Biological availability of different commercially available histidine products in feed for Atlantic salmon smolt

Abstract

A comparative nutritional study with post-smolt Atlantic salmon (Salmo salar L.) was performed over six weeks to investigate similarities between three suppliers of synthetic His at two dietary levels in a formulated extruded pellet for salmon, and how they affected feed utilization, fish performance, cataract development, digestibility, and biological efficacy. His source or dietary level of His did not affect feed utilization. Digestibility was similar between all experimental groups and the control group. No difference were found in organ indexes for His source, but the dietary level of His showed reduced growth in organ indexes for high supplementation level versus medium and control. Differences existed between experimental groups and the control group for fish performance, but these were assumed to be non-related to nutrition due to their inconsistency. His supplementation reduced cataract severity, while no difference was found between His sources. Tissue levels of His, anserine and NAH concentrations were similar between His sources.