Effects of Butyric Acid Supplementation on the Gut Microbiome and Growth Performance of Weanling Pigs Fed a Low-Crude Protein, Propionic Acid-Preserved Grain Diet

Abstract

Reducing crude protein (CP) in weaner pig diets lowers post-weaning diarrhoea risk but may impair growth performance. This study aimed to identify the beneficial effects of organic acid (OA)-preserved grain and butyric acid supplementation on gut health and growth in low-CP diets. At harvest, grain was divided into two batches: one dried at 65 °C, the other treated with a propionic acid. Ninety-six piglets (28 days old) were assigned to four treatments: (1) dried grain, (2) OA-preserved grain, (3) dried grain + 3% butyric acid, and (4) OA-preserved grain + 3% butyric acid. On day 8, microbial composition, inflammatory markers, volatile fatty acids, and intestinal morphology were assessed. The OA-preserved grain improved feed conversion ratio (p p p CXCL8 expression (p p p p Proteobacteria (p p Proteobacteria and Pasteurellaceae (p < 0.05). In conclusion, while OA-preserved grain improves feed efficiency, nutrient digestibility, and gut microbiota, supplementing butyric acid enhances nutrient digestibility but reduces feed intake, and their combination may disrupt the microbial balance.

Keywords

• piglets
• weaning
• organic acids
• butyric acid
• SCFAs
• cereal preservation