Effect of dietary vegetable lipid sources on the growth performance and whole-body fatty acid profile of giant trahira, Hoplias lacerdae

Aim of study: To evaluate which vegetable lipid source promotes better growth performance, whole-body composition and fatty acid profile for juvenile giant trahira (Hoplias lacerdae). Area of study: Fish Nutrition Laboratory of the University of Viçosa (UFV), MG, Brazil. Material and methods: A 50-day feed trial with four treatments, consisting of diets containing different vegetable lipid sources (canola, linseed, soybean or olive oil), was conducted with juveniles of 4.76 ± 0.50 cm and 1.97 ± 0.20 g. Main results: There were no effects of vegetable lipid sources on growth performance. Fish fed diets containing canola oil had higher body lipid deposition and fish fed with linseed oil had lower body lipid content (up to -19.29%) than fish from other treatments. Fish fed canola oil showed lower proportions of saturated fatty acids (up to -11.27%) in the body. Fish fed diets containing soybean oil and linseed oil showed the highest percentages of linoleic and α-linolenic fatty acids, respectively. Fish fed diets containing soybean and linseed oils also had higher total polyunsaturated fatty acids content (up to +81.14%). Fish fed diets containing linseed oil had lower content of monounsaturated fatty acids (up to -58.59%) and higher content of docosahexaenoic (up to +175%) and eicosapentaenoic (not detectable to detectable) acids. Research highlights: Juveniles of giant thraira can alter the whole-body fatty acid profile due to their ability to desaturate and elongate the n3 and n6 series fatty acids. Linseed oil was identified as lipid source for this fish species.