Effects of dietary glutamine supplementation on growth performance, antioxidant status and intestinal function in juvenile grass carp (Ctenopharyngodon idella)

Abstract

Glutamine (Gln) is a conditionally essential free amino acid that has been widely used in aquaculture. The present study showed that appropriate levels of dietary Gln could significantly improve growth performance and increase lipase and trypsin activity, mucosal thickness (MT) and the number of lymphocytes. The levels of glycine (Gly) in the 6 g/kg Gln group, threonine (Thr) in the 12 g/kg group and lysine (Lys) in the 6 and 9 g/kg group were increased significantly, while glutamate (Glu) and serine (Ser) concentrations decreased significantly with increasing dietary Gln levels from 3 to 12 g/kg. Moreover, the 12 g/kg dietary Gln level could improve the concentration of malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GSH‐PX) and the total antioxidant capacity (T‐AOC). In addition, 3 g/kg Gln upregulated the gene expression of aminopeptidase N (APN), caudal‐related homeobox gene (CDX2), L‐type amino acid transporter 2 (LAT2), oligopeptide transporter 1 (PEPT1), specificity proteins 1 (SP1) and 3 (SP3), and peroxisome proliferator‐activated receptor α (PPAR‐α) but downregulated PPAR‐γ gene expression compared to that in the control group. Taken together, these findings suggest that Gln could improve the growth performance, antioxidant status and intestinal function of grass carp.

Molecular Characterization and Nutrition Regulation of the Neutral Amino Acid Transporter ASCT2 in Triploid Crucian Carp

“…In this study, we found that the additions of glutamate and glutamine in daily feed increased the FCR and FR in triploid crucian carp. These results were consistent with the research in Atlantic salmon (Salmo salar L.) and grass carp [37,38]. By comparing the effects of glutamate additive on expression levels of ASCT2 between intestine and muscle, we found they had a similar trend.…”

Effects of dietary glutamine supplementation on growth performance, intestinal digestive ability, antioxidant status and hepatic lipid accumulation in Xenocypris davidi (Bleeker,1871)

“…In the present study, X. davidi fed with 6 g/kg and 9 g/kg of glutamine showed signi cant improvements in growth performance, which indicate that the appropriate levels of glutamine can promote sh growth. Similar ndings have been reported on half-smooth tongue sole (Cynoglossus semilaevis Günther) (Jingwei, et al, 2015), grass carp (Ctenopharyngodon idella) (Qu, et al, 2019), Jian carp (Cyprinus carpio var. Jian) (Hu, et al, 2015).…”

“…Glutamine increased the e ciency of the sh to utilise nutrients on their own, which was a key factor for the improved growth performance. Moreover, glutamine can improve sh intestine function with the improvement of intestinal structure and enhances the release of digestive enzymes (Chen, et al, 2009;Pohlenz, et al, 2012;Qu, et al, 2019), such like the way 6 g/kg and 9 g/kg group did. However, the growth performance of sea cucumber (Apostichopus japonicus Selenka) (Yu, et al, 2016) and Nile tilapia (Oreochromis niloticus) (Pereira, et al, 2017) was found to be reduced after feeding diets supplemented with high level of glutamine.…”

“…Glutamine is regarded as nutritionally nonessential amino acids for sh (Li, et al, 2020a). However, glutamine has been classi ed as a "functional amino acid" because of its several functions in animals, including promoting growth, enhancing intestinal health, and immunological modulation (Teng, et al, 2021;Qu, et al, 2019). Although the physiological requirements for glutamine are particularly high in all cultured animals, including livestock, poultry, and sh, conventional protein sources in feeds such as soybean meal (18 mg/kg) and shmeal (12.3 mg/kg) contain only low amounts of glutamine (Li, et al, 2020a;Li, et al, 2020b).…”

Effects of dietary fermented Saccharomyces cerevisiae extract (Hilyses) supplementation on growth, hematology, immunity, antioxidants, and intestinal health in Nile tilapia

“…These results agree with previous studies showing immunostimulant mixtures can beneficially affect digestive enzymes in fish 71 . Specifically, glutamine has been shown to stimulate production of digestive enzymes and regulate absorption of amino acids 72 . Similar effects of yeast supplements on enzyme activity were seen in shrimp fed fermented soybean meal 73 .…”