Lipid and fatty acid digestibility of fish and vegetable oils by pacus, Piaractus mesopotamicus

• Grant number: 11/18004-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2011
• End date: September 30, 2012
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Principal Investigator: Ligia Uribe Gonçalves
• Grantee: Mateus Nishimura Narazaki
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

In spite of the importance of oils as a source of energy and fatty acids required for normal fish growth and development, little attention has been paid in determining their digestibility for Brazilian freshwater fish. Vegetable oils are considered the main alternative sustainable in substitution of fish oil in feed for aquaculture. Therefore, the use of vegetable oils in fish diets should be evaluated thereby enabling the precise formulation of diets. The aim of this study is to determine the apparent digestibility coefficients (ADC) of lipids and fatty acids of different sources of oil for pacu. The determination of the ADC will be made by the indirect method using chromium oxide III as a marker in experimental diets. It will be prepared a reference diet (RD) and the experimental diets will be obtained by replacing 15% of RD for each ingredient test (oils: fish, soy, corn, flaxseed and canola). Pacu juveniles will be stocked into six cages / experimental unit, kept in circular tanks, where they will be fed to apparent satiation four times a day. After the last meal, the cages will be transferred to cylindrical-conical tanks for collection of decanted feces in collectors immersed in ice attached to the bottom of aquariums. The content of chromium oxide, lipid and fatty acid profile of diets and feces will be determined to calculate the ADCs. (AU)