The interactive regulatory effects of light exposure and bamboo fiber supplementation on growth performance, hormone levels, and gut microbiome composition in white-feathered broiler breeder chickens

This study investigated the interactive effects of light intensity (4 Lux vs. 5 Lux) and bamboo fiber supplementation (0% vs. 1%) on growth performance, reproductive hormones, antioxidant status, laying performance, egg quality, and intestinal flora in Arbor Acres broiler breeders. A total of 32,000 Arbor Acres white broiler breeder hens at 49 days of age were randomly assigned to four treatment groups: 4 Lux basal diet, 5 Lux basal diet, 4 Lux + 1% bamboo fiber, and 5 Lux + 1% bamboo fiber, with eight replicates per group and 1,000 hens per replicate. The experimental period was 126 days. Two-way ANOVA showed significant light × fiber interactions for estradiol, GSH-Px, MDA, and eggshell lightness L ( P < 0.05). Light intensity alone affected FSH, UA, and eggshell color a* ( P < 0.05). One-way ANOVA with post-hoc comparisons further showed that the 5 Lux + bamboo fiber group achieved the highest laying rate (45.40%) and significantly increased MT levels (54.61%). Compared to the 4 Lux group, the 5 Lux group showed increased FSH, E 2 , and GSH-Px activity, but decreased eggshell thickness ( P < 0.05). Relative to the 5 Lux group, the 5 Lux + bamboo fiber group exhibited increased GSH, MDA, and GSH-Px, but decreased E 2 , ALB, and γ-GT ( P < 0.05). This group also significantly reshaped the intestinal flora structure, increasing the Firmicutes/Bacteroidetes ratio from 1.91 to 19.34 and enriching beneficial bacteria such as Lactobacillus and Limosilactobacillus. Combined 5 Lux lighting and 1% bamboo fiber improved laying rate and antioxidant status. These results suggest that light intensity and fiber intake can be managed together to support breeder performance.