• 한국가금학회지
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• 제22권1호
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• pp.15-31
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• 1995

This study was carried out to develop a computer software system for poultry breeding by using microcomputer(PC). Through this study, SPPB(Statistical Package for Poultry Breeding) was designed and developed, which can help poultry breeder collect and analyse the chick records. A main feature of the system was the application of user-oriented procedure, for example, choice of the flock file, selection of the family size and the desired traits. Creation of the data files and the breeding files. calculation of the elementary statistics, estimation of the heritability and the genetic and phenotypic correlation coefficients can be obtained by user's choice of the sire and dam family size. Also, it is possible to estimate the various selection indices through this system. Easiness of using this system and the flexibility of the file management could help increasing the efficiency of related practical poultry breeding jobs. Correctness and relationships between the unit programs in the system were proved through the run-test of the SPPB using sample data. Because it wasn't able to collect breeding records at the commercial breeding farm, effectiveness of the system was not proved totally. Also. it will be necessary to develop the integrated software system which make possible to computerize the general works at breeding farm and the genetic analyses of the records from chick breeders.

• Asian-Australasian Journal of Animal Sciences
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• 제30권2호
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• pp.206-210
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• 2017

Objective: A study was conducted to test six threonine (Thr) levels (0.39%, 0.44%, 0.49%, 0.54%, 0.59%, and 0.64%) to estimate the optimal dietary Thr requirements for Longyan laying ducks from 17 to 45 wk of age. Methods: Nine hundred Longyan ducks aged 17 wk were assigned randomly to the six dietary treatments, where each treatment comprised six replicate pens with 25 ducks per pen. Results: Increasing the Thr level enhanced egg production, egg weight, egg mass, and the feed conversion ratio (FCR) (linearly or quadratically; p<0.05). The Haugh unit score, yolk color, albumen height, and the weight, percentage, thickness, and breaking strength of the eggshell did not response to increases in the Thr levels, but the albumen weight and its proportion increased significantly (p<0.05), whereas the yolk weight and its proportion decreased significantly as the Thr levels increased. Conclusion: According to a regression model, the optimal Thr requirement for egg production, egg mass, and FCR in Longyan ducks is 0.57%, while 0.58% is the optimal level for egg weight from 17 to 45 wk of age.

• Animal Bioscience
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• 제36권6호
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• pp.899-907
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• 2023

Objective: The better understanding of laying pattern of birds is crucial for developing breed-specific proper breeding scheme and management. Methods: Daily egg production until 50 wk of age of six chicken breeds including one layer (White Leghorn, WL), three dual-purpose (Rhode Island Red, RIR; Columbian Plymouth Rock, CR; and Barred Plymouth Rock, BR), one synthetic dwarf (DY), and one indigenous (Beijing-You Chicken, BYC) were used to characterize their clutch traits and egg production. The age at first egg, egg number, average and maximum clutch length, pause length, and number of clutches and pauses were calculated accordingly. Results: The egg number and average clutch length in WL, RIR, CR, and BR were higher than those in DY and BYC (p<0.01). The numbers of clutches and pauses, and pause length in WL, RIR, CR, and BR were lower than those in DY and BYC (p<0.01). The coefficient variations of clutch length in WL, RIR, CR, and BR (57.66%, 66.49%, 64.22%, and 55.35%, respectively) were higher than DY (41.84%) and BYC (36.29%), while the coefficient variations of egg number in WL, RIR, CR, and BR (9.10%, 9.97%, 10.82%, and 9.92%) were lower than DY (15.84%) and BYC (16.85%). The clutch length was positively correlated with egg number (r = 0.51 to 0.66; p<0.01), but not correlated with age at first egg in all breeds. Conclusion: The six breeds showed significant different clutch and egg production traits. Due to the selection history, the high and median productive layer breeds had higher clutch length than those of the less productive indigenous BYC. The clutch length is a proper selection criterion for further progress in egg production. The age at first egg, which is independent of clutch traits, is especially encouraged to be improved by selection in the BYC breed.

• 한국가금학회지
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• 제22권2호
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• pp.97-104
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• 1995

Recently, DNA fingerprinting has been utilized as the most powerful tool for genetic analysis and improvement of poultry. This technique enables us to solve several problems of poultry breeding ; traits of low heritability, difficulty in keeping the performance records, measuring in late of life, and sex limited traits. Application of DNA fingerprinting is chiefly focused to individual and population identification, evolution force, quantitative trait marker, introgression of new gene, and prediction of heterosis. Thus, research work on DNA fingerprinting will he accelerated to analyze genetic components exactly and improve the performance of poultry.

• Asian-Australasian Journal of Animal Sciences
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• 제12권1호
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• pp.1-4
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• 1999

Beijing White Chickens laying larger eggs and smaller eggs were respectively used as parental individuals for mating to produce the F1 progeny and then the F1 progeny individuals mated to produce 125 individuals of the F2 progeny. Three bands associated with the egg weight performance were identified from DNA fingerprints of the 125 individuals generated with a bovine minisatellite probe BM6.5B. The simple linear correlation analysis showed that the coefficients of correlation between frequencies of the three bands (DB1, DB2 and DB3) and egg weights were -0.6, -0.6 and 0.9, respectively.

• Journal of Microbiology and Biotechnology
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• 제26권6호
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• pp.1018-1025
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• 2016

Probiotics are considered as the best effective alternatives to antibiotics. The aim of this study was to characterize the probiotic potential of lactobacilli for use in swine farming by using in vitro evaluation methods. A total of 106 lactic acid bacterial isolates, originating from porcine feces, were first screened for the capacity to survive stresses considered important for putative probiotic strains. Sixteen isolates showed notable acid and bile resistance, antibacterial activity, and adherence to intestinal porcine epithelial cells (IPEC-1). One isolate, LR1, identified as Lactobacillus reuteri, was selected for extensive study of its probiotic and functional properties in IPEC-1 cell models. L. reuteri LR1 exhibited good adhesion to IPEC-1 cells and could inhibit the adhesion of enterotoxigenic Escherichia coli (ETEC) to IPEC-1 cells. L. reuteri LR1 could also modulate transcript and protein expression of cytokines involved in inflammation in IPEC-1 cells; the Lactobacillus strain inhibited the ETEC-induced expression of proinflammatory transcripts (IL-6 and TNF-α) and protein (IL-6), and increased the level of anti-inflammatory cytokine (IL-10). Measurement of the permeation of FD-4 showed that L. reuteri LR1 could maintain barrier integrity in monolayer IPEC-1 cells exposed to ETEC. Immunolocalization experiments showed L. reuteri LR1 could also prevent ETEC-induced tight junction ZO-1 disruption. Together, these results indicate that L. reuteri LR1 exhibits desirable probiotic properties and could be a potential probiotic for use in swine production.

• 월간양계
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• 제54권11호
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• pp.124-127
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• 2022

• Asian-Australasian Journal of Animal Sciences
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• 제26권12호
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• pp.1665-1671
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• 2013

Real-time quantitative PCR (qRT-PCR) is one of the important methods for investigating the changes in mRNA expression levels in cells and tissues. Selection of the proper reference genes is very important when calibrating the results of real-time quantitative PCR. Studies on the selection of reference genes in goat tissues are limited, despite the economic importance of their meat and dairy products. We used real-time quantitative PCR to detect the expression levels of eight reference gene candidates (18S, TBP, HMBS, YWHAZ, ACTB, HPRT1, GAPDH and EEF1A2) in ten tissues types sourced from Boer goats. The optimal reference gene combination was selected according to the results determined by geNorm, NormFinder and Bestkeeper software packages. The analyses showed that tissue is an important variability factor in genes expression stability. When all tissues were considered, 18S, TBP and HMBS is the optimal reference combination for calibrating quantitative PCR analysis of gene expression from goat tissues. Dividing data set by tissues, ACTB was the most stable in stomach, small intestine and ovary, 18S in heart and spleen, HMBS in uterus and lung, TBP in liver, HPRT1 in kidney and GAPDH in muscle. Overall, this study provided valuable information about the goat reference genes that can be used in order to perform a proper normalisation when relative quantification by qRT-PCR studies is undertaken.

• 한국가금학회지
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• 제20권3호
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• pp.161-170
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• 1993

Prospects are briefly reviewed for further advances in current poultry industry technology in the foreseeable future. It is concluded that in the most advanced industries progress should continue at a similar rate to the recent past in conventional genetics and breeding, nutrition and disease control. Significant benefits will also follow in the short-term from the application of molecular biotechnology to disease diagnosis and vaccine production. Technical advances now make it possible to produce transgenic chickens at acceptable success rates but applications of this technology to poultry breeding will not become significant till we have sufficient knowledge of the poultry genome, and especially the genes involved in production performance. For the undeveloped and less advanced industries it is argued that the level of advanced technologies to be implemented in those countries should be decided largely on market forces, informed by objective assessment of the diverse options available. The need for urgent international action on conservation of poultry genetic resources is also stressed.

• 한국가금학회지
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• 제23권2호
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• pp.77-84
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• 1996

The purpose of this paper is to introduce the present situation of broiler breeder industry, and to investigate some problems related to it in Korea. The number of broiler breeding farms were 231 in 1990. It peaked to 264 in 1992, but decreased afterward to 232 in 1995. The number of broiler parent stock were over 4 millions since 1992 except in 1993. The number of commercial chicks produced per breeding hen was around 100, which is far below to the suggested values of breeding companies. The number of hatching eggs produced per breeding hen were 168 eggs in US, 156~170 eggs in Thailand, and 160~170 eggs in China. Factors involved in the lowered performances of broiler parent stock in Korea appear to be 1) the poor isolation of breeding farms from commercial broiler farms, causing easy contamination with various diseases, 2) the failure to provide proper environment to the breeder, and 3) the failure to control body weight during laying periods.