Effects of dietary lysophospholipids on the performance of Pacific white shrimp (Litopenaeus vannamei) fed fish oil-and energyreduced diets

Rawiwan Limwachirakhom^1*Supawit Triwutanon²Yanjiao Zhang³Orapint Jintasataporn^1*

• ¹Faculty of Fisheries, Kasetsart University, Bangkok, Thailand
• ²Faculty of Veterinary Medicine, Kasetsart University, Kamphaeng, Thailand
• ³Key Laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture, Ocean University of China, Qingdao, Shandong Province, China

Introduction: Fish oil is a key component in aquatic feeds due to its high energy content, essential omega-3 fatty acids, and rich nutrient profile. However, its high cost necessitates sustainable alternatives. This study investigated the effects of dietary lysophospholipids (LPLs) on growth performance, digestive enzyme activity, and the expression of lipid metabolism-related genes in Pacific white shrimp (Litopenaeus vannamei). Methods: Juvenile shrimp (n = 400; initial weight: 1.55 ± 0.02 g) were randomly assigned to four dietary treatments in a 2 × 2 factorial design with four replicates per treatment: a positive control (PC) with 2% fish oil, a negative control (NC) with 1% fish oil, and two LPL-supplemented groups (NC+0.03% and NC+0.06% LPLs). After 8 weeks of feeding, growth performance, digestive enzyme activity, and gene expression related to lipid metabolsim were evaluated. Results: LPL supplementation (0.03% and 0.06%) significantly improved almost growth parameters such as total production, weight gain rate, specific growth rate, feed conversion ratio and protein efficiency ratio compared with the NC group (P < 0.05). The PC group showed significant improvement only in specific growth rate, feed conversion ratio, and protein efficiency ratio. Lipase activity was significantly higher in both LPL groups and the PC group than in the NC group, while protease, trypsin, and chymotrypsin activities were highest in the NC+0.06% LPLs group (P < 0.05). Amylase activity was significantly higher in the PC and NC+0.06% groups compared to others. LPL supplementation also significantly upregulated lipid metabolism genes, lipase (Lip) and delta fatty acid desaturase 6 (dFAD-6), along with the antioxidative stress gene superoxide dismutase (SOD) compared to NC group. In contrast, the PC group showed significant upregulation only of SOD compared to the NC group. Discussion: Dietary inclusion of 0.03%-0.06% LPLs effectively enhanced growth performance, nutrient utilization, and lipid metabolism, offering potential to reduce fish oil use by 1% in shrimp diets. These findings provide a basis for improving feed efficiency and sustainability in shrimp aquaculture.