Effects of dietary arachidonic acid on the growth performance, feed utilization and fatty acid metabolism of Chinese mitten crab (Eriocheir sinensis)

Abstract

A 12-week feeding trial was conducted to determine the effect of dietary arachidonic acid (ARA) levels on growth performance, feed utilization, muscle fatty acid composition and body proximate composition for juvenile Chinese mitten crab, Eriocheir sinensis. Six semi-purified diets containing 0.11% (control group, G1), 1.20% (G2), 2.37% (G3), 3.52% (G4), 4.76% (G5) and 7.39% (G6) ARA of total lipid content were formulated to feed six groups of crabs (the initial weight, 1.01 ± 0.12 g), respectively. Crabs in G3 showed the highest final weight, weight gain rate (WGR) and specific growth rate (SGR). The highest feed conversion ratio (FCR) was found in crabs in G1. In addition, the fatty acid composition of muscle was significantly affected by dietary ARA levels. For ARA, 22:2 and 20:5n-3, with the dietary ARA level increased, their contents increased first and then decreased, the highest values were all found in crabs of G4. High dietary ARA significantly affected the fatty acid composition of muscle in E. sinensis by increasing the relative expression of Srebp, while decreasing the relative expression of FAS, FAD 6 and ELOVL 6. Based on the results of the quadratic regression analysis of SGR and FCR, the optimum level of ARA for E. sinensis was suggested to be 4.54% and 3.88% of total lipid content, respectively.

Keywords

• Arachidonic acid
• Growth performance
• Feed utilization
• Fatty acid metabolism
• Eriocheir sinensis