Effects of dietary glutamate supplementation on growth performance, digestive enzyme activities and antioxidant capacity in intestine of grass carp (Ctenopharyngodon idella )

Abstract

A 56-day feeding trial was carried out to investigate the effect of dietary glutamate (Glu) supplementation on growth performance, digestive enzyme activities and intestinal antioxidant capacity of grass carp (Ctenopharyngodon idella). A total of 540 grass carp with average initial weight of 370 AE 3.8 g were fed three diets supplemented with 0, 8 and 16 g kg À1 Glu. The per cent weight gain, specific growth rate, feed conversion ratio, and protein and lipid productive value were significantly improved by dietary Glu supplementation. Feed intake, condition factor, visceral somatic index and perivisceral fat ratio were not significantly different between dietary groups. Hepatosomatic index, intestinal somatic index, intestine length index, intestine protein content, trypsin activity in hepatopancreas and intestine, lipase activity in proximal and mid-intestine (MI) and hepatopancreas, alkaline phosphatase and gamma-glutamyl transpeptidase activities in intestine, creatine kinase activities in the mid-and distal intestine, intestinal folds height in the proximal and MI were significantly increased with increased Glu. Malondialdehyde and protein carbonyl contents in the intestine decreased with increased Glu. Superoxide anion and hydroxyl radical scavenging ability, glutathione reducase, catalase and total superoxide dismutase activities, and glutathione content in the intestine were increased with increased Glu. These results suggested that dietary Glu supplementation increased intestinal antioxidant capacity, digestive and absorptive ability and improved fish growth.

Dietary glutamine supplementation effects on amino acid metabolism, intestinal nutrient absorption capacity and antioxidant response of gilthead sea bream (Sparus aurata) juveniles

“…In fish, evidences exist of a positive effect of dietary Gln and glutamate supplementation to the glutathione content of different tissues as result of the increased glutamate provision for glutathione biosynthesis (Zhu et al, 2011;Zhao et al, 2015). In the present study, increased total glutathione (tGSH) and reduced glutathione (GSH) levels were also observed in both liver and intestine of fish fed Gln supplemented …”

Comparative study on the utilization of different methionine sources by channel catfish, Ictalurus punctatus (Rafinesque, 1818)

“…In the studies on Jian carp (Zhou et al . ; Zhou, Zhao, Jiang, Feng & Liu ) and grass carp ( Ctenopharyngodon idella ) (Zhao, Hu, Zhou, Zeng, Feng, Liu, Jiang, Li, Li, Wu, Wu & Jiang ), the LPV were also found to be higher than 100%. The reason may be attributed to the synthesis of lipid from carbohydrate and protein.…”

Effects of lysine and methionine supplementation on growth, body composition and digestive function of grass carp (Ctenopharyngodon idella) fed plant protein diets using high-level canola meal

“…Then the intestines and hepatopancreas were frozen in liquid nitrogen and kept at À70°C until analysis. The intestines of another six fish from each tank were sampled to measure the height of intestinal folds according to Zhao et al (2015). The proximate compositions of fish carcass and diets were measured according to the methods of the Association of Official Analytical Chemists (Horwitz 2000).…”