Effects of specific breeding lines for organic dairy production in Denmark

Publikation: KonferencebidragKonferenceabstrakt til konferenceForskning

The aim of this study was to compare genetic gain in organic dairy production when running an environment-specific breeding program compared to one breeding program for both organic and conventional dairy production. Three different scenarios were simulated: running one breeding program for both environments (scenario 1), running two environment-specific breeding programs with selection of bulls across environments (scenario 2a), and running two environment-specific breeding programs with selection of bulls within each environment (scenario 2w). Genetic correlations between the trait in the two environments varied between 0 and 1. The reliability of predicting GEBVs was 0.65 in both environments. Each scenario was simulated for 30 years using stochastic simulation. In each environment, 1000 bull calves were genotyped. Each year 50 young bulls were selected within each breeding program to keep the rate of inbreeding approximately the same in the scenarios. Breeding animals were selected based on a total merit index. Preliminary results show that genetic gain for the organic breeding goal was higher for scenario 1 when the genetic correlation between the trait in the two environments was higher than 0.65, otherwise scenarios 2a and 2w yielded more genetic gain for the organic breeding goal. This low break-even genetic correlation is similar to previous studies, but it is expected that the break-even genetic correlation will increase when increasing the number of genotyped selection candidates. Below a correlation of about 0.80, scenarios 2a and 2w were similar in terms of genetic gain for the organic breeding goal. In scenario 2a, bulls could be selected across environments, but below a correlation of 0.8 they were not because bulls from the other environment were inferior. The effect of breeding goal differences, size of breeding programs, and a lower GEBV reliability on genetic gain will be further studied.
OriginalsprogEngelsk
Udgivelsesår2018
StatusUdgivet - 2018
Begivenhed69th Annual Meeting of the European Federation of Animal Science EAAP 2018 - Dubrovnik, Kroatien
Varighed: 27 aug. 201831 aug. 2018
Konferencens nummer: 69
http://www.eaap2018.org/

Konference

Konference69th Annual Meeting of the European Federation of Animal Science EAAP 2018
Nummer69
LandKroatien
ByDubrovnik
Periode27/08/201831/08/2018
Internetadresse

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