Open AccessDigestibility of the defatted microalgae N annochloropsis sp. and D esmodesmus sp. when fed to A tlantic salmon, S almo salar
Author(s) -
Gong Y.,
Guterres H.A.D.S.,
Huntley M.,
Sørensen M.,
Kiron V.
Publication year - 2018
Publication title -
aquaculture nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.941
H-Index - 79
eISSN - 1365-2095
pISSN - 1353-5773
DOI - 10.1111/anu.12533
Subject(s) - nannochloropsis , biology , food science , fish meal , biomass (ecology) , dry matter , tetraselmis , salmo , photobioreactor , botany , fish <actinopterygii> , algae , fishery , agronomy
The aim of the study was to investigate the apparent digestibility coefficient ( ADC ) of defatted biomass derived from microalgae Nannochloropsis sp. and Desmodesmus sp. when fed to Atlantic salmon postsmolts in seawater. Two experiments, one employing cold‐pelleted and the other employing extruded pellets, were carried out to determine the ADC of dry matter ( DM ), protein, ash and energy. The test feeds consisted of a fishmeal‐based reference feed and the algal biomass, at a ratio of 70:30, and yttrium oxide as the inert marker. The ADC of DM and protein in fish fed microalgae‐incorporated cold‐pelleted feeds were significantly higher for Nannochloropsis sp. compared with Desmodesmus sp. The Nannochloropsis sp. inclusion in extruded feeds also led to higher ADC s of DM and energy compared with Desmodesmus sp. The extrusion processing significantly increased the ADC of ash in both defatted microalgae biomass, as well as ADC s of DM in Nannochloropsis and protein in Desmodesmus sp. In conclusion, the microalga Nannochloropsis sp. was more digestible than Desmodesmus sp., and extrusion processing can be used as a means to improve digestibility of certain nutrients.