Effects of dietary lipid levels on the growth, digestive enzyme, feed utilization and fatty acid composition of Japanese sea bass (Lateolabrax japonicusL.) reared in freshwater

Abstract

Triplicate groups of 40 Japanese sea bass Lateolabrax japonicus reared in freshwater (average weight, 9.52 AE 0.47 g) were fed with six isonitrogenous ($ 46% crude protein) diets containing 6%, 8%, 10%, 12%, 14% or 16% lipid for 10 weeks respectively. The results showed that the maximum weight gain (WG), speci¢c growth rate (SGR), feed intake (FI) and protein e⁄ciency ratio (PER) all occurred at the 10% lipid level (Po0.05) and growth depression occurred when the dietary lipid level was over12%.Whole body and liver lipid concentrations were enhanced with the increase in the dietary lipid levels, but the muscle lipid content did not signi¢cantly change with the increase in the dietary lipid levels. Both liver pepsin and trypsin activities increased with dietary lipid levels ranging from 6% to 10%, and then decreased with a further increase in the dietary lipid content. Liver lipase activities showed a positive correlation with dietary lipid levels, but amylase activities were not markedly in£uenced by dietary lipid levels. High proportions of 18:1n-9, 20:1n-9, eicosapentaenoic acid (20:5n-3; EPA), 22:1n-11 and docosahexaenoic acid (22:6n-3; DHA), and low concentrations of n-6 fatty acids, particularly 18:2n-6 occurring in the liver and muscle, to some extent, re£ected the fatty acid composition in experimental diets. Ã Herring ¢sh meal and herring ¢sh oil were supplied by Shanghai Jin Yuan Trade (Shanghai, China). Other ingredients were supplied by Rizhao Liu he Feed Factory (Rizhao, China). wVitamin premix (mg kg À 1 diet):

Effects of dietary lipid levels on growth performance, whole body composition and fatty acid composition of juvenile gibel carp (Carassius auratus gibelio)

“…Several studies have reported on the effects of dietary lipid levels on fatty acid composition in fish (Martins, Valente & Lall 2007;Luo, Xu, Teng, Ding & Yan 2010;Han et al 2011;Xu et al 2011). We found that whole body n-3 PUFA content increased as dietary lipid levels increased, which indicated that high lipid diets enhanced n-3 PUFA deposition in juvenile gibel carp.…”

“…Several studies have reported on the effects of dietary lipid levels on fatty acid composition in fish (Martins, Valente & Lall ; Luo, Xu, Teng, Ding & Yan ; Han et al . ; Xu et al .…”

Development of Biopolymers as Binders for Feed for Farmed Aquatic Organisms

“…Amylase activity was higher in Pseudoplatystoma corruscans fed diets containing 13-25% of starch and similarly, it could be adjusted through the starch level of the diet in Colossoma macropomum (De Almeida et al, 2006) and Dentex dentex (Perez-Jimenez et al, 2009). A positive correlation has been observed between lipase and dietary lipid levels in Colossoma macropomum (De Almeida et al, 2006) and Lateolabrax japonicus (Luo et al, 2010). In any case the emerging picture in teleosts is one of wide complexity and variability due to the different of habitats and life histories of such vertebrates.…”

Effects of dietary protein and lipid levels on growth performance, feed utilization and body composition of juvenile hybrid grouper, Epinephelus fuscoguttatus×E. lanceolatus

“…Similarly, Lee and Kim (2001) reported the increased wholebody linoleic acid in masu salmon (Oncorhynchus masou Brevoort) as dietary lipid increased. However, results of some other studies showed the significant decrease of muscle and/or liver linoleic acid content by increasing dietary lipid in white seabass (Atractoscion nobilis) (López et al, 2009), Japanese seabass (Lateolabrax japonicus L.) (Luo et al, 2010) and orange spotted grouper (Li et al, 2015). It should be pointed out that in this study a mixture of soybean oil and linseed oil were used in high lipid diets which are considered as rich sources of linoleic and linolenic acids and this may be responsible for the increased muscle and liver linoleic acid contents.…”