The impaired intestinal mucosal immune system by valine deficiency for young grass carp (Ctenopharyngodon idella) is associated with decreasing immune status and regulating tight junction proteins transcript abundance in the intestine

This study investigated the effects of dietary valine on the growth, intestinal immune response, tight junction proteins transcript abundance and gene expression of immune-related signaling molecules in the intestine of young grass carp (Ctenopharyngodon idella). Six iso-nitrogenous diets containing graded levels of valine (4.3–19.1 g kg−1 diet) were fed to the fish for 8 weeks. The results showed that percentage weight gain (PWG), feed intake and feed efficiency of fish were the lowest in fish fed the valine-deficient diet (P