Breeding and Genetics Symposium I: How genomic selection has changed livestock breeding
Genomic selection increases accuracy of prediction and, with that, genetic trend; also in pigs. 50% extra trend is gradually becoming a conservative estimate. Theory and experience in other species shows that more is better: the more genotypes, and the more phenotypes, the higher the gain. The downside of this is that fewer and fewer breeding companies can bring up the resources to reach those numbers. Consolidation is the result and within companies the number of sire and dam lines is decreasing. On top of that the essence of current genomic selection is that the presence of existing or new rare alleles is ignored, with the risk of genetic variance. So fewer groups, fewer lines and breeds, and reducing genetic variance.
The upside is more possibilities for more difficult traits. Challenge experiments can be more effectively used as training populations, as are crossbred animals for dissection. Costprice of genotyping is down to a level that it could be cost effective to genotype individual crossbred sows for precision production management. Increased genetic trend, combined with precision production and production sorting of boars can lead to very cost efficient uniform production directed to very specific markets. Genomic selection is beneficial for the pig industry to maintain its competitive position against other types of meat in the short to medium term.
Developments for the (near) future are genome editing and interaction with other genotypes. The latter is linked to same species genotypes (pen mates), to pathogenic genotypes and to humans. Larger farms with larger groups of animals per age group and fewer and less experienced workers make autonomy of animals more important. Genomic models that estimate which animals do best for the net profit of the farm are needed, but difficult. In the end genomic selection is a powerful tool to create genetic trend and adapt pigs to local market environments. In the bigger picture of long term, worldwide sustainability there are some serious concerns.