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Sire evaluation of dairy cattle.
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Abstract: This thesis was carried out to investigate different methods for evaluating sires considering all the available information. Multiple-trait animal model with derivative free restricted maximum likelihood (DF-REML) and single-trait DF-REML analyses were utilized to obtain predicted breeding values (PBVs) for all the sires in the herd and the covariance components for the first three lactations of Friesian cattle. Also, a repeatability model using single-trait animal model DF-REML was evaluated in this study. All PBVs obtained from the three analyses in addition to an index utilized the PBVs of the multiple-trait analysis were compared.
It was concluded in this study that utilizing all the information and the interrelationships among the traits by using the multiple-trait analysis is recommended to obtain precise breeding values, variance components and covariance structures for the studied traits. Milk production in the first three lactations can be considered as different traits as there are some evidences indicated that genes affecting different lactations may change their expression from one lactation to another.
Key words: dairy cattle, Friesian, sire evaluation, multiple-trait, single-trait, repeatability, heritability, variance components, covariance structure, breeding values, animal model and DF-REML.
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| Publication year |
1998
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| Availability location |
مكتبة معهد بحوث الانتاج الحيوانى- شارع نادى الصيد - الدقى - الجيزة
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| Availability number |
593
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| Organization Name |
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| Country |
Egypt
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| Department |
Cattle Breeding Research Department
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| Author(s) from ARC |
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| Agris Categories |
Animal husbandry
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AGROVOC
TERMS |
Animal models.
Cows.
Dairy cattle.
Heritability.
Sire evaluation.
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| Publication Type |
PhD Thesis
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