Solid state fermentation of Ginkgo biloba leaves and its effects on antioxidant capacity and breast muscle quality of Broilers

Ginkgo biloba leaves, abundant in various bioactive ingredients, have promising applications as animal feed additives through microbial fermentation. In this study, we conducted an orthogonal optimization experiment with 7 factors and 3 levels using Ginkgo biloba leaves as the substrate, employing two probiotic strains Bacillus licheniformis and B. natto as the fermentation strains, respectively. The results indicated that the fermented leaves were enriched with probiotics and demonstrated ehanced levels of flavonoids, total amino acids, crude protein and aroma substances. Additionally, the palatability of the Ginkgo biloba leaf fermentation product as a feed additive was significantly improved. Specifically, the flavonoid content increased by 16.7% and 10.6%, total amino acids by 17.22% and 31.05%, total protein by 43.83% and 58.74%, and protease activities reached 1307 U/g and 1510 U/g, for B. licheniformis and B. natto , respectively. Furthermore, supplementation with 0.3% to 0.6% (mass fraction) of the Ginkgo biloba leaf fermentation product in broiler diets significantly improved feed efficiency to a certain extent, with the most significant improvement observed when 0.3% or 0.6% of B. natto fermented product was added ( P  < 0.05). Through biological solid-state fermentation and conversion, the biological activity, nutritional value, and palatability of Ginkgo biloba leaves were significantly enhanced. When used as a Ginkgo biloba leaf feed additive, it promoted the development of the thymus and spleen, improved the antioxidant capacity of broilers, and enhance muscle quality to a certain extent, thereby establishing a new pathway for the efficient and high-value utilization of Ginkgo biloba leaves.