The Effects of a Single Strain Bacillus subtilis DFM on pullet performance, laying hen performance, and egg quality when fed from day of hatch until 70 weeks

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Virginia Tech


Direct-fed microbials (DFM) are a method to increase bird performance and health when antibiotics are removed or limited in the diet. The objective of this experiment was to determine the effects of a single strain Bacillus subtilis DFM on pullet performance, layer performance, and egg quality when fed from day of hatch until 70 weeks of age. In total, 576 Hy-Line W-36 laying hen pullets were randomly divided between two treatments (Control and DFM) on day of hatch across 12 cages for each of the treatments and maintained on those respective treatments for 70-weeks. The DFM was added at a target dose of 300,000 cfu/kg of feed. At the end of the 17-week pullet phase, DFM fed pullets resulted in reduced feed intake, improved FCRm with both similar body weights (P = 0.98) and body composition (P > 0.05) to the control fed pullets. At 17 weeks, 72 birds were randomly selected from each treatment and moved to 12 laying hen cages. At the end of the 52-week laying hen phase, DFM-fed hens had significantly higher hen-day egg production (P = 0.02), but decreased egg weights. No differences were reported in egg mass or feed intake, but FCR was significantly improved (P = 0.02) on a per dozen eggs basis, and improved (P = 0.06) on a g/g basis by 7.1 points with DFM-fed hens having an FCR of 2.016 and control fed hens having and FCR of 2.087. Supplementation of diets with DFM resulted in a trend in egg specific gravity, but no differences were reported in shell breaking strength or shell weight. Overall, supplementation of the DFM lowered feed intake and improved FCR without affecting body composition in the pullet phase, and increased production and improved FCR during the egg laying phase.



DFM, laying hens, pullets, FCR, egg production