The Scandinavian experience of including reproductive traits in Breeding Programmes (original) (raw)

BSAP Occasional Publication, 2001

Abstract

Female fertility affects the culling rate as well as the direct reproduction costs and influences the calving interval and the calving season. It is therefore obvious that female fertility should be included in a Total Merit Index (TMI), which directs the genetic changes in dairy cattle selection. When the first TMI was introduced in Sweden in 1975 female fertility was included. A basic prerequisite for inclusion of fertility in the Scandinavian breeding programme was that milk recording, pedigree and AI-data were integrated in the same databases.The paper deals exclusively with the additive genetic effects on female fertility. The heritabilities of the measures used for female fertility are low, usually below 0.05. Despite this, the additive genetic variance is high as demonstrated by large differences between progeny groups. Thus, selection must be based on progeny testing of bulls on daughter groups of 100-150 daughters or more, which is the case in all the Scandinavian countries...

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