Aquaculture Reports (Jun 2022)
Dietary 18-carbon fatty acid unsaturation improves the muscle fiber development and meat quality of Megalobrama amblycephala
Abstract
The study aimed to investigate the effects of four fatty acids with the same carbon-chain length and different saturations, stearic acid (SA), oleic acid (OA), linoleic acid (LA), and linolenic acid (LNA), on the growth performance and muscle quality of Megalobrama amblycephala through in vivo and in vitro experiments. A total of 320 fish with similar initial weight (34.97 ± 0.14 g) were randomly fed 3% four kinds of 18-carbon fatty acids with different carbon saturation. Growth performance was assessed at the end of the feeding trial, and samples were collected for the corresponding indicators. Results showed that the weight gain rate (WGR) and specific growth rate (SGR) of unsaturated fatty acids groups were significantly increased (P < 0.05) than the SA group. Meanwhile, unsaturated fatty acids resulted in a significant increase in white muscle texture (hardness, adhesiveness, gumminess, and chewiness) (P < 0.05). With the increase of fatty acid unsaturation, the number of muscle fibers and density were significantly increased (P < 0.05), while the sarcomere length decreased. The gene expression of sirt1 and camk were significantly up-regulated in unsaturated fatty acids groups (P < 0.05), and the genes related to muscle fiber development were also increased significantly (P < 0.05). In vitro study, the primary muscle cells of Megalobrama amblycephala were treated for 24 h according to the references. The results showed that 250 μmol of unsaturated fatty acids OA, LA, and LNA significantly up-regulated the protein levels of p-Ampk, Camk, and Pax7 associated with muscle fiber development (P < 0.05). In conclusion, unsaturated fatty acids can promote muscle fiber development and meat quality because of the different saturations, which may be realized by activating AMPK and Ca2+-dependent signal pathways.
