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Most of the long-term genetic gains from optimum-contribution selection can be realised with restrictions imposed
We reasoned that optimum-contribution selection (OCS) with restrictions imposed during optimisation will realise most of the long-term genetic gains realised by OCS without restrictions. We used stochastic simulation to estimate long-term rates of genetic gain realised by breeding schemes using OCS without and with restrictions imposed during optimisation. In all but a few exceptions, the long-term rates of genetic gain realised by OCS with restrictions was 95-100% of the rates realised by OCS without restrictions. It was only when the restrictions became overly strict that we began to lose gain. We also present evidence from the Danish pig-breeding scheme for Duroc that practical implementation of OCS with restrictions increases genetic gains and decreases rates of inbreeding. OCS has gone from a selection method that was difficult to apply in practice, to one that is readily applicable to most breeding schemes.
Keywords:
Optimum-contribution selection
Breeding plans
Inbreeding
