Abstract
This study was conducted to investigate the effects of spray-dried porcine plasma protein (SDPP) or spray-dried chicken plasma protein (SDCP) supplementation in diets without the inclusion of antibiotics and zinc oxide (ZnO) on growth performance, fecal score, and fecal microbiota in early-weaned piglets. A total of 192 healthy weaning piglets (Duroc × Landrace × Yorkshire, 21 d old) were blocked by BW (6.53 ± 0.60 kg) and randomly assigned to 4 dietary treatments: negative control (NC, basal diet), positive control (PC), basal diet + ZnO at 2 g/kg and antibiotics at 0.8 g/kg), SDPP (containing 5% SDPP), and SDCP (containing 5% SDCP). The experiment lasted 14 d. The SDPP group had higher (P < 0.05) final BW, average daily gain and average daily feed intake than the NC and SDCP groups. The percentage of piglets with fecal scores at 2 or ≥2 was higher (P < 0.05) in the NC and SDCP groups than in the PC group. A decreased (P < 0.05) bacterial alpha diversity and Bacteroidetes abundance, but increased (P < 0.05) Firmicutes abundance were observed in the PC and SDPP groups when compared to the NC group. The relative abundance of Lactobacillus was higher (P < 0.05) in the SDPP than in the SDCP group, and that of Streptococcus was higher (P < 0.01) in the PC and SDPP groups than in the NC group. The PC group also had higher (P < 0.01) Faecalibacterium abundance than the NC and SDCP groups. Additionally, the SDCP group had higher (P < 0.05) serum urea nitrogen than those fed other diets, and lower (P < 0.10) short-chain fatty acids to branched-chain fatty acids ratio than the PC and SDPP groups. Overall, SDPP was a promising animal protein for piglets in increasing feed intake, modifying gut microbiota profile, reducing gut protein fermentation and alleviating diarrhea frequency, thus promoting growth performance, under the conditions with limited in-feed utilization of antibiotics and ZnO.