- THIS ARTICLE
- Full Text
- Full Text (PDF)
-
All Versions of this Article:
genetics.107.077818v1
177/3/1791 most recent - Alert me when this article is cited
- Alert me if a correction is posted
- SERVICES
- Email this article to a friend
- Similar articles in this journal
- Similar articles in PubMed
- Alert me to new issues of the journal
- Download to citation manager
- Reprints & Permissions
- CITING ARTICLES
- Citing Articles via HighWire
- Citing Articles via Google Scholar
- GOOGLE SCHOLAR
- Articles by Varona, L.
- Articles by Thompson, R.
- Search for Related Content
- PUBMED
- PubMed Citation
- Articles by Varona, L.
- Articles by Thompson, R.
Originally published as Genetics Published Articles Ahead of Print on August 24, 2007.
Genetics, Vol. 177, 1791-1799, November 2007, Copyright © 2007
doi:10.1534/genetics.107.077818
Analysis of Litter Size and Average Litter Weight in Pigs Using a Recursive Model
Luis Varona*,1,
Daniel Sorensen
and
Robin Thompson
,
* Genética i Millora Animal, IRTA, 25198 Lleida, Spain, Department of Genetics and Biotechnology, Faculty of Agricultural Sciences, University of Aarhus, DK-8830 Tjele, Denmark, School of Mathematical Sciences, University of London, London E1 4NS, United Kingdom and Centre for Mathematical and Computational Biology, Department of Biomathematics and Bioinformatics, Rothamsted Research, Harpenden AL5 2JQ, United Kingdom
1 Corresponding author: Genetica I Millora Animal, IRTA, Av. Rovira Roure 177, 25198 Lleida, Spain.
E-mail: luis.varona{at}irta.es
An analysis of litter size and average piglet weight at birth in Landrace and Yorkshire using a standard two-trait mixed model (SMM) and a recursive mixed model (RMM) is presented. The RMM establishes a one-way link from litter size to average piglet weight. It is shown that there is a one-to-one correspondence between the parameters of SMM and RMM and that they generate equivalent likelihoods. As parameterized in this work, the RMM tests for the presence of a recursive relationship between additive genetic values, permanent environmental effects, and specific environmental effects of litter size, on average piglet weight. The equivalent standard mixed model tests whether or not the covariance matrices of the random effects have a diagonal structure. In Landrace, posterior predictive model checking supports a model without any form of recursion or, alternatively, a SMM with diagonal covariance matrices of the three random effects. In Yorkshire, the same criterion favors a model with recursion at the level of specific environmental effects only, or, in terms of the SMM, the association between traits is shown to be exclusively due to an environmental (negative) correlation. It is argued that the choice between a SMM or a RMM should be guided by the availability of software, by ease of interpretation, or by the need to test a particular theory or hypothesis that may best be formulated under one parameterization and not the other.
This article has been cited by other articles:
 |
|
 |
|
  B. Heringstad, X.-L. Wu, and D. Gianola Inferring relationships between health and fertility in Norwegian Red cows using recursive models J Dairy Sci, April 1, 2009; 92(4): 1778 - 1784. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 O. Gonzalez-Recio, D. Gianola, N. Long, K. A. Weigel, G. J. M. Rosa, and S. Avendano Nonparametric Methods for Incorporating Genomic Information Into Genetic Evaluations: An Application to Mortality in Broilers Genetics, April 1, 2008; 178(4): 2305 - 2313. [Abstract] [Full Text] [PDF]
|
|