Juvenile rainbow trout responses to diets containing distillers dried grain with solubles, phytase, and amino acid supplements

ABSTRACT

Distillers dried grain with solubles (DDGS) was evaluated in juvenile Shasta-strain rainbow trout Oncorhynchus mykiss diets during a 36-day feeding trial. Two experimental diets containing either 10% or 20% DDGS with supplemented amino acids (lysine, methionine, isoleucine, and his-tidine) and phytase were compared to a fish meal-only control diet. Tanks of trout receiving diets containing either concentration of DDGS weighed significantly less at the end of the trial and had significantly poorer feed conversion ratios than tanks of fish being fed the fish meal- only control. There was no significant difference in individual fish length, weight, condition factor, or any fish health measurements among diet treatments. Both the hepatosomatic index and viscerosomatic index were significantly less in the fish fed 10% DDGS than those fed the con-trol diet. Body fat was significantly greater in the fish receiving 20% DDGS compared to fish fed either of the other two diets. Fillet composition, as determined by crude protein, crude lipid, ash, and water, was not significantly different among fish reared on any of the diets. There was also no significant difference in estimated protein digestibility coefficients among fish receiving any of the diets. The results suggest that DDGS, even if supplemented with essential amino acids and phytase, will lead to decreased juvenile rainbow trout growth at dietary concentrations of at 10% or greater.

AUTHORS

Michael E. Barnes1, Michael L. Brown2, Kurt A. Rosentrater3

1South Dakota Department of Game, Fish and Parks, McNenny State Fish Hatchery, Spearfish, USA; *Corresponding Author: mike.barnes@state.sd.us

2Department of Wildlife and Fisheries Sciences, South Dakota State University, Brookings, USA

3Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, USA

Received 20 December 2011; revised 19 January 2012; accepted 26 January 2012

Published by

Open Journal of Animal Sciences Vol.2, No.2, 69-77 (2012) 

doi:10.4236/ojas.2012.2201

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