THE IMPACT OF ENVIRONMENT AND ANTIMICROBIAL AGENTS ON THE GROWTH-RESPONSE OF EARLY-WEANED PIGS TO SPRAY-DRIED PORCINE PLASMA

Four 28-d experiments involving 360 weanling pigs were conducted to in vestigate the effects of including spray-dried porcine plasma (SDPP) i n 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 inc reasing levels of SDPP, but feed/gain from d 0 to 14 increased linearl y (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 de termine the effect of nursery environment on the performance of pigs f ed a diet containing 20% DSM or 8.3% SDPP. Pigs were housed in either an off-site, environmental chamber in newly purchased pens (experiment al nursery) or a more typical, on-farm, conventional nursery. Pigs in the experimental nursery performed superior to the pigs in the convent ional nursery from d 0 to 14 and from d 0 to 28 (P < .001). Growth rat e and feed intake were enhanced (P < .05) by feeding SDPP to pigs in t he conventional nursery, but the responses to SDPP were of considerabl y less magnitude in pigs housed in the experimental nursery, resulting in environment x diet interactions (P < .05). In Exp. 4, 120 pigs (7. 3 kg BW, 30 +/- 3 d of age) were used to investigate the effects of an timicrobial agents (AMA; Cu and antibiotics) on the response to SDPP. Diets consisting of 12% DSM or 5% SDPP, without or with AMA, were asse ssed. A corn-soybean meal negative control diet with AMA was included as a fifth diet. From d 0 to 14 and d 0 to 28, pigs fed DSM or SDPP gr ew faster (P < .09) and consumed more feed (P < .05) than those fed th e negative control. Also, pigs fed SDPP had greater (P < .001) gains a nd feed intakes than those fed DSM. The inclusion of AMA improved rate (P < .01) and efficiency of gain (P < .09) from d 0 to 14 and d 0 to 28 and increased (P < .001) feed intake from d 0 to 14. These results indicate that SDPP is an effective alternative to DSM for weanling pig s. The results also indicate that pigs reared in a conventional, on-fa rm nursery setting respond more to SDPP than those in a cleaner, off-s ite nursery, and that the growth-enhancing properties of SDPP are inde pendent of the responses to AMA.