Effects on Intestinal Mucosal Morphology, Productive Parameters and Microbiota Composition after Supplementation with Fermented Defatted Olives (FDO) in Laying Hens

The olive oil sector is currently adapting its traditional function to also become a supplier of high-value by-products that possess antioxidant, anti-inflammatory and antimicrobial properties. In this study, we evaluated the effect of the fermented defatted olives (FDO) on the intestinal health of laying hens. The morphology of the duodenal and cecal mucosa, the composition of the intestinal microbiota and the productivity of a batch of laying hens were evaluated after FDO supplementation. At early life stages, significant differences (p <0.001) were observed in duodenal villi height and in crypt depth of both the duodenum and the cecum in the FDO-supplemented group, indicating improved intestinal health in this group. Microbiota composition in the hatchery group supplemented with FDO had a higher abundance of Actinobacteria, Firmicutes and Proteobacteria, and higher bacterial diversity. During the production period, significant differences (p