Dietary Black Seed Effects on Growth Performance, Proximate Composition, Antioxidant and Histo-Biochemical Parameters of a Culturable Fish, Rohu (Labeo rohita)

SIMPLE SUMMARY: Stress-related losses are of major concern in aquaculture practices. Black seed is a medicinal plant species widely used as natural antioxidants and hepatic-nephric protector. Rohu is a commercially valuable culturable fish species. The present study was undertaken to assess the effects of dietary black seeds on the growth performance and antioxidant status of rohu. Fingerlings were fed on diets containing 0.0%, 1.0% and 2.5% black seed for 28 days. The results showed that rohu fed on black seed supplemented diets has increased growth rate. Moreover, black seed supplementation improved the muscles protein contents and antioxidant status as indicated by decreased lipid peroxidation and increased antioxidant enzymes levels in the liver, kidney, gills and brain of rohu. The black seed fed rohu showed decreased hepatic–nephric marker key-functioning marker enzymes levels. The histo-architecture of liver and kidney remained unchanged following black seed supplementation. Black seed is cheap and locally available in Pakistan. On the basis of the present study results, 2.5% black seed supplementation is suggested in rohu diet to increase its growth and avoid oxidative stress related losses. The results of the present study will be useful for nutritionists, aquaculturists and researchers in formulating aqua feeds. ABSTRACT: This feeding trial was conducted to investigate the effects of dietary black seed (Nigella sativa) supplementation on the growth performance, muscles proximate composition, antioxidant and histo-biochemical parameters of rohu (Labeo rohita). Fingerlings (8.503 ± 0.009 g) were fed on 0.0%, 1% and 2.5% black seed supplemented diets for 28 days. Fish sampling was done on the 7th, 14th, 21st and 28th day of experiment. The results of the present study indicated that black seed supplementation significantly increased growth performance and muscles protein contents of rohu over un-supplemented ones. Lipid peroxidation levels significantly decreased in all the studied tissues (liver, gills, kidney and brain) of black seed fed rohu, whereas the antioxidant enzymes (catalase, glutathione-S-transferase, glutathione peroxidase and reduced glutathione) activities were increased in all the studied tissues of black seed supplemented rohu at each sampling day. The hepatic-nephric marker enzymes levels were decreased for black seed fed rohu. The present study showed that tested black seed levels are safe for rohu. Black seed is cheaply available in local markets of Pakistan; therefore, based on the results of the present study, it is suggested that black seed has potential to be used as natural growth promoter and antioxidant in the diet of rohu.