| Abstrakt: |
This study aimed to investigate the impacts of three strains of probiotics (Bacillus spp. (B.)) and one prebiotic based on Saccharomyces cerevisiae cell wall (SCCW) supplements on performance, egg quality and immune-related gene expression of laying hens. The experiment lasted 16 weeks (52–68 weeks), during which 450 Hisex white layers at 52 weeks were randomly allocated into five dietary regimens (five replications of 18 birds per floor pen): T1, basal diet; T2, basal + 0.5 g/kg B. subtilis (DSM17299); T3, basal + 0.5 g/kg B. subtilis (DSM 5750) and B. licheniformis (DSM 5749); T4, basal + 0.4 g/kg B. subtilis PB6; and T5, basal + 0.25 g/kg SCCW. The results showed that hen-day egg production (HDEP) improved in T4 and T5, egg mass (EM) improved in T3, T4 and T5, and feed conversion ratio (FCR) improved in T4 and T5 compared to T1 (p <.001). Relative wet and dry yolk weight were higher in hens received T2, T4 and T5 (p <.05) and T2, T3, T4 and T5 (p <.001), respectively, compared to T1. Moreover, T2, T4 and T5 had higher expression of GnRH-2 gene compared to T1 (p <.01). In conclusion, the dietary inclusion of SCCW-based prebiotic (T5) and Bacillus spp. probiotic strains, especially T4 B. subtilis PB6 improved production performance, egg components and GnRH-II gene expression of laying hens during phase II of the production cycle and hold a great promise for boosting productivity and supporting health status of layers raised on AGPs-free diets. Highlights: Supplements used in this experiment improved laying hen's performance significantly compared to the un-supplemented group. Supplements improved significantly egg components and gene expression compared to the un-supplemented group. Saccharomyces cerevisiae cell wall-based prebiotic and B. subtilis PB6 showed better improvements for production performance, egg components and GnRH-II gene expression compared to other additives. [ABSTRACT FROM AUTHOR] |
