标题：Beneficial Effects of Dietary Bacillus subtilis and Citric Acid Supplementation on Growth Performance, Feed Efficiency and Body Composition of Juvenile Red Hybrid Tilapia ( O. Niloticus × O. mosambicus )
摘要：Background and Objective: Citric acid and Bacillus subtilis are commonly used as dietary supplements to improve growth performance of fish. Here we investigated the effects of dietary supplementation with Bacillus subtilis and citric acid on growth performance, feed efficiency and body composition of juvenile red hybrid tilapia. Materials and Methods: Over a 90-day experimental period, growth performance, feed utilization and body composition were measured and intestinal morphometric and histopathological examinations were performed for 120 fish divided into four groups (D1-D4). D1 received the control diet. For groups D2-D4, control diet was supplemented with: D2: 10 mL kg1 diet B. subtilis ; D3:10 mL kg1 B. subtilis and 5 g citric acid kg1 diet and D4:10 mL kg1 B. subtilis and 10 g citric acid kg1 diet. Results: Fish fed diets containing citric acid and B. subtilis exhibited significant improvements in body weight gain, specific growth rate, condition factor, feed conversion rate, feed efficiency, protein efficiency ratio, protein productive value and chemical composition relative to fish fed the control diet. Fish in D3 and D4 showed incremental increases in villi length in the duodenum and jejunum. Conclusion: Citric acid and B. subtilis supplementation had a synergistic effect to improve feed efficiency, growth performance and body composition as well as morphometric characteristics of juvenile red hybrid tilapia.
