Differential growth performance, intestinal antioxidant status and relative expression of Nrf2 and its target genes in young grass carp (Ctenopharyngodon idella) fed with graded levels of leucine

Dietary leucine improves flesh quality and alters mRNA expressions of Nrf2-mediated antioxidant enzymes in the muscle of grass carp ( Ctenopharyngodon idella )

“…Fish were fed four times per day for 8 weeks. The experiment condition was maintained as our previous study (Deng et al, 2014).…”

“…Our previous studies in grass carp (Ctenopharyngodon idella) have indicated that leucine has beneficial effects on intestinal antioxidant capacity and structural integrity, thus improving both growth and feed efficiency (Deng et al, 2014;Jiang et al, 2015a). The majority of fish growth is invested in accreting muscle tissue, forming the major part of the edible portion for consumers (Mommsen, 2001;Periago et al, 2005).…”

“…The present study is a part of a lager study and used the same growth trial as our previous study, which reported that leucine improved intestinal antioxidant status and that the optimal leucine requirement for growth is evaluated to be 13.0 g kg −1 diet (42.4 g kg − 1 protein) (Deng et al, 2014). The objectives of the present study were intended to further investigate the effects of dietary leucine on flesh parameters, muscle antioxidant capacity and the related signaling factors, which may provide partial theoretical basis to reveal the potential regulatory approach for flesh quality influenced by leucine in fish.…”

“…Meanwhile, the dietary optimal leucine levels based on the flesh quality for grass carp were also estimated. Table 1 shows the formulation of the basal diet which was the same as our previous study (Deng et al, 2014). Casein, fish meal and gelatin were used as the primary protein sources.…”

“…The mixture of crystalline amino acids without leucine was prepared according to the method described by Abidi and Khan (2007). Our previous study observed that the optimal leucine requirement for growth is 13.0 g kg −1 diet (Deng et al, 2014). Thus, the experimental diets were supplemented with L-leucine to provide leucine at 7.2 (unsupplemented control), 9.2, 11.2, 13.2, 15.2 and 17.2 g kg −1 of diet, while adjusting glycine to maintain the diets isonitrogenous, according to methods described by Cheng et al (2011).…”