Maternal Taishan Panshi San supplementation is associated with improved foal growth performance, accompanied by alterations in gut microbiota and metabolic profiles

Objective: To investigate the effects of Taishan Panshi San (TSPSS) supplementation on foal growth and immunity. Methods: Twelve pregnant mares and their foals were divided into three groups: control (NC), TSPSS every other month (GY), and TSPSS monthly (MY) from gestation day 30. Maternal blood was sampled on days 65, 185, and 305 for hormone analysis. Foals were assessed for growth, cytokines, antioxidants, and immunoglobulins at birth, and onset of diarrhea (FQ), from 30 to 120 days after birth. Intestinal microbiota and metabolites were analyzed. Results: spp. at 90 d, which were linked to steroid and amino acid metabolism. Short-chain fatty acids (such as acetate, etc.) decreased at FQ/30 d, with group-specific correlations. Conclusion: Maternal TSPSS supplementation during pregnancy may modulate placental gene expression and improve gut microbiota and metabolism, thereby promoting the growth and development of foals.