Effects of Fermented Soybean Meal on Growth Performance, Immune Response and Gut Function of Pigs

Experiments were conducted to study the effect of fermented soybean meal (FSM), which was soybean meal fermented by Lactobacillus and Aspergillus, to replace antibiotic and animal protein in pig feed. The experiments was divided to phaseⅠ(21-35 days of age) and phaseⅡ(35-70 days of age). Experimental feed were based on corn-soybean meal, the treatments were: 1) Antibiotic group: 21-35 and 35-70 days of age basal diet with 4% and 5% fish meal supplemented respectively, Chlortetracycline 130 ppm, Sulfathiazole 130 ppm, Penicillin 66 ppm, Halquinol 120 ppm. 2) FSM group: basal diet with 5% FSM to replace fish meal and antibiotics. The body weight gain, feed consumption and feed efficiency of pigs were recorded at 35, 70, 119 and 172 days of age. Blood sample analyzed the immune response with the concentrations of plasma immunoglobulin. The mucosa of jejunum was collected to analyze the concentrations of immunoglobulin A. The ileum, cecum and colon were collected to analyze bacterial composition and intestinal morphology. FSM had have more crude protein and soluble protein content in diet than commercial soybean meal (P<.05). 37 % of FSM proteins were below 1-2 kDa by FPLC. The results showed the growth performance of FSM group at 35 days of age was better than antibiotics group, but there were no significant difference at 70, 119 and 172 days of age. In diarrhea score, FSM group have more diarrhea pigs than antibiotics group during 35-70 days of age, but not in 21-35 days of age. The villus height and area in ileum were no significant difference thought experiment, but it decreased in jejunum of FSM group at 70 days of age when compared to antibiotics group (P<.05). There were no significant differences in the immune response and the microbial count in different parts of intestine between treatments. The results suggested that feed supplemented with FSM to replace antibiotics have the same immunity and microbial population with antibiotics group. In conclusion, the supplements of 5% FSM during 21-35 days of age have better performance than the antibiotics group. However, the FSM supplementation may not have the same effects as antibiotic supplementation in pig.