TITLE:
Effects of Dietary Soy Protein Concentrate on Growth, Digestive Enzymes Activities and Target of Rapamycin Signaling Pathway Regulation in Juvenile Soft-Shelled Turtle, Pelodiscus sinensis
AUTHORS:
Fan Zhou, Yaqin Wang, Li Tang, Yong Huang, Xueyan Ding, Zhongyang He
KEYWORDS:
Soft-Shelled Turtle P. sinensis, Soy Protein Concentrate, Growth Performance, Digestive Enzymes, Target of Rapamycin Signaling Pathway
JOURNAL NAME:
Agricultural Sciences,
Vol.6 No.3,
March
12,
2015
ABSTRACT: Soft-shelled turtle, Pelodiscus sinensis is important aquatic species in China, and searching for alternatives protein resources
to fish meal (FM)-based feeds in feed has become urgent and important for its sustainability
development. The present study was conducted to assess the effects of dietary soy
protein concentrate (SPC) on growth, digestive enzymes and target of rapamycin (TOR)
signaling pathway of juvenile P. sinensis (4.56 ± 0.09 g). SPC was applied to replace FM protein at 0%, 15%, 30% and 60% (designated
as T0, T15, T30 and T60, respectively), and each diet was fed to triplicate groups.
The results showed that there was no significant difference in growth performance
and feed utilization except of the turtles fed with T60 diet, of which showed poorer
daily weight gain and feed conversion rate. The pepsin/trypsin and Na+-K+ ATP-ase activities decreased dramatically when SPC level increased, and lipase activities
in liver and intestinal tract also showed decline tendency. However, amylase activities
were unaffected. No significant differences were observed in TOR, S6K1 and 4E-BP1
genes mRNA expression level of TOR signaling pathway among the treatments. However,
the relative phosphorylated level of these proteins decreased significantly when SPC level increased. The present
study indicated that high SPC substitution level would suppress digestive
enzymes and TOR signaling pathway proteins phosphorylated level and eventually result
in growth reduction of P. sinensis.