Prebiotics in Finfish: An Update - Aquaculture Nutrition: Gut Health, Probiotics and Prebiotics - page 376

GroBiotic ® -A level, as significant effects was noticed on total protein, albumin, creatinine,
C3, C4 and IgM. On the other hand, prebiotic supplementation (all inclusion levels) had no
effect on growth performance and survival.
Recently, Wu et al . (2013) investigated the effect of FOS (0.5, 1, 2, 4 and 8 g kg −1 )on
growth performance, body composition, intestinal enzyme activities and histology of blunt
snout bream ( Megalobrama amblycephala ; also known as Wuchang bream) fingerlings.
SGR and survival were significantly improved by FOS at 4 and 8 g kg −1 . In addition, FOS at
8gkg −1 significantly increased the body crude lipid level and decreased moisture content. Of
the intestinal enzyme activities, amylase and protease activity was significantly higher in fish
fed8gkg −1 FOS. Microvilli length in mid intestine was significantly higher when fish were
fed FOS.
Lochmann et al . (2011) investigated the effect of GroBiotic ® -A (20gkg −1 )ongrowth
performance, mineral composition and gut microbiota of fathead minnow in recirculating sys-
tems with low (35 mg CaCO 3 l −1 ) or moderate (141 mg CaCO 3 l −1 ) water hardness. Dietary
prebiotic application enhanced feed conversion which was attributed to potentially enhanced
nutrient absorption. GroBiotic ® -A decreased whole-body Na independently of water
hardness. The entire intestinal tract with content was used for bacteriological evaluations.
Six hundred and twenty-six isolates were identified, but only the most predominant genera
were presented; Acinetobacter was more abundant in fish fed with inclusion of prebiotic in
the diet.
14.6 SILURIFORMES
In contrast to the well documented effects of probiotics in catfish there is a paucity of infor-
mation regarding prebiotic applications (refer to Table 14.4).
Peterson et al . (2010) tested MOS (2g kg −1 ) in two basal dietary formulations - one which
was not extruded and did not float (MOS-sink) and one extruded floating diet (MOS-float)
(Brian Peterson, personal communication 2013). Both diet types were also produced without
MOS inclusion. Channel catfish ( Ictaluruspunctatus ) growth, FCR, survival and disease resis-
tance against Edwardsiella ictaluri were investigated. The results showed that survival after
Ed . ictaluri challenge was improved by dietary MOS-sink while no effect was noticed in the
MOS-float study. Growth and FCR were not improved by MOS inclusion. These results are in
agreement with the study of Welker et al . (2007), who also reported no differences in growth
performance in MOS fed channel catfish.
Silver catfish, also as known South American catfish ( Rhamdia quelen ), is a commercially
important species in Argentina and Brazil, and is mainly reared in intensive or semi-intensive
production systems. Recent investigations have sought to investigate the gut microbiota
(Pedrotti et al . 2013) and to test the efficacy of prebiotics applications (Hernández et al . 2012)
in this species. Hernández et al . (2012) investigated the effect of MOS (2g kg −1 ) on silver
catfish (0.11 ± 0.015 g) growth performance and survival, and reported no effect on growth
performance but a significant improvement of survival.
Readers with a specific interest in the gut microbiota of channel catfish and the initial studies
of prebiotics in catfish species are referred to the reviews of Ringø et al . (2010) and Burr
et al . (2012).