J. Anim Sci.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Southwood, O. I.
Right arrow Articles by Kennedy, B. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Southwood, O. I.
Right arrow Articles by Kennedy, B. W.

Journal of Animal Science, Vol 69, Issue 8 3177-3182, Copyright © 1991 by American Society of Animal Science

JOURNAL ARTICLE

Genetic and environmental trends for litter size in swine

O. I. Southwood and B. W. Kennedy
University of Guelph, Ontario, Canada.

Best linear unbiased predictors (BLUP) of breeding values for additive direct and additive maternal genetic effects were estimated from 3,944 purebred Yorkshire and Landrace first-parity litters recorded on the Quebec Record of Performance Sow Productivity Program and born between 1977 and 1987. Breeding values for gilts, dams, and sires were estimated using an individual animal model for measures of litter size of total number born (NOBN), number born alive (NOBA), and number weaned (NOWN). Environmental trends were estimated from average herd-year solutions, and genetic trends were estimated by regression of estimated breeding value on year of birth. Environmental trends were positive for all traits in both breeds but were significant only for NOWN in Landrace (.051 +/- .021 pigs/yr). Genetic trends were very small but were mainly negative for direct breeding value and combined direct and maternal breeding value. Significant estimates of genetic trends (P less than .05) were observed only within the Yorkshire breed, and these ranged from -.012 +/- .004 to .004 +/- .002 pigs/yr.


This article has been cited by other articles:


Home page
 J ANIM SCIHome page
H. Mesa, T. J. Safranski, K. A. Fischer, K. M. Cammack, and W. R. Lamberson
Selection for placental efficiency in swine: Genetic parameters and trends
J Anim Sci, May 1, 2005; 83(5): 983 - 991.
[Abstract] [Full Text] [PDF]

Home page
 J ANIM SCIHome page
L. H. Damgaard, L. Rydhmer, P. Lovendahl, and K. Grandinson
Genetic parameters for within-litter variation in piglet birth weight and change in within-litter variation during suckling
J Anim Sci, March 1, 2003; 81(3): 604 - 610.
[Abstract] [Full Text] [PDF]

Home page
 J ANIM SCIHome page
P. Chen, T. J. Baas, J. W. Mabry, K. J. Koehler, and J. C. M. Dekkers
Genetic parameters and trends for litter traits in U.S. Yorkshire, Duroc, Hampshire, and Landrace pigs
J Anim Sci, January 1, 2003; 81(1): 46 - 53.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1991 by the American Society of Animal Science.