 및 다리살 부위에서 증가하는 경향을 나타냈으나, 날개에서는 거의 차이가 없었다. 가열감량은 실신시간이 증가할수록 증가하였으나 보수력은 반대의 경향을 나타내었으며, 전단력은 50V(5초)가 1.38kg/05$\cm^2$이였고 50V(11초)는 1.65kg/05$\cm^2$를 나타나 실신시간이 길어질수록 증가하는 경향을 나타내었다. 외관평가에서 닭고기 1등급 출현율은 실신시간이 증가하면서 약간 증가하는 경향을 나타내었으며, PSE는 전처리구에서 0.02% 이하로 낮은 발생율을 나타내었고, 혈흔은 50V, 5초 처리구에서 0.11cm로 다른 처리구 0.04cm 보다 약간 증가하는 경향을 나타내었다. 관능 특성은 50V, 8초간 실신하는 처리구에서 다즙성, 연도, 향미가 우수하였으나, 실신시간에 따라서 일정한 경향을 나타내지 않았다. 실신시간에 따른 닭고기의 저장성은 지방산패도를 나타내는 TBARS 값은 저장 3일에 50V, 5초 처리구는 0.39mgMA/kg, 8초 0.42mgMA/kg, 11초 0.33mgMA/kg로 실신 시간에 따라서 일정한 경향을 보이지 않았으나 실신시간이 가장 긴 11초 처리구에서 5, 8초 처리구보다 유의적으로 낮게 나타났다. 단백질변성도의 값을 나타내는 VBN가는 전압이 낮은 처리보다 높은 처리에서 증가폭이 컸으며 전체적으로는 저장기간이 길어짐에 따라 증가하는 경향을 나타내었다.