Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1992-9-24
pubmed:abstractText
Records from 7,200 separate closed herds with either 12 or 25 sows that were mated to either four or eight boars per year were simulated by computer. Effects of selection method, herd size, and contemporary group variability on average genetic change, genetic variance, and inbreeding over 10 yr of selection were analyzed for traits with heritabilities of .1, .3, and .6. Selection of replacement animals was on individual phenotype or BLUP of breeding value using a reduced animal model. For both of these selection methods, two culling schemes were imposed: 1) based only on involuntary culling because of losses due to conception rate and age and 2) when an available replacement animal was projected to be superior to an existing breeding animal in the herd in addition to the involuntary culling. The contemporary group standard deviation was set at either .1 or .5 of a phenotypic standard deviation. Selection with BLUP gave 72, 36, and 12% more genetic improvement for heritabilities of .1, .3, and .6, respectively, than selection on individual phenotype after 10 yr. However, inbreeding increased 20 to 52% more rapidly and there was a decrease in genetic variance. Culling based on Scheme 2 increased genetic improvement over Scheme 1 by about 75% with coincident increases in inbreeding level and decreases in genetic variance. The largest changes in inbreeding and genetic variance were associated with culling on BLUP. Culling when a superior animal was available with individual phenotype had little effect on inbreeding and genetic variance. Use of four boars rather than eight boars and 25 rather than 12 sows per herd increased genetic response. Use of four boars also increased inbreeding and decreased genetic variance. Genetic variance was higher in herds with 25 sows, but the size of the sow herd had little effect on inbreeding. Contemporary group variation influenced only the genetic response of individual phenotypic selection with culling.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-8812
pubmed:author
pubmed:issnType
Print
pubmed:volume
70
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2338-48
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Effect of culling on selection response using phenotypic selection or best linear unbiased prediction of breeding values in small, closed herds of swine.
pubmed:affiliation
Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't