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Article: Modeling Nuisance Variables for Prediction of Service Sire Fertility
- Article from:
- Journal of Dairy Science
- Article date:
- July 1, 2008
- Author:
CopyrightCopyright American Dairy Science Association Jul 2008. Provided by ProQuest LLC. (Hide copyright information)
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ABSTRACT
The purpose of this research was to determine which (available) nuisance variables should be included in a model for phenotypic evaluation of US service sire conception rate (CR), based on field data. Alternative models were compared by splitting data into records for estimation and set-aside records, computing predictions using the estimation data, and then comparing predictions to bulls' average CR in the set-aside data. Breedings for estimation were from January 1, 2003, to June 30, 2005, and set-aside records spanned July 1, 2005, to June 30, 2006. Only matings with known outcomes were included in either data set. Correlations and mean differences were the main statistics used ...