Evaluation of dietary linoleic acid on growth as well as hepatopancreatic index, lipid accumulation oxidative stress and inflammation in Chinese mitten crabs (Eriocheir sinensis)

Abstract

This study aimed to investigate the effect of dietary linoleic acid (LA) on the growth, hepatopancreatic development and health of Eriocheir sinensis. Crabs (initial body weight: 28.53 ± 0.63 g) were fed with five formulated diets containing graded levels of LA (7, 14, 21, 28, 35 g/kg) for 90 days. Each diet was tested in four replicates. A significant (P < 0.05) increase in weight gain (WG) and specific growth rate (SGR) was observed as dietary LA levels vary 21–35 g/kg. 21 or 28 g/kg dietary LA promoted hepatopancreatic development, which was evidenced by an increased (P < 0.05) hepatopancreatic index (HSI) and decreased (P < 0.05) proportion of G2/M cells. Immunofluorescence analysis showed that the accumulation of hepatopancreatic lipid increased (P < 0.05) in 21 and 28 g/kg LA groups. These effects possibly were associated with increased (P < 0.05) expression of CPT1, ACO, FATP 4, FABP10 and FAS. In addition, increased (P < 0.05) malondialdehyde (MDA) and suppressed (P < 0.05) total antioxidant capacity (T-AOC) was observed in E. sinensis fed with 28 or 35 28 g/kg dietary LA. The expression of genes related to inflammation showed no significant difference among all groups. In conclusion, 21 or 28 g/kg dietary LA promoted growth, HSI and the accumulation of hepatopancreatic lipid; High-grade dietary LA (28 and 35 g/kg) did not induce inflammation and inhibit growth but posed a threat to oxidative stress.