Effect of lipid sources on growth performance, muscle composition, haemolymph biochemical indices and digestive enzyme activities of red swamp crayfish ( Procambarus clarkii )

Abstract

This study was conducted to determine the effects of different dietary lipid sources on red swamp crayfish (Procambarus clarkii). Six diets were formulated with the same lipid level (85 g/kg) to contain fish oil (FO), soybean oil (SO), corn oil (CO), palm oil (PO), lecithin oil (LO) and pork lard (PL) respectively. Each diet was fed to triplicate of 18 crayfish with an initial weight of (13.05 ± 0.60) g for 8 weeks. The results showed that crayfish fed diet SO had a significantly higher weight gain rate and specific growth rate than those fed diet CO, PO and PL, but there was no significant difference among crayfish fed diet FO, SO and LO. Crayfish fed diet PL had the highest feed conversion ratio and the lowest survival rate. Significantly increased muscle lipid contents were observed in groups PO and PL compared with other groups. Group FO had the highest values of EPA, DHA and n-3/n-6 ratio in muscle, followed by groups LO and SO. The haemolymph triacylglycerol content was the highest, whereas alkaline phosphatase activity was the lowest in crayfish fed diet PL. Moreover, a significant increase of total protein content was observed in the haemolymph of crayfish fed diet FO, SO and LO. In conclusion, crayfish fed diet FO, SO and LO showed better growth than those fed diet PL and PO without any signs of essential fatty acid deficiency.