Compound microbial fermentation of tofu whey wastewater enhances nutrient composition and growth performance in swine

Tofu whey wastewater (TWW) is nutrient-rich but commonly discarded in China, causing environmental pollution. Here, TWW fermented with Cyberlindnera jadinii , Lactobacillus plantarum , and Enterococcus faecalis (CMFTWW) was compared with naturally fermented TWW (NFTWW). CMFTWW showed lower pH, higher genistein and lactic acid, greater viable bacterial counts, enriched Lactobacillus and Streptococcus , and reduced Acetobacter . In weaned piglets, 15% CMFTWW improved weight gain and feed intake, reduced feed conversion ratio and diarrhea, elevated serum glucose, albumin, triglycerides, calcium, iron, and IgA, enhanced antioxidant capacity, and attenuated oxidative stress. Both CMFTWW and florfenicol enriched Clostridium_sensu_stricto_1 and Sutterella relative to controls, whereas CMFTWW further elevated Alloprevotella , Blautia and Terrisporobacter . In fattening pigs, CMFTWW increased weight gain and reduced feed conversion ratio, reduced diarrhea incidence and improved economic efficiency. This study provides preliminary evidence that compound microbial fermentation improves TWW quality and that CMFTWW can serve as a feed additive in healthy swine production.