Document Detail


Phenotypic and genetic effects on feed intake of laying hens in different years.
MedLine Citation:
PMID:  2047336     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Feed intake from 21 to 40 wk and from 41 to 60 wk of age of brown egg layers was analyzed. The full model contained BW, egg mass (EM) output, BW change (BWCH), and age at first egg as covariates in addition to effects of plumage condition class, sire, and dam. A reduced model contained the covariates only. Between 905 and 1,161, and 880 and 1,119 hens were available in the first and second periods, respectively. Averaged over 6 yr the full model explained 84 and 77%, the reduced model 73 and 63%, respectively, of the variance in feed consumption in the two periods. Regression coefficients for BW showed only a small variation between years as well as between periods. Variation was larger for the coefficients of EM and of BWCH. Larger coefficients were observed in the first period for both traits. The sequence of entering the reduced equation in a stepwise procedure was always BW, EM output, then BWCH. Averaged over 6 yr, the relative contribution of BW by its own to the accuracy of the regression model, was 68 and 60% in the two periods. Egg mass output then added 25 and 39%, and BWCH 7 and 2% in the first and second periods, respectively. The predictive value of the covariates changed with increasing age of the hens. A high average heritability of .48 could be estimated for the residual feed intake in both periods. This suggested enhanced selection response for efficiency.
Authors:
C Hagger
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Poultry science     Volume:  70     ISSN:  0032-5791     ISO Abbreviation:  Poult. Sci.     Publication Date:  1991 Mar 
Date Detail:
Created Date:  1991-07-15     Completed Date:  1991-07-15     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0401150     Medline TA:  Poult Sci     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  434-9     Citation Subset:  IM    
Affiliation:
Department of Animal Production, Swiss Federal Institute of Technology, Zurich.
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MeSH Terms
Descriptor/Qualifier:
Animals
Body Weight
Chickens / genetics,  physiology*
Eating / genetics*
Female
Genetic Variation
Oviposition
Phenotype
Regression Analysis

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