Impact of biotechnology on (cross)breeding programmes in pigs

Crossbreeding programmes in pigs exploit between breed complementarity of additive genetic effects and heterosis generated by non-additive genetic effects. Within breed, improvement programmes may focus on additive effects and hence the enhancement of complementarity, but non-additive variation is not generally used in within line selection or for mate selection at the multiplier or commercial level. In this paper, we discuss the impact of new biotechnological tools, particularly molecular markers, multiple ovulation and embryo transfer (MOET), and cloning, on structures and methods in crossbreeding. At the between line level, genetic marker information could allow better prediction of heterosis in novel crosses from information on genetic distances. Within the crossbreeding structure, the same technique might be applied at the multiplier and commercial level to exploit specific combining abilities of particular animals. Combining simple MOET and cloning protocols could radically alter the dissemination of crossbreeding benefits and their delivery to the farmer. The combination of MOET, cloning and genomic tools could result in speed genetics programmes, i.e. fast introgression and recurrent selection methods. Thus, the ultimate impact of biotechnology will be increased rates of progress, efficient use of variation, reduced genetic lag, and the removal of one or two tiers in the breeding pyramid. The costs of new technologies are discussed briefly. (C) 2000 Elsevier Science B.V. All rights reserved.