Effects of Dietary Sulforaphane Supplementation on Growth Performance, Intestinal Digestive Capacity, Barrier Function and Appetite-Regulating Gene Expression in Cyprinus carpio haematopterus

An 8-week nutrition experiment was carried out to research the role of sulforaphane (SFN) supplementation on growth, intestinal digestive capacity, intestinal barrier function and appetite-regulating gene expressions in Cyprinus carpio haematopterus. Fish (76.17 ± 0.23 g) were fed five experimental diets (namely, S1-5) containing 0, 5, 10, 15 and 20 mg kg−1 of SFN, respectively. Results showed that daily growth coefficient (DGC), growth rate per metabolic body weight, feed efficiency ratio, whole-body crude protein contents, intestinal lipase and protease activities, and expression of apelin, orexin and neuropeptide Y in brain, as well as mammalian target of rapamycin, zonula occludens 1, occludin, claudin-2 and claudin-3 in the intestine increased significantly as SFN levels increased in a 10 mg kg−1 diet, but decreased with further increasing SFN levels. Overall, SFN supplementation improves growth, appetite-regulating gene expressions, intestinal digestive capacity and barrier-related gene expressions of fish. Based on the quadratic regression analysis of DGC against SFN levels, optimal SFN was established to be a 9.71 mg kg−1 diet.