Coencapsulation of Multistrain Bacillus Spores With Alginate and Gracilaria Polysaccharide Enhances Stability, Egg Production, and Gut Health in Laying Hens

Stable and effective probiotic supplements are essential for sustainability in animal production. To optimize delivery systems and evaluate the in vivo performance of a multistrain spore‐forming probiotic for laying hens, a comparative study was conducted. Sodium alginate alone (AO) and an alginate– Gracilaria fisheri polysaccharide compound (AP) were evaluated as encapsulation matrices. This study aimed to assess the efficacy and safety of a multistrain probiotic supplement for laying hens. The supplement was formulated with spores from four promising Bacillus strains including Bacillus aryabhattai CKNJH11, Bacillus sp. THPS1, Lysinibacillus sp. PWR01, and Bacillus marisflavi OYNH19. The results showed that coencapsulating spores with AP demonstrated a significantly higher encapsulation yield ( p < 0.05) and improved survival under simulated gastrointestinal conditions, heat treatment, lysozyme exposure, and 60‐day storage. In vivo feeding trials with Hi‐sex Brown laying hens (35 weeks) showed that AP microcapsules delivering 1 × 10 6 spores/g feed significantly increased egg production (peak at 95.88%), body‐weight gain, and egg quality compared to the control and free‐spore groups ( p < 0.05). Feed conversion ratio (FCR) and Haugh unit (HU) remained unchanged ( p > 0.05) at 38 weeks. Additionally, hens fed the encapsulated probiotic spores demonstrated a notably decreased fecal Salmonella sp. level (5.29–5.40 log 10 CFU/g) when compared to control groups ( p < 0.05). Coencapsulating multistrain Bacillus spores with AP improved spore stability and maintained measurable production and gut‐health–related outcomes under laying hen conditions, supporting encapsulation‐matrix selection as a determinant of probiotic product performance in poultry production.