The effects of maternal parity, treatment, and their interaction on maternal and litter outcomes were analyzed by 2-way ANOVA. Replicate week was also included as a factor in full factorial statistical models in analyses of maternal BW, P2, and lactation performance, which varied between replicate weeks. Replicate week did not affect (P > 0.05) litter size or piglet size at birth and was not included in these models. Specific contrasts were performed to test a priori the hypotheses that short-term maternal pST treatment or long-term maternal pST treatment would increase litter weight and mean piglet birth weight, but would not impair subsequent maternal reproductive performance. Chi-square analysis was used to test the effects of maternal parity and treatment, and treatment within each parity, on dam removals. Pearson correlation tests were used to investigate relationships between mean litter birth size, survival, and preweaning growth. All statistical analyses were carried out using SPSS (SPSS Inc., Chicago, IL), and data are presented as mean ± SEM unless otherwise indicated.