Effects of yeast extract versus animal plasma in weanling pig diets on growth performance and intestinal morphology

Objectives: To evaluate the effects on growth performance and intestinal morphology when the nursery diet is supplemented with dried yeast extract protein (YP) or spray-dried animal plasma (AP) protein. Methods: In Experiment One (144 pigs) and Experiment Two (84 pigs), pigs were assigned at weaning (Day 0; approximately 19 days of age) to one of three diets with or without carbadox (55 mg per kg). The Control diet was used to create the other two diets by addition of AP or YP at 5.0% (Days I to 14) or 2.5% (Days 15 to 28). In Experiment Two, 42 pigs that had received AP. YP, or Control diets in the nursery were fed similar four-phase grower and finisher diets, without antimicrobials, to market weight (Day 130). Results: Overall, ADG and average daily feed intake were higher (P < .05) in pigs fed nursery diets containing AP or YP. compared to Control pigs. On Day 28, crypt depth and total intestinal wall thickness were smaller (P < .05) in pigs fed AP or YP diets, and villus width and lamina propria area were smaller (P < .05) in pigs fed the YP diet, than in Controls. Pigs fed the YP nursery diet had greater ADG to market weight than pigs that had been fed AP (P =.04) or Control nursery diets (P =.01). Implications: Nursery-pig growth performance was better when AP or YP was fed, and subsequent grower and finisher performance was better in pigs fed YP in the nursery.