Document Detail


Estimation of direct and maternal genetic variance for litter size in Canadian Yorkshire and Landrace swine using an animal model.
MedLine Citation:
PMID:  2384377     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Estimates of additive direct heritability (h2a) for traits such as litter size may be biased by maternal effects. The size of these effects was estimated using a derivative-free restricted maximum likelihood procedure under an animal model. First-parity records from Yorkshire (Y) and Landrace (L) gilts were obtained from the Quebec Record of Performance sow productivity program for 21,127 litters born between 1977 and 1987. Direct (sigma 2a) and maternal (sigma 2m) additive genetic variances, their covariance (sigma am) and error variance (sigma 2e) were estimated for total numbers born (NOBN), born alive (NOBA) and weaned (NOWN). Analysis of purebred Y and crossbred litters indicated that estimates of sigma 2a were of similar magnitude for all traits, with h2a ranging from .06 to .13. Except for L litters, estimates of sigma 2m were relatively low for NOBN and NOBA, and increased in size for NOWN, with h2m ranging from 0 to .08. Also, estimates of sigma am were negative, except for NOBN and NOBA with crossbred litters, and became increasingly negative for NOWN. Results from purebred L litters indicated there was a stronger negative correlation between direct and maternal genetic effects for NOBN and NOBA than for NOWN.
Authors:
O I Southwood; B W Kennedy
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of animal science     Volume:  68     ISSN:  0021-8812     ISO Abbreviation:  J. Anim. Sci.     Publication Date:  1990 Jul 
Date Detail:
Created Date:  1990-09-20     Completed Date:  1990-09-20     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  8003002     Medline TA:  J Anim Sci     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1841-7     Citation Subset:  IM    
Affiliation:
Centre for Genet. Improv. of Livest., Anim. and Poult., Sci., University of Guelph, Ontario, Canada.
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MeSH Terms
Descriptor/Qualifier:
Analysis of Variance
Animals
Female
Genetic Variation*
Litter Size / genetics*
Male
Swine / genetics*,  physiology

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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