Search
Author
Title
Vol.
Issue
Year
1st Page

Abstract

 

This article in

  1. Vol. 80 No. 9, p. 2263-2266
     
    Received: June 25, 2001
    Accepted: Feb 15, 2002
    Published:


    2 Corresponding author(s): ignacy@uga.edu
 View
 Download
 Share

doi:10.2527/2002.8092263x

Joint evaluation of purebreds and crossbreds in swine

  1. E. Lutaaya*1,
  2. I. Misztal*2,
  3. J. W. Mabry*3,
  4. T. Short,
  5. H. H. Timm and
  6. R. Holzbauer
  1. Department of Animal and Dairy Science, University of Georgia, Athens 30602;
    Pig Improvement Company, Franklin, KY; and
    Deutsch Pig Improvement Company, Germany

Abstract

Data from two purebred swine lines A (n = 6,022) and B (n = 24,170), and their reciprocal, cross C (n = 6,135), were used to examine gains in reliability of combined purebred and crossbred evaluation over conventional within-line evaluations using crossbred and pureline models. Random effects in the pureline model included additive, parental dominance, and litter. In the crossbred model, effects were as in the pureline model except traits of each line were treated as separate traits and two additive effects were present. The approximate model was the same as the pureline except it was used for all lines disregarding breed differences. The traits in the evaluation were lifetime daily gain (LDG) and backfat. When separate line evaluations were replaced by evaluations with crossbreds, mean reliabilities of predicted breeding values increased by 2 to 9% for purebreds and by 21 to 72% for crossbreds. Rank correlations between these breeding values were > 0.99 for purebreds but 0.85 to 0.87 for crossbreds. Rank correlations between predicted breeding values obtained from crossbred and approximate models were 0.98 to 0.99 for purebreds and 0.96 to 0.98 for crossbreds. When the number of crossbreds was small in comparison to purebreds, the increase in reliability by using the crossbred data and the crossbred model as opposed to purebred models was small for purebreds but large for crossbreds. The approximate model provided very similar rankings to the crossbred model for purebreds but rankings were less consistent for crossbreds.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2002. Copyright 2002 Journal of Animal Science