title: Dietary lipid level influences fatty acid profiles, tissue composition, and lipid peroxidation of soft-shelled turtle, Pelodiscus sinensis.
abstract: Dietary lipids containing equal portions of soybean oil and fish oil were fed to juvenile Chinese soft-shelled turtle, Pelodiscus sinensis, at supplementation level of 0 to 15% for 8 weeks. Tissue fat contents of turtles increased when dietary lipid concentration increased. Fatty acid profiles for turtles fed diets supplemented with 6% or higher levels of lipids were similar to those in dietary lipids. On absolute value basis, fatty acids of 14-, 16-, and 18-carbons in muscle of turtles fed diet without lipid supplementation were higher than those in the initial turtle muscle. Among them, C16:1 and C18:1 was approximately 4 and 2 fold higher, respectively, than that of the initial turtles. By contrast, absolute amounts of C20:5 and C22:6 in muscle of turtles fed diet without lipid supplementation were slightly less than those in the initial turtles. For turtles fed lipid supplemented diets, tissue C20:5 and C22:6, however, increased when dietary lipid level increased. These results suggest that soft-shelled turtles are capable of synthesizing fatty acids up to 18 carbons from other nutrients and that they may have limited or no ability to synthesize highly unsaturated fatty acids. Lipid peroxidation measured by thiobarbituric acid-reactive substances in tissues of turtles fed 12% and 15% lipids was greater (p<0.05) than that in turtles fed 3% to 9% lipids. This could be due to high lipid and unsaturated fatty acid content in these tissues. On lipid basis, lipid peroxidation in turtles fed diet without lipid supplementation was the highest among all groups suggesting the existence of antioxidant factors in the dietary lipids.
authors.affiliation: National Chiayi University, Department of Aquatic Biosciences, 300 University Road, Chiayi 600, Taiwan. chuhuang@mail.ncyu.edu.tw
authors.forename: Chen-Huei
authors.initials: CH
authors.lastname: Huang
authors.forename: Way-Yee
authors.initials: WY
authors.lastname: Lin
authors.forename: Jen-Hong
authors.initials: JH
authors.lastname: Chu
mesh_terms: D000273:Adipose Tissue; D000818:Animals; D001823:Body Composition / Q000502:physiology*; D004041:Dietary Fats / Q000008:administration & dosage / Q000378:metabolism*; D005227:Fatty Acids / Q000096:biosynthesis / Q000378:metabolism*; D005395:Fish Oils / Q000008:administration & dosage / Q000378:metabolism; D015227:Lipid Peroxidation / Q000502:physiology*; D018482:Muscle, Skeletal / Q000378:metabolism; D013024:Soybean Oil / Q000008:administration & dosage / Q000378:metabolism; D014426:Turtles / Q000378:metabolism*
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D005395:Fish Oils; D013024:Soybean Oil