A note on using biased parameter values and non-random mating to reduce rates of inbreeding in selection programmes

The value of a parameter such as heritability (h 2 ) or intra-dass correlation in best linear unbiased prediction (BLUP) with the animal model or a family selection index affects both the rate of response achieved and the rate of inbreeding. If in BLUP an estimate of h 2 is used which is biased upwards above its actual value, the rate of inbreeding can be substantially reduced with little reduction in the rate of response. Further, by mating individuals from families in which many are selected to others from families with few selected (compensatory mating), rates of inbreeding can be further reduced without substantial effect on response.