Growth performance, intestinal morphology, hepatopancreatic antioxidant capacity and growth‐related gene mRNA expressions of juvenile grass carp ( Ctenopharyngodon idellus ) as affected by graded levels of dietary arginine

Abstract

An 8‐week growth trial was conducted to investigate the effects of dietary Arg levels (7.6, 12.3, 17.9, 22.4 and 28.6 g/kg diet) on growth performance, hepatopancreatic antioxidant capacity, intestinal morphology and growth‐related gene expressions of juvenile grass carp (Ctenopharyngodon idellus). The results showed that SGR in Arg22 and Arg28 groups was lower than in Arg12 and Arg17 groups (p < 0.05). Serum NO content in Arg7 group was lower than other groups. Hepatopancreatic GSH‐Px activity was higher in Arg17 group than in Arg7 group, while MDA content showed the opposite trend. Hepatopancreatic IGF‐1 expression tended to increase with Arg from 7.6 to 22.4 g/kg and then decreased in Arg28 group (p < 0.05), while IGFBP‐1 expression increased with Arg level. Muscle mRNA expressions of TOR and S6K1 showed quadratic trends as dietary Arg level increased, which were higher in Arg17 group than in Arg22 and Arg28 groups (p < 0.05). Higher mRNA expression levels of y+LAT1, y+LAT2 and PepT1, as well as higher villus height and villus width in foregut, were all observed in Arg17 group. The optimal dietary Arg level based on SGR by the quadratic model was 15.3 g/kg diet for juvenile grass carp, corresponding to 54.7 g/kg dietary protein.

Interactive effects of stocking density and dietary supplementation with Nano selenium and garlic extract on growth, feed utilization, digestive enzymes, stress responses, and antioxidant capacity of grass carp, Ctenopharyngodon idella

“…This may suggest that the high stocking density (HD) tanks lose buffering capacity. However, TAN concentration, pH, alkalinity, water temperature, salinity, and dissolved oxygen were all in a safe range for the culture of grass carp (Chen, Zhang, Tan, Zhou, & Yao, 2019; Liu et al, 2018).…”

Dietary lysine affects growth performance, whole‐body composition and growth‐related gene expression in the yellow drum Nibea albiflora

“…Hevrøy et al (2007) indicated that lower lysine intake could decrease liver IGF‐I expression levels in Atlantic salmon; hence, a deficiency of dietary lysine could explain decreased IGF‐I expression in N. albiflora . However, excess dietary lysine also decreased IGF‐I expression in this study, and the reason may be that excess dietary lysine led to insulin resistance through a negative feedback system (Liang et al, 2016; Um, Alessio, & Thomas, 2006; Chen, Zhang, Tan, Zhou, & Yao, 2019). In this study, the muscle IGF‐IR gene expression of fish fed 13.1 g/kg diet was significantly lower than that of fish fed other diets, indicating that lysine deficiency seems to be compromising the function of IGFs in muscle, which is in agreement with the previous study of Azizi et al (2016), lysine deficiency decreased IGF‐IR mRNA levels.…”

“…However, excess dietary lysine also decreased IGF-I expression in this study, and the reason may be that excess dietary lysine led to insulin resistance through a negative feedback system (Liang et al, 2016;Um, Alessio, & Thomas, 2006;Chen, Zhang, Tan, Zhou, & Yao, 2019).…”

Growth performance, digestive and absorptive capacity of on‐growing grass carp ( Ctenopharyngodon idellus ) fed with graded level of dietary fibre from soybean hulls

“…The intestinal folds height in each intestine section was determined by a visual micrometre (inverted microscope A200 type, Zeiss, Germany), and the average value was taken as the measurement result according to Yan and Zhou (2006). Two sections of each sample and four villi of each section were randomly selected for measurement according to Chen et al., (2019).…”