Effects of fermented <i>Broussonetia papyrifera</i> on the laying performance, egg quality, and gut microbiota of Taihe silk chicken during the peak laying period

Abstract Taihe silk chicken ( Gallus gallus domesticus Brisson ) are prized for their nutritional value but face challenges like low productivity and feed efficiency. Broussonetia papyrifera (BP), rich in nutrients, is mainly used in ruminant feed. This study investigates the effects of fermented BP (FBP) on the laying performance, egg quality, and gut microbiota of Taihe silk chicken during peak laying period. A total of 240 chickens were randomly assigned to four treatments (five replicates/treatments) with a basal diet (CON), a basal diet + 2% FBP (T2), a basal diet + 4% FBP (T4), and a basal diet + 8% FBP (T8) for 75 d. Results showed that the average daily feed intake and yolk color in the 8% FBP group were significantly increased by 12.21% and 11.78%, respectively ( P &lt; 0.05). Yolk folate content of the 4% and 8% FBP groups was significantly increased by 32.73% and 59.76%, respectively ( P &lt; 0.05). Zinc content in the yolk of the 8% FBP group was significantly increased by 14.22% ( P &lt; 0.05). The FBP group influenced the fatty acid composition of the yolk, and 8% FBP significantly decreased the n -6 unsaturated fatty acid (PUFA) to n -3 PUFA ratio ( P &lt; 0.05). FBP also increased the ratio of villus height, and crypt depth significantly increased in the duodenum, jejunum and ileum ( P &lt; 0.05). The 16S rRNA sequencing revealed that FBP altered cecal microbiota, increasing the relative abundance of Bacteroides, Rikenellaceae_RC9_gut_group , and Alistipes , while reducing the relative abundance of Olsenella and Ruminococcaceae UCG-005. Correlation analysis suggests that the FBP may enhance the growth performance and egg composition by modulating gut microbiota. In conclusion, this study confirms that adding FBP to the diet improves egg quality, composition, intestinal structure, and gut microbiota in Taihe silk chicken. These insights are valuable for optimizing FBP utilization in Taihe silk chicken production.