The "International Symposium on Fish Nutrition and Feeding" (ISFNF), this year held in Brazil, Florianópolis, 2.-5. of June, is an important meeting place for researchers in the field of fish nutrition. Ann-Cecilie Hansen from the National Institute of Nutrition and Seafood Research (NIFES) in Norway is a PhD student at the University of Bergen. She received the award for her presentation of two feeding trials examining the effects of replacing fishmeal with plant protein in cod feed.
Plant protein replacing fish meal
Cod weighing 140 grams were fed feed with mixtures of soy meal, soyprotein concentrate, corn gluten and wheat gluten. The inclusion levels of the raw materials differed.
"Raw materials like soy meal, wheat gluten and soy protein concentrate appeared to have the most positive effect on the cod’s growth and health," says Dr Hansen.
In a new trial different protein mixtures of these raw materials was made. Fish meal was replaced by plant proteins from 0 to 100 per cent. The feed was given to cod of about 1.6 kilograms.
"Replacement levels up to 50 per cent had no negative effect on the growth or the health of the cod. Growth and feed utilisation was reduced by replacing over 50per cent of fish meal with plant meal," says Dr Hansen.
"However, replacement levels just over 50 per cent is unlikely to affect the cod negatively provided that amino acids, vitamins and minerals common in fish meal but in short supply in plant protein is added to the feed.
"At the 100 per cent replacement level intestinal changes which resembles inflammatory conditions was observed in the cod.
Cod need more proteins than salmon, and seems to have a higher tolerance for soy protein than salmon.