SELECTION INDEX POSSIBILITIES, PITFALLS, AND POTENTIAL CHANGES Michael MacNeil, PhD Delta G Miles...
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Transcript of SELECTION INDEX POSSIBILITIES, PITFALLS, AND POTENTIAL CHANGES Michael MacNeil, PhD Delta G Miles...
![Page 1: SELECTION INDEX POSSIBILITIES, PITFALLS, AND POTENTIAL CHANGES Michael MacNeil, PhD Delta G Miles City, Montana.](https://reader036.fdocuments.in/reader036/viewer/2022082711/56649ee55503460f94bf4fd2/html5/thumbnails/1.jpg)
SELECTION INDEX
POSSIBILITIES, PITFALLS, AND POTENTIAL CHANGES
Michael MacNeil, PhDDelta GMiles City, Montana
![Page 2: SELECTION INDEX POSSIBILITIES, PITFALLS, AND POTENTIAL CHANGES Michael MacNeil, PhD Delta G Miles City, Montana.](https://reader036.fdocuments.in/reader036/viewer/2022082711/56649ee55503460f94bf4fd2/html5/thumbnails/2.jpg)
Selection Index
• Decompose problem into two parts: prediction of EPD and estimation of economic values
• Where,
• Assuming,
![Page 3: SELECTION INDEX POSSIBILITIES, PITFALLS, AND POTENTIAL CHANGES Michael MacNeil, PhD Delta G Miles City, Montana.](https://reader036.fdocuments.in/reader036/viewer/2022082711/56649ee55503460f94bf4fd2/html5/thumbnails/3.jpg)
Selection Index
• Where, • Analytical direct solution• Approximation by method of finite differences• Linear programming
• Assuming,
![Page 4: SELECTION INDEX POSSIBILITIES, PITFALLS, AND POTENTIAL CHANGES Michael MacNeil, PhD Delta G Miles City, Montana.](https://reader036.fdocuments.in/reader036/viewer/2022082711/56649ee55503460f94bf4fd2/html5/thumbnails/4.jpg)
Selection Index
• Where, • Assuming,
![Page 5: SELECTION INDEX POSSIBILITIES, PITFALLS, AND POTENTIAL CHANGES Michael MacNeil, PhD Delta G Miles City, Montana.](https://reader036.fdocuments.in/reader036/viewer/2022082711/56649ee55503460f94bf4fd2/html5/thumbnails/5.jpg)
Possibilities• Use genetic selection to improve economic merit
• Maximize present value of genetic improvement
• Consistent implementation of selection criteria
• Use complete set of economically relevant traits
![Page 6: SELECTION INDEX POSSIBILITIES, PITFALLS, AND POTENTIAL CHANGES Michael MacNeil, PhD Delta G Miles City, Montana.](https://reader036.fdocuments.in/reader036/viewer/2022082711/56649ee55503460f94bf4fd2/html5/thumbnails/6.jpg)
Pitfalls• Temptation to think selection can overcome advantages of
heterosis
• Incomplete indexes• Ignore genetic antagonisms• Fail to address full production cycle• Don’t give some traits the attention they are due
• Poor estimates of genetic parameters • poor estimates of EPD
![Page 7: SELECTION INDEX POSSIBILITIES, PITFALLS, AND POTENTIAL CHANGES Michael MacNeil, PhD Delta G Miles City, Montana.](https://reader036.fdocuments.in/reader036/viewer/2022082711/56649ee55503460f94bf4fd2/html5/thumbnails/7.jpg)
Potential Changes• Incorporate additional traits
• Update genetic evaluation systems• Improved estimates of variance components• More appropriate models
• Make indexes more complete
• Make genetic evaluation of ERT more accurate• Incorporate genomic predictors / better relationships
• Enhance econometrics
• Increase ease of developing customized indexes