Response of zebrafish to royal jelly supplementation and differences in stocking density

Dietary supplementation with royal jelly (RJ) may improve growth, antioxidant gene expression, and intestinal capacity, possibly mitigate effects of stress induced by high stocking density (HSD) in zebrafish (Danio rerio). Effects HSD RJ on growth performance, capacity were investigated. A total 240 four-month-old used a 2 x factorial design, four treatments three replications. The consisted normal (NSD) (1 fish/L) (3 an unsupplemented commercial diet (0RJ) supplemented 10% (10RJ). experiment lasted 25 days. Daily weight gain, final body length, specific rate, survival recorded. On day 25, six fish per treatment euthanised their intestines analysed for superoxide dismutase (SOD2) catalase (CAT) expression. There no or SD interaction growth. High decreased daily gain 25.31%, length 2.70%, 16.85%. Stocking (SD) influenced SOD2 CAT expression capacity. HSD/0RJ group had lower than the HSD/10RJ NSD/0RJ groups. Supplementation did not harmful stress. These results indicate that promotes transcriptional suppression encoding enzymes form first line defence, resulting reduced elimination toxic substances occurrence oxidative