Journal ArticleDOI
Restriction of selection indexes.
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TLDR
The effect of gradual restriction of a particular trait on the index weighting factors and on the rate of gain for the aggregate genotype and its constituent traits can be readily plotted, and was nearly linear in several cases examined.Abstract:
A selection index may be restricted by requiring that the genetic changes it produces in one or more traits equal zero or some predetermined value, or are of specified sign. Retaining the equations of constraint explicitly in the system simplifies the index equations, facilitates the calculation of the 'genetic cost' of each restriction, and gives the economic value needed to stabilise any trait under selection with an unrestricted index. The effect of gradual restriction of a particular trait on the index weighting factors and on the rate of gain for the aggregate genotype and its constituent traits can be readily plotted, and was nearly linear in several cases examined.read more
Citations
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GENES: a software package for analysis in experimental statistics and quantitative genetics
TL;DR: GENES as mentioned in this paper is a software package used for data analysis and processing with different biometric models and is essential in genetic studies applied to plant and animal breeding It allows parameter estimation to analyze biological phenomena and is fundamental for the decision-making process and predictions of success and viability of selection strategies.
Journal ArticleDOI
Effective sizes of livestock populations to prevent a decline in fitness
TL;DR: It is concluded that a negative correlation between artificial and natural selection should be avoided and a large increase in the critical effective population size is needed to prevent a decline in fitness.
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Index selection for genetic improvement of quantitative characters.
TL;DR: The basic theory and various modifications of the selection index are reviewed and changes of parameters due to selection and sampling errors of parameter estimation are discussed.
Journal ArticleDOI
Selection index when genetic gains of individual traits are of primary concern
TL;DR: A new procedure for constructing economic weight free selection index, based on exclusively breeder's intention, is presented, which is applicable to the case in which the relative economic weight of each trait is unknown or difficult to assess because of no available standard for the assessment.
Journal ArticleDOI
Heritability of rectal temperature and genetic correlations with production and reproduction traits in dairy cattle
TL;DR: Rectal temperature during heat stress has moderate heritability, but genetic correlations with economically important traits mean that selection for RT could lead to lower productivity unless methods are used to identify genes affecting RT that do not adversely affect other traits of economic importance.
References
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Journal ArticleDOI
Problems of Selection with Restrictions
TL;DR: In this article, a linear function of a set of predictor variables is constructed so as to maximize its correlation with a criterion variable, subject to the condition that its correlations with other criterion variables y 2,..., y q are non-negative.