• Asian-Australasian Journal of Animal Sciences
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• 제28권12호
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• pp.1686-1695
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• 2015

Molecular marker selection has been an acceptable tool in the acceleration of the genetic response of desired traits to improve production performance in chickens. The crossbreds from commercial parent stock (PS) broilers with four Thai synthetic breeds; Kaen Thong (KT), Khai Mook Esarn (KM), Soi Nin (SN), and Soi Pet (SP) were used to study the association among chicken growth hormones (cGH) and the insulin-like growth factor (IGF-I) genes for growth and carcass traits; for the purpose of developing a suitable terminal breeding program for Thai broilers. A total of 408 chickens of four Thai broiler lines were genotyped, using polymerase chain reaction-restriction fragment length polymorphism methods. The cGH gene was significantly associated with body weight at hatching; at 4, 6, 8, 10 weeks of age and with average daily gain (ADG); during 2 to 4, 4 to 6, 0 to 6, 0 to 8, and 0 to 10 weeks of age in $PS{\times}KM$ chickens. For $PS{\times}KT$ populations, cGH gene showed significant association with body weight at hatching, and ADG; during 8 to 10 weeks of age. The single nucleotide polymorphism variant confirmed that allele G has positive effects for body weight and ADG. Within carcass traits, cGH revealed a tentative association within the dressing percentage. For the IGF-I gene polymorphism, there were significant associations with body weight at hatching; at 2, 4, and 6 weeks of age and ADG; during 0 to 2, 4 to 6, and 0 to 6 weeks of age; in all of four Thai broiler populations. There were tentative associations of the IGF-I gene within the percentages of breast muscles and wings. Thus, cGH gene may be used as a candidate gene, to improve growth traits of Thai broilers.

• Asian-Australasian Journal of Animal Sciences
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• 제23권4호
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• pp.437-443
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• 2010

To be economically profitable, the poultry industry demands an increase in stocking density, which could adversely affect chicken welfare. The current study was performed to investigate the effect of stocking density on stress-related, heat shock protein genes (HSP70 and HSP90), 3-hydroxyl-3-methyl-glutaryl coenzyme A reductase (HMGCR) gene and telomere length in broiler chickens. Seven-day-old broiler chickens were housed at High (0.0578 $m^2$/bird), Standard (0.077 $m^2$/bird) and Low (0.116 $m^2$/bird) stocking densities with 8 replicates each until 35 d of age. The growth performance, such as body weight gain and average daily feed intake, was found to be significantly (p<0.05) higher in the Low density group, but these parameters did not show any difference between the High and Standard groups. Other growth performance, such as feed conversion ratio and final feed intake, showed no difference among the treated groups. The expression levels of HSP70 and HMGCR were found to be elevated with the increase of stocking density. The expression level of these genes was significantly (p<0.05) higher in the High density stocked group compared with the other groups, whereas the expression levels were not significantly different between the Low and Standard groups. The expression levels of HSP90 did not show any significant changes among the treated groups. The telomeric length of the birds housed in High density was reduced significantly (p<0.05) when compared to that of the birds in Low density. These results clearly indicate that birds stocked at high density show physiological adaptive changes indicative of stress at gene transcriptional and telomere levels.

• Asian-Australasian Journal of Animal Sciences
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• 제23권7호
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• pp.946-951
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• 2010

The objective of this research was to evaluate the effects of dietary supplementation of blood meal (BM) as a source of histidine, and magnesium oxide (MgO) as a catalyst of carnosine synthetase, on carnosine (L-Car) content in the chicken breast muscle (CBM), laying performance, and egg quality of spent old hens. Four hundred eighty laying hens (Hy-Line$^{(R)}$ Brown), 95wk old, were allotted randomly into five replicates of six dietary treatments: T1; 100% basal diet, T2; 100% basal diet+MgO, T3; 97.5% basal diet+2.5% BM, T4; 97.5% basal diet+2.5% BM+MgO, T5; 95% basal diet+5% BM, T6; 95% basal diet+5% BM+MgO. Magnesium oxide was added at 0.3% of diets. The layers were fed experimental diets for 5wk. There were no significant differences in the weekly L-Car content in CBM among all treatments during the total experimental period, but some of the contrast comparisions showed higher L-Car in CBM of T6. The L-Car contents linearly decreased (p<0.01 or p<0.05) as the layers got older except in T4 (p>0.05). There were significant differences in egg weight (p<0.01) and soft and broken egg ratio (p<0.05). The control (T1) was highest in egg weight and T6 was lowest in soft and broken egg ratio. Among the parameters of egg quality, there were significant differences in eggshell strength (p<0.01) and egg yolk color (p<0.05). Magnesium oxide supplementation increased the eggshell strength and BM tended to decrease egg yolk color. Eggshell color, eggshell thickness, and Haugh unit were not influenced by BM and MgO. In conclusion, BM and MgO did not significantly influence the L-Car in CBM of spent layers. The L-Car content rapidly decreased as the layers became senescent. Eggshell strength was increased by MgO supplementation.

• Asian-Australasian Journal of Animal Sciences
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• 제28권9호
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• pp.1317-1326
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• 2015

This study investigated the metabolizable energy (ME) intake, net energy of production (NEp), heat production (HP), efficiencies of ME use for energy, lipid and protein retention as well as the performance of broiler chickens fed diets based on cassava chips or pellets with or without supplementation with an enzyme product containing xylanase, amylase, protease and phytase. The two products, cassava chips and pellets, were analysed for nutrient composition prior to feed formulation. The cassava chips and pellets contained 2.2% and 2.1% crude protein; 1.2% and 1.5% crude fat; and 75.1% and 67.8% starch, respectively. Lysine and methionine were 0.077%, 0.075%, and 0.017%, 0.020% protein material, respectively, while calculated ME was 12.6 and 11.7 MJ/kg, respectively. Feed intake to day 21 was lower (p<0.01) on the diet containing cassava chips compared to diets with cassava pellets. Enzyme supplementation increased (p<0.01) feed intake on all diets. Live weight at day 21 was significantly (p<0.01) reduced on the diet based on cassava chips compared to pellets, but an improvement (p<0.01) was noticed with the enzyme supplementation. Metabolizable energy intake was reduced (p<0.01) by both cassava chips and pellets, but was increased (p<0.01) on all diets by enzyme supplementation. The NEp was higher (p<0.01) in the maize-based diets than the diets containing cassava. Enzyme supplementation improved (p<0.01) NEp in all the diets. Heat production was highest (p<0.01) on diets containing cassava pellets than on cassava chips. It is possible to use cassava pellets in diets for broiler chickens at a level close to 50% of the diet to reduce cost of production, and the nutritive value of such diets can be improved through supplementation of enzyme products containing carbohydrases, protease, and phytase.

• 한국축산식품학회지
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• 제30권5호
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• pp.730-738
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• 2010

We developed predictive growth models for Staphylococcus aureus and Bacillus cereus on various food matrices consisting primarily of ready-to-eat (RTE) foods. A cocktail of three S. aureus strains, producing enterotoxins A, C, and D, or a B. cereus strain, were inoculated on sliced bread, cooked rice, boiled Chinese noodles, boiled bean sprouts, tofu, baked fish, smoked chicken, and baked hamburger patties at an initial concentration of 3 log CFU/g and stored at 8, 10, 13, 17, 24, and $30^{\circ}C$. Growth kinetic parameters were determined by the Gompertz equation. The square-root and Davey models were used to determine specific growth rate and lag time values, respectively, as a function of temperature. Model performance was evaluated based on bias and accuracy factors. S. aureus and B. cereus growth were most delayed on sliced bread. Overall, S. aureus growth was significantly (p<0.05) more rapid on animal protein foods than carbohydrate-based foods and vegetable protein foods. The fastest growth of S. aureus was observed on smoked chicken. B. cereus growth was not observed at 8 and $10^{\circ}C$. B. cereus growth was significantly (p<0.05) more rapid on vegetable protein foods than on carbohydrate-based foods. The secondary models developed in this study showed suitable performance for predicting the growth of S. aureus and B. cereus on various food matrices consisting of RTE foods.

• 한국가금학회지
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• 제40권1호
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• pp.57-65
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• 2013

김치의 주종 유산균의 하나인 Weissella koreensis(Wk)의 육계 사료용 probiotics로서 활용 가능성을 평가하기 위하여 육계 성장능력, 영양소 이용률, 면역능력, 장내 미생물, 계육품질에 미치는 영향을 평가하였다. 무첨가 육계사료를 대조구(Control)로 설정하고, 처리구로 생균 형태의 Wk를 0.1%(LWk 0.1), 0.5%(LWk 0.5) 첨가한 구와 사균 형태의 Wk 0.5%를 첨가한 구(KWk 0.5) 등 총 4처리를 두었다. 본 연구결과, 생균 형태의 LWk 첨가는 대조구와 사균 형태의 첨가구(KWk 0.5)에 비하여 증체율과 사료 효율을 유의적으로 개선시켰다. 영양소 이용률은 처리구 간에 차이가 없었으나, 조단백질 이용률이 사균(KWk 0.5) 첨가구에서 유의적으로 낮았다. 혈청 IgG 수준과 F낭의 상대적 크기는 KWk 0.5 첨가구가 가장 높았다. 생균 형태의 Wk 첨가로 맹장 내 총 혐기성 유산균의 수가 유의적으로 높아졌으나, 대장균의 수에는 변화가 없었다. 사료 내 김치유산균의 첨가는 생균이나 사균 모두 계육 지방산 조성, 계육의 산패 지연에는 영향을 나타내지 못하였다. 그러나 생균이나 사균, 첨가수준 모두가 전자코를 통한 육향에서는 차이를 나타내었다. 본 연구는 생균 형태 Wk가 육계 사료용 생균제로 활용 가능함을 보여주었다.

• 한국가금학회지
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• 제44권2호
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• pp.123-134
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• 2017

본 연구는 국산 신품종 토종닭을 개발하기 위하여 국내 토종닭 GPS 계통들을 대상으로 $5{\times}5$이면 교배조합 시험을 실시하여 교배조합별 성적을 토대로 최적의 종계 조합을 선발하고자 하였다. 총 25개 교배조합의 암컷 1,157수를 대상으로 주요 생산능력인 생존율, 체중, 시산일령, 난중, 일계산란율 및 산란지수를 조사하고 분석하였으며, 각 조합별 형질들의 잡종강세효과도 추정하였다. 분석 결과, 성계의 평균 생존율은 순계구가 67.7%, 교잡구가 77.1%로 나타났다. 체중 측정 결과, 이들 25개 조합은 뚜렷한 3개의 그룹 즉, 9개의 고체중구, 12개의 중체중구 및 4개의 저체중구로 구분되었다. 12주령 평균 체중은 고체중구는 $1,873.8{\pm}43.0g$, 중 체중구는 $1,595.4{\pm}56.6g$, 저 체중구는 $1,152.7{\pm}24.7g$이었으며, 순계구는 $1,560.2{\pm}339.3g$, 교잡구는 $1,640.9{\pm}213.7g$이었다. 산란능력에 있어 시산일령은 순계구는 $139.7{\pm}4.9$일, 교잡구는 $135.8{\pm}5.1$일이었고, 평균 난중은 순계구에서 $52.3{\pm}1.6g$, 교잡구는 $53.0{\pm}1.6g$이었다. 20주령부터 40주령까지의 산란지수는 순계구가 $58.3{\pm}12.9$개, 교잡구는 $69.2{\pm}10.4$개였다. 잡종강세 효과 추정에 있어 전체 조합에 대한 평균 생존율은 16.9%, 12주 체중은 5.4%, 시산일령은 -2.7%, 난중은 1.3% 및 일계 산란율은 14.3%의 잡종강세율을 나타내었다. 전반적으로 생존율 및 산란형질들의 잡종강세 효과가 성장형질에 비해 높게 나타났다. 이상을 종합할 때 최적의 실용계 생산을 위하여 부계통으로는 우수한 성장능력을 가진 HF 조합구의 선정이 바람직하고, 모계통으로는 우수한 산란능력을 가진 GW 및 FW 조합구의 선정이 바람직하리라 예측된다.

• 한국가금학회지
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• 제50권3호
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• pp.133-141
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• 2023

본 연구는 산란능력이 우수한 토종 산란형 종계를 개발하기 위하여 토착 로드종(Rhode-C, -D), 토착 레그혼종(Leghorn-F, -K) 및 한국재래계 황갈색종(KNC-Y), 총 5계통을 이용하여 5 × 5 이면교배조합(diallel cross-mating) 검정시험을 실시하였다. 생산능력의 검정은 10개 교배조합 1,060수를 대상으로 생존율, 체중, 초산일령, 난중 및 산란율을 조사하고, 조합별 생산능력 및 결합능력을 분석하였다. 분석 결과, 발생 후부터 48주령까지 전체 조합의 평균 생존율은 72.1±24.0%이고, 조합 간 유의적 차이를 보이며 YC조합의 생존율이 가장 높았고, DK조합의 생존율이 가장 낮았다(P<0.01). 결합능력 분석 결과, YC조합의 일반결합능력이 가장 높게 추정되었고, YD조합은 두 계통 간 특정결합능력이 가장 높았다. 체중의 경우, 모든 측정 주령에서 조합 간 유의한 차이가 있었는데 토착 Leghorn종과의 조합 자손들이 토착 Rhode종 및 한국재래계와의 조합 자손들보다 낮은 체중을 보였다(P<0.01). 초산일령 또한 조합 간 유의한 차이를 보이며 KNC-Y와의 교잡 자손들이 토착 Rhode종과의 교잡 자손들 보다 대체로 빠른 초산을 나타내었다(P<0.01). 산란율에 있어, 평균 일계산란율은 70.7±12.0%로써, 조합 간에 유의한 차이를 보이며 이들 중 CK조합이 86%로 가장 높은 산란율을 나타내었다(P<0.01). 산란율의 일반결합능력과 특정결합능력이 조합가에 미치는 영향은 거의 비슷한 것으로 일반결합능력은 Rhode-C가 가장 우수하였고, 교배조합 간 특정결합능력은 YD조합이 가장 높게 나타났다. 시산 및 40주령 난중 모두 조합 간의 유의한 차이를 보였고(P<0.01), 토착 Rhode종과 토착 Leghorn종 간 교잡 자손의 달걀이 KNC-Y 교잡 자손들의 달걀보다 무거웠다. 이상의 결과에 따라 산란형 토종닭 종계로서 부계는 생존율이 우수하고 산란율이 양호한 YC나 YD조합이, 모계는 산란능력이 우수하며 적절한 난중을 지닌 CF와 CK조합이 가장 바람직한 조합으로 사료된다.

• 한국축산식품학회지
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• 제34권5호
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• pp.622-629
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• 2014

The present study was conducted to compare the growth performance, carcass characteristics, and meat quality of the egg-type male growing chicken (EM), white-mini broiler (WB), and commercial broiler (Ross 308, CB). A total of 360 1-d-old chicks were reared together using a completely randomized design with 4 replicates for each group under the identical feeding and rearing conditions. The ADG and gain:feed were the highest in CB, intermediate in WB, and the lowest in EM (p<0.05), and the live and carcass weights of CB and EM were significantly higher than those of WB (p<0.05). The pH of breast meat from WB and CB was significantly higher (p<0.05) than that from EM with a similar body weight. The EM had the lowest moisture (p<0.05) and the highest protein content (p<0.05), whereas the fat and ash contents were not different among groups. The mystiric acid (C14:0), palmitoleic acid (C16:1 ${\omega}7$), and oleic acid (C18:1 ${\omega}9$) levels were significantly higher in breast meat from CB (p<0.05). The monounsaturated fatty acid (MUFA) content showed the highest (p<0.05) levels in CB. In contrast, the polyunsaturated fatty acid (PUFA) contents of breast meat, including linoleic acid (C18:2 ${\omega}6$) and arachidonic acid (C20:4 ${\omega}6$), were higher (p<0.05) in EM and WB than in CB. In conclusion, the EM and WB had less growth performances in comparison with CB, but they each had some unique features (taste, flavor, and physiological characteristics) when raised under the identical rearing and feeding conditions.

• 한국가금학회지
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• 제37권4호
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• pp.323-329
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• 2010

본 시험은 육계에 엄나무 잎 분말을 첨가량에 따라 급여하여 5주간 사육한 육계의 생산성과 계육의 일반성분, 도체 특성 및 혈액 성상을 조사하였다. 실험구는 엄나무 잎 분말을 첨가 급여하지 않은 처리구를 대조구, 엄나무 잎 분말 0.5% 급여구는 T1, 엄나무 잎 분말 1% 급여구는 T2, 그리고 엄나무 잎 분말 2.0% 급여구를 T3 등 4개 처리구로 나누어 사양하였다. 육계의 생산성은 처리구간 유의적인 변화는 없었고, 폐사율은 엄나무 잎 분말 급여구에서 낮아졌으며, 엄나무 잎 급여량에 의한 차이는 없었다. 계육의 일반성분은 엄나무 잎 분말 급여구에서 조지방 함량이 증가하였고(T3), 수분, 조단백질 및 조회분은 유의성이 없었다. 도체 특성 중도체중, 도체율, 간의 무게 및 비장 무게는 처리구간에 유의성이 없었고, 복강지방은 엄나무 잎 분말의 급여량이 늘어남에 따라 증가하는 경향으로 T3에서 유의적으로 무거웠다(P<0.05). 육계의 혈액 성상 중 HDL-cholesterol과 glucose는 엄나무 급여구에서 높았고, 총 콜레스테롤과 LDL-cholesterol 및 triglyceride는 낮아지는 결과이었다(P<0.05). 이러한 경향은 엄나무 잎 분말 1% 급여구부터 나타났다. 결론적으로 엄나무 잎 분말을 1% 이상 급여하면(T2) 육계의 폐사율이 낮아지고, 총콜레스테롤, LDL-cholesterol이감소하며, HDL-cholesterol이 증가함으로 혈액 조성을 개선할 가능성이 있는 것으로 판단된다.