The number of total pigs born by parity increased (P < 0.05) in a curvilinear manner to parity 5 but declined by parity 6 (Table 8). Live pigs born increased quadratically (P < 0.01) to parity 4; however, there was a decline thereafter. There was no apparent difference in the number of stillbirths or mummies by parity. Litter birth weights increased in a quadratic manner (P < 0.01) to parity 5, followed by a decline by parity 6, the latter response also reflected by their lower litter size. Pig birth BW, however, increased by parity (P < 0.05).Litter and pig BW at weaning (17 d) along with ADG of litters increased by parity (P < 0.05). The lowest pig BW and ADG responses during lactation occurred in parity 1 and indicate that the younger sows had lower