In the first experiment, 60 National Pig Development (NPD) gilts and 53 first-parity sows were randomly assigned to one of two gestation treatments and subsequently one of two lactation treatments. Throughout gestation the control group (gC) (gilts, n = 31; sows, n = 26) was fed at 1.4 times maintenance d-1, and the pattern group (gP) (gilts, n = 29; sows, n = 27) was fed in four stages based on body weight at d 1, d 30, d 60, and d 90. Each gestation group was further divided into two treatments for the 17-day lactation: the control group (lc) (gilts, n = 30; sows, n = 28) was 'full-fed', and the pattern group (lp) (gilts, n = 30; sows, n = 5) was fed in three stages based on body weight at d 1, d 6, and d 12. In the second experiment, 18 Cotswold gilts were randomly assigned to one of two gestation treatments and one of two lactation treatments. Throughout gestation, control gilts (gC) (n = 10) and the pattern group (gP) (n = 8) were fed as described in Experiment I. Each gestation treatment was further divided into two treatments for the 18-day lactation: control gilts (lc) (n = 9) were fed 'ad libitum', and the pattern group (lp) (n = 8) was fed in three stages based on body weight at d 1, d 6, and d 12. (Abstract shortened by UMI.)