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Models for genetic analysis of dystocia and calf mortality.
Year:
1989
Source of publication :
Journal of Dairy Science
Authors :
Weller, Joel Ira
;
.
Volume :
72
Co-Authors:
Weller, J.I., Department of Animal Sciences, University of Illinois, Urban 61801.
Gianola, D., Department of Animal Sciences, University of Illinois, Urban 61801.
Facilitators :
From page:
2633
To page:
2643
(
Total pages:
11
)
Abstract:
Calvings of 106,750 Israeli Holstein heifers were analyzed for dystocia and calf mortality, which were scored dichotomously. Models fitted included herd-year-season, sex of calf, calving age, calving month, sire of cow, sire of calf, and groups of sire of cow and calf. Herd-year-season, sire of cow and of calf, and residuals were random with diagonal variance-covariance matrices. Traits were analyzed with and without a herd-year-season effect, and dystocia was analyzed separately for male and female calvings and with both sexes combined. Variance components were estimated by REML for linear models and by the counterpart of REML for threshold models. Heritability estimates were two to four times larger in threshold than in linear models, but correlations between corresponding sire evaluations were all greater than .9. Correlations between evaluations computed with and without herd-year-season effects were .9 for sire of calf evaluations for dystocia and greater than .97 for all other evaluations. Correlations between sire evaluations computed separately for male and female calvings were between .3 and .7. Thus, calving difficulty is expressed differently in male and female calvings. Genetic trends were unfavorable for dystocia but favorable for calf mortality. Phenotypic trends were curvilinear with maxima in 1982 and 1983 for calf mortality and dystocia.
Note:
Related Files :
Animal
animal disease
cattle
Dystocia
Female
Genetics
Male
Models, Biological
pregnancy
Show More
Related Content
More details
DOI :
Article number:
Affiliations:
Database:
Scopus
Publication Type:
article
;
.
Language:
English
Editors' remarks:
ID:
27502
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:31
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Scientific Publication
Models for genetic analysis of dystocia and calf mortality.
72
Weller, J.I., Department of Animal Sciences, University of Illinois, Urban 61801.
Gianola, D., Department of Animal Sciences, University of Illinois, Urban 61801.
Models for genetic analysis of dystocia and calf mortality.
Calvings of 106,750 Israeli Holstein heifers were analyzed for dystocia and calf mortality, which were scored dichotomously. Models fitted included herd-year-season, sex of calf, calving age, calving month, sire of cow, sire of calf, and groups of sire of cow and calf. Herd-year-season, sire of cow and of calf, and residuals were random with diagonal variance-covariance matrices. Traits were analyzed with and without a herd-year-season effect, and dystocia was analyzed separately for male and female calvings and with both sexes combined. Variance components were estimated by REML for linear models and by the counterpart of REML for threshold models. Heritability estimates were two to four times larger in threshold than in linear models, but correlations between corresponding sire evaluations were all greater than .9. Correlations between evaluations computed with and without herd-year-season effects were .9 for sire of calf evaluations for dystocia and greater than .97 for all other evaluations. Correlations between sire evaluations computed separately for male and female calvings were between .3 and .7. Thus, calving difficulty is expressed differently in male and female calvings. Genetic trends were unfavorable for dystocia but favorable for calf mortality. Phenotypic trends were curvilinear with maxima in 1982 and 1983 for calf mortality and dystocia.
Scientific Publication
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