Carbohydrate nutrition in Atlantic salmon, Salmo salar L.: growth and feed utilization

TLDR

Undigested starch may impair lipid digestibility similarly to dietary fibre. The study fed five groups of 80‑g Atlantic salmon moist diets with starch levels ranging from 0 % to 31 %, decreasing protein proportionally. Starch levels above 9 % reduced starch digestibility, impaired growth and feed utilisation, increased particulate loss, and a diet containing about 9 % starch was deemed optimal.

Abstract

Five groups of Altantic salmon, Salmo salar L., (80 g postsmolt) were fed moist diets containing increasing levels of starch from 0% to 31% and concomitant decreasing levels of protein. The results showed that feeding a diet containing 22% lipid with no starch or a starch inclusion higher than 22% exerts negative effects on growth and feed utilization. A starch inclusion above 9% resulted in decreased starch digestibility, while protein digestibility was not influenced by the dietary starch content. Undigested starch is suggested to affect lipid digestibility in the same manner as dietary fibre. The reduced digestibility by high levels of dietary starch led to increased loss of particulate matter to the environment. Taking into account feed utilization and environmental aspects, the present experiment suggests that a diet containing approximately 9% starch is optimal.