By now, you have realized that Genomics offered nothing we did not already have—it just accelerated the turnover rate of sires available in most AI systems. Because of its heavy (40%) reliance on parent averages, the pedigree pathways in genomic breeds are getting narrower, full sisters to ranking bulls are now the preferred bull mommas rather than pedigree outliers. Phenotypic variation is much reduced, raising worries over the issue of inbreeding depression (canceling out the potential for genetic gain).
Then enters Zoetis (Genomic division of Pfizer) with something that does offer us new, useful information on the relative (genetic) incidence of six costly cow afflictions whose annual cost to dairying is in the hundreds of millions of dollars—dollars the current price of milk does not recover. The best defense against inbreeding effects is to select among the healthiest and most fertile breeding stock and linebreed desirable behavior. “aAa” will protect against inadvertent mating of similar genotypes, while positive selection for production, reproduction, feed efficiency and health will minimize failures.