Effects And Mechanism Of Adding Bacillus Lateralis To The Diet On The Performance Performance Of Broilers

The experiment studied the effects of different dosage of Bacillus lateralis on broiler production performance,slaughter performance,meat quality,antioxidant performance,cecal microflora and metabolism,and preliminarily explored its mechanism,in order to provide theoretical support for the application of related products in broiler production.In the experiment,healthy 1-day old male Yisheng 909 broilers with similar body conditions were selected and randomly divided into 4 treatments,with 8 replicates for each treatment and 10 chickens for each replicate.In the experiment,the control group was fed a basic diet,and the three experimental groups were supplemented with 100 mg/kg（Viable count≥5×10⁹ CFU/kg）,300 mg/kg(Viable count≥1.5×10¹⁰ CFU/kg),and 500 mg/kg(Viable count≥2.5×10¹⁰ CFU/kg)of Bacillus lateralis,respectively.The test period is 42 days in total.The test results show that:1.Effects of Bacillus subtilis on production performance,slaughter performance,and meat quality in broilers（1）Production performance:The addition of 300 mg/kg of Bacillus lateralis significantly improved the average daily weight gain and feed conversion rate of broilers throughout the experimental period（P<0.05）.（2）Slaughtering performance:The addition of Bacillus lateralis significantly improved the half clean bore rate（P<0.05）of broilers,decreased the leg muscle rate（P<0.05）,and significantly improved the full clean bore rate（P<0.05）of 300 and 500 mg/kg broilers.（3）Meat quality:The addition of 500 mg/kg of Bacillus lateralis significantly increased muscle water capacity（P<0.05）,and the 500 mg/kg group significantly increased the C18:3n3in muscle（P<0.05）;The proportion of C18:1n9t r in the 100 mg/kg and 500 mg/kg groups was significantly decreased（P<0.05）,while the proportion of C20:3n3 and C20:4n6 in the300 mg/kg group was significantly decreased（P<0.05）.2.Effect of Bacillus subtilis on serum biochemical indicators and antioxidant performance in broilers（1）Blood biochemical indicators:Adding 500 mg/kg of Bacillus lateralis significantly increased the content of TG in serum of 21 days broilers（P<0.05）;Adding 300 mg/kg of Bacillus lateralis significantly increased the content of TG and HDL-C in serum of 42 days broilers（P<0.05）.（2）Antioxidant capacity:At 21 days,the 300 mg/kg and 500 mg/kg supplementation groups significantly increased the activities of GSH-Px and CAT in serum（P<0.05）,increased the activity of GSH-Px in chest muscle（P<0.01）,and significantly decreased the content of MDA in chest muscle（P<0.05）.The 300 mg/kg group significantly increased the activities of GSH-Px in liver（P<0.01）,and the content of MDA significantly decreased（P<0.05）,The500 mg/kg group significantly increased the activity of SOD（P<0.05）;At 42 days,supplementation with Bacillus lateralis significantly reduced the serum MDA content of experimental chickens（P<0.05）,significantly increased the activities of T-AOC and GSH-Px in serum（P<0.05）,significantly increased the activities of SOD in chest muscle and GSH-Px in liver（P<0.05）,and significantly decreased the content of MDA in chest muscle（P<0.05）in the 500 mg/kg group.3.The effect of Bacillus subtilis on the microbiota and metabolic differences in the cecum（1）Microbial composition:The addition of Bacillus lateralis significantly increased the relative abundance of Thickwalled and Desulfurized bacteria at the phylum level（P<0.05）,while the addition of Bacillus faecalis,Clostridium,and Micrococcus at the genus level significantly increased（P<0.05）,（2）Metabolome analysis of cecal contents:93 different metabolites were selected from control group and treatment group,including 23 upregulated and 70 downregulated metabolites.Differential metabolites were significantly enriched in 32 pathways,including phenylalanine metabolism,glycine metabolism,butyrate metabolism,tricarboxylic acid cycle,unsaturated fatty acid metabolism and taurine metabolism.In summary,adding Bacillus lateralis to the diet can effectively improve the feed conversion rate of broilers,enhance the body’s antioxidant capacity,and improve meat quality and intestinal microflora composition.Under the experimental conditions,adding 300 mg/kg of Bacillus lateralis to the diet had a better effect.