Piglets which are heavier at weaning generally show a lower incidence of post weaning disease and mortality, superior growth rates and convert feed to gain with greater efficiency than smaller piglets. Weaning weight is largely determined by the yield and quality of milk available to the suckling piglet, and these parameters are becoming increasingly important with the large litter sizes produced by modern prolific sows.This experiment was designed to quantify milk production by sows of a modern commercial genotype and investigate possibilities for dietary manipulation of milk yield and composition as a means of increasing piglet performance.