Effects of Bacillus subtilis on growth performance, relative organ weight, meat quality, salmonella population, and blood profiles in broilers

Abstract Text: A total of 720 male and female ROSS308 broiler chicken [1 day old, initial BW 46.12 ± 0.51 g] were used in this 4-week trial (5 treatments with 9 replications/treatment and 16 chicks/pen). Dietary treatments were as follows: 1) CON (basal diet), 2) A (CON + 0.1% Bacillus subtilis B2A1.0×10⁹ cfu), 3) B (CON + 0.1% Bacillus subtilis B2A 1.0×10⁷ cfu), 4) C (CON + 0.1% Bacillus subtilis B2A 1.0×10⁸ cfu), and 5) D (CON + 0.1% Bacillus subtilis B2A 1.0×10⁹ cfu).The broilers were weighed and feed intake were recorded on d 1, 8, 18 and 28 for calculating body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR). All data were subjected to GLM procedures of SAS (1996), with pen as the experimental unit. Differences among treatments were separated by Duncan's multiple range tests; P < 0.05 was considered statistically significant. During 1-8 d, BWG was higher (163 vs.149 g; P < 0.05) in treatments D compared with treatment A. During 19-28 d, FI (1359 vs. 1242 g) and FCR were higher (1.776 vs. 1.613; P <0.05) in CON compared with treatment D. Overall (1-28 d), birds from CON treatment had higher (P < 0.05) FI (2286 vs. 2126 g) and FCR (1.658 vs. 1.538) than D treatment. The drip loss of birds from treatment A was lower (3.14 vs. 6.18 %; P < 0.05) than that of treatment C on d1. No difference (P > 0.05) was observed in relative organ weight and blood profiles among treatments. However, the salmonella populations in chicken fed with CON diet was higher (3.88 vs. 2.73, 2.83, 2.64, 2.75 log₁₀ cfu/g; P <0.05) compared with those fed with other four diets in large intestine. Moreover, the salmonella populations in CON treatment was higher (2.67 vs. 2.18 log₁₀cfu/g; P < 0.05) than that in treatment B in small intestine. In conclusion, Bacillus subtilis B2Apartially improved FCR, while decreasing salmonella populations in big or small intestine without any adverse effect on relative organ weight and blood profiles in broilers.

Keywords:

Bacillus subtilis, blood profiles, broilers, growth performance, meat quality, salmonella populations