Effect of a liquid culture of Enterococcus faecalis CGMCC1.101 cultivated by a high density process on the performance of weaned piglets

• A better way to cultivate a specific strain of Enterococcus faecalis using central composite design.
• A liquid culture of Enterococcus faecalis can improve the performance of weaned pigs.

This study developed a high density process using response surface methodology to cultivate Enterococcus faecalis CGMCC1.101 and subsequently investigated this liquid form product in improving the performance of weaned piglets. Exp. I was carried out to use a central composite design (CCD) for the optimization of carbon source, nitrogen sources and pH in the fermentation broth to raise the cell density of E. faecalis CGMCC1.101. Optimum conditions for growth of E. faecalis CGMCC1.101 were (g/l): beef extract, 12.5; yeast extract, 12.5; sucrose, 25; K2HPO4, 2; sodium acetate, 5; di-ammonium hydrogen citrate, 2; MgSO4, 0.2; MnSO4, 0.05; Tween 80, 1 ml/l with pH of 6.7. The ultimate biomass concentration of E. faecalis CGMCC1.101 using the optimized media reached 3.5×109 CFU/ml. In Exp. II, 108 weaned piglets (Duroc×Landrace×Large White), with an initial body weight of 8.9±2.5 kg, were randomly allocated to one of three treatments with six pens per treatment and six pigs per pen. Weaned piglets were fed either a corn-soybean meal based control diet or same diets supplemented with antibiotic (50 mg/kg Kitasamycin) or the liquid fermentation product (3.5×109 CFU/kg E. faecalis CGMCC1.101). The effects of the liquid culture of E. faecalis CGMCC1.101 on performance, intestinal microflora and morphology as well as nutrient digestibility in weaned piglets were investigated. The results of Exp. II demonstrate that the liquid culture of E. faecalis CGMCC1.101 can improve the efficiency of feed utilization and balance the microbial environment in weaned piglets.