Practical applications of molecular research on pigs

Molecular technology can be used as an adjunct to conventional breeding programmes. The idea is that naturally occurring variation in DNA sequences (markers) can be detected in potential breeders. If this DNA variation has previously been correlated with variation in an economically important trait, such as growth or meat quality or susceptibility to disease, it can be used to assist or accelerate the choice or rejection of animals as parents. In some cases, this will merely slightly speed up the rate of improvement for traits which are already easy to select, like backfat. In other cases, it may make it possible to make early decisions on the choice of parents for difficult-tomeasure but important traits, like meat quality, which can only be measured postslaughter. This process has been termed marker assisted selection (MAS) and it is the underlying rationale for the type of molecular study in pigs which will be described.