Prebiotics in Finfish: An Update - Aquaculture Nutrition: Gut Health, Probiotics and Prebiotics - page 375

the lowest ADC values. The authors stated that the bacterial communities of fish fed the
various prebiotics were not significantly modulated. This lack of intestinal modulation is con-
trary to the effects of MOS reported in other fish species, which might be suggestive of a
species-dependent effect or could be due to the different rearing conditions or possibly the use
of Cr 2 O 3 as internal indicator; previous studies have demonstrated that Cr 2 O 3 affects the
intestinal bacterial community of Arctic charr (Ringø 1993). Further studies should assess the
influence of dietary markers on the gut microbiota of fish with particular reference to studies
using feed additives such as prebiotics.
14.5.7 Golden shiner
The golden shiner, a native North American species which is widely pond cultured in the USA,
has been used in a number of prebiotic studies (Table 14.3). Previously it has been reported
that dietary GroBiotic ® -A can improve golden shiner resistance to Flavobacteriumcolumnare
(Sink et al . 2007; Sink and Lochmann 2008). More recently the effects of GroBiotic ® -A on
golden shiner growth performance, immune status and disease resistance have been investi-
gated (Lochmann et al . 2010a; 2010b).
The aim of the study of Lochmann etal . (2010a) was to determine the effects of a dairy-yeast
prebiotic (20 g kg −1 ) on growth, survival and non-specific immune response of golden shiners
held in indoor tanks and outdoor ponds. Growth and FCR were marginally improved by prebi-
otic application when the fish were reared indoors, while growth and FCR were not affected in
the outdoor trial. The authors suggested that these differences were reflective of the influence
of natural food. In the indoor experiment, whole body composition and alternative complement
activity were not affected by prebiotic supplementation. In another study using golden shiners
reared in ponds, Lochmann et al . (2010b) evaluated the effect of GroBiotic ® -A(20gkg −1 )
on growth, feed conversion (FC), survival, haemoglobin, non-specific immune response
and resistance against F. columnare . Individual weight gain, FC, survival, haemoglobin,
serum lysozyme and alternative complement activities were not affected by dietary prebiotic.
However, improved resistance against F . columnare was observed in confinement stressed
fish. The latter result is in accordance with previous studies showing improved survival
against F . columnare when the fish were fed GroBiotic ® -A (Sink et al . 2007; Sink and
Lochmann 2008).
14.5.8 Other Cyprinidae
In Caspian roach fry (0.67 ± 0.03 g), growth performance, innate immune parameters
(lysozyme, Ig, ACH50), digestive enzyme activities (amylase, lipase and protease) and
resistance to salinity stress were significantly improved with increasing levels of dietary FOS
(10, 20 and 30 g kg −1 ) (Soleimani et al . 2012).
To our knowledge only two studies using prebiotics in kutum have been carried out
(Akrami et al . 2010; Yousefian et al . 2012). In the study of Akrami et al . (2010), 1.5, 3
and 4.5 g MOS kg −1 were fed to kutum (∼742 g) but no significant differences in growth
performance (WG, SGR, FCR) or salinity stress resistance were reported. On the other hand,
the authors stated that fish fed 1.5 g MOS kg −1 had significant higher survival and intestinal
LAB counts. In their study with kutum fed GroBiotic ® -A (1, 2 and 3 g kg −1 ), Yousefian et al .
(2012) reported that the clearest effect was observed by feeding the fish (∼0.8 g) the highest