• Asian-Australasian Journal of Animal Sciences
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• 제18권11호
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• pp.1662-1668
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• 2005

This review has been done to examine sex-linked dwarf gene in broiler production in hot-humid climates. Introduction of sex-linked dwarf gene especially in hot harsh tropical environments brings a great advantage for broiler production. The heavy broiler parent suffers due to the stress of these adverse climates. Sex-linked dwarf genes reduce body weight, egg weight, but are superior for adaptability under harsh tropical environments, with a lower requirement for housing and feed, better survivability and reproductive fitness giving fewer defective eggs, more hatching eggs, better fertility, hatchability, feed conversion efficiency and resistance to disease. Overall the cost of chick production from dwarf hens is lower than from their normal siblings. Market weights of broilers from sexlinked dwarf dams is almost similar to those of broilers from normal dams with normal sires. But the net benefit of broiler production from sex-linked dwarf dams is found to be greater than that of broilers from normal dams. This will be the most important to the rural communities in Bangladesh and in other countries where the similar environment and socio-economic conditions exist. Therefore, sexlinked dwarf hens might be used in broiler breeding plan as well as broiler production in the tropics.

• Asian-Australasian Journal of Animal Sciences
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• 제17권8호
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• pp.1123-1130
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• 2004

Two experiments were conducted to examine the effects of dietary inclusion of xylose on growth performance, nutrient digestibility and xylose absorption in the portal-drained viscera of broiler chicks. In Exp. 1, ninety male 14 day-old broilers were used to study the effects of different inclusion levels (0, 5, 10, 20 and 40%) of D-xylose in the semi-purified diets on the growth and nutrient digestibility of broilers. In Exp. 2, One hundred and eight male broilers, fed by precision feeding at 22 day-old, were used to investigate the absorption and transportation of dietary xylose in the portal-drained viscera of broiler. The results of Exp. 1 indicated that the growth of broilers was gradually decreased as the xylose level increased (p<0.01). With the xylose supplementation increased, the moisture in broiler excreta was gradually elevated (p<0.01), AME and the digestibilities of crude protein and ether extract were significantly reduced and the digestibilities of xylose and arabinose were also decreased (p<0.01). The results of Exp. 2 showed that the concentrations of ribose, xylose and galactose in serum were significantly influenced by different dietary levels of xylose (p<0.01), but there's no apparent difference among rhamnose, glucose and arabinose (p>0.05). The xylose concentration in serum was highest in Vena Cava, middle in Portal Vein and lowest in Ulnar Vein within 6 h after precision feeding. And then the xylose concentration in Portal Vein and Ulnar Vein were higher than that of Vena Cava. The concentration of ribose, xylose and galactose in serum were also significantly changed with time prolongation (p<0.01). The concentration of xylose in serum was highest in the 40% xylose treatment, middle in the 20% xylose group and lowest in the control group. The glycogen contents in liver and muscle were linearly decreased as the level of xylose increased (p<0.01). The higher the dietary level of xylose was, the lower digestibility of dietary xylose was (p<0.10). 40% xylose markedly decreased the digestibility of dietary glucose (p<0.01). In conclusion, high levels of xylose in the diets inhibited the growth and nutrient digestibility of broiler. The outputs of xylose from the hydrolyzation of wheat-based diet by xylanase should have no adverse effects on broiler performance.

• 한국가금학회지
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• 제33권3호
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• pp.233-238
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• 2006

Lanthanum을 비롯한 17가지 특수 원소를 일컬어 희토(rare earth)라 한다. 본 연구에서는 육계사료에 희토의 첨가 효과를 알아보기 위하여 2회의 사양 시험을 실시하였다. 시험에 이용한 희토는 순도 99% 이상의 염화 희토 혼합물$(RECl_3)$로 $LaCl_3$ 36.52%, $LaCl_3$ 28.14%, $PrCl_3$ 11.24%, 그리고 기타 희토원소 24.11%로 구성된 흰색 분말 형태이었다. 희토 급여 사육기간은 5주간이었으며, 본 연구의 주요 목적은 희토 급여가 육계의 성장을 촉진할 수 있는지, 유해성은 없는지, 그리고 적정 사료 첨가 수준을 구명하였다. 육계의 복강 지방 축적에 대해서도 알아보았다. 첫 번째 사양 시험에서는 시판 배합 사료에 대한 희토 첨가 효과를 검토하였다. Cobb육계 1일령 병아리 360수를 사용하였으며, 사료에 희토를 0, 100, 200, 400, 800, 그리고 1,600 mg/kg 수준으로 첨가하였다. 육계의 성장은 희토 100 mg/kg 첨가 수준에서 가장 우수하였으며, 증체량은 대조구에 비해 8.9%가 증가하였고(1,669.9 vs. 1,533.8 g/chick), 사료 요구율도 낮았다(p<0.05). 희토는 1,600 mg/kg 수준으로 매우 높게 급여할지라도 성장이 저해되지 않았으며, 대조구와 같은 증체와 사료 요구율을 보였으므로, 과다 급여에 의한 중독증은 없을 것으로 사료되었다. 두 번째 사양 시험은 실험 1의 결과에서는 육계사료에서 성장능력의 극대화를 위한 희토의 적정 첨가 수준이 $100\sim200mg/kg$으로 예측되었으므로 좀더 근접한 적정 수준을 알아보고자 희토를 0, 50, 100, 150 mg/kg 수준으로 첨가하였다. 시험 사료는 시판 사료에 있을 수 있는 항생제나 기타 성장 촉진용 사료 첨가제를 첨가하기 위하여 자가 배합하였으며, Ross육계 1일령 병아리 360수를 이용하였다. 시험 결과 희토 50 mg/kg의 첨가가 증체량과 사료 요구율에서 대조구나 다른 처리구들에 비해 월등히 좋은 결과를 나타내었다(p<0.05). 이 시험에서는 첫 번째 시험에서 보이지 않았던, 생체중에 대한 복강 지방 비율이 현저하게 감소한 것으로 나타났다(p<0.05). 본 실험 결과 육계사료에 희토의 첨가는 육계의 성장을 촉진하였으며, 사료 요구율 개선하였다. 이외에도 복강지방이 낮아지는 경향을 보였지만 일관성이 없었으므로 추후의 연구가 필요하다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권9호
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• pp.1319-1325
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• 2002

Two experiments were conducted to evaluate the effect of early feed restriction on growth, feed conversion ratio (FCR) and mortality in unsexed broiler chickens. In Experiment 1, 350 one-day-old broiler chickens were divided into 7 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group and the other six groups were fed 25% ad libitum (25% multiplied by amount of feed intake of ad libitum chickens at the previous day) for 4 or 6 days, 50% ad libitum for 4 or 6 days, and 75% ad libitum for 4 or 6 days. In experiment 2, 500 broiler chickens were divided into 10 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group. Three ages of feed restriction initial timing (2, 4 or 6 days of age) and three types of feed restriction (physical restriction, meal feeding and diet dilution) were used ($3{\times}3$) in both experiments. They were feed-restricted for 6 days. Results showed that restricted broilers exhibited compensatory growth in both experiments except for diet dilution groups. In both experiments, FCR of restricted broilers was higher, whereas feed intake of them was lower during restriction period. FCR of restricted broilers was lower upon refeeding. Mortality was inconsistently affected by early feed restriction. Leg abnormality was lower in restricted broilers in both experiments. Level of feed restriction significantly influenced body weight, FCR and feed intake of restricted broilers (p<0.05), but duration of feed restriction had no effect. Type of restriction significantly affected body weight, feed intake and FCR (p<0.05). It appeared that to achieve the best result (complete compensatory growth and better FCR), broilers should be restricted at 25% ad libitum for 6 days (Experiment 1). Meal feeding started at 2 days of age would show the best performance (Experiment 2).

• Animal Bioscience
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• 제34권8호
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• pp.1342-1349
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• 2021

Objective: The aim of the present study was to investigate the effects of dietary supplementation of β-mannanase on growth performance, carcass characteristics, excreta microflora, blood constituents, and nutrient digestibility in broiler chickens. Methods: A total of 680 one-d-old Ross 308 (as hatched) broiler chickens were used in a 35-d growth assay. Chicks were sorted into pens with 17 birds/pen and 10 pens/treatment. Treatment diets were contained either 44% or 48% crude protein (CP) soybean meal (SBM) with or without β-mannanase. Results: Using SBM containing 48% CP led to an improvement (p<0.05) in feed conversion ratio (FCR) from d 1 to 14. Addition of β-mannanase to the diets significantly improved body weight gain (BWG) and FCR from d 1 to 14. During overall experimental period, BWG was affected (p<0.05) by CP level of SBM and inclusion of β-mannanase, but FCR and feed intake were not affected. Carcass characteristics were not influenced by treatment diets. The results showed that digestibility of dry matter (DM), nitrogen (N), and energy was not affected by CP level of SBM and/or inclusion of β-mannanase. Among essential amino acids (EAA) apparent digestibility of valine, methionine, and leucine improved (p<0.05) by the addition of β-mannanase to the diets. The results demonstrated that ileal digestibility of DM, N, and energy was not affected by treatment diets. Among EAA, the ileal digestibility of valine and arginine was higher (p<0.05) in the diets containing 48% CP SBM and/or β-mannanase. Excreta Lactobacillus count increased (p<0.05) by the addition of β-mannanase to the diets. Blood urea nitrogen, creatinine, and total protein level were not affected by treatments. Conclusion: Feeding chickens with diets containing 44% CP SBM resulted in detrimental effects on growth performance and digestibility of nutrients, but addition of β-mannanase to the 44% CP diet improved the growth performance of chickens without any effects on carcass characteristics.

• 대한수의학회지
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• 제34권3호
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• pp.457-463
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• 1994

Insulin-like growth factor-I(IGF-I) plays an important role in the regulation of mammalian and poultry growth. IGF-I has many actions in different tissues, which include metabolic, mitogenic, and differentiative actions. IGF-I induces insulin-like effects - such as increased cell glucose uptake and glycogen sysnthesis, however several physiological actions of IGF-I may not have been identified yet. In order to investigate the effect on growth in broiler chicken treated with exogenous insulin-like growth factor-I, 30 chickens were injected $50{\mu}g$ reconbinant human IGF- I (rhIGF- I ) per kg body weight as experimental group and 30 ckickens saline subcutanously as control, 3 times according to ages from 2 to 35 days. We established radioimmunoassay method by which we can measure chicken IGF- I (cIGF- I ) as in rhIGF- I assay. The results obtained were as follows; 1) The dilution curve showed in parallelism between rhIGF- I and cIGF- I in the Sep-pak $C_{18}$ cartridge plasma extracts. 2) The body weight of broiler chicken were significantly increased at 31 days($1,176.50{\pm}99.79g$) and 35 days($1,252.84{\pm}125.21g$) of age in treatment groups, compared with control group($1,011.88{\pm}40.22g,\;1,111.32{\pm}153.67g$). The liver and kidney weights on 35 days$(35.24{\pm}5.18g,\;11.05{\pm}1.47g)$ were significantly higher in rhIGF- I treated group than control group($30.95{\pm}4.04g,\;10.01{\pm}1.60g$) 3) The plasma concentration of IGF- l and total protein in rhIGF- I treated group were $58.17{\pm}1.69ng/ml$, $3.75{\pm}0.62g/dl$ respectively compared with control group $45.70{\pm}1.64ng/ml$, $2.32{\pm}0.53g/dl$. The results suggest that exogenous rhIGF- I increased total body weight, liver and kidney weights in broiler chicken, and it may increase IGF- I and total protein concentration in serum.

• 한국가금학회지
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• 제45권2호
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• pp.81-88
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• 2018

본 연구에서는 농산부산물의 사료첨가 급여가 육계의 생산성과 혈액성상에 미치는 효과를 메타분석이라는 통계적 방법을 이용하여 조사하였다. 본 분석에 사용된 연구논문들은 모두 대한민국에 소재한 일반 상업 육계농가에서 사양시험을 수행하였고, 농산부산물의 사료첨가 급여 효과를 조사하였다. 총 11개의 연구논문에서 32개의 실험들을 메타분석에 이용하였다. 사양 단계는 총 사육일수를 기준으로 두 단계로 구분하였고, 생산성으로는 체중, 증체량, 사료섭취량 그리고 사료요구율을 평가하였다. 그리고 도체중, 도체율, 간장 및 비장 무게에 대한 효과를 평가하였다. 혈액성상으로는 혈중 포도당, 콜레스테롤, 중성지방, 고밀도지방단백 및 저밀도 지방단백함량에 대한 효과를 조사하였다. 농산부산물의 사료첨가 급여는 육계의 출하체중을 유의적으로 증가시키는 결과를 나타내었다. 사료요구율도 농산부산물을 사료첨가하여 급여한 처리구에서 유의적으로 낮게 나타났다. 즉, 농산부산물의 사료첨가급여는 육계 생산성을 개선할 수 있는 가능성이 존재함을 확인할 수 있었다. 도체중, 도체율, 간장 및 비장 무게에서는 유의적인 처리효과를 관찰할 수 없었으나, 복강지방은 농산부산물 급여 처리에 의해 유의적으로 감소하는 것을 확인하였다. 혈액성상에 있어서는 총 콜레스테롤 함량 및 중성지방 수치가 처리효과에 의해 유의적으로 감소하였고, 고밀도지방단백은 유의적으로 증가하였다. 일련의 결과를 통하여 농산부산물의 사료첨가 급여는 육계의 혈액성상 개선과 복강내 지방 침착 억제를 통한 생산성 개선의 효과를 갖는 것을 알 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권9호
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• pp.1313-1319
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• 2013

This study investigated the effects of low levels of water-soluble pentosans (WSP), alkaline-extractable pentosans (AEP), and xylanase on the growth and organ development of broiler chicks. Three hundred and fifty 1-d-old female broiler chicks were randomly allocated into seven experimental groups of five pen replicates, with ten chicks per replicate. The control group consumed a corn-soybean meal-based diet. Six dietary treatment groups consumed the basal diet supplemented with one of the following: WSP at 50 mg/kg (WSP50) or 100 mg/kg (WSP100); AEP at 50 mg/kg (AEP50) or 100 mg/kg (AEP100); or xylanase at 3 mg/kg (Xase3) or 6 mg/kg (Xase6). Data including the body weight, digestive organ weights, gut length, rectal digesta viscosity, and gut microflora and pH were collected on d 5, 10, and 15. When compared to the control group, WSP50 promoted body weight gain and organ growth throughout the study, calculated as 3-d averages (p<0.05). WSP100 increased weight gain and enhanced organ development (proventriculus, gizzard, and gut) on d 10 (p<0.05), but the 3-d averages were not different from the control group except for the weight of gizzard. Both Xase3 and Xase6 increased the 3-d average weight gain and the growth of the gizzard (p<0.05). WSP50 increased the digesta viscosity compared to Xase3 on d 10 and 15 (p<0.05). WSP50, Xase3, and Xase6 increased the concentration of Lactobacillus in the rectum when compared to the control group (p<0.05), but only Xase3 lowered the digesta pH in the ileum and cecum on d 10 and 15. AEP had minimal influence on the growth and organ development of broilers. The results showed that low levels of WSP, AEP, and xylanase had different effects and underlying mechanisms on the growth and organ development of broiler chicks. WSP50 could increase the growth performance of broilers fed a corn-soybean meal-based diet.

• Asian-Australasian Journal of Animal Sciences
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• 제21권3호
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• pp.414-419
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• 2008

A feeding trial was conducted to investigate the effects of the addition of corn distiller's dried grains with solubles (DDGS) to broiler diets on growth performance and meat characteristics. A total of 3,200 d-old, unsexed Cobb-500 broiler chicks were randomly allotted to 16 pens (replicates), with 200 chicks per pen. There were four diet treatments (0, 5, 10, and 15% DDGS), and four replicates per treatment. From 8 to 21 d of age, the birds were fed broiler starter diets containing similar energy (TMEn 3,100 kcal/kg) and protein (21.6%) contents. From 22 to 35 d of age, they were fed grower diets containing similar nutrients (3,150 kcal/kg, 19.5% crude protein). No significant difference was found in growth performances among the four treatments. As the DDGS level increased, the concentration of unsaturated fatty acids in meat increased (p<0.05). The color scores of breast and thigh muscles were not significantly influenced by DDGS, however, the yellowness of shank increased significantly by the addition of DDGS. The hardness of breast and thigh meats was not affected by the addition of DDGS. It was shown that the use of DDGS in broiler diets up to 15% could decrease the feed cost by replacing part of corn and soybean meal, without any negative effect on growth performance and meat qualities.

• Asian-Australasian Journal of Animal Sciences
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• 제24권2호
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• pp.258-263
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• 2011

This experiment was conducted to evaluate the effects of dietary wild-ginseng adventitious root meal (WGM) on growth performance, blood profiles, relative organ weight and meat quality of broiler chickens. A total of 480, 2-day-old male broiler chicks (BW = $42.8{\pm}1.38\;g$) were randomly allocated to 1 of 4 dietary treatments (6 cages with 20 broilers per cage). Dietary treatments were: i) CON (basal diet), ii) WGM0.1 (basal diet+0.1% WGM), iii) WGM0.2 (basal diet+0.2% WGM) and iv) WGM0.3 (basal diet+ 0.3% WGM). Birds fed WGM0.3 diet (p<0.05) had a higher feed intake (FI) than those fed the CON diet during weeks 1 to 3. During weeks 3 to 5, dietary WGM0.1 treatment led to a higher (p<0.05) BW gain (BWG) and feed intake (FI) compared with the CON and WGM0.3 treatments. Overall, birds fed WGM0.1 improved BWG and FI compared with those fed the CON treatment. A greater lymphocyte count was observed (p<0.05) in WGM0.2 and WGM0.3 treatments compared with the CON treatment; dietary WGM decreased (p<0.05) the total cholesterol concentration compared with the CON group. The inclusion of WGM increased the relative weight of spleen and bursa of fabricius (p<0.05) compared with CON, while less abdominal fat was observed in the WGM0.3 treatment (p<0.05) compared with CON. The 2-thiobarbituric acid reactive substances (TBARS) of breast muscle were decreased (p<0.05) by WGM supplementation. Overall, our results indicated that the use of WGM at the 0.1% level could enhance growth performance in broilers. The supplementation of WGM could induce a decreased TBARS, abdominal fat and serum cholesterol in broiler chickens.