February 15-18, 2009 Washington State Convention Center Seattle ...

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EVALUATION OF THE ABILITY OF CHICKEN 42 POULTRY PRODUCT, CHICKEN 70%
POULTRY BY-PRODUCT BLEND, AND CHICKEN AND EGG CONCENTRATE (102190) TO
REPLACE FISH MEAL IN RAINBOW TROUT Oncorhynchus mykiss STARTER DIETS
Wendy M. Sealey * , Frederic T. Barrows, Qing Pan, David A. J. Stone and Ronald W. Hardy
Hagerman Fish Culture Experiment Station
University of Idaho
3059F National Fish Hatchery Road
Hagerman, ID 83332 USA
wsealey@uidaho.edu
Poultry meal products have been successfully used to replace fish meal in diets for rainbow trout. However, the potential for
these products to replace fish meal depends on consistency of their digestible nutritional composition. Therefore, the aim of the
current study was to assess the ability of three different commercially-available branded poultry products to maintain growth
and disease resistance of juvenile rainbow trout Oncorhynchus mykiss when substituted for 100% of the fishmeal component
of a typical starter diet.
A practical-type fish meal-based starter diet was formulated to meet or exceed the nutrient requirements of juvenile rainbow
trout and to contain 48% crude protein and 18% crude lipid. Test diets were formulated by substituting 100% of the fishmeal
with Chicken 42 poultry product, Chicken 70% protein poultry by-product blend (Chicken 70), and Chicken and Egg Concentrate
(102190). Rainbow trout (College of Southern Idaho, House Creek strain) were used in this study. Fertilized eggs were
obtained, hatched and fry grown to approximately 0.5 g. At stocking, rainbow trout were counted into groups (50 fish) with six
replicate tanks of fish for each diet. Trout were reared in 140-L tanks supplied with 4 L/min of constant temperature (14.8°C)
flow-through spring water and fed their respective diets four times daily for 8 weeks. Following the feeding trial, fish (n=3)
were randomly selected from each tank for whole body proximate analyses and fish performance indices. To examine disease
resistance, a sub sample of fish from each tank was challenged by subcutaneous injection with Flavobacterium psychrophilum.
Fish were monitored for mortality and fed their respective diets for 28 d following challenge.
All of the poultry product-based diets supported growth, nutrient retention and feed conversion ratios of rainbow trout fry equal
to or greater than those observed for fry fed fish meal-based diets. Fish fed Chicken 42 had significantly greater growth than
all other diets; fish fed Chicken 70 had similar growth to those fed fish meal and both had reduced growth as compared to those
fish fed Chicken and Egg Concentrate or Chicken 42. Protein and energy retention efficiencies reflected those trends observed
for growth. Feed conversion ratios were acceptable for all diets and ranged from 0.83 to 1.05. In contrast, no significant effect
of diet was observed following experimental challenge with Flavobacterium psychrophilum. These data suggest that the
examined poultry products can be used in place of fish meal in starter diets for rainbow trout fry without detrimentally affecting
growth and disease resistance.