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Non-ruminants Full-length research article Optimization of solid-state fermentation conditions of Bacillus licheniformis and its effects on Clostridium perfringens-induced necrotic enteritis in broilers ABSTRACT-In the present study, we examined the growth parameters of Bacillus licheniformis in solid-state fermentation (SSF) and evaluated the effects of Bacillus licheniformis-fermented products on Clostridium perfringens-challenged broilers. During four and six days of SSF, the highest viable biomass was observed at 5% glucose, 10% soybean meal, 3% yeast, and 50% initial moisture content. The Bacillus licheniformis SSF products were heat-and acid-resistant. Furthermore, the fermented products were able to inhibit the growth of Clostridium perfringens and Staphylococcus aureus in vitro. In feeding experiments, in a similar manner to the antibiotic treatment group, dietary supplementation of Bacillus licheniformis-fermented products significantly improved intestinal morphology and necrotic lesions under Clostridium perfringens challenge, accompanied by increased IFN-γ mRNA expression in the spleen and bursa of Fabricius. These results together suggest that Bacillus licheniformis-fermented products have potential for development as feed additives and use as possible substitutes for antibiotics to treat Clostridium perfringens in the poultry industry.

-This study was aimed at investigating the effects of a defined concentration of Fusarium mycotoxins, deoxynivalenol (DON) and zearalenone (ZON) incorporated into feeds on growth performance, blood biochemistry, and immune response of pigs and the alleviating effects of a mycotoxin degrading enzyme (MDE) on the toxicity of Fusarium mycotoxins. A total of 48 weaning pigs was randomly allotted to four treatments (two replicates per treatment) including a control, Toxins (1 ppm DON and 250 ppb ZON), Toxin+MDE (1 ppm DON, 250 ppb ZON and 1.5 kg MDE per ton of feed), and MDE alone (1.5 kg per ton of feed) for a 6 week challenged trial. The results in different criteria including growth performance, serum biochemistry parameters, alveolar macrophage activity, antibody titers of pseudorabies (PR) vaccine and cytokine secretion profile showed that DON and ZON consistently impaired pigs after 6 week exposure. Based on these findings, we suggest that the combination of DON and ZON confers a chemical multi-organ toxicity in pigs and MDE provides a partial or complete toxic sparing effect of mycotoxins. déoxynivalénol / zéaralénone / performance de croissance / réponse immunitaire / porc

A b s t r a c tSoybean meal is the main vegetable protein source in animal feed. Soybean meal contains several anti-nutritional factors, which directly affect digestion and absorption of soy protein, thereby reducing growth performance and value in animals. Fermented soybean meal is rich in probiotics and functional metabolites, which facilitates soybean protein digestion, absorption and utilization in piglets. However, the mixed solid-state fermentation (SSF) conditions of soybean meal remain to be optimized. In this study, we investigated the optimal parameters for SSF of soybean meal by Lactobacillus species and Clostridium butyricum. The results showed that two days of fermentation was sufficient to increase the viable count of bacteria, lactic acid levels and degradation of soybean protein in fermented soybean meal at the initial moisture content of 50%. The pH value, lowering sugar content and oligosaccharides in fermented soybean meal, was significantly reduced at the initial moisture content of 50% after two days of fermentation. Furthermore, the exogenous proteases used in combination with probiotics supplementation were further able to enhance the viable count of bacteria, degradation of soybean protein and lactic acid level in the fermented soybean meal. In addition, the pH value and sugar content in fermented soybean meal were considerably reduced in the presence of both proteases and probiotics. Furthermore, the fermented soybean meal also showed antibacterial activity against Staphy lococcus aureus and Escherichia coli. These results together suggest that supplementation of both proteases and probiotics in SSF improves the nutritional value of fermented soybean meal and this is suitable as a protein source in animal feed.

Bacillus species are commonly used as probiotics in the poultry feed industry for preventing infectious diseases and improving productivity by altering gastrointestinal microbiota. The growth parameters of Bacillus subtilis for surfactin production in fermentation and the benefits of surfactin on broiler chickens remain unclear. In this study, we examined the growth parameters of B. subtilis in fermentation and evaluated the effects of surfactin from B. subtilis-fermented products on Clostridium perfringens-induced necrotic enteritis and growth performance in broilers. Results showed that the highest viable biomass of B. subtilis was observed at 10% molasses and 2% yeast supplementation during fermentation. The 4- and 6-day fermented B. subtilis products were heat-, acid- and bile-resistant. Furthermore, the 4-day fermented B. subtilis products with the highest surfactin concentration showed the maximal antimicrobial activity against pathogens, including Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and C. perfringens. Dietary B. subtilis-fermented product supplementation in broilers significantly improved intestinal morphology and necrotic lesions under C. perfringens challenge. Bacillus subtilis treatments could enhance broiler productivity, as well as promote bone quality and intestinal morphology. These results together indicate that B. subtilis-fermented products containing surfactin have potential for the development as feed additives and use as possible substitutes for antibiotics to treat C. perfringens in the poultry industry.