Four 28-d experiments involving 360 weanling pigs were conducted to investigate the effects of including spray-dried porcine plasma (SDPP) in diets from d 0 to 14 after weaning followed by feeding a common diet from d 14 to d 28. In Exp. 1, 80 weanling pigs (4.9 kg BW, 17 +/- 1 d of age) were used to determine the effects of substituting 0, 3, 6, 9, or 12% SDPP for dried skim milk (DSM) and L-lysine.HCl. Growth rate and feed intakes from d 0 to 14 and d 0 to 28 were not affected by increasing levels of SDPP, but feed/gain from d 0 to 14 increased linearly (P < .001) as the level of SDPP increased. In Exp. 2 and 3, 160 pigs (80 pigs in each trial; 5.4 kg BW, 18 +/- 2 d of age) were used to determine the effect of nursery environment on the performance of pigs fed a diet containing 20% DSM or 8.3% SDPP. Pigs were housed in either an off-site, environmental chamber in newly purchased pens (experimental nursery) or a more typical, on-farm, conventional nursery. Pigs in the experimental nursery performed superior to the pigs in the conventional nursery from d 0 to 14 and from d 0 to 28 (P < .001). Growth rate and feed intake were enhanced (P < .05) by feeding SDPP to pigs in the conventional nursery, but the responses to SDPP were of considerably less magnitude in pigs housed in the experimental nursery, resulting in environment x diet interactions (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)