41,486 research outputs found

    Genetic Improvement of Weaning Weight, Yearling Weight, Body Weight Gain and Body Dimension of Bali Cattle

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    The aim of the research was to evaluate the genetic improving of production traits selected of Balicattle. Four hundred and twenty eight data of weaning weight, yearling weight and body weight gainwere used to estimate genetic improvement for those traits. One hundred and seven data of bodydimension (body weight, chest circumference, body length and withers height) at 24 months old wereused to estimate genetic improving for those traits. The estimation of genetic and environmentalvariance and co-variance component, and heritability were found by animal model. The fix effect ofweaning weight, yearling weight and body weight gain was rainfall, age of measurement and year ofbirth, whereas the fix effect of body dimension depend on each trait. The result showed that heritabilityof weaning weight, yearling weight, body weight gain, body weight, chest circumference, body lengthand withers height was 0.090.15, 0.270.13, 0.470.15, 0.070.19, 0.500.19, 0.340.28, 0.600.21,respectively. Genetic improvement of all traits have had a different pattern in selection responses. Alltraits did not show genetic improvement due to selection for

    Genetic Improvement of Livestock for Organic Farming Systems

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    Organic farming which experienced a constant rise over the last two decades is a system based on sustainability and on a concept tending towards functional integrity. Legislation as well as the wish to produce separately from conventional farming raise the question whether organic farming should be conducted completely apart from conventional farming or not. This paper discusses the aspects that affect animal breeding under these circumstances, e.g., maintaining genetic diversity by using local breeds and possible G×E interactions which might occur when breeds adapted to conventional farming systems are used in organic farming. Ways of modelling G×E are presented, moreover examples of G×E in dairy cattle, swine, and poultry are given. Trends in selection index theory–designing multi-trait breeding goals including functional traits on one hand, and developing methods for using customised selection indices on the other hand–support breeding work for organic farming systems. It is concluded that before the technical issues can be addressed, all parties involved, farmers, consumers as well as legislators, have to agree on the socio-cultural conditions under which organic farming should be conducted

    Cassava genetic improvement

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    Mango genetic improvement

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    Modelling Genetic Improvement Landscapes with Local Optima Networks

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    Local optima networks are a compact representation of the global structure of a search space. They can be used for analysis and visualisation. This paper provides one of the first analyses of program search spaces using local optima networks. These are generated by sampling the search space by recording the progress of an Iterated Local Search algorithm. Source code mutations in comparison and Boolean operators are considered. The search spaces of two small benchmark programs, the triangle and TCAS programs, are analysed and visualised. Results show a high level of neutrality, i.e. connected test-equivalent mutants. It is also generally relatively easy to find a path from a random mutant to a mutant that passes all test cases

    Mango genetic improvement

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    Genetic improvement of the herbivorous blunt snout bream (Megalobrama amblycephala)

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    Selection experiments with the herbivorous blunt snout bream or Wuchang bream (Megalobrama amblycephala) were started in 1985. Mass selection for size and length/depth ratio resulted in a significant increase in growth and better shape, while inbreeding led to a significant decrease in growth. The total selection ratio from fry to mature brooders was about 0.03 per cent per generation. In the grow out stage, the average daily body weight gains of two lines of fifth generation (F5) fish were 29 per cent and 20 per cent respectively more than the control group, with an average of 5.8 per cent and 4 per cent improvements per generation, respectively. The body was 4 per cent deeper in ratio of standard length/body depth. The effects of inbreeding were examined by crossing full-sibs, the offspring of which were kept without selection. The third generation inbred fish showed 17 per cent lower growth as compared to the control group, with an average of 7.5 per cent per generation. The results demonstrate that selection is a powerful tool to improve the economic traits of the blunt snout bream, but inbreeding can rapidly lead to a reduction in performance. In 2000, the 6th generation of selected bream was certified by the Chinese Ministry of Agriculture as a good breed for aquaculture

    From drawing board to dining table: the success story of the GIFT project

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    As compared to crops and livestock, the genetic enhancement of fish is in its infancy. While significant progress has been achieved in the genetic improvement of temperate fish such as salmonids, no efforts were made until the late 1980s for the genetic improvement of tropical finfish, which account for about 90 percent of global aquaculture production. This paper traces the history of the Genetic Improvement of Farmed Tilapia (GIFT) project initiated in 1988 by the WorldFish Center and its partners for the development of methods for genetic enhancement of tropical finfish using Nile tilapia (Oreochromis niloticus) as a test species. It also describes the impacts of the project on the adoption of these methods for other species and the dissemination of improved breeds in several countries in Asia and the Pacific.GIFT, Tilapia culture, WorldFish Center, Genetics Oreochromis Niloticus
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