Potato protein concentrate with low content of solanidine glycoalkaloids in diets for Atlantic salmon (Salmo salar)

Summary

Previous testing of standard potato protein concentrate (PPC) in salmonid diets resulted in severe appetite loss. This has been attributed to the solanidine glycoalkaloids (SGA) in the PPC, among which α-solanine and α-chaconine are the best known. The present study investigated the nutritional value of a PPC with reduced SGA content (SGA<100 μg g−1) as a partial fish meal (FM) substitute in diets for Atlantic salmon. FM and wheat were replaced by low-SGA PPC in increments, producing four extruded diets containing 0%, 7%, 14%, and 21% PPC. Each diet was fed to triplicate groups of 82 g salmon maintained in 8–13 °C seawater. The experiment lasted 84 days, divided into three periods. Appetite, feed conversion, and retention of N and energy were not affected by dietary treatment. All groups of fish grew to final individual weights ranging 249–256 g. There were no significant differences in apparent macronutrient or amino acid digestibility among groups fed different diets. In conclusion, low-SGA PPC is well suited for partial FM substitution in salmon diets.