Effects of marine hydrolysates in wheat gluten meal‐based diet on the growth, haemato‐biochemical, immunological and antioxidant status of GIFT tilapia reared in floating cages

Abstract

This study was conducted to evaluate the effects of supplementation of tuna hydrolysate (TH), squid hydrolysate (SH) and mixture of both hydrolysates in wheat gluten meal (WGM)-based diets on the growth, haemato-biochemical, immunological parameters and antioxidant indicators of GIFT tilapia. Experimental fish were fed different diets, namely a control diet containing fishmeal (FM) without WGM and hydrolysate; a WGM diet without FM and hydrolysate (WGM); a WGM diet without FM and 5 g/kg TH (WGM-TH); a WGM diet without FM and 5 g/kg SH (WGM-SH); and a WGM diet without FM and mixture of 5 g/kg of TH and SH (WGM-Mix). A total of 450 fish (9.83 ± 0.01 g) were fed on the five experimental diets in triplicate groups for 8 weeks. The growth performance and feed utilization indices of the fish were found to be significantly higher in WGM supplemented with TH diet followed by WGM-SH, WGM-Mix and WGM diets. There was no significant impact in blood and serum biochemical parameters among the treatments. The immunological and antioxidant indicators were not significantly different between hydrolysate-supplemented diets; however, they were significantly greater than hydrolysate-unsupplemented diets (control and WGM diets). Based on the results, it is suggested that FM can be replaced by WGM for better growth performance even without the supplementation of hydrolysates, whereas hydrolysates are considered important for better immunological responses and antioxidant status of GIFT tilapia.