• Title, Summary, Keyword: Breeding

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Entering and Exiting Routes of Hynobius leechii to a Breeding Site and Staying Time within the Site

  • Sung, Ha-Cheol;Lee, Jung-Hyun;Park, Dae-Sik
    • The Korean Journal of Ecology
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    • v.28 no.5
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    • pp.237-243
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    • 2005
  • To study entering and exiting routes of male and female Hynobius leechii to a breeding site and staying time of them within the breeding site, we monitored a breeding population located in the research forests of Kangwon National University. The breeding site was surrounded by a drift fence associated with nine pitfall traps. The breeding season of this population was about one month, from 16 March to 13 April, 2005. Breeding males arrived earlier at the breeding pond than females did. The operational sex ratio (OSR), defined as the ratio of males to females which are ready to mate, over a breeding season was female-biased as 0.67 male vs 1 female (57 males vs 87 females), but daily OSRs, OSR in a particular day, within the breeding pond were male-biased with $1.36\sim7.5$ male vs f female in six days out of seven investigated days. While breeding males stayed in the breeding pond for about 11 days, breeding females left the pond as soon as they completed oviposition. However, the females stayed at terrestrial areas near the pond for about seven days before completely leaving the breeding site. Entering and exiting routes to the breeding site were different between males and females, and between ovulated and oviposited females. Both males and females arrived earlier at the breeding site stayed longer within the site. Males stayed longer within the breeding site lost more body weight.

Present and Future of Hot Pepper Genomics

  • Kang, Byeong-Cheorl;Nahm, Seok Hyeon;Huh, Jin-Hoe;Yu, Hyun-Sook;Kim, Minwoo;Yoo, Eun Young;Lee, Je Min;Kim, Yong Min;Kim, Shinje;Kim, Byung-Dong
    • The Korea Genome Conference
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    • pp.38.2-38.2
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    • 2002
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Estimation of L-threonine requirements for Longyan laying ducks

  • Fouad, A.M.;Zhang, H.X.;Chen, W.;Xia, W.G.;Ruan, D.;Wang, S.;Zheng, C.T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.2
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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.

In Vitro Evaluation of Swine-Derived Lactobacillus reuteri: Probiotic Properties and Effects on Intestinal Porcine Epithelial Cells Challenged with Enterotoxigenic Escherichia coli K88

  • Wan, Zhilin;Wang, Li;Chen, Zhuang;Ma, Xianyong;Yang, Xuefen;Zhang, Jian;Jiang, Zongyong
    • Journal of Microbiology and Biotechnology
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    • v.26 no.6
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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.

Chicken Breeding with Local Breeds in China - A Review

  • Jiang, X.;Groen, A.F.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.10
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    • pp.1482-1498
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    • 2000
  • This paper reviews the meat-type chicken breeding with local breeds in China. The quality chickens are defined as purebred final products of local breeds, and semi-quality chickens as crossbreds of local breeds with specialized broiler (sire or dam) lines from western breeding organizations. The present status of the chicken production and the market in China, in comparison with the western countries, is reviewed, indicating that there is large market demand for (semi-) quality chickens in the present and future China. Breeding for (semi-) quality chickens emphasizes the sensory quality of chicken meat. The present status of breeding for (semi-) quality chickens with the local breeds is illustrated, including breeding goals and the existing breeding programs. The potential role of local breeds in breeding programs in China is discussed in relation to both providing higher quality (than commercial hybrid broilers) of chicken meat for the local market and meeting the objectives of genetic resource conservation. Besides, further research topics on breeding for (semi-) quality chickens are suggested.

An Economic Effect of the selective breeding program on the Oliver flounder Aquaculture (넙치양식 선발육종사업의 경제효과)

  • Hwang, Jin-Wook;Myeong, Jeong-In
    • The Journal of Fisheries Business Administration
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    • v.41 no.1
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    • pp.113-128
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    • 2010
  • This study is aimed to analyze the economic feasibility of the selective breeding program on the Oliver flounder aquaculture. First of all, in order to evaluate this program, we review the concept and research trend on the selective breeding. The objective of this research is the selective breeding program on the Oliver flounder aquaculture in the Genetics and Breeding Research Center, NFRDI. It was conducted to investigated economic effects of three factors of the selective breeding program on the Oliver flounder aquaculture such as fast growth, disease resistance and increase exports. The results of economic analysis of the selective breeding program on the Oliver flounder aquaculture are as follows; First, there were the significant meaning of the economic effects on the technology of the selective breeding program by fast growth, disease resistance and increase exports. Second, we analyzed in the economic feasibility of the selective breeding program on the Oliver flounder aquaculture from 2004 to 2020, internal rate of return(IRR) was 419%, a benefit-cost ratio was shown to be 24.92, net present value(NPV) was 989,942,464 thousand won, which indicates the economic feasibility of the selective breeding program is very high. Finally, in order to improve the economic feasibility, there is need to be focused on the efficient the selective breeding program on the Oliver flounder aquaculture.

New Strategy of Forest Tree Breeding for Society, Forest Science, and Forestry in Korea

  • Choi, Yong-Eui;Kim, Chul-Woo;Yi, Jae-Seon
    • Journal of Forest and Environmental Science
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    • v.24 no.1
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    • pp.15-25
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    • 2008
  • Social and scientific changes, i.e., global warming, desertification, pollution, biodiversity, bioenergy, plant variety protection, biotechnology, timber demand, reforestation in North Korea, and etc., were reviewed for new strategy of forest tree breeding in Korea. Diversified breeding goals, globalization of breeding target species, multidisciplinary research approaches, manpower networking, establishment of new administrative and research units in KFS and KFRI were proposed. Principles suggested for new tree breeding strategy are: 1) multi-disciplinary approach in settlement of objectives, breeding methods, and etc., 2) expansion of target trees including foreign species, 3) fulfillment of both domestic and international demands for forest tree breeding, 4) establishment of breeding program well-grounded on genetic resources conservation, 5) acknowledgement of breeding products (i.e., variety, technique, gene, and etc.) as goods, and 6) provision of more research opportunities for young scientists. Lastly, ongoing tree breeding project in Indonesia and NTFP R&D Center at the College of Forest and Environmental Sciences, Kangwon National University were introduced as examples of desirable breeding projects based on target species diversification, multidisciplinary approach, and manpower networking.

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