The effect of salmonella inhibitors supplementation on egg production, egg quality, blood profiles, and excreta salmonella in laying hens

Abstract Text: This study was conducted to investigate the effect of salmonella inhibitors supplementation on egg production, egg quality, blood profiles and excreta salmonella in laying hens. A total of 288 ISA-brown laying hens (40-week-old) were selected for a 5-wk feeding trial. Hens were randomly allocated into 6 treatments with 4 replications per treatment, and 12 hens per replication, according to a completely randomized design.The experimental treatments included: 1) NC (basal diet), 2) PC (basal diet + 0.1%virginiamycin, antibiotics), 3) A (NC + 0.1% Bacillus subtilis1.0×10¹⁰cfu/kg), 4) B (NC + 0.1% Bacillus subtilisRX71.0×10¹⁰cfu/kg) and 5) C (NC + 0.1% Bacillus subtilis B2A 1.0×10¹⁰cfu/kg), 6) D (NC+0.1% Bacillus subtilis RX7 1.0×10⁹cfu/kg). Daily records of egg production and feed consumption were kept throughout the experimental period. Egg production was expressed as an average production of hen per day, which was calculated from the total number of eggs divided by the number of experimental time (week as a unit) and summarized on an average basis. All data were arranged to evaluate by analysis of variance following the GLM procedure in a completely randomized design using the SAS software program (SAS Institute, 1996). Laying hens were blocked with identical age. The difference among treatment was compared using the Duncan’s multiple range tests. The treatment effect was observed significant with the probability value below 0.05. Egg production was higher (96 vs. 90, 91 %; P<0.05) in treatment B than in NC and PC treatments at 3wk. Eggshell thickness was higher (40.87 vs. 40.24, 40.32 mm^-2; P<0.05) in treatment D than in NC and PC treatments at 1wk. B and D treatments had higher (41.17, 41.17 vs. 40.48, 40.51, 40.64, 40.53 mm^-2; P<0.0.5) eggshell thickness than those in other treatments at 3wk. But, no differences (P>0.05) on eggshell color, egg weight, yolk height, yolk color, haugh unit and eggshell strength were observed during the whole experiment.There was no difference (P>0.05) in WBC, RBC, lymphocyte and haptoglobin among dietary treatments. Excreta Salmonella was higher (2.59 vs. 2.23, 2.28, 2.28, 2.28, 2.29 log₁₀cfu/g; P<0.05) in NC treatment compared with those other treatments. In conclusion, dietary salmonella inhibitors have no effects on eggshell color, egg weight, yolk height, yolk color, haugh unit and eggshell strength and blood profiles in laying hens. However, Bacillus subtilis supplementation improved egg production, eggshell thickness and excreta salmonella in laying hens

Keywords: egg production, eggshell thickness, excreta salmonella, laying hens, salmonella inhibitors.