INCLUDING GENETIC-RELATIONSHIPS IN SELECTION DECISIONS - ALTERNATIVE METHODOLOGIES

Investigations are made of variations in an iterative methodology prev iously introduced for reducing inbreeding by including genetic relatio nships in selection decisions, using adjusted estimated breeding value s (EBV). An alternative computing strategy for maximising the value of the population selection criterion is shown to involve less computati on, which results in function values as great or greater than the orig inal method. Alteration of weights for different types of relationship s in the adjusted EBV has no detectable effect on genetic gain at a gi ven level of inbreeding. Selection using the adjusted EBV method in on e sex and truncation on EBV in the other sex results in less genetic g ain at a given level of inbreeding than using adjusted EBV in both sex es, but results in more gain at a given level of inbreeding than three selection strategies that do not include genetic relationships in sel ection decisions. The advantage of the adjusted EBV method over these three methods is retained when selection is for a sex-limited trait.