Interplay between heritability, genetic correlation and economic weighting in a selection index with and without genomic information. (30th August 2013)

• Record Type: Journal Article
• Authors: Haberland, A.M.; Pimentel, E.C.G.; Ytournel, F.; Erbe, M.; Simianer, H.
• Is Part Of: Journal of animal breeding and genetics. Volume 130:Number 6(2013:Dec.)
• Page Start: 456
• Page End: 467
• Publication Date: 2013-08-30
• Subjects: Livestock -- Breeding -- Periodicals; Livestock -- Genetics -- Periodicals; 636.0820
• DOI: 10.1111/jbg.12051
• Languages: English
• ISSNs: 0931-2668

Abstract

<abstract abstract-type="main" id="jbg12051-abs-0001"> <title>Summary</title> <p>The availability of genomic information demands proper evaluation on how the kind (phenotypic versus genomic) and the amount of information influences the interplay of heritability (<italic>h</italic><sup>2</sup>), genetic correlation (<alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg3x90pp69" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:09312668:media:jbg12051:jbg12051-math-0001" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mi>r</mml:mi></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>G</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mi>G</mml:mi></mml:mrow><mml:mrow><mml:mi>j</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:msub></mml:mrow></mml:math></alternatives>) and economic weighting of traits with regard to the standard deviation of the index (<italic>σ</italic><sub>I</sub>). As <italic>σ</italic><sub>I</sub> is directly proportional to response to selection, it was the chosen parameter for comparing the indices. Three selection indices incorporating conventional and genomic information for a two trait (<italic>i</italic> and <italic>j</italic>) breeding goal were compared. Information sources were chosen corresponding to pig breeding applications. Index I incorporating an own performance in trait <italic>j</italic> served as reference scenario. In index II, additional information in both traits was contributed by a varying number of full‐sibs (2, 7, 50). In index III, the conventional own performance in trait <italic>j</italic> was combined with genomic information for both traits. The number of animals in the reference population (<italic>N</italic><sub>P</sub> = 1000, 5000, 10 000) and thus the accuracy of GBVs were varied. With more information included in the index, <italic>σ</italic><sub>I</sub> became more independent of <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg3x90pp7v" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:09312668:media:jbg12051:jbg12051-math-0002" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mi>r</mml:mi></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>G</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mi>G</mml:mi></mml:mrow><mml:mrow><mml:mi>j</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:msub></mml:mrow></mml:math></alternatives>, <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg3x90pp1j" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:09312668:media:jbg12051:jbg12051-math-0003" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mrow><mml:mi>h</mml:mi></mml:mrow><mml:mrow><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msubsup></mml:mrow></mml:math></alternatives> and relative economic weighting. This applied for index II (more full‐sibs) and for index III (more accurate GBVs). Standard deviations of index II with seven full‐sibs and index III with <italic>N</italic><sub>P</sub> = 1000 were similar when both traits had the same heritability. If the heritability of trait <italic>j</italic> was reduced (<alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg3x90pp3n" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:09312668:media:jbg12051:jbg12051-math-0004" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mrow><mml:mi>h</mml:mi></mml:mrow><mml:mrow><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msubsup></mml:mrow></mml:math></alternatives> = 0.1), <italic>σ</italic><sub>I</sub> of index III with <italic>N</italic><sub>P</sub> = 1000 was clearly higher than for index II with seven full‐sibs. When enhancing the relative economic weight of trait <italic>j</italic>, the decrease in <italic>σ</italic><sub>I</sub> of the conventional full‐sib index was much stronger than for index III. Our results imply that <italic>N</italic><sub>P</sub> = 1000 can be considered a minimum size for a reference population in pig breeding. These conclusions also hold for comparing the accuracies of the indices.</p> </abstract>