Genetic improvement is permanent and cumulative. Improvements made in one generation are passed onto the next. In the UK two selection indexes are currently available to the dairy industry, they are PIN (Profit Index; production only) and £PLI (Profitable Lifetime Index; production plus lifespan). Much of the current and anticipated index research and development will be on broader breeding goals that include health and fertility traits. Economic responses expected for PIN and £PLI over a 20 year period were calculated in addition to a hypothetical index where it was assumed that PTAs (predicted transmitting abilities) for mastitis (M) and calving interval (CI) were available (£PLI+M+CI).