Coping with suboptimal water temperature: modifications in blood parameters, body composition, and postingestive-driven diet selection in Nile tilapia fed two vegetable oil blends

Animal

C.A.L. de Almeida¹  R. Fortes-Silva¹  C.K.L. de Almeida¹  R.R. Paulino²  P.V. Rosa²  R.T. Pereira²  E. de Fátima Ferreira Martins³  M. Bessonart⁴ 

[1] Department of Animal Science and Veterinary Medicine, Campus Salvador, Federal University of Bahia (UFBA), 40170-110, Bahia, Brazil;Department of Animal Science, University of Lavras (UFLA), 37200-000 Lavras, Brazil;Laboratory of Feeding Behavior and Fish Nutrition, Center of Agricultural Sciences, Environmental and Biological (CCAAB/NEPA/AQUAUFRB), Campus Cruz das Almas, Federal University of Bahia (UFRB), 44380-000, Bahia, Brazil;Natural Resources Laboratory, Institute of Ecology and Environmental Sciences, Faculty of Sciences, Universidad de la República, Iguá, 4225 Montevideo, Uruguay;

关键词: Diet self-selection;    Fatty acids;    Feed formulation;    Proximate analysis;    Subtropical aquaculture;   

DOI  :  

来源: DOAJ

【 摘 要 】

The world tilapia production faces seasonal variations. However, very few nutritional studies have addressed suboptimal temperature. We evaluated the effect of two temperatures (20 or 30 °C) and two vegetable oil blends (one rich in corn oil (COR) and one rich linseed oil (LIN)) on tilapia growth, body composition, and blood parameters using a 2×2 factorial design with the following treatments: COR-20; LIN-20; COR-30; LIN-30 (Trial 1). In addition, we also evaluated the effect of postingestive signals of dietary oils when the organoleptic properties of diets were isolated (Trial 2). In the Trial 1, 256 fish (15.36 ± 0.14 g) were placed in 16 aquariums and submitted during 30 days to the 2×2 factorial designs: COR-20; LIN-20; COR-30; LIN-30. The temperatures were established in two independent water recirculation systems. In the Trial 2, 96 fish (34.02 ± 0.79 g) were placed in 12 aquariums and subjected to the same experimental design of Trial 1, but to evaluate fish feeding behavior. They were allowed to select the encapsulated diets provided in different feeding halls to evaluate if diet preferences are influenced by postingestive signals. As the Trial 1 results show, diets had no significant effects on growth, dietary protein use, and body centesimal composition, but 30 °C induced the best performance and protein deposition (P < 0.05). LIN-20 showed lower very-low-density lipoprotein and cortisol, but higher high-density lipoprotein (HDL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and triglycerides (TG) than COR-20 (P < 0.05). COR-30 presented higher HDL, AST, ALT, TG, and cortisol than LIN-30. The fish fed COR showed lower C20:5n-3 (EPA) and higher n-6 than fish fed LIN (P < 0.05). The fish fed LIN had high n-3 highly unsaturated fatty acid. ∑ polyunsaturated fatty acid was higher at 30 °C. Finally, the tilapia in Trial 2 showed clear diet intake regulation and preference for LIN (P < 0.05), regardless of temperature. In short, lipid sources had no influence on tilapia performance; however, temperature affects carcass lipid deposition as well as fatty acids profile. Notably, the preference for linseed oil can suggest nutritional metabolic issues, contributing to animal behavior knowledge.

【 授权许可】

Unknown