Technical Abstract: Embryo transfer (ET) has contributed to increasing selection intensity in cattle breeding for many years. Preimplantation DNA testing offers the opportunity to increase selection response further through increasing within-family selection intensity. Further increases in between-family selection intensity, such as through producing more progeny per donor would likely be counterproductive as it would increase inbreeding even faster. DNA testing now offers the promise of increasing the accuracy of selection. It must be emphasized that this promise has not yet been fully realized to the extent of accounting for most of the genetic variation for any quantitative trait. However, it seems reasonable to assume that within the foreseeable future, the accuracy of DNA testing will reach the point that progeny testing and selecting directly on phenotypes acquired late in life will become unnecessary. Therefore, generation interval may soon become the limiting factor determining response to selection. Advanced reproductive technologies associated with ET have great potential to increase selection response through reducing generation interval.