Linked Life Data

1526901

Source:http://linkedlifedata.com/resource/pubmed/id/1526901

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1992-10-20
pubmed:abstractText
Standard linear adjustment of weaning weight to a constant age has been shown to introduce bias in the adjusted weight due to nonlinear growth from birth to weaning of beef calves. Ten years of field records from the five strains of Beefbooster Cattle Alberta Ltd. seed stock herds were used to investigate the use of correction factors to adjust standard 180-d weight (WT180) for this bias. Statistical analyses were performed within strain and followed three steps: 1) the full data set was split into an estimation set (ES) and a validation set (VS), 2) WT180 from the ES was used to develop estimates of correction factors using a model including herd (H), year (YR), age of dam (DA), sex of calf (S), all two and three-way interactions, and any significant linear and quadratic covariates of calf age at weaning deviated from 180 d (DEVCA) and interactions between DEVCA and DA, S or DA x S, and 3) significant DEVCA coefficients were used to correct WT180 from the VS, then WT180 and the corrected weight (WTCOR) from the VS were analyzed with the same model as in Step 2 and significance of DEVCA terms were compared. Two types of data splitting were used. Adjusted R2 was calculated to describe the proportion of total variation of DEVCA terms explained for WT180 from the ES. The DEVCA terms explained .08 to 1.54% of the total variation for the five strains. Linear and quadratic correction factors were both positive and negative. Bias in WT180 from the ES within 180 +/- 35 d of age ranged from 2.8 to 21.7 kg.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-8812
pubmed:author
pubmed:issnType
Print
pubmed:volume
70
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1333-41
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Correcting bias from the standard linear adjustment of weaning weight to an age-constant basis for beef calves.
pubmed:affiliation
Department of Animal and Range Science, Montana State University, Bozeman 59717.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't