9th World Congress on Genetics Applied to Livestock Production
August 1-6, 2010
International Committee for World Congresses on Genetics Applied to Livestock Production
[en] Female fertility ; index
[en] A useful method to express female fertility of the Walloon dairy cattle using direct and indirect female fertility information was considered. Data were based on results of the genetic evaluation of pregnancy rate for 606,328 Holstein cows and on INTERBULL proofs of female fertility for 88,496 bulls. A direct female fertility index (DFF), using INTERBULL proofs, was developed from results of a principal component analysis carried out on 6 published foreign female fertility indexes. An indirect female fertility index (IFF) was also developed from ten other traits evaluated in Walloon Region. Theory of selection index was used to combine DFF and IFF in a global index called combined female fertility index (CFF). This index allowed young bulls to have better reliabilities with an average increase of 12% leading to extra 4,019 of publishable bulls for female fertility.