Rutin Improved the Meat Quality and Hepatointestinal Health of Nile Tilapia ( <i>Oreochromis niloticus</i> ) After High‐Level Fava Bean Feeding

A high-level fava beans diet has been proven to enhance the texture characteristics of tilapia muscle, yet it can also induce hepatointestinal injury. Rutin, as a nutritional additive, has antioxidant and immune-boosting effects. This study explored the regulatory effect of 150 and 300 mg/kg rutin on the muscle characteristics and hepatointestinal health of tilapia after being fed with a 60% fava beans diet. Two hundred and forty tilapias (average weight: 371.50 ± 9.29 g) were evenly divided into four groups and fed with the diet of groups C0 (0% fava bean), R0 (60% fava bean), R1 (60% fava bean + 150 mg/kg rutin), and R2 (60% fava bean + 300 mg/kg rutin) for 10 weeks, respectively. The results indicated that the growth performance in R1 and R2 showed no significant changes compared to R0, while muscle hardness, gumminess, and resilience increased, along with an elevation in muscle crude protein deposition. The addition of 150 and 300 mg/kg rutin enhanced the antioxidant capacity (AOC) of the muscles, liver, and intestines, alleviated liver damage by regulating liver lipid metabolism compared with R0. Dietary supplementation with 150 mg/kg rutin improved the composition of intestinal microbiota, significantly upregulating the abundance of beneficial bacteria <i>Muribaculaceae</i> unclassified and reduced the abundance of harmful bacteria <i>Rhodobacteraceae</i>, <i>Chloroplast_unclassified</i>, and <i>Rothia</i>. In summary, rutin can effectively function as a nutritional supplement to alleviate liver and intestinal damage caused by 60% fava bean feed, while also improving muscle texture simultaneously. This study provides a crucial theoretical basis for optimizing crispy tilapia aquaculture through rutin supplementation, promoting innovation in aquatic feed formulations.