• 한국가금학회지
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• 제48권2호
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• pp.59-67
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• 2021

This study investigated the morphological features, growth, and meat yield performance of Pekin (P), Nageswari (N), and their reciprocal F₁ crossbreds (P♂×N♀ and N♂×P♀). A total of 301-day-old ducklings were reared in four different pens up to 20 weeks of age under intensive management conditions. Feeding and management practices were similar for all individuals throughout the experimental period. The morphology and plumage pattern of F₁ crossbreds were similar to those of indigenous Nageswari ducks because of the dominant inheritance of the extended Black allele (E locus). Genotype had significant differences (P<0.05) among the four genotypes in morphometric measurements, except wing and shank length. Growth performance was highly significant among the four genotypes (P<0.001) from one-day to 12 weeks of age. The average live weights of P, N, P♂×N♀ and N♂×P♀ crossbred genotypes at 12 weeks of age were 2038.35±29.74, 1542.44±33.61, 1851.85±28.59 and 1691.08±27.80 g, respectively. Meat yield parameters varied significantly (P<0.05) among the different genotypes for all studied traits, except for liver and gizzard weight. Moreover, no significant differences (P>0.05) were observed between P and P♂×N♀ crossbred for important meat yield traits such as hot carcass weight, dressing%, back half weight, drumstick with thigh weight and breast meat weight. Remarkably, the P♂×N♀ crossbreed possesses 50% native inheritance, which contributes to better adaptation in a hot-humid environment. Our results revealed that the P♂×N♀ genotype could be suitable for higher meat production with better adaptability in the agro-climatic conditions of Bangladesh.

• Asian-Australasian Journal of Animal Sciences
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• 제16권9호
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• pp.1247-1253
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• 2003

Selection for increased milk production in dairy cows has often resulted in a higher incidence of disease and thus incurred a greater health costs. Considerable interests have been shown in breeding dairy cattle for disease resistance in recent years. This paper discusses the limitations of breeding dairy cattle for genetic resistance in six parts: 1) complexity of disease resistance, 2) difficulty in estimating genetic parameters for planning breeding programs against disease, 3) undesirable relationship between production traits and disease, 4) disease as affected by recessive genes, 5) new mutation of the pathogens, and 6) variable environmental factors. The hidden problems of estimating genetic and phenotypic parameters involving disease incidence were examined in terms of categorical nature, non-independence, heterogeneity of error variance, non-randomness, and automatic relationship between disease and production traits. In light of these limitations, the prospect for increasing genetic resistance by conventional breeding methods would not be so bright as we like. Since the phenomenon of disease is the result of a joint interaction among host genotype, pathogen genotype and environment, it becomes essential to adopt an integrated approach of increasing genetic resistance of the host animals, manipulating the pathogen genotypes, developing effective vaccines and drugs, and improving the environmental conditions. The advances in DNA-based technology show considerable promise in directly manipulating host and pathogen genomes for genetic resistance and producing vaccines and drugs for prevention and medication to promote the wellbeing of the animals.

• 한국가금학회지
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• 제32권4호
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• pp.231-237
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• 2005

본 연구는 축산연구소에서 1995년부터 2001년까지 7세대에 걸쳐 능력 검정된 11,583수에 대한 자료를 이용하여 한국 재래 닭에 대한 경제형질의 육종가를 추정한 바 그 결과를 요약하면 다음과 같다. 육종가의 추정치는 적갈색, 황갈색, 회갈색, 흑색 및 백색계통의 150일령 체중에서 각각 $-16.563\~-0.474,\;-14.714\~9.272,\;-25.186\~12.953,\;-15.549\~6.329$ 및 $-10.708\~20.284g$이었고, 270일령 체중에서 각각 $-18.836\~21.700,\;-23.025\~11.297,\;-28.368\~18.156,\;-18.264\~14.963$ 및 $-25.112\~10.132g$이었다. 산란능력의 육종가 추정치는 적갈색, 황갈색, 회갈색, 흑색 및 백색 계통의 시산일령에서 각각 $-1.236\~0.047,\;-1.509\~0.298, \;-1.362\~0.114,\;-1.435\~0.199$ 및 $-1.385\~0.718$ 일 이었고, 시산난중은 각각 $-0.105\~0.075,\;0.109\~0.042,\;-0.166\~0.084,\;-0.l19\~0.066$ 및 $-0.l12\~0.0279$ 이었고, 270일령 난중은 각각 $-0.120\~0.398,\; -0.205\~0.173,\;-0.256\~0.091,\;-0.051\~0.132$ 및 $-0.070\~0.101g$ 이었으며, 270일령 산란수는 각각 $0.298\~1.807,\;-0.049\~l.146,\;-0.396\~l.125,\;-1.205\~1.173$ 및 $-0.474\~2.641$개 이었다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권9호
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• pp.1430-1438
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• 2019

Objective: This experiment was designed to determine the effects of coated cysteamine hydrochloride (CC) on muscle fiber characteristics, amino acid composition and transporters gene expression in the longissimus dorsi muscle (LDM) of finishing pigs. Methods: Two hundred and sixteen Duroc/Landrace/Yorkshire cross-bred male finishing pigs were fed with a corn-soybean basal diet supplemented with 0, 70, and 140 mg/kg cysteamine. Each group contained eight replicates of nine pigs per replicate. After 29 days, one pig was randomly selected from each replicate and slaughtered. Blood and LDM samples were collected and analyzed. Results: The results showed that supplemental dietary CC increased (p<0.05) the muscle fiber density. And CC supplementation also up-regulated (p<0.05) the expression of myosin heavy chain 1 (MyHC1) and MyHC2x mRNA levels, and down-regulated (p<0.05) MyHC2b expression in the LDM. Additionally, supplemental dietary CC reduced (p<0.05) the concentration of total cholesterol in the plasma and enhanced (p<0.05) the concentrations of essential amino acid and total amino acid in the LDM. The relative expression levels of chloramphenicol acetyltransferase 2, $b^{0,+}$ amino acid transporter, and $y^+$-L-type amino acid transporter 1 were upregulated (p<0.05) in the LDM when pigs were fed with the dietary CC of 70 mg/kg. Conclusion: Cysteamine supplementation could increase fiber density and distribution of fiber types. It also improved the deposition of protein in the LDM by up-regulated the expression of amino acid transporters.

• 한국육종학회지
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• 제40권2호
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• pp.106-112
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• 2008

International conferences to block the spread of Avian bird flu occurred in Beijing, 2006 and others warned of the seriousness of the H5N1 strain. The meetings succeeded in generating billions of dollars from USA, EU and World Bank. Migratory birds seem to play a major role in the spread of the aggressive strain globally from Asia to Europe and Africa. Experiences of tolerance breeding of maize (Zea mays L.) for four decades against 20 biotic stresses suggest that the prime cause of the occurrence of H5N1 strain was due to the human beings' counter-efforts against nature. Excessive use of chemicals (spray and injection) in the commercial poultry farms had created high selection pressure on virus. The new strain had mutated for survival. Attempting to eliminate the virus by chemicals for 100% control is a dangerous way to control biotic stresses. This can create more aggressive strains. A solution would be to build up tolerability of the commercial animals against the virus. Improvement of poultry cage environments and respect for nature must be integrated. Potential foes must be watched.

• 한국가금학회지
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• 제23권3호
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• pp.153-160
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• 1996

Though pheasants (Korean ring-necked pheasant) have been raised for several decades, their behavior and wild nature are far from domestication. The pheasant is a seasonal breeding species and lays a limited number of eggs in a breeding season. The growth rate and feed efficiency of pheasants are very low as compaired with those of chicken for meat purpose. In addition, the breeder's access to one's herd for care is not easy. From these reasons, pheasants seem to be unsuitable for meat production in a large flock at present. However, pheasant raising is expected to increase slowly in accordance with rising demand for special poultry meat. Therefore, it is necessary to improve techniques about raising, feeding and rnanagement, so that the consumer price of pheasant meat can be lowered down reasonably.

• 오리마을
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• 통권70호
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• pp.50-51
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• 2009

The duck meat market has grown significantly in recent years and is likely to continue with genetic and husbandry advances, making duck increasingly competitive to other poultry and meat products. Duck meat currently represents less than 10% of total poultry meat production and is largely concentrated in China and southern Asia.

• Animal Bioscience
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• 제37권8호
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• pp.1345-1354
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• 2024

Objective: The objective of this study was to identify candidate genes that play important roles in skeletal muscle development in ducks. Methods: In this study, we investigated the transcriptional sequencing of embryonic pectoral muscles from two specialized lines: Liancheng white ducks (female) and Cherry valley ducks (male) hybrid Line A (LCA) and Line C (LCC) ducks. In addition, prediction of target genes for the differentially expressed mRNAs was conducted and the enriched gene ontology (GO) terms and Kyoto encyclopedia of genes and genomes signaling pathways were further analyzed. Finally, a protein-to-protein interaction network was analyzed by using the target genes to gain insights into their potential functional association. Results: A total of 1,428 differentially expressed genes (DEGs) with 762 being up-regulated genes and 666 being down-regulated genes in pectoral muscle of LCA and LCC ducks identified by RNA-seq (p<0.05). Meanwhile, 23 GO terms in the down-regulated genes and 75 GO terms in up-regulated genes were significantly enriched (p<0.05). Furthermore, the top 5 most enriched pathways were ECM-receptor interaction, fatty acid degradation, pyruvate degradation, PPAR signaling pathway, and glycolysis/gluconeogenesis. Finally, the candidate genes including integrin b3 (Itgb3), pyruvate kinase M1/2 (Pkm), insulin-like growth factor 1 (Igf1), glucose-6-phosphate isomerase (Gpi), GABA type A receptor-associated protein-like 1 (Gabarapl1), and thyroid hormone receptor beta (Thrb) showed the most expression difference, and then were selected to verification by quantitative real-time polymerase chain reaction (qRT-PCR). The result of qRT-PCR was consistent with that of transcriptome sequencing. Conclusion: This study provided information of molecular mechanisms underlying the developmental differences in skeletal muscles between specialized duck lines.

• 한국가금학회지
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• 제51권2호
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• pp.27-37
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• 2024

The poultry plays a crucial role in the animal industry, providing humans with efficient, high-quality animal protein. The rapid growth and short generational intervals of broilers offer significant benefits compared to other economic animals. This growth and increased muscle mass in modern commercial broilers result from advancements in breeding. However, the high productivity of contemporary broilers indicates they are approaching their physiological limits, with excessive fat accumulation becoming a significant industry issue. This not only reduces lean meat yield and feed efficiency but also negatively impacts consumers, especially due to problematic abdominal fat, which consumes more energy than lean meat production. Laying hens, reared for extended periods, maintain high productivity, producing a substantial number of eggs. This productivity in laying hens, akin to broilers, stems from genetic selection and breeding. For egg production, laying hens require physiological support for necessary nutrients. In this context, yolk fat accumulation is a critical physiological process. Lipoproteins, essential in avian lipid metabolism, are vital for yolk and body fat accumulation. Understanding these lipoproteins and their metabolism is key to developing healthier, more productive animals, offering economic benefits to farmers and improved nutritional quality to consumers. This review focuses on the physiological aspects of dietary fat transport, fatty acid biosynthesis in the liver, fat accumulation in the abdomen and muscles, and lipid deposition in egg yolks in chickens. It also highlights recent research trends in the regulation of fat metabolism in poultry.

• 한국가금학회지
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• 제40권3호
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• pp.223-234
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• 2013

Poultry industry is abounding day by day as it engrosses less cost of investment per bird as compared to large animals. Poultry have the most copious genomic tool box amongst domestic animals for the detection of quantitative trait loci (QTL) and marker assisted selection (MAS). Use of multiple markers and least square techniques for mapping of QTL affecting quality and production traits in poultry is in vogue. Examples of genetic tests that are available to or used in industry programs are documented and classified into causative mutations (direct markers), linked markers in population-wide linkage disequilibrium (LD) with the QTL (LD markers), and linked markers in population wide equilibrium with the QTL (LE markers). Development of genome-wide SNP assays, role of 42 K, 60 K (Illumina) and 600 K (Affymetrix$^{(R)}$ Axim$^{(R)}$) SNP chip with next generation sequencing for identification of single nucleotide polymorphism (SNP) has been documented. Hybridization based, PCR based, DNA chip and sequencing based are the major segments of DNA markers which help in conducting of MAS in poultry. Economic index-marker assisted selection (EI-MAS) provides platform for simultaneous selection for production traits while giving due weightage to their marginal economic values by calculating predicted breeding value, using information on DNA markers which are normally associated with relevant QTL. Understanding of linkage equilibrium, linkage dis-equilibrium, relation between the markers and gene of interest are quite important for success of MAS. This kind of selection is the most useful tool in enhancing disease resistance by identifying candidate genes to improve the immune response. The application of marker assisted selection in selection procedures would help in improvement of economic traits in poultry.