Received 24 May 2013
Received in revised form
3 August 2013
Accepted 8 August 2013
Available online 20 August 2013
Keywords:
Galactooligosaccharide (GOS)
Prebiotic
Intestinal microbiota
Growth
Stress resistance
abstract
The aim of this study was to assess the effects of galactooligosaccharide (GOS), on the growth performance,
stress resistance and intestinal microbiota of Caspian roach (Rutilus rutilus) fry. Specimens
(1.36 0.03 g) were fed either a basal control diet (0% GOS, non-supplemented) or the basal diet supplemented
with 1% and 2% of GOS. After 7 weeks of the feeding trials, growth factors (final weight,
weight gain, specific growth rate, condition factor and food conversion ratio) as well as body composition,
resistance to salinity stress and autochthonous intestinal microbiota were assessed. Results
demonstrated that at the end of the trial growth factors (final weight, weight gain, SGR, FCR) were
significantly higher in 2% GOS fed fish (P < 0.05). In addition, supplementation of GOS significantly
increased both survival rate (P < 0.05), and resistance to a salinity stress challenge of prebiotic fed groups
(P < 0.05). However, body composition and the total autochthonous intestinal heterotrophic bacteria
counts remained unaffected in different treatments (P > 0.05). Nevertheless, autochthonous lactic acid
bacteria levels were significantly elevated in fish fed 2% dietary GOS (P < 0.05). These results confirm that
GOS improves growth performance, stress resistance and modulates intestinal microbiota by increasing
lactic acid bacteria of Caspian roach fry, a very important fish species in the Caspian Sea.
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