Spray-dried plasma protein is commonly used in weanling diets due its functional components and high concentration of digestible amino acids. Hydrolyzed spray-dried bovine plasma (H-SDBP) is a new source of spray-dried plasma protein that may be used as a protein source in diets for weanling pigs. There are, however, no data to demonstrate the efficacy of this novel source. Pigs fed diets spray-dried plasma protein have increased growth performance when exposed to a challenge model; therefore, it is possible that H-SDBP improves performance of challenged pigs similarly as other sources of spray-dried plasma protein. Therefore, an experiment was conducted to test the hypothesis that dietary inclusion of H-SDBP is as effective as spray-dried bovine plasma (SDBP) in increasing growth performance of weanling pigs housed in uncleaned pens.