It is generally recognised that the nutritional and metabolic status of the sow during lactation can influence its subsequent reproductive capacity. Thus sows which mobilise large quantities of body weight during lactation have extended weaning to oestrus intervals and reduced litter sizes. However, it is not known how nutrition during lactation may influence metabolic efficiency in the post-weaning period, especially in relation to the accumulation of body reserves. The present experiment was therefore designed to investigate the effect of feeding level during lactation on nutrient partitioning and metabolic efficiency in the weaned sow.